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Sample records for canonical wnt pathway

  1. Activation of the Canonical Wnt Signaling Pathway Induces Cementum Regeneration.

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    Han, Pingping; Ivanovski, Saso; Crawford, Ross; Xiao, Yin

    2015-07-01

    Canonical Wnt signaling is important in tooth development but it is unclear whether it can induce cementogenesis and promote the regeneration of periodontal tissues lost because of disease. Therefore, the aim of this study is to investigate the influence of canonical Wnt signaling enhancers on human periodontal ligament cell (hPDLCs) cementogenic differentiation in vitro and cementum repair in a rat periodontal defect model. Canonical Wnt signaling was induced by (1) local injection of lithium chloride; (2) local injection of sclerostin antibody; and (3) local injection of a lentiviral construct overexpressing β-catenin. The results showed that the local activation of canonical Wnt signaling resulted in significant new cellular cementum deposition and the formation of well-organized periodontal ligament fibers, which was absent in the control group. In vitro experiments using hPDLCs showed that the Wnt signaling pathway activators significantly increased mineralization, alkaline phosphatase (ALP) activity, and gene and protein expression of the bone and cementum markers osteocalcin (OCN), osteopontin (OPN), cementum protein 1 (CEMP1), and cementum attachment protein (CAP). Our results show that the activation of the canonical Wnt signaling pathway can induce in vivo cementum regeneration and in vitro cementogenic differentiation of hPDLCs. PMID:25556853

  2. Retinoic acid suppresses the canonical Wnt signaling pathway in embryonic stem cells and activates the noncanonical Wnt signaling pathway

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    Osei-Sarfo, Kwame; Gudas, Lorraine J.

    2014-01-01

    Embryonic stem cells (ESCs) have both the ability to self-renew and to differentiate into various cell lineages. Retinoic acid (RA), a metabolite of Vitamin A, has a critical function in initiating lineage differentiation of ESCs through binding to the retinoic acid receptors (RARs). Additionally, the Wnt signaling pathway plays a role in pluripotency and differentiation, depending on the activation status of the canonical and noncanonical pathways. The activation of the canonical Wnt signaling pathway, which requires the nuclear accumulation of β-catenin and its interaction with Tcf1/Lef at Wnt response elements, is involved in ESC stemness maintenance. The noncanonical Wnt signaling pathway, through actions of Tcf3, can antagonize the canonical pathway. We show that RA activates the noncanonical Wnt signaling pathway, while concomitantly inhibiting the canonical pathway. RA increases the expression of ligands and receptors of the noncanonical Wnt pathway (Wnt 5a, 7a, Fzd2 and Fzd6), downstream signaling, and Tcf3 expression. RA reduces the phosphorylated β-catenin level by 4-fold, though total β-catenin levels don't change. We show that RA signaling increases the dissociation of Tcf1 and the association of Tcf3 at promoters of genes that regulate stemness (e.g. NR5A2,Lrh-1) or differentiation (eg. Cyr61, Zic5). Knockdown of Tcf3 increases Lrh-1 transcript levels in mESCs and prevents the RA-associated, ∼4-fold increase in Zic5, indicating that RA requires Tcf3 to effect changes in Zic5 levels. We demonstrate a novel role for RA in altering the activation of these two Wnt signaling pathways and show that Tcf3 mediates some actions of RA during differentiation. PMID:24648413

  3. Components of the canonical and non-canonical Wnt pathways are not mis-expressed in pituitary tumors.

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    Leandro Machado Colli

    Full Text Available INTRODUCTION: Canonical and non-canonical Wnt pathways are involved in the genesis of multiple tumors; however, their role in pituitary tumorigenesis is mostly unknown. OBJECTIVE: This study evaluated gene and protein expression of Wnt pathways in pituitary tumors and whether these expression correlate to clinical outcome. MATERIALS AND METHODS: Genes of the WNT canonical pathway: activating ligands (WNT11, WNT4, WNT5A, binding inhibitors (DKK3, sFRP1, β-catenin (CTNNB1, β-catenin degradation complex (APC, AXIN1, GSK3β, inhibitor of β-catenin degradation complex (AKT1, sequester of β-catenin (CDH1, pathway effectors (TCF7, MAPK8, NFAT5, pathway mediators (DVL-1, DVL-2, DVL-3, PRICKLE, VANGL1, target genes (MYB, MYC, WISP2, SPRY1, TP53, CCND1; calcium dependent pathway (PLCB1, CAMK2A, PRKCA, CHP; and planar cell polarity pathway (PTK7, DAAM1, RHOA were evaluated by QPCR, in 19 GH-, 18 ACTH-secreting, 21 non-secreting (NS pituitary tumors, and 5 normal pituitaries. Also, the main effectors of canonical (β-catenin, planar cell polarity (JNK, and calcium dependent (NFAT5 Wnt pathways were evaluated by immunohistochemistry. RESULTS: There are no differences in gene expression of canonical and non-canonical Wnt pathways between all studied subtypes of pituitary tumors and normal pituitaries, except for WISP2, which was over-expressed in ACTH-secreting tumors compared to normal pituitaries (4.8x; p = 0.02, NS pituitary tumors (7.7x; p = 0.004 and GH-secreting tumors (5.0x; p = 0.05. β-catenin, NFAT5 and JNK proteins showed no expression in normal pituitaries and in any of the pituitary tumor subtypes. Furthermore, no association of the studied gene or protein expression was observed with tumor size, recurrence, and progressive disease. The hierarchical clustering showed a regular pattern of genes of the canonical and non-canonical Wnt pathways randomly distributed throughout the dendrogram. CONCLUSIONS: Our data reinforce previous reports

  4. Identification of 2-aminopyrimidine derivatives as inhibitors of the canonical Wnt signaling pathway.

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    Del Bello, Fabio; Farande, Aniket; Giannella, Mario; Piergentili, Alessandro; Quaglia, Wilma; Benicchi, Tiziana; Cappelli, Federico; Nencini, Arianna; Salerno, Massimiliano; Thomas, Russell J; Travagli, Massimilano; Varrone, Maurizio

    2015-09-01

    The canonical Wnt signaling pathway plays a fundamental role in embryonic as well as in adult development. Consequently, dysregulation of the pathway has been linked to a wide spectrum of pathological conditions. In a program aimed at the identification of small molecule inhibitors of the canonical Wnt pathway we identified a series of 2-aminopyrimidine derivatives which specifically inhibited the pathway with minimal or no sign of cellular toxicity. The hit molecules 1 and 2 showed promising inhibitory activity with IC50 values of approximately 10 μM, but low solubility and metabolic stability. During the early stage of the hit series exploration, the pyrimidine core was variously decorated to obtain active compounds with a better physico-chemical profile. In particular, compound 13 showed Wnt inhibition activity comparable to hit molecules 1 and 2, with improved physico-chemical properties. Therefore, this series of compounds may be considered a promising starting point for the design of novel small molecule inhibitors of the canonical Wnt pathway. PMID:26233797

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

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    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.

  6. Alzheimer Disease: Crosstalk between the Canonical Wnt/Beta-Catenin Pathway and PPARs Alpha and Gamma

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    Vallée, Alexandre; Lecarpentier, Yves

    2016-01-01

    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 (CNS). 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.

  7. 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.

  8. Impact of laminitis on the canonical Wnt signaling pathway in basal epithelial cells of the equine digital laminae.

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    Le Wang

    Full Text Available The digital laminae is a two layer tissue that attaches the distal phalanx to the inner hoof wall, thus suspending the horse's axial skeleton in the hoof capsule. This tissue fails at the epidermal:dermal junction in laminitic horses, causing crippling disease. Basal epithelial cells line the laminar epidermal:dermal junction, undergo physiological change in laminitic horses, and lose versican gene expression. Versican gene expression is purportedly under control of the canonical Wnt signaling pathway and is a trigger for mesenchymal-to-epithelial transition; thus, its repression in laminar epithelial cells of laminitic horses may be associated with suppression of the canonical Wnt signaling pathway and loss of the epithelial cell phenotype. In support of the former contention, we show, using laminae from healthy horses and horses with carbohydrate overload-induced laminitis, quantitative real-time polymerase chain reaction, Western blotting after sodium dodecylsulfate polyacrylamide gel electrophoresis, and immunofluorescent tissue staining, that positive and negative regulatory components of the canonical Wnt signaling pathway are expressed in laminar basal epithelial cells of healthy horses. Furthermore, expression of positive regulators is suppressed and negative regulators elevated in laminae of laminitic compared to healthy horses. We also show that versican gene expression in the epithelial cells correlates positively with that of β-catenin and T-cell Factor 4, consistent with regulation by the canonical Wnt signaling pathway. In addition, gene and protein expression of β-catenin correlates positively with that of integrin β4 and both are strongly suppressed in laminar basal epithelial cells of laminitic horses, which remain E-cadherin(+/vimentin(-, excluding mesenchymal transition as contributing to loss of the adherens junction and hemidesmosome components. We propose that suppression of the canonical Wnt signaling pathway, and

  9. β-Catenin-dependent pathway activation by both promiscuous "canonical" WNT3a-, and specific "noncanonical" WNT4- and WNT5a-FZD receptor combinations with strong differences in LRP5 and LRP6 dependency.

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    Ring, Larisa; Neth, Peter; Weber, Christian; Steffens, Sabine; Faussner, Alexander

    2014-02-01

    The WNT/β-catenin signalling cascade is the best-investigated frizzled receptor (FZD) pathway, however, whether and how specific combinations of WNT/FZD and co-receptors LRP5 and LRP6 differentially affect this pathway are not well understood. This is mostly due to the fact that there are 19 WNTs, 10 FZDs and at least two co-receptors. In our attempt to identify the signalling capabilities of specific WNT/FZD/LRP combinations we made use of our previously reported TCF/LEF Gaussia luciferase reporter gene HEK293 cell line (Ring et al., 2011). Generation of WNT/FZD fusion constructs - but not their separate transfection - without or with additional isogenic overexpression of LRP5 and LRP6 in our reporter cells permitted the investigation of specific WNT/FZD/LRP combinations. The canonical WNT3a in fusion to almost all FZDs was able to induce β-catenin-dependent signalling with strong dependency on LRP6 but not LRP5. Interestingly, noncanonical WNT ligands, WNT4 and WNT5a, were also able to act "canonically" but only in fusion with specific FZDs and with selective dependence on LRP5 or LRP6. These data and extension of this experimental setup to the poorly characterized other WNTs should facilitate deeper insight into the complex WNT/FZD signalling system and its function. PMID:24269653

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

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    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.

  11. Human cytomegalovirus infection dysregulates the canonical Wnt/β-catenin signaling pathway.

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    Magdalena Angelova

    Full Text Available Human Cytomegalovirus (HCMV is a ubiquitous herpesvirus that currently infects a large percentage of the world population. Although usually asymptomatic in healthy individuals, HCMV infection during pregnancy may cause spontaneous abortions, premature delivery, or permanent neurological disabilities in infants infected in utero. During infection, the virus exerts control over a multitude of host signaling pathways. Wnt/β-catenin signaling, an essential pathway involved in cell cycle control, differentiation, embryonic development, placentation and metastasis, is frequently dysregulated by viruses. How HCMV infection affects this critical pathway is not currently known. In this study, we demonstrate that HCMV dysregulates Wnt/β-catenin signaling in dermal fibroblasts and human placental extravillous trophoblasts. Infection inhibits Wnt-induced transcriptional activity of β-catenin and expression of β-catenin target genes in these cells. HCMV infection leads to β-catenin protein accumulation in a discrete juxtanuclear region. Levels of β-catenin in membrane-associated and cytosolic pools, as well as nuclear β-catenin, are reduced after infection; while transcription of the β-catenin gene is unchanged, suggesting enhanced degradation. Given the critical role of Wnt/β-catenin signaling in cellular processes, these findings represent a novel and important mechanism whereby HCMV disrupts normal cellular function.

  12. 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.

  13. Dose-dependent effect of estrogen suppresses the osteo-adipogenic transdifferentiation of osteoblasts via canonical Wnt signaling pathway.

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    Bo Gao

    Full Text Available Fat infiltration within marrow cavity is one of multitudinous features of estrogen deficiency, which leads to a decline in bone formation functionality. The origin of this fat is unclear, but one possibility is that it is derived from osteoblasts, which transdifferentiate into adipocytes that produce bone marrow fat. We examined the dose-dependent effect of 17β-estradiol on the ability of MC3T3-E1 cells and murine bone marrow-derived mesenchymal stem cell (BMMSC-derived osteoblasts to undergo osteo-adipogenic transdifferentiation. We found that 17β-estradiol significantly increased alkaline phosphatase activity (P<0.05; calcium deposition; and Alp, Col1a1, Runx2, and Ocn expression levels dose-dependently. By contrast, 17β-estradiol significantly decreased the number and size of lipid droplets, and Fabp4 and PPARγ expression levels during osteo-adipogenic transdifferentiation (P<0.05. Moreover, the expression levels of brown adipocyte markers (Myf5, Elovl3, and Cidea and undifferentiated adipocyte markers (Dlk1, Gata2, and Wnt10b were also affected by 17β-estradiol during osteo-adipogenic transdifferentiation. Western blotting and immunostaining further showed that canonical Wnt signaling can be activated by estrogen to exert its inhibitory effect of osteo-adipogenesis. This is the first study to demonstrate the dose-dependent effect of 17β-estradiol on the osteo-adipogenic transdifferentiation of MC3T3-E1 cells and BMMSCs likely via canonical Wnt signaling. In summary, our results indicate that osteo-adipogenic transdifferentiation modulated by canonical Wnt signaling pathway in bone metabolism may be a new explanation for the gradually increased bone marrow fat in estrogen-inefficient condition.

  14. Role of L1CAM in the Regulation of the Canonical Wnt Pathway and Class I MAGE Genes.

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    Shkurnikov, M Yu; Knyazev, E N; Wicklein, D; Schumacher, U; Samatov, T R; Tonevitskii, A G

    2016-04-01

    Molecule L1CAM is specific for nerve cells and tumors of various localizations. The expression of L1CAM is significantly higher in melanoma in comparison with benign nevi and correlates with the progress of melanoma and transition from radial to vertical growth. Monoclonal antibodies to L1CAM effectively and specifically attenuate melanoma growth, though stimulates the epithelial-mesenchymal transition. shRNA-mediated knock-down of L1CAM showed the involvement of L1CAM in regulation of activity of the canonical Wnt pathway and expression of genes of class I melanoma-associated antigens (MAGE). PMID:27165065

  15. Bisphenol-A Mediated Inhibition of Hippocampal Neurogenesis Attenuated by Curcumin via Canonical Wnt Pathway.

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    Tiwari, Shashi Kant; Agarwal, Swati; Tripathi, Anurag; Chaturvedi, Rajnish Kumar

    2016-07-01

    Bisphenol A (BPA) is an environmental xenoestrogenic endocrine disruptor, utilized for production of consumer products, and exerts adverse effects on the developing nervous system. Recently, we found that BPA impairs the finely tuned dynamic processes of neurogenesis (generation of new neurons) in the hippocampus of the developing rat brain. Curcumin is a natural polyphenolic compound, which provides neuroprotection against various environmental neurotoxicants and in the cellular and animal models of neurodegenerative disorders. Here, we have assessed the neuroprotective efficacy of curcumin against BPA-mediated reduced neurogenesis and the underlying cellular and molecular mechanism(s). Both in vitro and in vivo studies showed that curcumin protects against BPA-induced hippocampal neurotoxicity. Curcumin protects against BPA-mediated reduced neural stem cells (NSC) proliferation and neuronal differentiation and enhanced neurodegeneration. Curcumin also enhances the expression/levels of neurogenic and the Wnt pathway genes/proteins, which were reduced due to BPA exposure in the hippocampus. Curcumin-mediated neuroprotection against BPA-induced neurotoxicity involved activation of the Wnt/β-catenin signaling pathway, which was confirmed by the use of Wnt specific activators (LiCl and GSK-3β siRNA) and inhibitor (Dkk-1). BPA-mediated increased β-catenin phosphorylation, decreased GSK-3β levels, and β-catenin nuclear translocation were significantly reversed by curcumin, leading to enhanced neurogenesis. Curcumin-induced protective effects on neurogenesis were blocked by Dkk-1 in NSC culture treated with BPA. Curcumin-mediated enhanced neurogenesis was correlated well with improved learning and memory in BPA-treated rats. Overall, our results conclude that curcumin provides neuroprotection against BPA-mediated impaired neurogenesis via activation of the Wnt/β-catenin signaling pathway. PMID:25963729

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

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    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.

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

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    Wang, Jinjin; Zhao, Jingzhi; Zhang, Jianfeng; Luo, Xinping; Gao, Kaiping; Zhang, Ming; Li, Linlin; Wang, Chongjian; Hu, Dongsheng

    2015-06-01

    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. PMID:26083111

  18. The role of the Wnt canonical signaling in neurodegenerative diseases.

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    Libro, Rosaliana; Bramanti, Placido; Mazzon, Emanuela

    2016-08-01

    The Wnt/β-catenin or Wnt canonical pathway controls multiple biological processes throughout development and adult life. Growing evidences have suggested that deregulation of the Wnt canonical pathway could be involved in the pathogenesis of neurodegenerative diseases. The Wnt canonical signaling is a pathway tightly regulated, which activation results in the inhibition of the Glycogen Synthase Kinase 3β (GSK-3β) function and in increased β-catenin activity, that migrates into the nucleus, activating the transcription of the Wnt target genes. Conversely, when the Wnt canonical pathway is turned off, increased levels of GSK-3β promote β-catenin degradation. Hence, GSK-3β could be considered as a key regulator of the Wnt canonical pathway. Of note, GSK-3β has also been involved in the modulation of inflammation and apoptosis, determining the delicate balance between immune tolerance/inflammation and neuronal survival/neurodegeneration. In this review, we have summarized the current acknowledgements about the role of the Wnt canonical pathway in the pathogenesis of some neurodegenerative diseases including Alzheimer's disease, cerebral ischemia, Parkinson's disease, Huntington's disease, multiple sclerosis and amyotrophic lateral sclerosis, with particular regard to the main in vitro and in vivo studies in this field, by reviewing 85 research articles about.

  19. Activation of canonical Wnt signaling pathway promotes proliferation and self-renewal of rat hepatic oval cell line WB-F344 in vitro

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    Ying Zhang; Xin-Min Li; Fu-Kui Zhang; Bao-En Wang

    2008-01-01

    AIM:To investigate the effect of activation of canonical Wnt signaling pathway on the proliferation and differentiation of hepatic oval cells in vitro.METHODS:WB-F344 cells were treated with recombinant Wnt3a (20,40,80,160,200 ng/mL) in serum-free medium for 24 h.Cell proliferation was measured by Brdu incorporation analysis; untreated WB-F344 cells were taken as controls.After treatment with Wnt3a (160 ng/mL) for 24 h,subcellular localization and protein expression of β-catenin in WB-F344 cells treated and untreated with Wnt3a were examined by immunofluorescence staining and Western blot analysis.CyclinD1 mRNA expression was determined by semi-quantitative reverse-transcript polymerase chain reaction (RT-PCR).The mRNA levels of some phenotypic markers (AFP,CK-19,ALB) and two hepatic nuclear factors (HNF-4,HNF-d) were measured by RT-PCR.Expressions of CK-19 and AFP protein were detected by Western blot analysis.RESULTS:Wnt3a promoted proliferation of WB-F344 cells.Stimulation of WB-F344 cells with recombinant Wnt3a resulted in accumulation of the transcriptional activator β-catenin,together with its translocation into the nuclei,and up-regulated typical Wnt target gene CyclinD1.After 3 d of Wnt3a treatment in the absence of serum,WB-F344 cells retained their bipotential to express several specific phenotypic markers of hepatocytes and cholangiocytes,such as AFP and CK-19,following activation of the canonical Wnt signaling pathway.CONCLUSION:The canonical Wnt signaling pathway promotes proliferation and self-renewal of rat hepatic oval cells.

  20. The low-density lipoprotein receptor-related protein 10 is a negative regulator of the canonical Wnt/{beta}-catenin signaling pathway

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    Jeong, Young-Hee; Sekiya, Manami; Hirata, Michiko; Ye, Mingjuan; Yamagishi, Azumi [Department of Molecular and Biochemical Nutrition, Graduate School of Human Life Science, Osaka City University, Osaka 558-8585 (Japan); Lee, Sang-Mi; Kang, Man-Jong [Department of Animal Science, College of Agriculture and Life Science, Chonnam National University, Gwangju 500-757 (Korea, Republic of); Hosoda, Akemi; Fukumura, Tomoe; Kim, Dong-Ho [Department of Molecular and Biochemical Nutrition, Graduate School of Human Life Science, Osaka City University, Osaka 558-8585 (Japan); Saeki, Shigeru, E-mail: saeki@life.osaka-cu.ac.jp [Department of Molecular and Biochemical Nutrition, Graduate School of Human Life Science, Osaka City University, Osaka 558-8585 (Japan)

    2010-02-19

    Wnt signaling pathways play fundamental roles in the differentiation, proliferation and functions of many cells as well as developmental, growth, and homeostatic processes in animals. Low-density lipoprotein receptor (LDLR)-related protein (LRP) 5 and LRP6 serve as coreceptors of Wnt proteins together with Frizzled receptors, triggering activation of canonical Wnt/{beta}-catenin signaling. Here, we found that LRP10, a new member of the LDLR gene family, inhibits the canonical Wnt/{beta}-catenin signaling pathway. The {beta}-catenin/T cell factor (TCF) transcriptional activity in HEK293 cells was activated by transfection with Wnt3a or LRP6, which was then inhibited by co-transfection with LRP10. Deletion of the extracellular domain of LRP10 negated its inhibitory effect. The inhibitory effect of LRP10 was consistently conserved in HEK293 cells even when GSK3{beta} phosphorylation was inhibited by incubation with lithium chloride and co-transfection with constitutively active S33Y-mutated {beta}-catenin. Nuclear {beta}-catenin accumulation was unaffected by LRP10. The present studies suggest that LRP10 may interfere with the formation of the {beta}-catenin/TCF complex and/or its binding to target DNA in the nucleus, and that the extracellular domain of LRP10 is critical for inhibition of the canonical Wnt/{beta}-catenin signaling pathway.

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

    Directory of Open Access Journals (Sweden)

    Marina Pasca di Magliano

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

  2. Hepatic Progenitor Cells Contribute to the Progression of 2-Acetylaminofluorene/Carbon Tetrachloride-Induced Cirrhosis via the Non-Canonical Wnt Pathway.

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    Jiamei Chen

    Full Text Available Hepatic progenitor cells (HPCs appear to play an important role in chronic liver injury. In this study, cirrhosis was induced in F-344 rats (n = 32 via subcutaneous injection of 50% carbon tetrachloride (CCl4 twice a week for 8 weeks. Then, 30% CCl4 was administered in conjunction with intragastric 2-acetylaminofluorine (2-AAF for 4 weeks to induce activation of HPCs. WB-F344 cells were used to provide direct evidence for differentiation of HPCs to myofibroblasts. The results showed that after administration of 2-AAF, the hydroxyproline content and the expressions of α-SMA, Col I, Col IV, TGF-β1, CD68, TNF-α, CK19 and OV6 were significantly increased. OV6 and α-SMA were largely co-expressed in fibrous septum and the expressions of Wnt5b, frizzled2, frizzled3 and frizzled6 were markedly increased, while β-catenin expression was not statistically different among the different groups. Consistent with the above results, WB-F344 cells, treated with TGF-β1 in vitro, differentiated into myofibroblasts and α-SMA, Col I, Col IV, Wnt5b and frizzled2 expressions were significantly increased, while β-catenin expression was decreased. After blocking the non-canonical Wnt pathway via WIF-1, the Wnt5b level was down regulated, and α-SMA and F-actin expressions were significantly decreased in the WIF-1-treated cells. In conclusion, these results indicate that HPCs appear to differentiate into myofibroblasts and exhibit a profibrotic effect in progressive cirrhosis via activation of the non-canonical Wnt pathway. Blocking the non-canonical Wnt pathway can inhibit the differentiation of HPCs into myofibroblasts, suggesting that blocking this pathway and changing the fate of differentiated HPCs may be a potential treatment for cirrhosis.

  3. Hepatic Progenitor Cells Contribute to the Progression of 2-Acetylaminofluorene/Carbon Tetrachloride-Induced Cirrhosis via the Non-Canonical Wnt Pathway.

    Science.gov (United States)

    Chen, Jiamei; Zhang, Xiao; Xu, Ying; Li, Xuewei; Ren, Shuang; Zhou, Yaning; Duan, Yuyou; Zern, Mark; Zhang, Hua; Chen, Gaofeng; Liu, Chenghai; Mu, Yongping; Liu, Ping

    2015-01-01

    Hepatic progenitor cells (HPCs) appear to play an important role in chronic liver injury. In this study, cirrhosis was induced in F-344 rats (n = 32) via subcutaneous injection of 50% carbon tetrachloride (CCl4) twice a week for 8 weeks. Then, 30% CCl4 was administered in conjunction with intragastric 2-acetylaminofluorine (2-AAF) for 4 weeks to induce activation of HPCs. WB-F344 cells were used to provide direct evidence for differentiation of HPCs to myofibroblasts. The results showed that after administration of 2-AAF, the hydroxyproline content and the expressions of α-SMA, Col I, Col IV, TGF-β1, CD68, TNF-α, CK19 and OV6 were significantly increased. OV6 and α-SMA were largely co-expressed in fibrous septum and the expressions of Wnt5b, frizzled2, frizzled3 and frizzled6 were markedly increased, while β-catenin expression was not statistically different among the different groups. Consistent with the above results, WB-F344 cells, treated with TGF-β1 in vitro, differentiated into myofibroblasts and α-SMA, Col I, Col IV, Wnt5b and frizzled2 expressions were significantly increased, while β-catenin expression was decreased. After blocking the non-canonical Wnt pathway via WIF-1, the Wnt5b level was down regulated, and α-SMA and F-actin expressions were significantly decreased in the WIF-1-treated cells. In conclusion, these results indicate that HPCs appear to differentiate into myofibroblasts and exhibit a profibrotic effect in progressive cirrhosis via activation of the non-canonical Wnt pathway. Blocking the non-canonical Wnt pathway can inhibit the differentiation of HPCs into myofibroblasts, suggesting that blocking this pathway and changing the fate of differentiated HPCs may be a potential treatment for cirrhosis. PMID:26087010

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

    Science.gov (United States)

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

    2016-04-01

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

  5. 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

    2013-01-01

    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. PMID:23520208

  6. Abnormal expression of key genes and proteins in the canonical Wnt/β-catenin pathway of articular cartilage in a rat model of exercise-induced osteoarthritis

    OpenAIRE

    LIU, SHEN-SHEN; ZHOU, PU; Zhang, Yanqiu

    2016-01-01

    To investigate the molecular pathogenesis of the canonical Wnt/β-catenin pathway in exercise-induced osteoarthritis (OA), 30 male healthy Sprague Dawley rats were divided into three groups (control, normal exercise-induced OA and injured exercise-induced OA groups) in order to establish the exercise-induced OA rat model. The mRNA and protein expression levels of Runx-2, BMP-2, Ctnnb1, Sox-9, collagen II, Mmp-13, Wnt-3a and β-catenin in chon-drocytes were detected by reverse transcription-quan...

  7. Activation of the canonical Wnt pathway leads to loss of hematopoietic stem cell repopulation and multilineage differentiation block

    DEFF Research Database (Denmark)

    Kirstetter, Peggy; Anderson, Kristina; Porse, Bo T;

    2006-01-01

    of hematopoietic stem cell function was associated with decreased expression of Cdkn1a (encoding the cell cycle inhibitor p21(cdk)), Sfpi1, Hoxb4 and Bmi1 (encoding the transcription factors PU.1, HoxB4 and Bmi-1, respectively) and altered integrin expression in Lin(-)Sca-1(+)c-Kit(+) cells, whereas PU.1......Wnt signaling increases hematopoietic stem cell self-renewal and is activated in both myeloid and lymphoid malignancies, indicating involvement in both normal and malignant hematopoiesis. We report here activated canonical Wnt signaling in the hematopoietic system through conditional expression...... of a stable form of beta-catenin. This enforced expression led to hematopoietic failure associated with loss of myeloid lineage commitment at the granulocyte-macrophage progenitor stage; blocked erythrocyte differentiation; disruption of lymphoid development; and loss of repopulating stem cell activity. Loss...

  8. Bone morphogenetic protein 2-induced human dental pulp cell differentiation involves p38 mitogen-activated protein kinase-activated canonical WNT pathway

    Institute of Scientific and Technical Information of China (English)

    Jing Yang; Ling Ye; Tian-Qian Hui; Dong-Mei Yang; Ding-Ming Huang; Xue-Dong Zhou; Jeremy J Mao; Cheng-Lin Wang

    2015-01-01

    Both bone morphogenetic protein 2 (BMP2) and the wingless-type MMTV integration site (WNT)/b-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis. Cross-talk between BMP2 and WNT/b-catenin in osteoblast differentiation and bone formation has been identified. However, the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown. Here, we demonstrate that BMP2 promotes the differentiation of human dental pulp cells (HDPCs) by activating WNT/b-catenin signalling, which is further mediated by p38 mitogen-activated protein kinase (MAPK) in vitro. BMP2 stimulation upregulated the expression of b-catenin in HDPCs, which was abolished by SB203580 but not by Noggin or LDN193189. Furthermore, BMP2 enhanced cell differentiation, which was not fully inhibited by Noggin or LDN193189. Instead, SB203580 partially blocked BMP2-induced b-catenin expression and cell differentiation. Taken together, these data suggest a possible mechanism by which the elevation of b-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway, which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.

  9. Wnt/Ca2+ signaling pathway: a brief overview

    Institute of Scientific and Technical Information of China (English)

    Antara De

    2011-01-01

    The non-canonical Wnt/Ca2+ signaling cascade is less characterized than their canonical counterpart,the Wnt/β-catenin pathway.The non-canonical Wnt signaling pathways are diverse,defined as planer cell polarity pathway,Wnt-RAP1 signaling pathway,Wnt-Ror2 signaling pathway,Wnt-PKA pathway,Wnt-GSK3MT pathway,Wnt-aPKC pathway,Wnt-RYK pathway,Wnt-mTOR pathway,and Wnt/calcium signaling pathway.All these pathways exhibit a considerable degree of overlap between them.The Wnt/Ca2+ signaling pathway was deciphered as a crucial mediator in development.However,now there is substantial evidence that the signaling cascade is involved in many other molecular phenomena.Many aspects of Wnt/Ca2+ pathway are yet enigmatic.This review will give a brief overview of the fundamental and evolving concepts of the Wnt/Ca2+ signaling pathway.

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

    Directory of Open Access Journals (Sweden)

    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

  11. Curcumin-loaded nanoparticles potently induce adult neurogenesis and reverse cognitive deficits in Alzheimer's disease model via canonical Wnt/β-catenin pathway.

    Science.gov (United States)

    Tiwari, Shashi Kant; Agarwal, Swati; Seth, Brashket; Yadav, Anuradha; Nair, Saumya; Bhatnagar, Priyanka; Karmakar, Madhumita; Kumari, Manisha; Chauhan, Lalit Kumar Singh; Patel, Devendra Kumar; Srivastava, Vikas; Singh, Dhirendra; Gupta, Shailendra Kumar; Tripathi, Anurag; Chaturvedi, Rajnish Kumar; Gupta, Kailash Chand

    2014-01-28

    Neurogenesis, a process of generation of new neurons, is reported to be reduced in several neurodegenerative disorders including Alzheimer's disease (AD). Induction of neurogenesis by targeting endogenous neural stem cells (NSC) could be a promising therapeutic approach to such diseases by influencing the brain self-regenerative capacity. Curcumin, a neuroprotective agent, has poor brain bioavailability. Herein, we report that curcumin-encapsulated PLGA nanoparticles (Cur-PLGA-NPs) potently induce NSC proliferation and neuronal differentiation in vitro and in the hippocampus and subventricular zone of adult rats, as compared to uncoated bulk curcumin. Cur-PLGA-NPs induce neurogenesis by internalization into the hippocampal NSC. Cur-PLGA-NPs significantly increase expression of genes involved in cell proliferation (reelin, nestin, and Pax6) and neuronal differentiation (neurogenin, neuroD1, neuregulin, neuroligin, and Stat3). Curcumin nanoparticles increase neuronal differentiation by activating the Wnt/β-catenin pathway, involved in regulation of neurogenesis. These nanoparticles caused enhanced nuclear translocation of β-catenin, decreased GSK-3β levels, and increased promoter activity of the TCF/LEF and cyclin-D1. Pharmacological and siRNA-mediated genetic inhibition of the Wnt pathway blocked neurogenesis-stimulating effects of curcumin. These nanoparticles reverse learning and memory impairments in an amyloid beta induced rat model of AD-like phenotypes, by inducing neurogenesis. In silico molecular docking studies suggest that curcumin interacts with Wif-1, Dkk, and GSK-3β. These results suggest that curcumin nanoparticles induce adult neurogenesis through activation of the canonical Wnt/β-catenin pathway and may offer a therapeutic approach to treating neurodegenerative diseases such as AD, by enhancing a brain self-repair mechanism. PMID:24467380

  12. Primary cilia are not required for normal canonical Wnt signaling in the mouse embryo.

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    Polloneal Jymmiel R Ocbina

    Full Text Available Sonic hedgehog (Shh signaling in the mouse requires the microtubule-based organelle, the primary cilium. The primary cilium is assembled and maintained through the process of intraflagellar transport (IFT and the response to Shh is blocked in mouse mutants that lack proteins required for IFT. Although the phenotypes of mouse IFT mutants do not overlap with phenotypes of known Wnt pathway mutants, recent studies report data suggesting that the primary cilium modulates responses to Wnt signals.We therefore carried out a systematic analysis of canonical Wnt signaling in mutant embryos and cells that lack primary cilia because of loss of the anterograde IFT kinesin-II motor (Kif3a or IFT complex B proteins (Ift172 or Ift88. We also analyzed mutant embryos with abnormal primary cilia due to defects in retrograde IFT (Dync2h1. The mouse IFT mutants express the canonical Wnt target Axin2 and activate a transgenic canonical Wnt reporter, BAT-gal, in the normal spatial pattern and to the same quantitative level as wild type littermates. Similarly, mouse embryonic fibroblasts (MEFs derived from IFT mutants respond normally to added Wnt3a. The switch from canonical to non-canonical Wnt also appears normal in IFT mutant MEFs, as both wild-type and mutant cells do not activate the canonical Wnt reporter in the presence of both Wnt3a and Wnt5a.We conclude that loss of primary cilia or defects in retrograde IFT do not affect the response of the midgestation embryo or embryo-derived fibroblasts to Wnt ligands.

  13. Neuronal development and axon growth are altered by glyphosate through a WNT non-canonical signaling pathway.

    Science.gov (United States)

    Coullery, Romina P; Ferrari, María E; Rosso, Silvana B

    2016-01-01

    The growth and morphological differentiation of neurons are critical events in the establishment of proper neuronal connectivity and functioning. The developing nervous system is highly susceptible to damage caused by exposure to environmental contaminants. Glyphosate-containing herbicides are the most used agrochemicals in the world, particularly on genetically modified plants. Previous studies have demonstrated that glyphosate induces neurotoxicity in mammals. Therefore, its action mechanism on the nervous system needs to be determined. In this study, we report about impaired neuronal development caused by glyphosate exposure. Particularly, we observed that the initial axonal differentiation and growth of cultured neurons is affected by glyphosate since most treated cells remained undifferentiated after 1 day in culture. Although they polarized at 2 days in vitro, they elicited shorter and unbranched axons and they also developed less complex dendritic arbors compared to controls. To go further, we attempted to identify the cellular mechanism by which glyphosate affected neuronal morphology. Biochemical approaches revealed that glyphosate led to a decrease in Wnt5a level, a key factor for the initial neurite development and maturation, as well as inducing a down-regulation of CaMKII activity. This data suggests that the morphological defects would likely be a consequence of the decrease in both Wnt5a expression and CaMKII activity induced by glyphosate. Additionally, these changes might be reflected in a subsequent neuronal dysfunction. Therefore, our findings highlight the importance of establishing rigorous control on the use of glyphosate-based herbicides in order to protect mammals' health.

  14. Ptk7 and Mcc, Unfancied Components in Non-Canonical Wnt Signaling and Cancer

    Science.gov (United States)

    Dunn, Norris Ray; Tolwinski, Nicholas S.

    2016-01-01

    Human development uses a remarkably small number of signal transduction pathways to organize vastly complicated tissues. These pathways are commonly associated with disease in adults if activated inappropriately. One such signaling pathway, Wnt, solves the too few pathways conundrum by having many alternate pathways within the Wnt network. The main or “canonical” Wnt pathway has been studied in great detail, and among its numerous downstream components, several have been identified as drug targets that have led to cancer treatments currently in clinical trials. In contrast, the non-canonical Wnt pathways are less well characterized, and few if any possible drug targets exist to tackle cancers caused by dysregulation of these Wnt offshoots. In this review, we focus on two molecules—Protein Tyrosine Kinase 7 (Ptk7) and Mutated in Colorectal Cancer (Mcc)—that do not fit perfectly into the non-canonical pathways described to date and whose roles in cancer are ill defined. We will summarize work from our laboratories as well as many others revealing unexpected links between these two proteins and Wnt signaling both in cancer progression and during vertebrate and invertebrate embryonic development. We propose that future studies focused on delineating the signaling machinery downstream of Ptk7 and Mcc will provide new, hitherto unanticipated drug targets to combat cancer metastasis. PMID:27438854

  15. Expression of canonical WNT/β-CATENIN signaling components in the developing human lung

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    Zhang Mingfeng

    2012-07-01

    Full Text Available Abstract Background The WNT/β-CATENIN signaling cascade is crucial for the patterning of the early lung morphogenesis in mice, but its role in the developing human lung remains to be determined. In this study, expression patterns of canonical WNT/β-CATENIN signaling components, including WNT ligands (WNT2, WNT7B, receptors ( FZD4, FZD7, LRP5, LRP6, transducers ( DVL2, DVL3, GSK-3β, β-CATENIN, APC, AXIN2, transcription factors ( TCF4, LEF1 and antagonists ( SOSTDC1 were examined in human embryonic lung at 7, 12, 17 and 21 weeks of gestation (W by real-time qRT-PCR and in situ hybridization. Results qRT-PCR analysis showed that some of these components were gradually upregulated, while some were significantly downregulated from the 7 W to the 12 W. However, most components reached a high level at 17 W, with a subsequent decrease at 21 W. In situ hybridization showed that the canonical WNT ligands and receptors were predominantly located in the peripheral epithelium, whereas the canonical WNT signal transducers and transcription factors were not only detected in the respiratory epithelium, but some were also scattered at low levels in the surrounding mesenchyme in the developing human lung. Furthermore, Western blot, qRT-PCR and histological analysis demonstrated that the β-CATENIN-dependent WNT signaling in embryonic human lung was activated in vitro by CHIR 99021 stimulation. Conclusions This study of the expression patterns and in vitro activity of the canonical WNT/β-CATENIN pathways suggests that these components play an essential role in regulation of human lung development.

  16. Ligand-Independent Canonical Wnt Activity in Canine Mammary Tumor Cell Lines Associated with Aberrant LEF1 Expression

    Science.gov (United States)

    van Wolferen, Monique E.; Rao, Nagesha A. S.; Grizelj, Juraj; Vince, Silvijo; Hellmen, Eva; Mol, Jan A.

    2014-01-01

    Pet dogs very frequently develop spontaneous mammary tumors and have been suggested as a good model organism for breast cancer research. In order to obtain an insight into underlying signaling mechanisms during canine mammary tumorigenesis, in this study we assessed the incidence and the mechanism of canonical Wnt activation in a panel of 12 canine mammary tumor cell lines. We show that a subset of canine mammary cell lines exhibit a moderate canonical Wnt activity that is dependent on Wnt ligands, similar to what has been described in human breast cancer cell lines. In addition, three of the tested canine mammary cell lines have a high canonical Wnt activity that is not responsive to inhibitors of Wnt ligand secretion. Tumor cell lines with highly active canonical Wnt signaling often carry mutations in key members of the Wnt signaling cascade. These cell lines, however, carry no mutations in the coding regions of intracellular Wnt pathway components (APC, β-catenin, GSK3β, CK1α and Axin1) and have a functional β-catenin destruction complex. Interestingly, however, the cell lines with high canonical Wnt activity specifically overexpress LEF1 mRNA and the knock-down of LEF1 significantly inhibits TCF-reporter activity. In addition, LEF1 is overexpressed in a subset of canine mammary carcinomas, implicating LEF1 in ligand-independent activation of canonical Wnt signaling in canine mammary tumors. We conclude that canonical Wnt activation may be a frequent event in canine mammary tumors both through Wnt ligand-dependent and novel ligand–independent mechanisms. PMID:24887235

  17. Ligand-independent canonical Wnt activity in canine mammary tumor cell lines associated with aberrant LEF1 expression.

    Directory of Open Access Journals (Sweden)

    Ana Gracanin

    Full Text Available Pet dogs very frequently develop spontaneous mammary tumors and have been suggested as a good model organism for breast cancer research. In order to obtain an insight into underlying signaling mechanisms during canine mammary tumorigenesis, in this study we assessed the incidence and the mechanism of canonical Wnt activation in a panel of 12 canine mammary tumor cell lines. We show that a subset of canine mammary cell lines exhibit a moderate canonical Wnt activity that is dependent on Wnt ligands, similar to what has been described in human breast cancer cell lines. In addition, three of the tested canine mammary cell lines have a high canonical Wnt activity that is not responsive to inhibitors of Wnt ligand secretion. Tumor cell lines with highly active canonical Wnt signaling often carry mutations in key members of the Wnt signaling cascade. These cell lines, however, carry no mutations in the coding regions of intracellular Wnt pathway components (APC, β-catenin, GSK3β, CK1α and Axin1 and have a functional β-catenin destruction complex. Interestingly, however, the cell lines with high canonical Wnt activity specifically overexpress LEF1 mRNA and the knock-down of LEF1 significantly inhibits TCF-reporter activity. In addition, LEF1 is overexpressed in a subset of canine mammary carcinomas, implicating LEF1 in ligand-independent activation of canonical Wnt signaling in canine mammary tumors. We conclude that canonical Wnt activation may be a frequent event in canine mammary tumors both through Wnt ligand-dependent and novel ligand-independent mechanisms.

  18. KLF4 transcriptionally activates non-canonical WNT5A to control epithelial stratification.

    Science.gov (United States)

    Tetreault, Marie-Pier; Weinblatt, Daniel; Shaverdashvili, Khvaramze; Yang, Yizeng; Katz, Jonathan P

    2016-05-17

    Epithelial differentiation and stratification are essential for normal homeostasis, and disruption of these processes leads to both injury and cancer. The zinc-finger transciption factor KLF4 is a key driver of epithelial differentiation, yet the mechanisms and targets by which KLF4 controls differentiation are not well understood. Here, we define WNT5A, a non-canonical Wnt ligand implicated in epithelial differentiation, repair, and cancer, as a direct transcriptional target that is activated by KLF4 in squamous epithelial cells. Further, we demonstrate functionally that WNT5A mediates KLF4 control of epithelial differentiation and stratification, as treatment of keratinocytes with WNT5A rescues defective epithelial stratification resulting from KLF4 loss. Finally, we show that the small GTPase CDC42 is regulated by KLF4 in a WNT5A dependent manner. As such, we delineate a novel pathway for epithelial differentiation and stratification and define potential therapeutic targets for epithelial diseases.

  19. Role of the Wnt pathway in thyroid cancer

    Directory of Open Access Journals (Sweden)

    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.

  20. Neuroprotective Potential of Novel Multi-Targeted Isoalloxazine Derivatives in Rodent Models of Alzheimer's Disease Through Activation of Canonical Wnt/β-Catenin Signalling Pathway.

    Science.gov (United States)

    Machhi, Jatin; Sinha, Anshuman; Patel, Pratik; Kanhed, Ashish M; Upadhyay, Pragnesh; Tripathi, Ashutosh; Parikh, Zalak S; Chruvattil, Ragitha; Pillai, Prakash P; Gupta, Sarita; Patel, Kirti; Giridhar, Rajani; Yadav, Mange Ram

    2016-05-01

    Previous reports suggest that Alzheimer's disease is protected by cholinesterase inhibitors. We synthesized some isoalloxazine derivatives and evaluated them using in vitro cholinesterase inhibition assay. Two of the compounds (7m and 7q) were figured out as potent cholinesterase inhibitors. They further showed anti-Aβ aggregatory activity in the in vitro assay. The current study deals with the evaluation of neuroprotective potentials of the potent compounds (7m and 7q) using different in vitro and in vivo experiments. The compounds were first assessed for their tendency to cross blood-brain barrier using in vitro permeation assay. They were evaluated using scopolamine-induced amnesic mice model. Additionally, ROS scavenging and anti-apoptotic properties of 7m and 7q were established against Aβ1-42-induced toxicity in rat hippocampal neuronal cells. 7m and 7q were also evaluated using Aβ1-42-induced Alzheimer's rat model. Lastly, their involvement in Wnt/β-catenin pathway was also demonstrated. The results indicated good CNS penetration for 7m and 7q. The neuroprotective effects of 7m and 7q were evidenced by improved cognitive ability in both scopolamine and Aβ1-42-induced Alzheimer's-like condition in rodents. The in vivo results also confirmed their anti-cholinesterase and anti-oxidant potential. Immunoblot results showed that treatment with 7m and 7q decreased Aβ1-42, p-tau, cleaved caspase-3, and cleaved PARP levels in Aβ1-42-induced Alzheimer's rat brain. Additionally, immunoblot results demonstrated that 7m and 7q activated the Wnt/β-catenin pathway as evidenced by increased p-GSK-3, β-catenin, and neuroD1 levels in Aβ1-42-induced Alzheimer's rat brain. These findings have shown that isoalloxazine derivatives (7m and 7q) could be the potential leads for developing effective drugs for the treatment of AD. PMID:26797524

  1. WNT signaling enhances breast cancer cell motility and blockade of the WNT pathway by sFRP1 suppresses MDA-MB-231 xenograft growth

    OpenAIRE

    Matsuda, Yutaka; Schlange, Thomas; Oakeley, Edward J.; Boulay, Anne; Nancy E Hynes

    2009-01-01

    Introduction In breast cancer, deregulation of the WNT signaling pathway occurs by autocrine mechanisms. WNT ligands and Frizzled receptors are coexpressed in primary breast tumors and cancer cell lines. Moreover, many breast tumors show hypermethylation of the secreted Frizzled-related protein 1 (sFRP1) promoter region, causing low expression of this WNT antagonist. We have previously shown that the WNT pathway influences proliferation of breast cancer cell lines via activation of canonical ...

  2. Secreted Frizzled-related protein-2 (sFRP2) augments canonical Wnt3a-induced signaling

    Energy Technology Data Exchange (ETDEWEB)

    Marschall, Zofia von [Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD (United States); Fisher, Larry W., E-mail: lfisher@dir.nidcr.nih.gov [Craniofacial and Skeletal Diseases Branch, NIDCR, NIH, DHHS, Bethesda, MD (United States)

    2010-09-24

    Research highlights: {yields} sFRP2 enhances the Wnt3a-induced {beta}-catenin stabilization and its nuclear translocation. {yields} sFRP2 enhances LRP6 phosphorylation and Wnt3a/{beta}-catenin transcriptional reporter activity. {yields} Dickkopf-1 (DKK1) fully antagonizes both Wnt3a/sFRP2-induced LRP6 phosphorylation and transcriptional activity. {yields} sFRP2 enhances expression of genes known to be regulated by Wnt3a signaling. -- Abstract: Secreted Frizzled-related proteins (sFRP) are involved in embryonic development as well as pathological conditions including bone and myocardial disorders and cancer. Because of their sequence homology with the Wnt-binding domain of Frizzled, they have generally been considered antagonists of canonical Wnt signaling. However, additional activities of various sFRPs including both synergism and mimicry of Wnt signaling as well as functions other than modulation of Wnt signaling have been reported. Using human embryonic kidney cells (HEK293A), we found that sFRP2 enhanced Wnt3a-dependent phosphorylation of LRP6 as well as both cytosolic {beta}-catenin levels and its nuclear translocation. While addition of recombinant sFRP2 had no activity by itself, Top/Fop luciferase reporter assays showed a dose-dependent increase of Wnt3a-mediated transcriptional activity. sFRP2 enhancement of Wnt3a signaling was abolished by treatment with the Wnt antagonist, Dickkopf-1 (DKK1). Wnt-signaling pathway qPCR arrays showed that sFRP2 enhanced the Wnt3a-mediated transcriptional up-regulation of several genes regulated by Wnt3a including its antagonists, DKK1, and Naked cuticle-1 homolog (NKD1). These results support sFRP2's role as an enhancer of Wnt/{beta}-catenin signaling, a result with biological impact for both normal development and diverse pathologies such as tumorigenesis.

  3. Controlled levels of canonical Wnt signaling are required for neural crest migration.

    Science.gov (United States)

    Maj, Ewa; Künneke, Lutz; Loresch, Elisabeth; Grund, Anita; Melchert, Juliane; Pieler, Tomas; Aspelmeier, Timo; Borchers, Annette

    2016-09-01

    Canonical Wnt signaling plays a dominant role in the development of the neural crest (NC), a highly migratory cell population that generates a vast array of cell types. Canonical Wnt signaling is required for NC induction as well as differentiation, however its role in NC migration remains largely unknown. Analyzing nuclear localization of β-catenin as readout for canonical Wnt activity, we detect nuclear β-catenin in premigratory but not migratory Xenopus NC cells suggesting that canonical Wnt activity has to decrease to basal levels to enable NC migration. To define a possible function of canonical Wnt signaling in Xenopus NC migration, canonical Wnt signaling was modulated at different time points after NC induction. This was accomplished using either chemical modulators affecting β-catenin stability or inducible glucocorticoid fusion constructs of Lef/Tcf transcription factors. In vivo analysis of NC migration by whole mount in situ hybridization demonstrates that ectopic activation of canonical Wnt signaling inhibits cranial NC migration. Further, NC transplantation experiments confirm that this effect is tissue-autonomous. In addition, live-cell imaging in combination with biophysical data analysis of explanted NC cells confirms the in vivo findings and demonstrates that modulation of canonical Wnt signaling affects the ability of NC cells to perform single cell migration. Thus, our data support the hypothesis that canonical Wnt signaling needs to be tightly controlled to enable migration of NC cells. PMID:27341758

  4. Controlled levels of canonical Wnt signaling are required for neural crest migration.

    Science.gov (United States)

    Maj, Ewa; Künneke, Lutz; Loresch, Elisabeth; Grund, Anita; Melchert, Juliane; Pieler, Tomas; Aspelmeier, Timo; Borchers, Annette

    2016-09-01

    Canonical Wnt signaling plays a dominant role in the development of the neural crest (NC), a highly migratory cell population that generates a vast array of cell types. Canonical Wnt signaling is required for NC induction as well as differentiation, however its role in NC migration remains largely unknown. Analyzing nuclear localization of β-catenin as readout for canonical Wnt activity, we detect nuclear β-catenin in premigratory but not migratory Xenopus NC cells suggesting that canonical Wnt activity has to decrease to basal levels to enable NC migration. To define a possible function of canonical Wnt signaling in Xenopus NC migration, canonical Wnt signaling was modulated at different time points after NC induction. This was accomplished using either chemical modulators affecting β-catenin stability or inducible glucocorticoid fusion constructs of Lef/Tcf transcription factors. In vivo analysis of NC migration by whole mount in situ hybridization demonstrates that ectopic activation of canonical Wnt signaling inhibits cranial NC migration. Further, NC transplantation experiments confirm that this effect is tissue-autonomous. In addition, live-cell imaging in combination with biophysical data analysis of explanted NC cells confirms the in vivo findings and demonstrates that modulation of canonical Wnt signaling affects the ability of NC cells to perform single cell migration. Thus, our data support the hypothesis that canonical Wnt signaling needs to be tightly controlled to enable migration of NC cells.

  5. 间充质干细胞增殖、衰老及分化:Wnt信号通路经典与非经典的调控作用%Proliferation, senescence and differentiation of mesenchymal stem cells:canonical and non-canonical regulations of Wnt signaling pathway

    Institute of Scientific and Technical Information of China (English)

    施剑明; 邬亚华; 耿书国; 殷明

    2014-01-01

    背景:间充质干细胞作为再生医学及组织工程领域中的重要种子细胞来源,对其不同生物学特性的调控机制一直是目前研究的热点。  目的:综述Wnt信号通路调控间充质干细胞增殖、衰老及分化的研究进展。  方法:应用计算机检索2002至2014年PubMed数据库及CNKI数据库,以“mesenchymal stem cel s, Wnt signaling pathway,proliferation,senescence,differentiation”或“间充质干细胞,Wnt信号通路,增殖,衰老,分化”为关键词进行检索,重点对44篇文章进行分析。  结果与结论:Wnt信号通路广泛参与调控间充质干细胞多种生物学特性。经典Wnt信号通路对间充质干细胞增殖及向成骨细胞分化具有双向调控作用,并能够促进其衰老及向神经细胞分化,抑制其向脂肪细胞分化;非经典Wnt信号通路则参与促进间充质干细胞衰老及向成骨细胞分化,抑制其增殖及向脂肪细胞分化,不参与其向神经细胞分化,为其应用于骨组织工程、神经损伤修复等领域提供了新的研究靶点。%BACKGROUND:As mesenchymal stem cells are commonly used as seed cells in studies of regenerative medicine and tissue engineering, the regulatory mechanism of their biological characteristics is a current research focus. OBJECTIVE:To summarize the regulations of Wnt signaling pathway on proliferation, senescence and differentiation of mesenchymal stem cells. METHODS:PubMed database and CNKI database were retrieved by computer using the key words of“mesenchymal stem cells, Wnt signaling pathway, proliferation, senescence, differentiation”in Chinese and English, respectively, between 2002 and 2014. Final y, 44 articles were included in result analysis. RESULTS AND CONCLUSION:Wnt signaling pathway is widely involved in the regulations of the biological characteristics of mesenchymal stem cells. Canonical Wnt signaling pathway reveals a bi

  6. Effects of broadband ultraviolet B on non-canonical Wnt pathways in human epidermal melanocytes%宽谱中波紫外线对人表皮黑素细胞非经典Wnt通路的作用研究

    Institute of Scientific and Technical Information of China (English)

    王辉; 林彤; 王千秋

    2015-01-01

    , CCK-8 assay was performed to evaluate the proliferative activity of melanocytes, dopa oxidation assay to estimate the activity of tyrosinase, and sodium hydroxide (NaOH)-lysis method was used to determine melanin content.Real-time fluorescence-based quantitative PCR was conducted to measure the mRNA expressions of genes involved in non-canonical Wnt pathways in melanocytes after irradiation with BB-UVB at 30, 50 and 100 mJ/cm2.Western blot was carried out to determine the expressions of proteins involved in non-canonical Wnt pathways in melanocytes before and after irradiation with BB-UVB of 100 mJ/cm2.The melanocytes receiving no treatment served as the control group.Statistical analysis was carried out by one-way analysis of variance followed by least significant difference (LSD)-t test for multiple group comparisons and by the independent sample t test for two-group comparisons.Results After irradiation with BB-UVB at 10-300 mJ/cm2, the proliferative activity of melanocytes was gradually reduced compared with the control group (all P < 0.05), and the survival rate of melanocytes was less than 50% when the irradiation dose of BB-UVB was higher than 100 mJ/cm2.Furthermore, tyrosinase activity gradually increased in melanocytes after irradiation with BB-UVB at 10-100 mJ/cm2 compared with the control group, and the increase was statistically significant at the radiation dose of 100 mJ/cm2 (P < 0.05).Compared with the control group, the WIF-1 mRNA expression level decreased, while c-Jun N-terminal kinase (JNK), microphthalmia-associated transcription factor (MITF), Ras-related C3 botulinum toxin substrate 1 (RAC 1) and tyrosinase (TYR) mRNA expression levels increased in melanocytes after irradiation with BB-UVB at 30, 50 and 100 mJ/cm2 (all P < 0.05);the WNT5A mRNA expression significantly decreased in melanocytes irradiated with 30 and 50 mJ/cm2 BB-UVB, but increased in those irradiated with 100 mJ/cm2 BB-UVB (all P < 0.05).The radiation with 100 mJ/cm2 BB

  7. Complement C1q Activates Canonical Wnt Signaling and Promotes Aging-Related Phenotypes

    OpenAIRE

    Atsuhiko T. Naito; Sumida, Tomokazu; Nomura, Seitaro; Liu, Mei-Lan; Higo, Tomoaki; NAKAGAWA, AKITO; Okada, Katsuki; Sakai, Taku; Hashimoto, Akihito; Hara, Yurina; Shimizu, Ippei; Zhu, Weidong; Toko, Haruhiro; Katada, Akemi; Akazawa, Hiroshi

    2012-01-01

    Wnt signaling plays critical roles in development of various organs and pathogenesis of many diseases, and augmented Wnt signaling has recently been implicated in mammalian aging and aging-related phenotypes. We here report that complement C1q activates canonical Wnt signaling and promotes aging-associated decline in tissue regeneration. Serum C1q concentration is increased with aging, and Wnt signaling activity is augmented during aging in the serum and in multiple tissues of wild-type mice,...

  8. Andrographolide activates the canonical Wnt signalling pathway by a mechanism that implicates the non-ATP competitive inhibition of GSK-3β: autoregulation of GSK-3β in vivo.

    Science.gov (United States)

    Tapia-Rojas, Cheril; Schüller, Andreas; Lindsay, Carolina B; Ureta, Roxana C; Mejías-Reyes, Cristóbal; Hancke, Juan; Melo, Francisco; Inestrosa, Nibaldo C

    2015-03-01

    Wnt/β-catenin signalling is an important pathway that regulates multiple biological processes, including cell adhesion and determination of cell fate during animal development; in the adult nervous system it regulates the structure and function of synapses. Wnt-signalling dysfunction is associated with several neurodegenerative diseases such as schizophrenia and Alzheimer's disease. The use of natural compounds is an interesting strategy in the search for drugs with the therapeutic potential to activate this signalling pathway. In the present study, we report that andrographolide (ANDRO), a component of Andrographis paniculata, is a potent activator of Wnt signalling. Our results indicate that ANDRO activates this pathway, inducing the transcription of Wnt target genes by a mechanism that bypasses Wnt ligand binding to its receptor. In vitro kinase assays demonstrate that ANDRO inhibits glycogen synthase kinase (GSK)-3β by a non-ATP-competitive, substrate-competitive mode of action. In silico analyses suggest that ANDRO interacts with the substrate-binding site of GSK-3β. Finally, we demonstrated that the increase seen in the levels of GSK-3β phosphorylated at Ser⁹ is the result of an autoregulatory mechanism of the kinase in vivo, although not through activation of protein phosphatase type 1. Our results suggest that ANDRO could be used as a potential therapeutic drug for disorders caused by Wnt-signalling dysfunction such as neurodegenerative diseases. PMID:25423492

  9. Wnt signalling pathway parameters for mammalian cells.

    Directory of Open Access Journals (Sweden)

    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

  10. Canonical and non-canonical pathways of osteoclast formation

    OpenAIRE

    Knowles, H.J.; Athanasou, N A

    2009-01-01

    Physiological and pathological bone resorption is mediated by osteoclasts, multinucleated cells which are formed by the fusion of monocyte / macrophage precursors. The canonical pathway of osteoclast formation requires the presence of the receptor activator for NFkB ligand (RANKL) and macrophage colony stimulating factor (M-CSF). Noncanonical pathways of osteoclast formation have been described in which cytokines / growth factors can substitute for RANKL or M-CSF to...

  11. 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.

  12. Comprehensive Expression of Wnt Signaling Pathway Genes during Development and Maturation of the Mouse Cochlea.

    Directory of Open Access Journals (Sweden)

    Ruishuang Geng

    Full Text Available In the inner ear Wnt signaling is necessary for proliferation, cell fate determination, growth of the cochlear duct, polarized orientation of stereociliary bundles, differentiation of the periotic mesenchyme, and homeostasis of the stria vascularis. In neonatal tissue Wnt signaling can drive proliferation of cells in the sensory region, suggesting that Wnt signaling could be used to regenerate the sensory epithelium in the damaged adult inner ear. Manipulation of Wnt signaling for regeneration will require an understanding of the dynamics of Wnt pathway gene expression in the ear. We present a comprehensive screen for 84 Wnt signaling related genes across four developmental and postnatal time points.We identified 72 Wnt related genes expressed in the inner ear on embryonic day (E 12.5, postnatal day (P 0, P6 and P30. These genes included secreted Wnts, Wnt antagonists, intracellular components of canonical signaling and components of non-canonical signaling/planar cell polarity.A large number of Wnt signaling molecules were dynamically expressed during cochlear development and in the early postnatal period, suggesting complex regulation of Wnt transduction. The data revealed several potential key regulators for further study.

  13. MMTV-Wnt1 and -DeltaN89beta-catenin induce canonical signaling in distinct progenitors and differentially activate Hedgehog signaling within mammary tumors.

    Directory of Open Access Journals (Sweden)

    Brigitte Teissedre

    Full Text Available Canonical Wnt/beta-catenin signaling regulates stem/progenitor cells and, when perturbed, induces many human cancers. A significant proportion of human breast cancer is associated with loss of secreted Wnt antagonists and mice expressing MMTV-Wnt1 and MMTV-DeltaN89beta-catenin develop mammary adenocarcinomas. Many studies have assumed these mouse models of breast cancer to be equivalent. Here we show that MMTV-Wnt1 and MMTV-DeltaN89beta-catenin transgenes induce tumors with different phenotypes. Using axin2/conductin reporter genes we show that MMTV-Wnt1 and MMTV-DeltaN89beta-catenin activate canonical Wnt signaling within distinct cell-types. DeltaN89beta-catenin activated signaling within a luminal subpopulation scattered along ducts that exhibited a K18(+ER(-PR(-CD24(highCD49f(low profile and progenitor properties. In contrast, MMTV-Wnt1 induced canonical signaling in K14(+ basal cells with CD24/CD49f profiles characteristic of two distinct stem/progenitor cell-types. MMTV-Wnt1 produced additional profound effects on multiple cell-types that correlated with focal activation of the Hedgehog pathway. We document that large melanocytic nevi are a hitherto unreported hallmark of early hyperplastic Wnt1 glands. These nevi formed along the primary mammary ducts and were associated with Hedgehog pathway activity within a subset of melanocytes and surrounding stroma. Hh pathway activity also occurred within tumor-associated stromal and K14(+/p63(+ subpopulations in a manner correlated with Wnt1 tumor onset. These data show MMTV-Wnt1 and MMTV-DeltaN89beta-catenin induce canonical signaling in distinct progenitors and that Hedgehog pathway activation is linked to melanocytic nevi and mammary tumor onset arising from excess Wnt1 ligand. They further suggest that Hedgehog pathway activation maybe a critical component and useful indicator of breast tumors arising from unopposed Wnt1 ligand.

  14. Identification of p62/SQSTM1 as a component of non-canonical Wnt VANGL2-JNK signalling in breast cancer.

    Science.gov (United States)

    Puvirajesinghe, Tania M; Bertucci, François; Jain, Ashish; Scerbo, Pierluigi; Belotti, Edwige; Audebert, Stéphane; Sebbagh, Michael; Lopez, Marc; Brech, Andreas; Finetti, Pascal; Charafe-Jauffret, Emmanuelle; Chaffanet, Max; Castellano, Rémy; Restouin, Audrey; Marchetto, Sylvie; Collette, Yves; Gonçalvès, Anthony; Macara, Ian; Birnbaum, Daniel; Kodjabachian, Laurent; Johansen, Terje; Borg, Jean-Paul

    2016-01-01

    The non-canonical Wnt/planar cell polarity (Wnt/PCP) pathway plays a crucial role in embryonic development. Recent work has linked defects of this pathway to breast cancer aggressiveness and proposed Wnt/PCP signalling as a therapeutic target. Here we show that the archetypal Wnt/PCP protein VANGL2 is overexpressed in basal breast cancers, associated with poor prognosis and implicated in tumour growth. We identify the scaffold p62/SQSTM1 protein as a novel VANGL2-binding partner and show its key role in an evolutionarily conserved VANGL2-p62/SQSTM1-JNK pathway. This proliferative signalling cascade is upregulated in breast cancer patients with shorter survival and can be inactivated in patient-derived xenograft cells by inhibition of the JNK pathway or by disruption of the VANGL2-p62/SQSTM1 interaction. VANGL2-JNK signalling is thus a potential target for breast cancer therapy. PMID:26754771

  15. Canonical Wnt/β-catenin signalling is essential for optic cup formation.

    Directory of Open Access Journals (Sweden)

    Anna-Carin Hägglund

    Full Text Available A multitude of signalling pathways are involved in the process of forming an eye. Here we demonstrate that β-catenin is essential for eye development as inactivation of β-catenin prior to cellular specification in the optic vesicle caused anophthalmia in mice. By achieving this early and tissue-specific β-catenin inactivation we find that retinal pigment epithelium (RPE commitment was blocked and eye development was arrested prior to optic cup formation due to a loss of canonical Wnt signalling in the dorsal optic vesicle. Thus, these results show that Wnt/β-catenin signalling is required earlier and play a more central role in eye development than previous studies have indicated. In our genetic model system a few RPE cells could escape β-catenin inactivation leading to the formation of a small optic rudiment. The optic rudiment contained several neural retinal cell classes surrounded by an RPE. Unlike the RPE cells, the neural retinal cells could be β-catenin-negative revealing that differentiation of the neural retinal cell classes is β-catenin-independent. Moreover, although dorsoventral patterning is initiated in the mutant optic vesicle, the neural retinal cells in the optic rudiment displayed almost exclusively ventral identity. Thus, β-catenin is required for optic cup formation, commitment to RPE cells and maintenance of dorsal identity of the retina.

  16. How the Wnt signaling pathway protects from neurodegeneration: the mitochondrial scenario

    Science.gov (United States)

    Arrázola, Macarena S.; Silva-Alvarez, Carmen; Inestrosa, Nibaldo C.

    2015-01-01

    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. PMID:25999816

  17. Molecular Genetics of Intracranial Meningiomas with Emphasis on Canonical Wnt Signalling.

    Science.gov (United States)

    Pećina-Šlaus, Nives; Kafka, Anja; Lechpammer, Mirna

    2016-07-15

    Research over the last decade recognized the importance of novel molecular pathways in pathogenesis of intracranial meningiomas. In this review, we focus on human brain tumours meningiomas and the involvement of Wnt signalling pathway genes and proteins in this common brain tumour, describing their known functional effects. Meningiomas originate from the meningeal layers of the brain and the spinal cord. Most meningiomas have benign clinical behaviour and are classified as grade I by World Health Organization (WHO). However, up to 20% histologically classified as atypical (grade II) or anaplastic (grade III) are associated with higher recurrent rate and have overall less favourable clinical outcome. Recently, there is emerging evidence that multiple signalling pathways including Wnt pathway contribute to the formation and growth of meningiomas. In the review we present the synopsis on meningioma histopathology and genetics and discuss our research regarding Wnt in meningioma. Epithelial-to-mesenchymal transition, a process in which Wnt signalling plays an important role, is shortly discussed.

  18. ACTIVITY OF CANONICAL WNT SIGNAL SYSTEM IN HYALINE CARTILAGE ARTICULAR CHONDROCYTES IN PROCESS OF SYNOVIAL JOINT DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    A.O. Molotkov

    2009-03-01

    Full Text Available Canonical and non-canonical Wnt systems are essential regulators of chondrogenesis and bone development. However, the roles of these systems in synovial joint development are not well studied. To determine if canonical Wnt system is active in developing articular chondrocytes we used immunohistochemistry for в-galactosidase and doublecortin (cell-type specific marker for articular chondrocytes to double label sections through joint regions of E14.5, E18.5, P10 and adult mice. Here the following results are presented. Canonical Wnt signal system does not work in developing articular chondrocytes at early embryonic stages (E14.5; it is active in the articular chondrocytes at late embryonic stages (E16.5-E18.5 and during postnatal development (P7-P10, but is turned off again in the adult articular chondrocytes. These results suggest that canonical Wnt signaling is being regulated during articular chondrocytes differentiation and joint formation.

  19. 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. PMID:24158438

  20. The roles of APC and Axin derived from experimental and theoretical analysis of the Wnt pathway.

    Directory of Open Access Journals (Sweden)

    Ethan Lee

    2003-10-01

    Full Text Available Wnt signaling plays an important role in both oncogenesis and development. Activation of the Wnt pathway results in stabilization of the transcriptional coactivator beta-catenin. Recent studies have demonstrated that axin, which coordinates beta-catenin degradation, is itself degraded. Although the key molecules required for transducing a Wnt signal have been identified, a quantitative understanding of this pathway has been lacking. We have developed a mathematical model for the canonical Wnt pathway that describes the interactions among the core components: Wnt, Frizzled, Dishevelled, GSK3beta, APC, axin, beta-catenin, and TCF. Using a system of differential equations, the model incorporates the kinetics of protein-protein interactions, protein synthesis/degradation, and phosphorylation/dephosphorylation. We initially defined a reference state of kinetic, thermodynamic, and flux data from experiments using Xenopus extracts. Predictions based on the analysis of the reference state were used iteratively to develop a more refined model from which we analyzed the effects of prolonged and transient Wnt stimulation on beta-catenin and axin turnover. We predict several unusual features of the Wnt pathway, some of which we tested experimentally. An insight from our model, which we confirmed experimentally, is that the two scaffold proteins axin and APC promote the formation of degradation complexes in very different ways. We can also explain the importance of axin degradation in amplifying and sharpening the Wnt signal, and we show that the dependence of axin degradation on APC is an essential part of an unappreciated regulatory loop that prevents the accumulation of beta-catenin at decreased APC concentrations. By applying control analysis to our mathematical model, we demonstrate the modular design, sensitivity, and robustness of the Wnt pathway and derive an explicit expression for tumor suppression and oncogenicity.

  1. Canonical and non-canonical Wnt signaling control the regeneration of amputated rodent vibrissae follicles.

    Science.gov (United States)

    Yuan, Yan-Ping; Huang, Keng; Xu, Yan-Min; Chen, Xian-Cai; Li, Hai-Hong; Cai, Bo-Zhi; Liu, Yang; Zhang, Huan; Li, Yu; Lin, Chang-Min

    2016-02-01

    Although mammals are notoriously poor at regeneration compared with many lower-order species, the hair follicle, particular to mammals, is capable of regeneration following partial amputation. The detailed internal mechanism of this phenomenon is still unclear. Development and regrowth of the hair follicle depends on dermal-epidermal interaction within the hair follicle. Previous studies have shown that Wnt/β-catenin, Shh, Bmp, PDGF, TGF and Notch signals all take part in the development and growth of the hair follicle, and the Wnt/β-catenin signaling additionally plays an indispensable role in hair follicle morphogenesis and regrowth. In this study, we investigated the localization, as well as, protein levels of Wnt/β-catenin signaling molecules during amputated whisker follicle regeneration. PMID:26742765

  2. IGF-1R inhibition in mammary epithelia promotes canonical Wnt signaling and Wnt1-driven tumors

    Science.gov (United States)

    Rota, Lauren M.; Albanito, Lidia; Shin, Marcus E.; Goyeneche, Corey L.; Shushanov, Sain; Gallagher, Emily J.; LeRoith, Derek; Lazzarino, Deborah A.; Wood, Teresa L.

    2014-01-01

    Triple-negative breast cancers (TNBC) are an aggressive disease subtype which unlike other subtypes lack an effective targeted therapy. Inhibitors of the insullin-like growth factor receptor (IGF-1R) have been considered for use in treating TNBC. Here we provide genetic evidence that IGF-1R inhibition promotes development of Wnt1-mediated murine mammary tumors that offer a model of TNBC. We found that in a double transgenic mouse model carrying activated Wnt-1 and mutant IGF-1R, a reduction in IGF-1R signaling reduced tumor latency and promoted more aggressive phenotypes. These tumors displayed a squamal cell phenotype with increased expression of keratins 5/6 and β-catenin. Notably, cell lineage analyses revealed an increase in basal (CD29hi/CD24+) and luminal (CD24+/CD61+/CD29lo) progenitor cell populations, along with increased Nanog expression and decreased Elf5 expression. In these doubly transgenic mice, lung metastases developed with characteristics of the primary tumors, unlike MMTV-Wnt1 mice. Mechanistic investigations showed that pharmacological inhibition of the IGF-1R in vitro was sufficient to increase the tumorsphere-forming efficiency of MMTV-Wnt1 tumor cells. Tumors from doubly transgenic mice also exhibited an increase in the expression ratio of the IGF-II-sensitive, A isoform of the insulin receptor vs the IR-B isoform, which in vitro resulted in enhanced expression of β-catenin. Overall, our results revealed that in Wnt-driven tumors an attenuation of IGF-1R signaling accelerates tumorigenesis and promotes more aggressive phenotypes, with potential implications for understanding TNBC pathobiology and treatment. PMID:25092896

  3. Wnt signaling pathway in non-small cell lung cancer.

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    Stewart, David J

    2014-01-01

    Wnt/β-catenin alterations are prominent in human malignancies. In non-small cell lung cancer (NSCLC), β-catenin and APC mutations are uncommon, but Wnt signaling is important in NSCLC cell lines, and Wnt inhibition reduces proliferation. Overexpression of Wnt-1, -2, -3, and -5a and of Wnt-pathway components Frizzled-8, Dishevelled, Porcupine, and TCF-4 is common in resected NSCLC and is associated with poor prognosis. Conversely, noncanonical Wnt-7a suppresses NSCLC development and is often downregulated. Although β-catenin is often expressed in NSCLCs, it was paradoxically associated with improved prognosis in some series, possibly because of E-cadherin interactions. Downregulation of Wnt inhibitors (eg, by hypermethylation) is common in NSCLC tumor cell lines and resected samples; may be associated with high stage, dedifferentiation, and poor prognosis; and has been reported for AXIN, sFRPs 1-5, WIF-1, Dkk-1, Dkk-3, HDPR1, RUNX3, APC, CDX2, DACT2, TMEM88, Chibby, NKD1, EMX2, ING4, and miR-487b. AXIN is also destabilized by tankyrases, and GSK3β may be inactivated through phosphorylation by EGFR. Preclinically, restoration of Wnt inhibitor function is associated with reduced Wnt signaling, decreased cell proliferation, and increased apoptosis. Wnt signaling may also augment resistance to cisplatin, docetaxel, and radiotherapy, and Wnt inhibitors may restore sensitivity. Overall, available data indicate that Wnt signaling substantially impacts NSCLC tumorigenesis, prognosis, and resistance to therapy, with loss of Wnt signaling inhibitors by promoter hypermethylation or other mechanisms appearing to be particularly important. Wnt pathway antagonists warrant exploration clinically in NSCLC. Agents blocking selected specific β-catenin interactions and approaches to increase expression of downregulated Wnt inhibitors may be of particular interest. PMID:24309006

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

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

    2016-01-01

    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. PMID:27590724

  5. Signalling through the type 1 insulin-like growth factor receptor (IGF1R interacts with canonical Wnt signalling to promote neural proliferation in developing brain

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    Qichen Hu

    2012-07-01

    Full Text Available Signalling through the IGF1R [type 1 IGF (insulin-like growth factor receptor] and canonical Wnt signalling are two signalling pathways that play critical roles in regulating neural cell generation and growth. To determine whether the signalling through the IGF1R can interact with the canonical Wnt signalling pathway in neural cells in vivo, we studied mutant mice with altered IGF signalling. We found that in mice with blunted IGF1R expression specifically in nestin-expressing neural cells (IGF1RNestin−KO mice the abundance of neural β-catenin was significantly reduced. Blunting IGF1R expression also markedly decreased: (i the activity of a LacZ (β-galactosidase reporter transgene that responds to Wnt nuclear signalling (LacZTCF reporter transgene and (ii the number of proliferating neural precursors. In contrast, overexpressing IGF-I (insulin-like growth factor I in brain markedly increased the activity of the LacZTCF reporter transgene. Consistently, IGF-I treatment also markedly increased the activity of the LacZTCF reporter transgene in embryonic neuron cultures that are derived from LacZTCF Tg (transgenic mice. Importantly, increasing the abundance of β-catenin in IGF1RNestin−KO embryonic brains by suppressing the activity of GSK3β (glycogen synthase kinase-3β significantly alleviated the phenotypic changes induced by IGF1R deficiency. These phenotypic changes includes: (i retarded brain growth, (ii reduced precursor proliferation and (iii decreased neuronal number. Our current data, consistent with our previous study of cultured oligodendrocytes, strongly support the concept that IGF signalling interacts with canonical Wnt signalling in the developing brain to promote neural proliferation. The interaction of IGF and canonical Wnt signalling plays an important role in normal brain development by promoting neural precursor proliferation.

  6. Components of Intraflagellar Transport Complex A Function Independently of the Cilium to Regulate Canonical Wnt Signaling in Drosophila.

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    Balmer, Sophie; Dussert, Aurore; Collu, Giovanna M; Benitez, Elvira; Iomini, Carlo; Mlodzik, Marek

    2015-09-28

    The development of multicellular organisms requires the precisely coordinated regulation of an evolutionarily conserved group of signaling pathways. Temporal and spatial control of these signaling cascades is achieved through networks of regulatory proteins, segregation of pathway components in specific subcellular compartments, or both. In vertebrates, dysregulation of primary cilia function has been strongly linked to developmental signaling defects, yet it remains unclear whether cilia sequester pathway components to regulate their activation or cilia-associated proteins directly modulate developmental signaling events. To elucidate this question, we conducted an RNAi-based screen in Drosophila non-ciliated cells to test for cilium-independent loss-of-function phenotypes of ciliary proteins in developmental signaling pathways. Our results show no effect on Hedgehog signaling. In contrast, our screen identified several cilia-associated proteins as functioning in canonical Wnt signaling. Further characterization of specific components of Intraflagellar Transport complex A uncovered a cilia-independent function in potentiating Wnt signals by promoting β-catenin/Armadillo activity. PMID:26364750

  7. LMO2 attenuates tumor growth by targeting the Wnt signaling pathway in breast and colorectal cancer

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    Liu, Ye; Huang, Di; Wang, Zhaoyang; Wu, Chao; Zhang, Zhao; Wang, Dan; Li, Zongjin; Zhu, Tianhui; Yang, Shuang; Sun, Wei

    2016-01-01

    The proto-oncogene LIM-domain only 2 (lmo2) was traditionally considered to be a pivotal transcriptional regulator in hematopoiesis and leukemia. Recently, the cytosolic localization of LMO2 was revealed in multiple epithelial tissues and a variety of solid tumors. However, the function of LMO2 in these epithelia and solid tumors remains largely unclear. The Wnt signaling pathway is a crucial determinant of development, and abnormalities in several key segments of this pathway contribute to oncogenesis. The current study demonstrated that LMO2 participates in the regulation of canonical Wnt signaling in the cytoplasm by binding to Dishevelled-1/2 (DVL-1/2) proteins. These interactions occurred at the PDZ domain of Dishevelled, and LMO2 subsequently attenuated the activation of the key factor β-catenin in the canonical Wnt signaling pathway. Meanwhile, significantly decreased expression of LMO2 was detected in breast and colorectal cancers, and the downregulation of LMO2 in these cells increased cell proliferation and reduced apoptosis. Taken together, the data in this study revealed a novel crosstalk between LMO2 and the Wnt signaling pathway during tumorigenesis and suggested that LMO2 might be a tumor suppressor in certain solid tumors, in contrast to its traditional oncogenic role in the hematopoietic system. PMID:27779255

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

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    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.

  9. HPRT deficiency coordinately dysregulates canonical Wnt and presenilin-1 signaling: a neuro-developmental regulatory role for a housekeeping gene?

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    Tae Hyuk Kang

    Full Text Available We have used microarray-based methods of global gene expression together with quantitative PCR and Western blot analysis to identify dysregulation of genes and aberrant cellular processes in human fibroblasts and in SH-SY5Y neuroblastoma cells made HPRT-deficient by transduction with a retrovirus stably expressing an shRNA targeted against HPRT. Analysis of the microarray expression data by Gene ontology (GO and Gene Set Enrichment Analysis (GSEA as well as significant pathway analysis by GeneSpring GX10 and Panther Classification System reveal that HPRT deficiency is accompanied by aberrations in a variety of pathways known to regulate neurogenesis or to be implicated in neurodegenerative disease, including the canonical Wnt/β-catenin and the Alzheimer's disease/presenilin signaling pathways. Dysregulation of the Wnt/β-catenin pathway is confirmed by Western blot demonstration of cytosolic sequestration of β-catenin during in vitro differentiation of the SH-SY5Y cells toward the neuronal phenotype. We also demonstrate that two key transcription factor genes known to be regulated by Wnt signaling and to be vital for the generation and function of dopaminergic neurons; i.e., Lmx1a and Engrailed 1, are down-regulated in the HPRT knockdown SH-SY5Y cells. In addition to the Wnt signaling aberration, we found that expression of presenilin-1 shows severely aberrant expression in HPRT-deficient SH-SY5Y cells, reflected by marked deficiency of the 23 kDa C-terminal fragment of presenilin-1 in knockdown cells. Western blot analysis of primary fibroblast cultures from two LND patients also shows dysregulated presenilin-1 expression, including aberrant proteolytic processing of presenilin-1. These demonstrations of dysregulated Wnt signaling and presenilin-1 expression together with impaired expression of dopaminergic transcription factors reveal broad pleitropic neuro-regulatory defects played by HPRT expression and suggest new directions for

  10. Is the Wnt/β-catenin pathway involved in the anti-inflammatory activity of glucocorticoids in spinal cord injury?

    Science.gov (United States)

    Libro, Rosaliana; Giacoppo, Sabrina; Bramanti, Placido; Mazzon, Emanuela

    2016-09-28

    The Wnt canonical or the Wnt/β-catenin pathway has been implicated in the regulation of several physiopathological pathways such as inflammation. Glucocorticoids (GCs) are administered widely to treat inflammation in several diseases, including spinal cord injury (SCI). The aim of this study was to evaluate whether the Wnt canonical pathway is involved in experimental SCI and whether it is implicated in the anti-inflammatory activity of two different GCs: the methylprednisolone sodium succinate (MPSS), considered the standard treatment for acute SCI, and mometasone furoate (MF), mainly administered for the treatment of airway and skin diseases. Experimental SCI was induced in mice by surgical spinal cord compression at the T6-T7 level. Then, mice were treated with MPSS (6 mg/kg) or MF (0.1 mg/kg) for 7 days until they were killed. Both GCs were found to modulate the Wnt canonical pathway, but in particular, the MF treatment was shown to restore completely the downregulated pathway in SCI. The MF treatment also significantly increased peroxisome proliferator-activated receptor-γ, a Wnt target gene with anti-inflammatory properties, compared with MPSS, and it also inhibited the levels of the proinflammatory cytokines interleukin 1β and tumor necrosis factor-α. Here, we suggest that MF has more efficacy than MPSS in inhibiting inflammation in an SCI experimental model and we propose the β-catenin/peroxisome proliferator-activated receptor-γ axis as the mechanism by which MF exerts these beneficial effects.

  11. Norcantharidin inhibits Wnt signal pathway via promoter demethylation of WIF-1 in human non-small cell lung cancer.

    Science.gov (United States)

    Xie, Junran; Zhang, Yaping; Hu, Xuming; Lv, Ran; Xiao, Dongju; Jiang, Li; Bao, Qi

    2015-05-01

    Wingless-type (Wnt) family of secreted glycoproteins is a group of signal molecules implicated in oncogenesis. Abnormal activation of Wnt signal pathway is associated with a variety of human cancers, including non-small cell lung cancer (NSCLC). Wnt antagonists, such as the secreted frizzled-related protein (SFRP) family, Wnt inhibitory factor-1 (WIF-1) and cerberus, inhibit Wnt signal pathway by directly binding to Wnt molecules. Norcantharidin (NCTD) is known to possess anticancer activity but less nephrotoxicity than cantharidin. In this study, we found that NCTD inhibited cell proliferation, induced apoptosis, arrested cell cycle and suppressed cell invasion/migration in vitro. Additionally, Wnt signal pathway transcription was also suppressed. NCTD treatment blocked cytoplasmic translocation of beta-catenin into the nucleus. Alterations of apoptosis-related proteins, such as Bax, cleaved caspase-3 (pro-apoptotic) and Bcl-2 (anti-apoptotic), had been detected. Furthermore, the expression levels of WIF-1 and SFRP1 were significantly increased in NCTD-treated groups compared with negative control (NC) groups. Abnormal methylation was observed in NC groups, while NCTD treatment promoted WIF-1 demethylation. The present study revealed that NCTD activated WIF-1 via promoter demethylation, inhibiting the canonical Wnt signal pathway in NSCLC, which may present a new therapeutic target in vivo. PMID:25814287

  12. Molecular Genetics of Intracranial Meningiomas with Emphasis on Canonical Wnt Signalling

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    Nives Pećina-Šlaus

    2016-07-01

    Full Text Available Research over the last decade recognized the importance of novel molecular pathways in pathogenesis of intracranial meningiomas. In this review, we focus on human brain tumours meningiomas and the involvement of Wnt signalling pathway genes and proteins in this common brain tumour, describing their known functional effects. Meningiomas originate from the meningeal layers of the brain and the spinal cord. Most meningiomas have benign clinical behaviour and are classified as grade I by World Health Organization (WHO. However, up to 20% histologically classified as atypical (grade II or anaplastic (grade III are associated with higher recurrent rate and have overall less favourable clinical outcome. Recently, there is emerging evidence that multiple signalling pathways including Wnt pathway contribute to the formation and growth of meningiomas. In the review we present the synopsis on meningioma histopathology and genetics and discuss our research regarding Wnt in meningioma. Epithelial-to-mesenchymal transition, a process in which Wnt signalling plays an important role, is shortly discussed.

  13. Wnt signaling pathway improves central inhibitory synaptic transmission in a mouse model of Duchenne muscular dystrophy.

    Science.gov (United States)

    Fuenzalida, Marco; Espinoza, Claudia; Pérez, Miguel Ángel; Tapia-Rojas, Cheril; Cuitino, Loreto; Brandan, Enrique; Inestrosa, Nibaldo C

    2016-02-01

    The dystrophin-associated glycoprotein complex (DGC) that connects the cytoskeleton, plasma membrane and the extracellular matrix has been related to the maintenance and stabilization of channels and synaptic receptors, which are both essential for synaptogenesis and synaptic transmission. The dystrophin-deficient (mdx) mouse model of Duchenne muscular dystrophy (DMD) exhibits a significant reduction in hippocampal GABA efficacy, which may underlie the altered synaptic function and abnormal hippocampal long-term plasticity exhibited by mdx mice. Emerging studies have implicated Wnt signaling in the modulation of synaptic efficacy, neuronal plasticity and cognitive function. We report here that the activation of the non-canonical Wnt-5a pathway and Andrographolide, improves hippocampal mdx GABAergic efficacy by increasing the number of inhibitory synapses and GABA(A) receptors or GABA release. These results indicate that Wnt signaling modulates GABA synaptic efficacy and could be a promising novel target for DMD cognitive therapy. PMID:26626079

  14. Extracellular matrix stiffness dictates Wnt expression through integrin pathway.

    Science.gov (United States)

    Du, Jing; Zu, Yan; Li, Jing; Du, Shuyuan; Xu, Yipu; Zhang, Lang; Jiang, Li; Wang, Zhao; Chien, Shu; Yang, Chun

    2016-01-01

    It is well established that extracellular matrix (ECM) stiffness plays a significant role in regulating the phenotypes and behaviors of many cell types. However, the mechanism underlying the sensing of mechanical cues and subsequent elasticity-triggered pathways remains largely unknown. We observed that stiff ECM significantly enhanced the expression level of several members of the Wnt/β-catenin pathway in both bone marrow mesenchymal stem cells and primary chondrocytes. The activation of β-catenin by stiff ECM is not dependent on Wnt signals but is elevated by the activation of integrin/ focal adhesion kinase (FAK) pathway. The accumulated β-catenin then bound to the wnt1 promoter region to up-regulate the gene transcription, thus constituting a positive feedback of the Wnt/β-catenin pathway. With the amplifying effect of positive feedback, this integrin-activated β-catenin/Wnt pathway plays significant roles in mediating the enhancement of Wnt signal on stiff ECM and contributes to the regulation of mesenchymal stem cell differentiation and primary chondrocyte phenotype maintenance. The present integrin-regulated Wnt1 expression and signaling contributes to the understanding of the molecular mechanisms underlying the regulation of cell behaviors by ECM elasticity. PMID:26854061

  15. Extracellular matrix stiffness dictates Wnt expression through integrin pathway.

    Science.gov (United States)

    Du, Jing; Zu, Yan; Li, Jing; Du, Shuyuan; Xu, Yipu; Zhang, Lang; Jiang, Li; Wang, Zhao; Chien, Shu; Yang, Chun

    2016-02-08

    It is well established that extracellular matrix (ECM) stiffness plays a significant role in regulating the phenotypes and behaviors of many cell types. However, the mechanism underlying the sensing of mechanical cues and subsequent elasticity-triggered pathways remains largely unknown. We observed that stiff ECM significantly enhanced the expression level of several members of the Wnt/β-catenin pathway in both bone marrow mesenchymal stem cells and primary chondrocytes. The activation of β-catenin by stiff ECM is not dependent on Wnt signals but is elevated by the activation of integrin/ focal adhesion kinase (FAK) pathway. The accumulated β-catenin then bound to the wnt1 promoter region to up-regulate the gene transcription, thus constituting a positive feedback of the Wnt/β-catenin pathway. With the amplifying effect of positive feedback, this integrin-activated β-catenin/Wnt pathway plays significant roles in mediating the enhancement of Wnt signal on stiff ECM and contributes to the regulation of mesenchymal stem cell differentiation and primary chondrocyte phenotype maintenance. The present integrin-regulated Wnt1 expression and signaling contributes to the understanding of the molecular mechanisms underlying the regulation of cell behaviors by ECM elasticity.

  16. Wnt Signaling Translocates Lys48-Linked Polyubiquitinated Proteins to the Lysosomal Pathway

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    Hyunjoon Kim

    2015-05-01

    Full Text Available Cellular proteins are degraded in either proteasomes or lysosomes depending on the types of ubiquitin chains that covalently modify them. It is not known whether the choice between these two pathways is physiologically regulated. The Lys48-polyubiquitin chain is the major signal directing proteins for degradation in proteasomes. Here, we report the unexpected finding that canonical Wnt signaling translocates some K48-linked polyubiquitinated proteins to the endolysosomal pathway. Proteasomal target proteins, such as β-catenin, Smad1, and Smad4, were targeted into endolysosomes in a process dependent on GSK3 activity. Relocalization was also dependent on Axin1 and the multivesicular body (MVB proteins HRS/Vps27 and Vps4. The Wnt-induced accumulation of K48-linked polyubiquitinated proteins in endolysosomal organelles was accompanied by a transient decrease in cellular levels of free mono-ubiquitin, which may contribute to Wnt-regulated stabilization of proteins (Wnt/STOP. We conclude that Wnt redirects Lys48-polyubiquitinated proteins that are normally degraded in proteasomes to endolysosomes.

  17. Integration of Shh and Wnt Signaling Pathways Regulating Hematopoiesis.

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    Zhou, Zhigang; Wan, Liping; Wang, Chun; Zhou, Kun

    2015-12-01

    To investigate the spatial and temporal programmed expression of Shh and Wnt members during key stages of definitive hematopoiesis and the possible mechanism of Shh and Wnt signaling pathways regulating the proliferation of hematopoietic progenitor cells (HPCs). Spatial and temporal programmed gene expression of Shh and Wnt signaling during hematopoiesis corresponded with c-kit(+)lin(-) HPCs proliferation. C-kit(+)Lin(-) populations derived from aorta-gonad-mesonephros (AGM) of Balb/c mice at E10.5 with increased expression of Shh and Wnt3a demonstrated a greater potential for proliferation. Additionally, supplementation with soluble Shh N-terminal peptide promoted the proliferation of c-kit(+)Lin(-) populations by activating the Wnt signaling pathway, an effect which was inhibited by blocking Shh signaling. A specific inhibitor of wnt signaling was capable of inhibiting Shh-induced proliferation in a similar manner to shh inhibitor. Our results provide valuable information on Shh and Wnt signaling involved in hematopoiesis and highlight the importance of interaction of Shh and Wnt signaling in regulating HPCs proliferation. PMID:26378473

  18. Wnt Pathway Activation in Long Term Remnant Rat Model

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    E. Banon-Maneus

    2014-01-01

    Full Text Available Progression of chronic kidney disease (CKD is characterized by deposition of extracellular matrix. This is an irreversible process that leads to tubulointerstitial fibrosis and finally loss of kidney function. Wnt/β-catenin pathway was reported to be aberrantly activated in the progressive damage associated with chronic organ failure. Extensive renal ablation is an experimental model widely used to gain insight into the mechanisms responsible for the development of CKD, but it was not evaluated for Wnt/β-catenin pathway. This study aimed to elucidate if the rat 5/6 renal mass reduction model (RMR is a good model for the Wnt/β-catenin activation and possible next modulation. RMR model was evaluated at 12 and 18 weeks after the surgery, when CKD is close to end-stage kidney disease demonstrated by molecular and histological studies. Wnt pathway components were analyzed at mRNA and protein level. Our results demonstrate that Wnt pathway is active by increase of β-catenin at mRNA level and nuclear translocation in tubular epithelium as well as some target genes. These results validate the RMR model for future modulation of Wnt pathway, starting at shorter time after the surgery.

  19. Wnts enhance neurotrophin-induced neuronal differentiation in adult bone-marrow-derived mesenchymal stem cells via canonical and noncanonical signaling pathways.

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    Hung-Li Tsai

    Full Text Available Wnts were previously shown to regulate the neurogenesis of neural stem or progenitor cells. Here, we explored the underlying molecular mechanisms through which Wnt signaling regulates neurotrophins (NTs in the NT-induced neuronal differentiation of human mesenchymal stem cells (hMSCs. NTs can increase the expression of Wnt1 and Wnt7a in hMSCs. However, only Wnt7a enables the expression of synapsin-1, a synaptic marker in mature neurons, to be induced and triggers the formation of cholinergic and dopaminergic neurons. Human recombinant (hrWnt7a and general neuron makers were positively correlated in a dose- and time-dependent manner. In addition, the expression of synaptic markers and neurites was induced by Wnt7a and lithium, a glycogen synthase kinase-3β inhibitor, in the NT-induced hMSCs via the canonical/β-catenin pathway, but was inhibited by Wnt inhibitors and frizzled-5 (Frz5 blocking antibodies. In addition, hrWnt7a triggered the formation of cholinergic and dopaminergic neurons via the non-canonical/c-jun N-terminal kinase (JNK pathway, and the formation of these neurons was inhibited by a JNK inhibitor and Frz9 blocking antibodies. In conclusion, hrWnt7a enhances the synthesis of synapse and facilitates neuronal differentiation in hMSCS through various Frz receptors. These mechanisms may be employed widely in the transdifferentiation of other adult stem cells.

  20. 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.

  1. A phenotypic screen in zebrafish identifies a novel small-molecule inducer of ectopic tail formation suggestive of alterations in non-canonical Wnt/PCP signaling.

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    Evelien Gebruers

    Full Text Available Zebrafish have recently emerged as an attractive model for the in vivo bioassay-guided isolation and characterization of pharmacologically active small molecules of natural origin. We carried out a zebrafish-based phenotypic screen of over 3000 plant-derived secondary metabolite extracts with the goal of identifying novel small-molecule modulators of the BMP and Wnt signaling pathways. One of the bioactive plant extracts identified in this screen - Jasminum gilgianum, an Oleaceae species native to Papua New Guinea - induced ectopic tails during zebrafish embryonic development. As ectopic tail formation occurs when BMP or non-canonical Wnt signaling is inhibited during the tail protrusion process, we suspected a constituent of this extract to act as a modulator of these pathways. A bioassay-guided isolation was carried out on the basis of this zebrafish phenotype, identifying para-coumaric acid methyl ester (pCAME as the active compound. We then performed an in-depth phenotypic analysis of pCAME-treated zebrafish embryos, including a tissue-specific marker analysis of the secondary tails. We found pCAME to synergize with the BMP-inhibitors dorsomorphin and LDN-193189 in inducing ectopic tails, and causing convergence-extension defects in compound-treated embryos. These results indicate that pCAME may interfere with non-canonical Wnt signaling. Inhibition of Jnk, a downstream target of Wnt/PCP signaling (via morpholino antisense knockdown and pharmacological inhibition with the kinase inhibitor SP600125 phenocopied pCAME-treated embryos. However, immunoblotting experiments revealed pCAME to not directly inhibit Jnk-mediated phosphorylation of c-Jun, suggesting additional targets of SP600125, and/or other pathways, as possibly being involved in the ectopic tail formation activity of pCAME. Further investigation of pCAME's mechanism of action will help determine this compound's pharmacological utility.

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

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    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.

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

    International Nuclear Information System (INIS)

    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

  4. Three-dimensional culture of sebaceous gland cells revealing the role of prostaglandin E{sub 2}-induced activation of canonical Wnt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Go J., E-mail: medical21go@yahoo.co.jp; Saya, Hideyuki

    2013-09-06

    Highlights: •Three-dimensional culture generates “semi-vivo” sebaceous glands. •Xenograft model failed to mimic the biology of sebaceous glands in vivo. •Proinflammatory cytokine PGE{sub 2} enhances Wnt signal activity in the organoids. •PGE{sub 2} influences on the mitochondrial and lipid metabolism in the organoids. •Considering 3R agenda, “semi-vivo” sebaceous glands are useful for research. -- Abstract: Background: Prostaglandin E{sub 2} (PGE{sub 2}) is a proinflammatory mediator and activates the canonical Wnt–β-catenin signaling pathway in hematopoietic stem cells. The SZ95 cell line was established from human sebaceous gland cells and is studied as a model system for these cells. Given that 2D culture of SZ95 cells does not recapitulate the organization of sebaceous glands in situ, we developed a 3D culture system for these cells and examined the effects of PGE{sub 2} on cell morphology and function. Results: SZ95 cells maintained in 3D culture formed organoids that mimicked the organization of sebaceous glands in situ, including the establishment of a basement membrane. Organoids exposed to PGE{sub 2} were larger and adopted a more complex organization compared with control organoids. PGE{sub 2} activated the canonical Wnt signaling pathway as well as increased cell viability and proliferation, mitochondrial metabolism, and lipid synthesis in the organoids. Conclusions: Culture of SZ95 cells in 3D culture system recapitulates the structure and susceptibility to PGE{sub 2} of sebaceous glands in situ and should prove useful for studies of the response of these glands to inflammation and other environmental stressors. Our results also implicate PGE{sub 2}-induced activation of canonical Wnt signaling pathway in regulation of the morphology,proliferation, and function of “semi-vivo” sebaceous glands.

  5. Three-dimensional culture of sebaceous gland cells revealing the role of prostaglandin E2-induced activation of canonical Wnt signaling

    International Nuclear Information System (INIS)

    Highlights: •Three-dimensional culture generates “semi-vivo” sebaceous glands. •Xenograft model failed to mimic the biology of sebaceous glands in vivo. •Proinflammatory cytokine PGE2 enhances Wnt signal activity in the organoids. •PGE2 influences on the mitochondrial and lipid metabolism in the organoids. •Considering 3R agenda, “semi-vivo” sebaceous glands are useful for research. -- Abstract: Background: Prostaglandin E2 (PGE2) is a proinflammatory mediator and activates the canonical Wnt–β-catenin signaling pathway in hematopoietic stem cells. The SZ95 cell line was established from human sebaceous gland cells and is studied as a model system for these cells. Given that 2D culture of SZ95 cells does not recapitulate the organization of sebaceous glands in situ, we developed a 3D culture system for these cells and examined the effects of PGE2 on cell morphology and function. Results: SZ95 cells maintained in 3D culture formed organoids that mimicked the organization of sebaceous glands in situ, including the establishment of a basement membrane. Organoids exposed to PGE2 were larger and adopted a more complex organization compared with control organoids. PGE2 activated the canonical Wnt signaling pathway as well as increased cell viability and proliferation, mitochondrial metabolism, and lipid synthesis in the organoids. Conclusions: Culture of SZ95 cells in 3D culture system recapitulates the structure and susceptibility to PGE2 of sebaceous glands in situ and should prove useful for studies of the response of these glands to inflammation and other environmental stressors. Our results also implicate PGE2-induced activation of canonical Wnt signaling pathway in regulation of the morphology,proliferation, and function of “semi-vivo” sebaceous glands

  6. A novel role for the tumour suppressor Nitrilase1 modulating the Wnt/β-catenin signalling pathway.

    Science.gov (United States)

    Mittag, Sonnhild; Valenta, Tomas; Weiske, Jörg; Bloch, Laura; Klingel, Susanne; Gradl, Dietmar; Wetzel, Franziska; Chen, Yuan; Petersen, Iver; Basler, Konrad; Huber, Otmar

    2016-01-01

    Nitrilase1 was classified as a tumour suppressor in association with the fragile histidine-triad protein Fhit. However, knowledge about nitrilase1 and its tumour suppressor function is still limited. Whereas nitrilase1 and Fhit are discrete proteins in mammals, they are merged in Drosophila melanogaster and Caenorhabditis elegans. According to the Rosetta-Stone hypothesis, proteins encoded as fusion proteins in one organism and as separate proteins in another organism may act in the same signalling pathway. Although a direct interaction of human nitrilase1 and Fhit has not been shown, our previous finding that Fhit interacts with β-catenin and represses its transcriptional activity in the canonical Wnt pathway suggested that human nitrilase1 also modulates Wnt signalling. In fact, human nitrilase1 forms a complex with β-catenin and LEF-1/TCF-4, represses β-catenin-mediated transcription and shows an additive effect together with Fhit. Knockdown of human nitrilase1 enhances Wnt target gene expression. Moreover, our experiments show that β-catenin competes away human nitrilase1 from LEF-1/TCF and thereby contributes to the activation of Wnt-target gene transcription. Inhibitory activity of human nitrilase1 on vertebrate Wnt signalling was confirmed by repression of Wnt-induced double axis formation in Xenopus embryogenesis. In line with this finding, the Drosophila fusion protein Drosophila NitFhit directly binds to Armadillo and represses the Wingless pathway in reporter gene assays. Genetic experiments confirmed the repressive activity of Drosophila NitFhit on Wingless signalling in the Drosophila wing imaginal disc. In addition, colorectal tumour microarray analysis revealed a significantly reduced expression of human nitrilase1 in poorly differentiated tumours. Taken together, repression of the canonical Wnt pathway represents a new mechanism for the human nitrilase1 tumour suppressor function. PMID:27462437

  7. Effect of activation of canonical Wnt signaling by the Wnt-3a protein on the susceptibility of PC12 cells to oxidative and apoptotic insults

    Energy Technology Data Exchange (ETDEWEB)

    Kawamoto, E.M. [Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil); Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD (United States); Gleichmann, M. [Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD (United States); Yshii, L.M.; Sá Lima, L. de [Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil); Mattson, M.P. [Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD (United States); Scavone, C. [Departamento de Farmacologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, São Paulo, SP (Brazil)

    2011-11-25

    Wnt proteins are involved in tissue development and their signaling pathways play an important role during embryogenesis. Wnt signaling can promote cell survival, which is beneficial for neurons, but could also lead to tumor development in different tissues. The present study investigated the effects of a Wnt protein on the susceptibility of a neural tumor cell line (PC12 cells) to the cytotoxic compounds ferrous sulfate (10 mM), staurosporine (100 and 500 nM), 3-nitropropionic acid (5 mM), and amyloid β-peptide (Aβ{sub 25-35}; 50 µM). Cells (1 × 10{sup 6} cells/mL) were treated with the Wnt-3a recombinant peptide (200 ng/mL) for 24 h before exposure to toxic insults. The Wnt-3a protein partially protected PC12 cells, with a 6-15% increase in cell viability in the presence of toxic agents, similar to the effect measured using the MTT and lactate dehydrogenase cell viability assays. The Wnt-3a protein increased protein expression of β-catenin by 52% compared to control. These findings suggest that Wnt signaling can protect neural cells against apoptosis induced by toxic agents, which are relevant to the pathogenesis of Alzheimer's and Huntington's diseases.

  8. Effect of activation of canonical Wnt signaling by the Wnt-3a protein on the susceptibility of PC12 cells to oxidative and apoptotic insults

    International Nuclear Information System (INIS)

    Wnt proteins are involved in tissue development and their signaling pathways play an important role during embryogenesis. Wnt signaling can promote cell survival, which is beneficial for neurons, but could also lead to tumor development in different tissues. The present study investigated the effects of a Wnt protein on the susceptibility of a neural tumor cell line (PC12 cells) to the cytotoxic compounds ferrous sulfate (10 mM), staurosporine (100 and 500 nM), 3-nitropropionic acid (5 mM), and amyloid β-peptide (Aβ25-35; 50 µM). Cells (1 × 106 cells/mL) were treated with the Wnt-3a recombinant peptide (200 ng/mL) for 24 h before exposure to toxic insults. The Wnt-3a protein partially protected PC12 cells, with a 6-15% increase in cell viability in the presence of toxic agents, similar to the effect measured using the MTT and lactate dehydrogenase cell viability assays. The Wnt-3a protein increased protein expression of β-catenin by 52% compared to control. These findings suggest that Wnt signaling can protect neural cells against apoptosis induced by toxic agents, which are relevant to the pathogenesis of Alzheimer's and Huntington's diseases

  9. Effect of activation of canonical Wnt signaling by the Wnt-3a protein on the susceptibility of PC12 cells to oxidative and apoptotic insults

    Directory of Open Access Journals (Sweden)

    E.M. Kawamoto

    2012-01-01

    Full Text Available Wnt proteins are involved in tissue development and their signaling pathways play an important role during embryogenesis. Wnt signaling can promote cell survival, which is beneficial for neurons, but could also lead to tumor development in different tissues. The present study investigated the effects of a Wnt protein on the susceptibility of a neural tumor cell line (PC12 cells to the cytotoxic compounds ferrous sulfate (10 mM, staurosporine (100 and 500 nM, 3-nitropropionic acid (5 mM, and amyloid β-peptide (Aβ25-35; 50 µM. Cells (1 x 10(6 cells/mL were treated with the Wnt-3a recombinant peptide (200 ng/mL for 24 h before exposure to toxic insults. The Wnt-3a protein partially protected PC12 cells, with a 6-15% increase in cell viability in the presence of toxic agents, similar to the effect measured using the MTT and lactate dehydrogenase cell viability assays. The Wnt-3a protein increased protein expression of β-catenin by 52% compared to control. These findings suggest that Wnt signaling can protect neural cells against apoptosis induced by toxic agents, which are relevant to the pathogenesis of Alzheimer’s and Huntington’s diseases.

  10. Distinct Patterns of Wnt3a and Wnt5a Signaling Pathway in the Lung from Rats with Endotoxic Shock.

    Directory of Open Access Journals (Sweden)

    Hiong-Ping Hii

    Full Text Available Septic shock is a syndrome with severe hypotension and multiple organ dysfunction caused by an imbalance between pro-inflammatory and anti-inflammatory response. The most common risk factor of acute lung injury is severe sepsis. Patients with sepsis-related acute respiratory distress syndrome have higher mortality. Recent studies reveal regulatory roles of Wnt3a and Wnt5a signaling in inflammatory processes. Wnt3a signaling has been implicated in anti-inflammatory effects, whereas Wnt5a signaling has been postulated to have pro-inflammatory properties. However, the balance between Wnt3a and Wnt5a signaling pathway in the lung of rats with endotoxic shock has not been determined. Thus, we investigated the major components of Wnt3a and Wnt5a signaling pathway in the lung of endotoxemic rats. Male Wistar rats were intravenously infused with saline or lipopolysaccharide (LPS, 10 mg/kg. The changes of hemodynamics, biochemical variables, and arterial blood gas were examined during the experimental period. At 6 h after saline or LPS, animals were sacrificed, and lungs were obtained for analyzing superoxide production, water accumulation, histologic assessment, and protein expressions of Wnt3a and Wnt5a signaling pathway. Animals that received LPS showed circulatory failure, multiple organ dysfunction, metabolic acidosis, hyperventilation, lung edema, and high mortality. The lung from rats with endotoxic shock exhibited significant decreases in the levels of Wnt3a, Fzd1, Dsh1, phosphorylated GSK-3β at Ser9, and β-catenin. In contrast, the expressions of Wnt5a, Fzd5, and CaMKII were up-regulated in the lung of endotoxemic rats. These findings indicate the major components of Wnt3a and Wnt5a signaling in the lung are disturbed under endotoxic insult.

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

    Directory of Open Access Journals (Sweden)

    Natasha Webb

    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.

  12. The Research Progress about Wnt Pathway of Lung Cancer Stem Cells

    Directory of Open Access Journals (Sweden)

    Xiaojiang LI

    2011-08-01

    Full Text Available Being the most critical signaling molecule in the Wnt pathway, the Wnt/β-catenin signaling pathway plays an important role in the maintenance of the cell proliferation and clone formation of lung cancer stem cells. Since it is closely related to the WNT pathway, the proliferation of lung cancer stem cells can be restrained by blocking the WNT pathway or influencing its key protein. Such method provides a new method for the treatment of lung cancer. By summarizing the state of-the-art research of lung cancer stem cells and the Wnt pathway from 2005 to 2010, their relationship is investigated.

  13. 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.

  14. Wnt5a controls neurite development in olfactory bulb interneurons

    Directory of Open Access Journals (Sweden)

    Youngshik Choe

    2011-06-01

    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. Canonical Wnt activity regulates trunk neural crest delamination linking BMP/noggin signaling with G1/S transition.

    Science.gov (United States)

    Burstyn-Cohen, Tal; Stanleigh, Jonathan; Sela-Donenfeld, Dalit; Kalcheim, Chaya

    2004-11-01

    Delamination of premigratory neural crest cells depends on a balance between BMP/noggin and on successful G1/S transition. Here, we report that BMP regulates G1/S transition and consequent crest delamination through canonical Wnt signaling. Noggin overexpression inhibits G1/S transition and blocking G1/S abrogates BMP-induced delamination; moreover, transcription of Wnt1 is stimulated by BMP and by the developing somites, which concomitantly inhibit noggin production. Interfering with beta-catenin and LEF/TCF inhibits G1/S transition, neural crest delamination and transcription of various BMP-dependent genes, which include Cad6B, Pax3 and Msx1, but not that of Slug, Sox9 or FoxD3. Hence, we propose that developing somites inhibit noggin transcription in the dorsal tube, resulting in activation of BMP and consequent Wnt1 production. Canonical Wnt signaling in turn stimulates G1/S transition and generation of neural crest cell motility independently of its proposed role in earlier neural crest specification. PMID:15456730

  16. Wnt-/-β-catenin pathway signaling in human hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    Jaques; Waisberg; Gabriela; Tognini; Saba

    2015-01-01

    The molecular basis of the carcinogenesis of hepatocellular carcinoma(HCC) has not been adequately clarified, which negatively impacts the development of targeted therapy protocols for this overwhelming neoplasia. The aberrant activation of signaling in the HCC is primarily due to the deregulated expression of the components of the Wnt-/-β-catenin. This leads to the activation of β-catenin/T-cell factor-dependent target genes that control cell proliferation, cell cycle, apoptosis, and cell motility. The deregulation of the Wnt pathway is an early event in hepatocarcinogenesis. An aggressive phenotype was associated with HCC, since this pathway is implicated in the proliferation, migration, and invasiveness of cancer cells, regarding the cell’s own survival. The disruption of the signaling cascade Wnt-/-β-catenin has shown anticancer properties in HCC’s clinical evaluations of therapeutic molecules targeted for blocking the Wnt signaling pathway for the treatment of HCC, and it represents a promising perspective. The key to bringing this strategy in to clinical practice is to identify new molecules that would be effective only in tumor cells with aberrant signaling β-catenin.

  17. Structural Biology of Wnt Signaling Pathway

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Wnt signals are involved in different processes in development such as segmentation, cell proliferation, and cell morphology. It is well known that dishevelled (DSH/DVL) proteins mediate Wnt signaling by regulating the level of-catenin, which binds to transcription factor such as T-cell factor and regulate transcription. DSH has three well defined domains. The N-terminal domain is referred to as DIX, a central domain called PDZ, and a domain called DEP located in the C-terminal of DSH. The DEP domain is conserved among a set of proteins that share the common ability to regulate various GTPases.Nuclear magnetic resonance spectroscopy revealed that the DEP domain of mouse DVL1 comprises a three-helix bundle, a β-hairpin “arm,” and two short β-strands at the C-terminal region. On the basis of our findings, we conclude that DEP interacts with regulators upstream of DVL via the strong electrostatic dipolarity on the molecule's surface created by Lys 434, Asp 445, and Asp 448; the electrostatic dipole and the putative membrane-binding site are at two different locations.

  18. Wnt Signaling in Bone

    Science.gov (United States)

    Kubota, Takuo; Michigami, Toshimi; Ozono, Keiichi

    2010-01-01

    Wnt signaling is involved not only in embryonic development but also in maintenance of homeostasis in postnatal tissues. Multiple lines of evidence have increased understanding of the roles of Wnt signaling in bone since mutations in the LRP5 gene were identified in human bone diseases. Canonical Wnt signaling promotes mesenchymal progenitor cells to differentiate into osteoblasts. The canonical Wnt/β-catenin pathway possibly through Lrp6, a co-receptor for Wnts as well as Lrp5, in osteoblasts regulates bone resorption by increasing the OPG/RANKL ratio. However, endogenous inhibitors of Wnt signaling including sclerostin block bone formation. Regulation of sclerostin appears to be one of the mechanisms of PTH anabolic actions on bone. Since sclerostin is almost exclusively expressed in osteocytes, inhibition of sclerostin is the most promising design. Surprisingly, Lrp5 controls bone formation by inhibiting serotonin synthesis in the duodenum, but not by directly promoting bone formation. Pharmacological intervention may be considered in many components of the canonical Wnt signaling pathway, although adverse effects and tumorigenicity to other tissues are important. More studies will be needed to fully understand how the Wnt signaling pathway actually influences bone metabolism and to assure the safety of new interventions. PMID:23926379

  19. Induction of CXC chemokines in human mesenchymal stemcells by stimulation with secreted frizzled-related proteinsthrough non-canonical Wnt signaling

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    AIM To investigate the effect of secreted frizzledrelatedproteins (sFRPs) on CXC chemokine expressionin human mesenchymal stem cells (hMSCs).METHODS: CXC chemokines such as CXCL5 andCXCL8 are induced in hMSCs during differentiation withosteogenic differentiation medium (OGM) and may beinvolved in angiogenic stimulation during bone repair.hMSCs were treated with conditioned medium (CM) fromL-cells expressing non-canonical Wnt5a protein, or withcontrol CM from wild type L-cells, or directly with sFRPsfor up to 10 d in culture. mRNA expression levels of bothCXCL5 and CXCL8 were quantitated by real-time reversetranscriptase-polymerase chain reaction and secretedprotein levels of these proteins determined by ELISA.Dose- (0-500 ng/mL) and time-response curves weregenerated for treatment with sFRP1. Signal transductionpathways were explored by western blot analysis withpan- or phosphorylation-specific antibodies, through useof specific pathway inhibitors, and through use of siRNAstargeting specific frizzled receptors (Fzd)-2 and 5 or the receptor tyrosine kinase-like orphan receptor-2 (RoR2)prior to treatment with sFRPs.RESULTS: CM from L-cells expressing Wnt5a, a noncanonicalWnt, stimulated an increase in CXCL5 mRNAexpression and protein secretion in comparison to controlL-cell CM. sFRP1, which should inhibit both canonicaland non-canonical Wnt signaling, surprisingly enhancedthe expression of CXCL5 at 7 and 10 d. Dickkopf1, aninhibitor of canonical Wnt signaling prevented the sFRPstimulatedinduction of CXCL5 and actually inhibitedbasal levels of CXCL5 expression at 7 but not at 10 d posttreatment. In addition, all four sFRPs isoforms inducedCXCL8 expression in a dose- and time-dependent mannerwith maximum expression at 7 d with treatment at 150ng/mL. The largest increases in CXCL5 expression wereseen from stimulation with sFRP1 or sFRP2. Analysis ofmitogen-activated protein kinase signaling pathwaysin the presence of OGM showed sFRP1

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Wnt signaling stimulates transcriptional outcome of the hedgehog pathway by stabilizing GLI1 mRNA

    OpenAIRE

    Noubissi, Felicite K.; Goswami, Srikanta; Sanek, Nicholas A.; Kawakami, Kazuyuki; Minamoto, Toshinari; Moser, Amy; Grinblat, Yevgenya; Spiegelman, Vladimir S.

    2009-01-01

    Wnt and Hedgehog signaling pathways play central roles in embryogenesis, stem cell maintenance, and tumorigenesis. However, the mechanisms by which these two pathways interact are not well understood. Here, we identified a novel mechanism by which Wnt signaling pathway stimulates the transcriptional output of Hedgehog signaling. Wnt/β-catenin signaling induces expression of an RNA-binding protein, CRD-BP, which in turn binds and stabilizes GLI1 mRNA, causing an elevation of GLI1 expression an...

  2. Wnt signaling stimulates transcriptional outcome of the Hedgehog pathway by stabilizing GLI1 mRNA

    OpenAIRE

    Noubissi, Felicite K.; Goswami, Srikanta; Sanek, Nicholas A.; Kawakami, Kazuyuki; Minamoto, Toshinari; Moser, Amy; Grinblat, Yevgenya; Spiegelman, Vladimir S.

    2009-01-01

    Wnt and Hedgehog signaling pathways play central roles in embryogenesis, stem cell maintenance, and tumorigenesis. However, mechanisms by which these two pathways interact are not well-understood. Here, we identified a novel mechanism by which Wnt signaling pathway stimulates the transcriptional output of Hedgehog signaling. Wnt/β-catenin signaling induces expression of an RNA-binding protein, CRD-BP, which, in turn, binds and stabilizes GLI1 mRNA, causing an elevation of GLI1 expression and ...

  3. The Research Progress about Wnt Pathway of Lung Cancer Stem Cells

    OpenAIRE

    Li, Xiaojiang; Jia, Yingjie; Wenzhi ZHANG; Zhang, Ying; Li, Baole; Minna HUANG; Bao, Fangfang; Wu, Jianguo; Lou, Yi

    2011-01-01

    Being the most critical signaling molecule in the Wnt pathway, the Wnt/β-catenin signaling pathway plays an important role in the maintenance of the cell proliferation and clone formation of lung cancer stem cells. Since it is closely related to the WNT pathway, the proliferation of lung cancer stem cells can be restrained by blocking the WNT pathway or influencing its key protein. Such method provides a new method for the treatment of lung cancer. By summarizing the state of-the-art research...

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

    Science.gov (United States)

    López-Escobar, Beatriz; Cano, David A.; Rojas, Anabel; de Felipe, Beatriz; Palma, Francisco; Sánchez-Alcázar, José A.; Henderson, Deborah; Ybot-González, Patricia

    2015-01-01

    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. PMID:25540130

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Inhibition of the Wnt palmitoyltransferase porcupine suppresses cell growth and downregulates the Wnt/β-catenin pathway in gastric cancer

    OpenAIRE

    Mo, Min-Li; LI, MENG-RU; Chen, Zhao; LIU, XING-WEI; Sheng, Qing; Zhou, Hai-Meng

    2013-01-01

    Similarly to the Wnt protein palmitoyltransferase, porcupine (PPN) is essential to the activation of the Wnt/β-catenin signaling pathway. However, little is known about the role of PPN activity in human gastric cancer, one of the most common causes of cancer-related mortality. Real-time quantitative PCR was used to detect the expression levels of PPN in paired gastric cancer tissues. Cell proliferation, migration and invasion assays were performed following treatment using a newly developed s...

  7. Wnt signaling in osteosarcoma.

    Science.gov (United States)

    Lin, Carol H; Ji, Tao; Chen, Cheng-Fong; Hoang, Bang H

    2014-01-01

    Osteosarcoma (OS) is the most common primary bone malignancy diagnosed in children and adolescents with a high propensity for local invasion and distant metastasis. Despite current multidisciplinary treatments, there has not been a drastic change in overall prognosis within the last two decades. With current treatments, 60-70 % of patients with localized disease survive. Given a propensity of Wnt signaling to control multiple cellular processes, including proliferation, cell fate determination, and differentiation, it is a critical pathway in OS disease progression. At the same time, this pathway is extremely complex with vast arrays of cross-talk. Even though decades of research have linked the role of Wnt to tumorigenesis, there are still outstanding areas that remain poorly understood and even controversial. The canonical Wnt pathway functions to regulate the levels of the transcriptional co-activator β-catenin, which ultimately controls key developmental gene expressions. Given the central role of this mediator, inhibition of Wnt/β-catenin signaling has been investigated as a potential strategy for cancer control. In OS, several secreted protein families modulate the Wnt/β-catenin signaling, including secreted Frizzled-related proteins (sFRPs), Wnt inhibitory protein (WIF), Dickkopf proteins (DKK-1,2,3), sclerostin, and small molecules. This chapter focuses on our current understanding of Wnt/β-catenin signaling in OS, based on recent in vitro and in vivo data. Wnt activates noncanonical signaling pathways as well that are independent of β-catenin which will be discussed. In addition, stem cells and their association with Wnt/β-catenin are important factors to consider. Ultimately, the multiple canonical and noncanonical Wnt/β-catenin agonists and antagonists need to be further explored for potential targeted therapies. PMID:24924167

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

    Science.gov (United States)

    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.

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

    Science.gov (United States)

    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. PMID:26645985

  10. Transcriptional regulation of Wnt inhibitory factor-1 by Miz-1/c-Myc

    OpenAIRE

    Licchesi, JDF; Van Neste, L; Tiwari, VK; Cope, L; Lin, X.; Baylin, SB; Herman, JG

    2010-01-01

    The Wnt signaling pathway is capable of self-regulation through positive and negative feedback mechanisms. For example, the oncoprotein c-Myc, which is upregulated by Wnt signaling activity, participates in a positive feedback loop of canonical Wnt signaling through repression of Wnt antagonists DKK1 and SFRP1. In this study, we investigated the mechanism of Wnt inhibitory factor-1 (WIF-1) silencing. Mapping of CpG island methylation of the WIF-1 promoter reveals regional methylation (–295 to...

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

    Science.gov (United States)

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

    2014-06-01

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

  12. The Wnt pathway: a key network in cell signalling dysregulated by viruses.

    Science.gov (United States)

    van Zuylen, Wendy J; Rawlinson, William D; Ford, Caroline E

    2016-09-01

    Viruses are obligate parasites dependent on host cells for survival. Viral infection of a cell activates a panel of pattern recognition receptors that mediate antiviral host responses to inhibit viral replication and dissemination. Viruses have evolved mechanisms to evade and subvert this antiviral host response, including encoding proteins that hijack, mimic and/or manipulate cellular processes such as the cell cycle, DNA damage repair, cellular metabolism and the host immune response. Currently, there is an increasing interest whether viral modulation of these cellular processes, including the cell cycle, contributes to cancer development. One cellular pathway related to cell cycle signalling is the Wnt pathway. This review focuses on the modulation of this pathway by human viruses, known to cause (or associated with) cancer development. The main mechanisms where viruses interact with the Wnt pathway appear to be through (i) epigenetic modification of Wnt genes; (ii) cellular or viral miRNAs targeting Wnt genes; (iii) altering specific Wnt pathway members, often leading to (iv) nuclear translocation of β-catenin and activation of Wnt signalling. Given that diverse viruses affect this signalling pathway, modulating Wnt signalling could be a generalised critical process for the initiation or maintenance of viral pathogenesis, with resultant dysregulation contributing to virus-induced cancers. Further study of this virus-host interaction may identify options for targeted therapy against Wnt signalling molecules as a means to reduce virus-induced pathogenesis and the downstream consequences of infection. Copyright © 2016 John Wiley & Sons, Ltd.

  13. Take the Wnt out of the inflammatory sails: modulatory effects of Wnt in airway diseases.

    Science.gov (United States)

    Reuter, Sebastian; Beckert, Hendrik; Taube, Christian

    2016-02-01

    Bronchial asthma and chronic obstructive pulmonary disease (COPD) are chronic diseases that are associated with inflammation and structural changes in the airways and lungs. Recent findings have implicated Wnt pathways in critically regulating inflammatory responses, especially in asthma. Furthermore, canonical and noncanonical Wnt pathways are involved in structural changes such as airway remodeling, goblet cell metaplasia, and airway smooth muscle (ASM) proliferation. In COPD, Wnt pathways are not only associated with structural changes in the airways but also involved in the development of emphysema. The present review summarizes the role and function of the canonical and noncanonical Wnt pathway with regard to airway inflammation and structural changes in asthma and COPD. Further identification of the role and function of different Wnt molecules and pathways could help to develop novel therapeutic options for these diseases. PMID:26595171

  14. Concurrent Transient Activation of Wnt/{beta}-Catenin Pathway Prevents Radiation Damage to Salivary Glands

    Energy Technology Data Exchange (ETDEWEB)

    Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States); Boyer, Arthur [Department of Radiology, Scott and White Hospital, Temple, Texas (United States); Liu, Fei, E-mail: fliu@medicine.tamhsc.edu [Institute for Regenerative Medicine, Scott and White Hospital, Molecular and Cellular Medicine Department, Texas A and M Health Science Center, Temple, Texas (United States)

    2012-05-01

    Purpose: Many head and neck cancer survivors treated with radiotherapy suffer from permanent impairment of their salivary gland function, for which few effective prevention or treatment options are available. This study explored the potential of transient activation of Wnt/{beta}-catenin signaling in preventing radiation damage to salivary glands in a preclinical model. Methods and Materials: Wnt reporter transgenic mice were exposed to 15 Gy single-dose radiation in the head and neck area to evaluate the effects of radiation on Wnt activity in salivary glands. Transient Wnt1 overexpression in basal epithelia was induced in inducible Wnt1 transgenic mice before together with, after, or without local radiation, and then saliva flow rate, histology, apoptosis, proliferation, stem cell activity, and mRNA expression were evaluated. Results: Radiation damage did not significantly affect activity of Wnt/{beta}-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/{beta}-catenin pathway in submandibular glands of male mice but not in those of females. Concurrent transient activation of the Wnt pathway prevented chronic salivary gland dysfunction following radiation by suppressing apoptosis and preserving functional salivary stem/progenitor cells. In contrast, Wnt activation 3 days before or after irradiation did not show significant beneficial effects, mainly due to failure to inhibit acute apoptosis after radiation. Excessive Wnt activation before radiation failed to inhibit apoptosis, likely due to extensive induction of mitosis and up-regulation of proapoptosis gene PUMA while that after radiation might miss the critical treatment window. Conclusion: These results suggest that concurrent transient activation of the Wnt/{beta}-catenin pathway could prevent radiation-induced salivary gland dysfunction.

  15. Phosphorylation of Sox9 is required for neural crest delamination and is regulated downstream of BMP and canonical Wnt signaling.

    Science.gov (United States)

    Liu, Jessica A J; Wu, Ming-Hoi; Yan, Carol H; Chau, Bolton K H; So, Henry; Ng, Alvis; Chan, Alan; Cheah, Kathryn S E; Briscoe, James; Cheung, Martin

    2013-02-19

    Coordination of neural crest cell (NCC) induction and delamination is orchestrated by several transcription factors. Among these, Sry-related HMG box-9 (Sox9) and Snail2 have been implicated in both the induction of NCC identity and, together with phoshorylation, NCC delamination. How phosphorylation effects this function has not been clear. Here we show, in the developing chick neural tube, that phosphorylation of Sox9 on S64 and S181 facilitates its SUMOylation, and the phosphorylated forms of Sox9 are essential for trunk neural crest delamination. Both phosphorylation and to a lesser extent SUMOylation, of Sox9 are required to cooperate with Snail2 to promote delamination. Moreover, bone morphogenetic protein and canonical Wnt signaling induce phosphorylation of Sox9, thereby connecting extracellular signals with the delamination of NCCs. Together the data suggest a model in which extracellular signals initiate phosphorylation of Sox9 and its cooperation with Snail2 to induce NCC delamination. PMID:23382206

  16. Zebrafish foxo3b negatively regulates canonical Wnt signaling to affect early embryogenesis.

    Directory of Open Access Journals (Sweden)

    Xun-wei Xie

    Full Text Available FOXO genes are involved in many aspects of development and vascular homeostasis by regulating cell apoptosis, proliferation, and the control of oxidative stress. In addition, FOXO genes have been showed to inhibit Wnt/β-catenin signaling by competing with T cell factor to bind to β-catenin. However, how important of this inhibition in vivo, particularly in embryogenesis is still unknown. To demonstrate the roles of FOXO genes in embryogenesis will help us to further understand their relevant physiological functions. Zebrafish foxo3b gene, an orthologue of mammalian FOXO3, was expressed maternally and distributed ubiquitously during early embryogenesis and later restricted to brain. After morpholino-mediated knockdown of foxo3b, the zebrafish embryos exhibited defects in axis and neuroectoderm formation, suggesting its critical role in early embryogenesis. The embryo-developmental marker gene staining at different stages, phenotype analysis and rescue assays revealed that foxo3b acted its role through negatively regulating both maternal and zygotic Wnt/β-catenin signaling. Moreover, we found that foxo3b could interact with zebrafish β-catenin1 and β-catenin2 to suppress their transactivation in vitro and in vivo, further confirming its role relevant to the inhibition of Wnt/β-catenin signaling. Taken together, we revealed that foxo3b played a very important role in embryogenesis and negatively regulated maternal and zygotic Wnt/β-catenin signaling by directly interacting with both β-catenin1 and β-catenin2. Our studies provide an in vivo model for illustrating function of FOXO transcription factors in embryogenesis.

  17. The Wnt5a/Ror2 pathway is associated with determination of the differentiation fate of bone marrow mesenchymal stem cells in vascular calcification.

    Science.gov (United States)

    Xin, Huaping; Xin, Fang; Zhou, Shaoqiong; Guan, Siming

    2013-03-01

    Accumulating evidence have demonstrated that mesenchymal stem cells (MSCs) are involved in the initiation and progression of various vascular diseases. Canonical Wnt signaling controls the fate of MSCs, and plays an important role in vascular calcification. However, vascular calcification can be inhibited by the non-canonical Wnt signaling pathway Wnt5a/Ror2. This study aimed to investigate whether the Wnt5a/Ror2 pathway is associated with determination of the differentiation fate of MSCs in vascular calcification. Direct co-cultures were established by seeding smooth muscle cells (SMCs) or calcified SMCs and MSCs together at ratios of SMCs or calcified SMCs 15x104; SMCs or calcified SMCs 5x104: MSCs 10x104, SMCs or calcified SMCs 10x104: MSCs 5x104. Osteosynthesis-inducing medium (OS) was added to the culture medium in the groups of MSCs with non-calcified SMCs. Cells were cultured for nine days. Osteoblastic differentiation was evaluated by cell morphology and the activity of alkaline phosphatase (ALP) in cell lysates and ALP staining. Furthermore, we investigated the inhibition of Wnt signaling, and observed that the members of the non-canonical signaling pathway Wnt5a/Ror2 were expressed in each group. Additionally, MSCs cultured in culture media with OS did not differentiate into an osteoblast phenotype when in direct contact with non-calcified SMCs, irrespective of the number of MSCs. However, an osteoblast phenotype was observed when MSCs were cultured in media without OS differentiation towards direct contact with calcified SMCs, and the levels of osteoblastic markers had a direct correlation with the number of MSCs. Of note, the Wnt5a protein was associated with the levels of calcification, thus, although rarely detected in non-calcification, Ror2 mRNA in the non-calcified groups was significantly higher compared to that in the calcified groups. Therefore, the Wnt5a/Ror2 pathway is associated with determination of the differentiation fate of bone marrow

  18. Wnt pathway activity in breast cancer sub-types and stem-like cells

    OpenAIRE

    Rebecca Lamb; Ablett, Matthew P.; Katherine Spence; Göran Landberg; Sims, Andrew H.; Clarke, Robert B.

    2013-01-01

    Wnt signalling has been implicated in stem cell regulation however its role in breast cancer stem cell regulation remains unclear.Methods: We used a panel of normal and breast cancer cell lines to assess Wnt pathway gene and protein expression, and for the investigation of Wnt signalling within stem cell-enriched populations, mRNA and protein expression was analysed after the selection of anoikis-resistant cells. Finally, cell lines and patient-derived samples were used to investigate Wnt pat...

  19. Cholangiocarcinoma, gone without the Wnt?

    Science.gov (United States)

    Noll, Anne Tr; Cramer, Thorsten; Olde Damink, Steven Wm; Schaap, Frank G

    2016-09-18

    Cholangiocarcinoma (CCA) is a relatively rare malignancy of the intra- or extra-hepatic bile ducts that is classified according to its anatomical localization as intrahepatic, perihilar or distal. Overall, CCA has a dismal prognosis due to typical presentation at an advanced irresectable stage, lack of effective non-surgical treatments, and a high rate of disease recurrence. CCA frequently arises on a background of chronic liver inflammation and cholestasis. Chronic inflammation is accompanied by enhanced cell turnover with generation of additional inflammatory stimuli, and a microenvironment rich in pro-inflammatory mediators and proliferative factors that enable accumulation of mutations, transformation and expansion of mutated cells. A recent study by Boulter et al implicates the Wnt signaling cascade in cholangiocarcinogenesis. Wnt ligands Wnt7B and Wnt10A were found to be highly overexpressed in human CCA tissue. Wnt7B protein was present throughout the tumor stroma, and often co-localized with a subset of CD68(+) macrophages. To address in a direct manner whether Wnt signaling is engaged in development of CCA, Boulter et al explored the Wnt signaling pathway in an experimental model that recapitulates the multi-stage progression of human CCA. Wnt ligands found to be elevated in human CCA were also upregulated during the course of CCA development following thioacetamide treatment. Wnt10a increased during the (pre-cancerous) regenerative phase, while Wnt7b induction paralleled tumor growth. Along with upregulation of target genes, the findings demonstrate that the canonical Wnt pathway is progressively activated during cholangio-carcinogenesis. Macrophage depletion, eliminating a major source of Wnt7b, prevented activation of the canonical Wnt cascade, and resulted in reduced number and volume of tumors in this model. Moreover, specific inhibitors of the canonical Wnt pathway (ICG-001 and C-59) caused reduction of tumor area and number, in xenograft and

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

    Directory of Open Access Journals (Sweden)

    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.

  1. Polycomb group genes Psc and Su(z)2 restrict follicle stem cell self-renewal and extrusion by controlling canonical and noncanonical Wnt signaling.

    Science.gov (United States)

    Li, Xinghua; Han, Yue; Xi, Rongwen

    2010-05-01

    Stem cells are critical for maintaining tissue homeostasis and are commonly governed by their niche microenvironment, although the intrinsic mechanisms controlling their multipotency are poorly understood. Polycomb group (PcG) genes are epigenetic silencers, and have emerged recently as important players in maintaining stem cell multipotency by preventing the initiation of differentiation programs. Here we describe an unexpected role of specific PcG genes in allowing adult stem cell differentiation and preventing stem cell-derived tumor development. We show that Posterior sex combs (Psc), which encodes a core Polycomb-repressive complex 1 (PRC1) component, functions redundantly with a similar gene, Suppressor of zeste two [Su(z)2], to restrict follicle stem cell (FSC) self-renewal in the Drosophila ovary. FSCs carrying deletion mutations of both genes extrude basally from the epithelium and continue to self-propagate at ectopic sites, leading to the development of FSC-like tumors. Furthermore, we show that the propagation of the mutant cells is driven by sustained activation of the canonical Wnt signaling pathway, which is essential for FSC self-renewal, whereas the epithelial extrusion is mediated through the planar cell polarity pathway. This study reveals a novel mechanism of epithelial extrusion, and indicates a novel role of polycomb function in allowing adult stem cell differentiation by antagonizing self-renewal programs. Given evolutionary conservation of PcG genes from Drosophila to mammals, they could have similar functions in mammalian stem cells and cancer.

  2. Inhibitory mechanisms of two Uncaria tomentosa extracts affecting the Wnt-signaling pathway.

    Science.gov (United States)

    Gurrola-Díaz, Carmen Magdalena; García-López, Pedro Macedonio; Gulewicz, Krzysztof; Pilarski, Radoslaw; Dihlmann, Susanne

    2011-06-15

    Uncaria tomentosa ("uña de gato"; "cat's claw"), a woody vine native to the Amazon rainforest, is commonly used in South American traditional medicine to treat a broad spectrum of diseases. Although recent studies have reported anti-inflammatory and anti-proliferative properties of different alkaloids extracted from this plant, the underlying molecular mechanisms of these effects have not been elucidated yet. Our study investigates the inhibitory mechanisms of Uncaria tomentosa extracts on the Wnt-signaling pathway, a central regulator of development and tissue homoeostasis. A modified cell-based luciferase assay for screening inhibitors of the Wnt-pathway was used for analysis. Three cancer cell lines displaying different levels of aberrant Wnt-signaling activity were transfected with Wnt-signaling responsive Tcf-reporter plasmids and treated with increasing concentrations of two Uncaria tomentosa bark extracts. Wnt-signaling activity was assessed by luciferase activity and by expression of Wnt-responsive target genes. We show that both, an aqueous and an alkaloid-enriched extract specifically inhibit Wnt-signaling activity in HeLa, HCT116 and SW480 cancer cells resulting in reduced expression of the Wnt-target gene: c-Myc. The alkaloid-enriched extract (B/S(rt)) was found to be more effective than the aqueous extract (B/W(37)). The strongest effect was observed in SW480 cells, displaying the highest endogenous Wnt-signaling activity. Downregulation of Wnt-signaling by a dominant negative-TCF-4 variant in non-cancer cells rendered the cells insensitive towards treatment with B/S(rt). B/Srt was less toxic in non-cancer cells than in cancer cells. Our data suggest that the broad spectrum of pharmacological action of Uncaria tomentosa involves inhibition of the Wnt-signaling pathway, downstream of beta-Catenin activity. PMID:21156346

  3. Inhibitory mechanisms of two Uncaria tomentosa extracts affecting the Wnt-signaling pathway.

    Science.gov (United States)

    Gurrola-Díaz, Carmen Magdalena; García-López, Pedro Macedonio; Gulewicz, Krzysztof; Pilarski, Radoslaw; Dihlmann, Susanne

    2011-06-15

    Uncaria tomentosa ("uña de gato"; "cat's claw"), a woody vine native to the Amazon rainforest, is commonly used in South American traditional medicine to treat a broad spectrum of diseases. Although recent studies have reported anti-inflammatory and anti-proliferative properties of different alkaloids extracted from this plant, the underlying molecular mechanisms of these effects have not been elucidated yet. Our study investigates the inhibitory mechanisms of Uncaria tomentosa extracts on the Wnt-signaling pathway, a central regulator of development and tissue homoeostasis. A modified cell-based luciferase assay for screening inhibitors of the Wnt-pathway was used for analysis. Three cancer cell lines displaying different levels of aberrant Wnt-signaling activity were transfected with Wnt-signaling responsive Tcf-reporter plasmids and treated with increasing concentrations of two Uncaria tomentosa bark extracts. Wnt-signaling activity was assessed by luciferase activity and by expression of Wnt-responsive target genes. We show that both, an aqueous and an alkaloid-enriched extract specifically inhibit Wnt-signaling activity in HeLa, HCT116 and SW480 cancer cells resulting in reduced expression of the Wnt-target gene: c-Myc. The alkaloid-enriched extract (B/S(rt)) was found to be more effective than the aqueous extract (B/W(37)). The strongest effect was observed in SW480 cells, displaying the highest endogenous Wnt-signaling activity. Downregulation of Wnt-signaling by a dominant negative-TCF-4 variant in non-cancer cells rendered the cells insensitive towards treatment with B/S(rt). B/Srt was less toxic in non-cancer cells than in cancer cells. Our data suggest that the broad spectrum of pharmacological action of Uncaria tomentosa involves inhibition of the Wnt-signaling pathway, downstream of beta-Catenin activity.

  4. Wnt通路及抑制因子对黑素细胞调控作用的研究进展%Regulation of melanocytes by Wnt signaling pathways and their inhibitory factors

    Institute of Scientific and Technical Information of China (English)

    王辉; 王千秋; 林彤

    2015-01-01

    Wnt signaling pathways include a canonical pathway and a noncanonical pathway,and are composed mainly of Wnt ligands,receptors on cellular membrane,cytoplasmic signal transduction molecules and nuclear transcriptional factors.They are associated with a variety of human diseases,such as tumor,osteoporosis,senescence and degenerative disorders.Wnt proteins together with their downstream effectors regulate cell proliferation,migration,differentiation and melanin synthesis through different mechanisms.Both the canonical Wnt3a and noncanonical Wnt5a ligands are important ligands influencing melanin synthesis in melanocytes.Microphthalmia-associtated transcription factor affects nuclear transcriptional regulation.Moreover,Wnt inhibitory factors participate in the regulation of melanocyte function by counteracting Wnt signaling pathways.%Wnt信号通路包括经典通路和非经典通路,主要由Wnt配体蛋白、细胞膜上受体、胞质内信号转导和核内转录调控等部分组成,与肿瘤、骨质疏松、衰老、退化障碍等多种人类疾病有关.Wnt蛋白及其下游的信号因子通过不同机制调控了黑素细胞增殖、迁移、分化和黑素的合成过程.经典通路Wnt3a和非经典通路Wnt5a是影响黑素细胞黑素合成的重要配体蛋白,小眼畸形相关转录因子影响细胞核内的转录调控.Wnt蛋白抑制因子通过对Wnt通路的拮抗作用也参与了对黑素细胞功能的调控.

  5. Biochemical Methods to Analyze Wnt Protein Secretion.

    Science.gov (United States)

    Glaeser, Kathrin; Boutros, Michael; Gross, Julia Christina

    2016-01-01

    Wnt proteins act as potent morphogens in various aspects of embryonic development and adult tissue homeostasis. However, in addition to its physiological importance, aberrant Wnt signaling has been linked to the onset and progression of different types of cancer. On the cellular level, the secretion of Wnt proteins involves trafficking of lipid-modified Wnts from the endoplasmic reticulum (ER) to Golgi and further compartments via the Wnt cargo receptor evenness interrupted. Others and we have recently shown that Wnt proteins are secreted on extracellular vesicles (EVs) such as microvesicles and exosomes. Although more details about specific regulation of Wnt secretion steps are emerging, it remains largely unknown how Wnt proteins are channeled into different release pathways such as lipoprotein particles, EVs and cytonemes. Here, we describe protocols to purify and quantify Wnts from the supernatant of cells by either assessing total Wnt proteins in the supernatant or monitoring Wnt proteins on EVs. Purified Wnts from the supernatant as well as total cellular protein content can be investigated by immunoblotting. Additionally, the relative activity of canonical Wnts in the supernatant can be assessed by a dual-luciferase Wnt reporter assay. Quantifying the amount of secreted Wnt proteins and their activity in the supernatant of cells allows the investigation of intracellular trafficking events that regulate Wnt secretion and the role of extracellular modulators of Wnt spreading. PMID:27590148

  6. 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.

  7. Absolute beta-catenin concentrations in Wnt pathway-stimulated and non-stimulated cells.

    Science.gov (United States)

    Sievers, S; Fritzsch, C; Grzegorczyk, M; Kuhnen, C; Müller, O

    2006-01-01

    The intracellular level of the proto-oncoprotein beta-catenin is a parameter for the activity of the Wnt pathway, which has been linked to carcinogenesis. The paper introduces a novel sandwich-based ELISA for the determination of the beta-catenin concentration in lysates from cells or tissues. The advantages of the method were proven by determining beta-catenin levels in cell lines and in cells after activation of the Wnt pathway. Analysis revealed high beta-catenin concentrations in the cell lines HeLa, KB, HT1080, MCF-7, U-87 and U-373, which had not been described before. Beta-catenin concentrations were compared in HEK293 and C57MG cells after activation of the Wnt pathway. The beta-catenin concentrations increased by different factors depending on whether the Wnt pathway was activated by incubation with LiCl or with Wnt-3a-conditioned medium. This finding indicated that the beta-catenin level depends on the way and level of Wnt pathway activation. The quantitative analysis of beta-catenin in colorectal tumours revealed high beta-catenin levels in tumours with truncating mutations in the APC gene. PMID:16760136

  8. 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.

  9. Modulation of WNT/β-catenin pathway in melanoma by biologically active components derived from plants.

    Science.gov (United States)

    Gajos-Michniewicz, Anna; Czyz, Malgorzata

    2016-03-01

    Metastatic melanoma is an aggressive cancer, often resistant to treatment. Therefore, it is essential to determine the molecular mechanisms leading to melanoma or underlying resistance to therapy, and the response to targeted inhibition of the RAS/BRAF/MEK/ERK pathway was a good lesson in this respect. Aberrant WNT/β-catenin pathway is observed in melanoma, and the modulators of this signaling cascade have been under investigation in the context of therapy as well as chemoprevention. Several natural compounds were recognized as being capable of targeting elements of the WNT/β-catenin pathway in various cancers, however, only a few of them can modulate this pathway in melanoma. This review examines recent research on the role of the WNT/β-catenin pathway in tumor development and maintenance, as well as summarizes the current knowledge concerning the modulation of this pathway in melanoma by active compounds of natural origin. PMID:26851176

  10. Expression of secreted Wnt pathway components reveals unexpected complexity of the planarian amputation response.

    Science.gov (United States)

    Gurley, Kyle A; Elliott, Sarah A; Simakov, Oleg; Schmidt, Heiko A; Holstein, Thomas W; Sánchez Alvarado, Alejandro

    2010-11-01

    Regeneration is widespread throughout the animal kingdom, but our molecular understanding of this process in adult animals remains poorly understood. Wnt/β-catenin signaling plays crucial roles throughout animal life from early development to adulthood. In intact and regenerating planarians, the regulation of Wnt/β-catenin signaling functions to maintain and specify anterior/posterior (A/P) identity. Here, we explore the expression kinetics and RNAi phenotypes for secreted members of the Wnt signaling pathway in the planarian Schmidtea mediterranea. Smed-wnt and sFRP expression during regeneration is surprisingly dynamic and reveals fundamental aspects of planarian biology that have been previously unappreciated. We show that after amputation, a wounding response precedes rapid re-organization of the A/P axis. Furthermore, cells throughout the body plan can mount this response and reassess their new A/P location in the complete absence of stem cells. While initial stages of the amputation response are stem cell independent, tissue remodeling and the integration of a new A/P address with anatomy are stem cell dependent. We also show that WNT5 functions in a reciprocal manner with SLIT to pattern the planarian mediolateral axis, while WNT11-2 patterns the posterior midline. Moreover, we perform an extensive phylogenetic analysis on the Smed-wnt genes using a method that combines and integrates both sequence and structural alignments, enabling us to place all nine genes into Wnt subfamilies for the first time. PMID:20707997

  11. A novel role for MuSK and non-canonical Wnt signaling during segmental neural crest cell migration.

    Science.gov (United States)

    Banerjee, Santanu; Gordon, Laura; Donn, Thomas M; Berti, Caterina; Moens, Cecilia B; Burden, Steven J; Granato, Michael

    2011-08-01

    Trunk neural crest cells delaminate from the dorsal neural tube as an uninterrupted sheet; however, they convert into segmentally organized streams before migrating through the somitic territory. These neural crest cell streams join the segmental trajectories of pathfinding spinal motor axons, suggesting that interactions between these two cell types might be important for neural crest cell migration. Here, we show that in the zebrafish embryo migration of both neural crest cells and motor axons is temporally synchronized and spatially restricted to the center of the somite, but that motor axons are dispensable for segmental neural crest cell migration. Instead, we find that muscle-specific receptor kinase (MuSK) and its putative ligand Wnt11r are crucial for restricting neural crest cell migration to the center of each somite. Moreover, we find that blocking planar cell polarity (PCP) signaling in somitic muscle cells also results in non-segmental neural crest cell migration. Using an F-actin biosensor we show that in the absence of MuSK neural crest cells fail to retract non-productive leading edges, resulting in non-segmental migration. Finally, we show that MuSK knockout mice display similar neural crest cell migration defects, suggesting a novel, evolutionarily conserved role for MuSK in neural crest migration. We propose that a Wnt11r-MuSK dependent, PCP-like pathway restricts neural crest cells to their segmental path.

  12. Complex and dynamic patterns of Wnt pathway gene expression in the developing chick forebrain

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    Lumsden Andrew

    2009-09-01

    Full Text Available Abstract Background Wnt signalling regulates multiple aspects of brain development in vertebrate embryos. A large number of Wnts are expressed in the embryonic forebrain; however, it is poorly understood which specific Wnt performs which function and how they interact. Wnts are able to activate different intracellular pathways, but which of these pathways become activated in different brain subdivisions also remains enigmatic. Results We have compiled the first comprehensive spatiotemporal atlas of Wnt pathway gene expression at critical stages of forebrain regionalisation in the chick embryo and found that most of these genes are expressed in strikingly dynamic and complex patterns. Several expression domains do not respect proposed compartment boundaries in the developing forebrain, suggesting that areal identities are more dynamic than previously thought. Using an in ovo electroporation approach, we show that Wnt4 expression in the thalamus is negatively regulated by Sonic hedgehog (Shh signalling from the zona limitans intrathalamica (ZLI, a known organising centre of forebrain development. Conclusion The forebrain is exposed to a multitude of Wnts and Wnt inhibitors that are expressed in a highly dynamic and complex fashion, precluding simple correlative conclusions about their respective functions or signalling mechanisms. In various biological systems, Wnts are antagonised by Shh signalling. By demonstrating that Wnt4 expression in the thalamus is repressed by Shh from the ZLI we reveal an additional level of interaction between these two pathways and provide an example for the cross-regulation between patterning centres during forebrain regionalisation.

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Regulation of hematopoiesis and the hematopoietic stem cell niche by Wnt signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Michael J Nemeth; David M Bodine

    2007-01-01

    Hematopoietic stem cells (HSCs) are a rare population of cells that are responsible for life-long generation of blood cells of all lineages. In order to maintain their numbers, HSCs must establish a balance between the opposing cell fates of self-renewal (in which the ability to function as HSCs is retained) and initiation of hematopoietic differentiation. Multiple signaling pathways have been implicated in the regulation of HSC cell fate. One such set of pathways are those activated by the Wnt family of ligands. Wnt signaling pathways play a crucial role during embryogenesis and deregulation of these pathways has been implicated in the formation of solid tumors. Wnt signaling also plays a role in the regulation of stem cells from multiple tissues, such as embryonic, epidermal, and intestinal stem cells. However, the function of Wnt signaling in HSC biology is still controversial. In this review, we will discuss the basic characteristics of the adult HSC and its regulatory microenvironment, the "niche", focusing on the regulation of the HSC and its niche by the Wnt signaling pathways.

  15. Genome-wide RNAi screen reveals a new role of a WNT/CTNNB1 signaling pathway as negative regulator of virus-induced innate immune responses.

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    Martin Baril

    Full Text Available To identify new regulators of antiviral innate immunity, we completed the first genome-wide gene silencing screen assessing the transcriptional response at the interferon-β (IFNB1 promoter following Sendai virus (SeV infection. We now report a novel link between WNT signaling pathway and the modulation of retinoic acid-inducible gene I (RIG-I-like receptor (RLR-dependent innate immune responses. Here we show that secretion of WNT2B and WNT9B and stabilization of β-catenin (CTNNB1 upon virus infection negatively regulate expression of representative inducible genes IFNB1, IFIT1 and TNF in a CTNNB1-dependent effector mechanism. The antiviral response is drastically reduced by glycogen synthase kinase 3 (GSK3 inhibitors but restored in CTNNB1 knockdown cells. The findings confirm a novel regulation of antiviral innate immunity by a canonical-like WNT/CTNNB1 signaling pathway. The study identifies novel avenues for broad-spectrum antiviral targets and preventing immune-mediated diseases upon viral infection.

  16. 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

  17. Wnt/β-Catenin and Retinoic Acid Receptor Signaling Pathways Interact to Regulate Chondrocyte Function and Matrix Turnover*

    OpenAIRE

    Yasuhara, Rika; Yuasa, Takahito; Williams, Julie A.; Byers, Stephen W.; Shah, Salim; Pacifici, Maurizio; Iwamoto, Masahiro; Enomoto-Iwamoto, Motomi

    2009-01-01

    Activation of the Wnt/β-catenin and retinoid signaling pathways is known to tilt cartilage matrix homeostasis toward catabolism. Here, we investigated possible interactions between these pathways. We found that all-trans-retinoic acid (RA) treatment of mouse epiphyseal chondrocytes in culture did increase Wnt/β-catenin signaling in the absence or presence of exogenous Wnt3a, as revealed by lymphoid enhancer factor/T-cell factor/β-catenin reporter activity and β-catenin nuclear accumulation. T...

  18. Epigenetic regulation of Wnt signaling pathway gene SRY-related HMG-box 17 in papillary thyroid carcinoma

    Institute of Scientific and Technical Information of China (English)

    LI Jing-yi; HAN Chao; ZHENG Li-li; GUO Ming-zhou

    2012-01-01

    Background SRY-related HMG-box 17 (SOX17) encodes a member of the SOX (SRY-related HMG-box) family of transcription factors involved in the regulation of embryonic development and in the determination of the cell fate.Recently,it was considered as a tumor suppressor gene to inhibit canonical Wnt/β-catenin signaling pathway in several malignancies.However,the function of SOX17 in thyroid cancer was unknown.Therefore,we investigated the epigenetic changes and the function of SOX17 in thyroid cancer.Methods The methylation status of the promoter region of SOX17 was detected using methylation-specific PCR in 63 papillary thyroid carcinoma (PTC) tissue,10 normal thyroid tissue,and two thyroid cancer cell lines.Semi-quantitative RT-PCR was used to assess mRNA expression of SOX17 before and after 5-aza-2′-deoxycytidine treatment in thyroid cancer cell lines.Expression of SOX17 and β-catenin were detected by immunohistochemistry in PTC and adjacent tissue.Luciferase reporter assay,colony formation,transfection,and Western blotting were employed to analyze the effect of SOX17 on thyroid cancer cell proliferation and the function of SOX17 in the Wnt signal pathway.Results Loss of SOX17 expression was correlated to the promoter region hypermethylation in thyroid cancer cell lines.Re-expression of SOX17 was found in TPC-1 cell line after 5-aza-2′-deoxycytidine treatment.In primary thyroid cancer,60.3% (38/63) were methylated and 39.7% (25/63) unmethylated.But no methylation was found in noncancerous thyroid tissues.Methylation of SOX17 was associated reversely with β-catenin expression in the cytoplasm or nucleus significantly in the PTC (P <0.05).Colony formation was inhibited by re-expression of SOX17 in TPC-1 cells.SOX17 suppressed the Wnt signaling pathway and the HMG domain was essential for this effect.Conclusions SOX17 was frequently methylated in human PTC.Loss of SOX17 expression was induced by promoter region hypermethylation.SOX17 inhibited thyroid

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

    Directory of Open Access Journals (Sweden)

    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.

  20. 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.

  1. Intersection of Hippo/YAP and Wnt/β-catenin signaling pathways

    Institute of Scientific and Technical Information of China (English)

    Wesley M.Konsavage; Gregory S.Yochum

    2013-01-01

    Traditionally,signaling pathways have been perceived to act in an autonomous manner to regulate tissue morphology,size,differentiation,and development.Recent evidence suggests that these pathways often intersect and regulate one another to elicit an appropriate response to a complex set of stimuli.Two pathways known to be important for development,growth,and homeostasis are the Wnt/β-catenin and the Hippo/YAP pathways.Growing data indicate that these two pathways influence each other in a number of ways to properly regulate tissue growth and repair.Deregulation of these pathways often contributes to tumorigenesis.In this review,we will discuss the points of intersection between the Wnt/β-catenin and Hippo/YAP pathways and how these interactions contribute to homeostasis,organ repair,and tumorigenesis.

  2. Wnt signaling control of bone cell apoptosis

    Institute of Scientific and Technical Information of China (English)

    Peter V N Bodine

    2008-01-01

    Wnts are a large family of growth factors that mediate essential biological processes like embryogenesis, morphogenesis and organogenesis. These proteins also play a role in oncogenesis, and they regulate apoptosis in many tissues. Wnts bind to a membrane receptor complex comprised of a frizzled (FZD) G-protein-coupled receptor and a low-density , lipoprotein (LDL) receptor-related protein (LRP). The formation of this ligand-receptor complex initiates a number of signaling cascades that include the canonical/beta-catenin pathway as well as several noncanonical pathways. In recent years, canonical Wnt signaling has been reported to play a significant role in the control of bone formation. Clinical studies have found that mutations in LRP-5 are associated with reduced bone mineral density (BMD) and fractures. Investigations of knockout and transgenic mouse models of Wnt pathway components have shown that canonical Wnt signaling modulates most aspects of osteoblast physiology including proliferation, differentiation, function and apoptosis. Transgenic mice expressing a gain of function mutant of LRP-5 in bone, or mice lacking the Wnt antagonist secreted frizzled-related protein-1, exhibit elevated BMD and suppressed osteoblast apoptosis. In addition, preclinical studies with pharmacologic compounds such as those that inhibit glycogen synthase kinase-3p support the importance of the canonical Wnt pathway in modulation of bone formation and osteoblast apoptosis.

  3. Blockade of Wnt/β-Catenin Pathway Aggravated Silica-Induced Lung Inflammation through Tregs Regulation on Th Immune Responses

    Directory of Open Access Journals (Sweden)

    Wujing Dai

    2016-01-01

    Full Text Available CD4+ T cells play an important role in regulating silica-induced inflammation and fibrosis. Recent studies showed that Wnt/β-catenin pathway could modulate the function and the differentiation of CD4+ T cells. Therefore, Wnt/β-catenin pathway may participate in the development and progress of silicosis. To investigate the role of Wnt/β-catenin pathway, we used lentivirus expressing β-catenin shRNA to block the Wnt/β-catenin pathway by intratracheal instillation to the mice model of silicosis. Treatment of lentivirus could significantly aggravate the silica-induced lung inflammation and attenuated the fibrosis at the late stage. By analyzing CD4+ T cells, we found that blockade of Wnt/β-catenin pathway suppressed regulatory T cells (Tregs. Reciprocally, enhanced Th17 response was responsible for the further accumulation of neutrophils and production of proinflammatory cytokines. In addition, blockade of Wnt/β-catenin pathway delayed the Th1/Th2 polarization by inhibiting Tregs and Th2 response. These results indicated that Wnt/β-catenin pathway could regulate Tregs to modulate Th immune response, which finally altered the pathological character of silicosis. Our study suggested that Wnt/β-catenin pathway might be a potential target to treat the silica-induced inflammation and fibrosis.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    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.

  6. Reciprocal interaction of Wnt and RXR-α pathways in hepatocyte development and hepatocellular carcinoma.

    Directory of Open Access Journals (Sweden)

    Jinyu Li

    Full Text Available Genomic analysis of human hepatocellular carcinoma (HCC is potentially confounded by the differentiation state of the hepatic cell-of-origin. Here we integrated genomic analysis of mouse HCC (with defined cell-of-origin along with normal development. We found a major shift in expression of Wnt and RXR-α pathway genes (up and down, respectively coincident with the transition from hepatoblasts to hepatocytes. A combined Wnt and RXR-α gene signature categorized HCCs into two subtypes (high Wnt, low RXR-α and low Wnt, high RXR-α, which matched cell-of-origin in mouse models and the differentiation state of human HCC. Suppression of RXR-α levels in hepatocytes increased Wnt signaling and enhanced tumorigenicity, whereas ligand activation of RXR-α achieved the opposite. These results corroborate that there are two main HCC subtypes that correspond to the degree of hepatocyte differentation and that RXR-α, in part via Wnt signaling, plays a key functional role in the hepatocyte-like subtype and potentially could serve as a selective therapeutic target.

  7. 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.

  8. 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.

  9. Enhancement of canonical Wnt/β-catenin signaling activity by HCV core protein promotes cell growth of hepatocellular carcinoma cells.

    Directory of Open Access Journals (Sweden)

    Jiao Liu

    Full Text Available BACKGROUND: The Hepatitis C virus (HCV core protein has been implicated as a potential oncogene or a cofactor in HCV-related hepatocellular carcinoma (HCC, but the underlying mechanisms are unknown. Overactivation of the Wnt/β-catenin signaling is a major factor in oncogenesis of HCC. However, the pathogenesis of HCV core-associated Wnt/β-catenin activation remains to be further characterized. Therefore, we attempted to determine whether HCV core protein plays an important role in regulating Wnt/β-catenin signaling in HCC cells. METHODOLOGY: Wnt/β-catenin signaling activity was investigated in core-expressing hepatoma cells. Protein and gene expression were examined by Western blot, immunofluorescence staining, RT-qPCR, and reporter assay. PRINCIPAL FINDINGS: HCV core protein significantly enhances Tcf-dependent transcriptional activity induced by Wnt3A in HCC cell lines. Additionally, core protein increases and stabilizes β-catenin levels in hepatoma cell line Huh7 through inactivation of GSK-3β, which contributes to the up-regulation of downstream target genes, such as c-Myc, cyclin D1, WISP2 and CTGF. Also, core protein increases cell proliferation rate and promotes Wnt3A-induced tumor growth in the xenograft tumor model of human HCC. CONCLUSIONS/SIGNIFICANCE: HCV core protein enhances Wnt/β-catenin signaling activity, hence playing an important role in HCV-associated carcinogenesis.

  10. Reciprocal requirements for Eda/Edar/NF-κB and Wnt/β-catenin signaling pathways in hair follicle induction

    Science.gov (United States)

    Zhang, Yuhang; Tomann, Philip; Andl, Thomas; Gallant, Natalie M.; Huelsken, Joerg; Jerchow, Boris; Birchmeier, Walter; Paus, Ralf; Piccolo, Stefano; Mikkola, Marja L.; Morrisey, Edward E.; Overbeek, Paul A.; Scheidereit, Claus; Millar, Sarah E.; Schmidt-Ullrich, Ruth

    2009-01-01

    SUMMARY Wnt/β-catenin and NF-κB signaling mechanisms provide central controls in development and disease, but how these pathways intersect is unclear. Using hair follicle induction as a model system, we show that patterning of dermal Wnt/β-catenin signaling requires epithelial β-catenin activity. We find that Wnt/β-catenin signaling is absolutely required for NF-κB activation, and that Edar is a direct Wnt target gene. Wnt/β-catenin signaling is initially activated independently of Eda/Edar/NF-κB activity in primary hair follicle primordia. However, Eda/Edar/NF-κB signaling is required to refine the pattern of Wnt/β-catenin activity, and to maintain this activity at later stages of placode development. We show that maintenance of localized expression of Wnt10b and Wnt10a requires NF-κB signaling, providing a molecular explanation for the latter observation, and identify Wnt10b as a direct NF-κB target. These data reveal a complex interplay and inter-dependence of Wnt/β-catenin and Eda/Edar/NF-κB signaling pathways in initiation and maintenance of primary hair follicle placodes. PMID:19619491

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

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    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.

  12. Overexpression of Wnt5a Promotes Angiogenesis in NSCLC

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    Lingli Yao

    2014-01-01

    Full Text Available To evaluate Wnt5a expression and its role in angiogenesis of non-small-cell lung cancer (NSCLC, immunohistochemistry and CD31/PAS double staining were performed to examine the Wnt5a expression and we analyze the relationships between Wnt5a and microvessel density (MVD, vasculogenic mimicry (VM, and some related proteins. About 61.95% of cases of 205 NSCLC specimens exhibited high expression of Wnt5a. Wnt5a expression level was upregulated in the majority of NSCLC tissues, especially in squamous cell carcinoma, while its expression level in adenocarcinoma was the lowest. Wnt5a was also found more frequently expressed in male patients than in female patients. Except for histological classification and gender, little association was found between Wnt5a and clinicopathological features. Moreover, Wnt5a was significantly correlated with prognosis. Overall, Wnt5a-positive expression in patients with NSCLC indicated shorter survival time. As for vascularization in NSCLC, Wnt5a showed close association with VM and MVD. In addition, Wnt5a was positively related with β-catenin-nu, VE-cadherin, MMP2, and MMP9. The results demonstrated that overexpression of Wnt5a may play an important role in NSCLC angiogenesis and it may function via canonical Wnt signal pathway. This study will provide evidence for further research on NSCLC and also will provide new possible target for NSCLC diagnosis and therapeutic strategies.

  13. 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...

  14. Pulsating fluid flow modulates gene expression of proteins involved in Wnt signaling pathways in osteocytes

    NARCIS (Netherlands)

    A. Santos; A.D. Bakker; B. Zandieh-Doulabi; C.M. Semeins; J. Klein-Nulend

    2009-01-01

    Strain-derived flow of interstitial fluid activates signal transduction pathways in osteocytes that regulate bone mechanical adaptation. Wnts are involved in this process, but whether mechanical loading modulates Wnt signaling in osteocytes is unclear. We assessed whether mechanical stimulation by p

  15. NDRG1 overexpression promotes the progression of esophageal squamous cell carcinoma through modulating Wnt signaling pathway

    Science.gov (United States)

    Ai, Runna; Sun, Yulin; Guo, Zhimin; Wei, Wei; Zhou, Lanping; Liu, Fang; Hendricks, Denver T.; Xu, Yang; Zhao, Xiaohang

    2016-01-01

    ABSTRACT N-myc down-regulated gene 1 (NDRG1) has been shown to regulate tumor growth and metastasis in various malignant tumors and also to be dysregulated in esophageal squamous cell carcinoma (ESCC). Here, we show that NDRG1 overexpression (91.9%, 79/86) in ESCC tumor tissues is associated with poor overall survival of esophageal cancer patients. When placed in stable transfectants of the KYSE 30 ESCC cell line generated by lentiviral transduction with the ectopic overexpression of NDRG1, the expression of transducin-like enhancer of Split 2 (TLE2) was decreased sharply, however β−catenin was increased. Mechanistically, NDRG1 physically associates with TLE2 and β−catenin to affect the Wnt pathway. RNA interference and TLE2 overexpression studies demonstrate that NDRG1 fails to active Wnt pathway compared with isogenic wild-type controls. Strikingly, NDRG1 overexpression induces the epithelial mesenchymal transition (EMT) through activating the Wnt signaling pathway in ESCC cells, decreased the expression of E-cadherin and enhanced the expression of Snail. Our study elucidates a mechanism of NDRG1-regulated Wnt pathway activation and EMT via affecting TLE2 and  β-catenin expression in esophageal cancer cells. This indicates a pro-oncogenic role for NDRG1 in esophageal cancer cells whereby it modulates tumor progression. PMID:27414086

  16. The Wnt signalling pathway is upregulated in an in vitro model of acquired tamoxifen resistant breast cancer

    International Nuclear Information System (INIS)

    Acquired resistance to Tamoxifen remains a critical problem in breast cancer patient treatment, yet the underlying causes of resistance have not been fully elucidated. Abberations in the Wnt signalling pathway have been linked to many human cancers, including breast cancer, and appear to be associated with more metastatic and aggressive types of cancer. Here, our aim was to investigate if this key pathway was involved in acquired Tamoxifen resistance, and could be targeted therapeutically. An in vitro model of acquired Tamoxifen resistance (named TamR) was generated by growing the estrogen receptor alpha (ER) positive MCF7 breast cancer cell line in increasing concentrations of Tamoxifen (up to 5 uM). Alterations in the Wnt signalling pathway and epithelial to mesenchymal transition (EMT) in response to Tamoxifen and treatment with the Wnt inhibitor, IWP-2 were measured via quantitative RT-PCR (qPCR) and TOP/FOP Wnt reporter assays. Resistance to Tamoxifen, and effects of IWP-2 treatment were determined by MTT proliferation assays. TamR cells exhibited increased Wnt signalling as measured via the TOP/FOP Wnt luciferase reporter assays. Genes associated with both the β-catenin dependent (AXIN2, MYC, CSNK1A1) and independent arms (ROR2, JUN), as well as general Wnt secretion (PORCN) of the Wnt signalling pathway were upregulated in the TamR cells compared to the parental MCF7 cell line. Treatment of the TamR cell line with human recombinant Wnt3a (rWnt3a) further increased the resistance of both MCF7 and TamR cells to the anti-proliferative effects of Tamoxifen treatment. TamR cells demonstrated increased expression of EMT markers (VIM, TWIST1, SNAI2) and decreased CDH1, which may contribute to their resistance to Tamoxifen. Treatment with the Wnt inhibitor, IWP-2 inhibited cell proliferation and markers of EMT. These data support the role of the Wnt signalling pathway in acquired resistance to Tamoxifen. Further research into the mechanism by which activated Wnt

  17. Evaluating the Role of Wnt Signal Transduction in Promoting the Development of the Heart

    Directory of Open Access Journals (Sweden)

    Leonard M. Eisenberg

    2007-01-01

    Full Text Available Wnts are a family of secreted signaling proteins that are encoded by 19 distinct genes in the vertebrate genome. These molecules initiate several signal transduction pathways: the canonical Wnt, Wnt/Ca2+, and Wnt/planar cell polarity pathways. Wnt proteins have major impact on embryonic development, tumor progression, and stem cell differentiation. Wnt signal transduction also influences the formation of the heart, yet many issues concerning the involvement of Wnt regulation in initiating cardiac development remain unresolved. In this review, we will examine the published record to discern (a what has been shown by experimental studies on the participation of Wnt signaling in cardiogenesis, and (b what are the important questions that need to be addressed to understand the importance and function of Wnt signal transduction in facilitating the development of the heart.

  18. Functional Genomic Analyses Identify Pathways Dysregulated by Progranulin Deficiency Implicating Wnt Signaling

    OpenAIRE

    Rosen, Ezra Y.; Wexler, Eric M; Versano, Revital; Coppola, Giovanni; Gao, Fuying; Winden, Kellen D.; Oldham, Michael C.; Martens, Lauren Herl; Zhou, Ping; Farese, Robert V; Geschwind, Daniel H.

    2011-01-01

    Progranulin (GRN) mutations cause frontotemporal dementia (FTD), but GRN’s function in the CNS remains largely unknown. To identify the pathways downstream of GRN, we used weighted gene co-expression network analysis (WGCNA) to develop a systems-level view of transcriptional alterations in a human neural progenitor model of GRN-deficiency. This highlighted key pathways such as apoptosis and ubiquitination in GRN deficient human neurons, while revealing an unexpected major role for the Wnt sig...

  19. Inducible tumor necrosis factor (TNF) receptor-associated factor-1 expression couples the canonical to the non-canonical NF-κB pathway in TNF stimulation.

    Science.gov (United States)

    Choudhary, Sanjeev; Kalita, Mridul; Fang, Ling; Patel, Kershaw V; Tian, Bing; Zhao, Yingxin; Edeh, Chukwudi B; Brasier, Allan R

    2013-05-17

    The NF-κB transcription factor mediates the inflammatory response through distinct (canonical and non-canonical) signaling pathways. The mechanisms controlling utilization of either of these pathways are largely unknown. Here we observe that TNF stimulation induces delayed NF-κB2/p100 processing and investigate the coupling mechanism. TNF stimulation induces TNF-associated factor-1 (TRAF-1) that directly binds NF-κB-inducing kinase (NIK) and stabilizes it from degradation by disrupting its interaction with TRAF2·cIAP2 ubiquitin ligase complex. We show that TRAF1 depletion prevents TNF-induced NIK stabilization and reduces p52 production. To further examine the interactions of TRAF1 and NIK with NF-κB2/p100 processing, we mathematically modeled TRAF1·NIK as a coupling signaling complex and validated computational inference by siRNA knockdown to show non-canonical pathway activation is dependent not only on TRAF1 induction but also NIK stabilization by forming TRAF1·NIK complex. Thus, these integrated computational-experimental studies of TNF-induced TRAF1 expression identified TRAF1·NIK as a central complex linking canonical and non-canonical pathways by disrupting the TRAF2-cIAP2 ubiquitin ligase complex. This feed-forward kinase pathway is essential for the activation of non-canonical pathway. PMID:23543740

  20. The role of the Wnt/β-catenin pathway in the effect of implant topography on MG63 differentiation.

    Science.gov (United States)

    Wang, Wei; Zhao, Lingzhou; Ma, Qianli; Wang, Qintao; Chu, Paul K; Zhang, Yumei

    2012-11-01

    Wnt/β-catenin signaling plays a key role in bone formation. To assess the role of this signaling cascade in the response of osteoblasts to the implant topography, human MG63 osteoblasts are cultured on micropitted/nanotubular surface topographies (MNTs) and the transcriptional expressions of Wnt/β-catenin pathway receptors, activators, and inhibitors are measured. β-catenin signaling and cell differentiation are studied in the absence and presence of exogenous Dickkopf 1 (Dkk1) on the MNTs and exogenous Wnt3a on a smooth surface. The expressions of the Wnt/β-catenin pathway receptor low-density lipoprotein receptor-related protein 6 and pathway ligand Wnt3a are up-regulated by the MNTs whereas those of the pathway inhibitors including Dkk1/2 and secreted frizzled-related protein 1/2 are down-regulated by the MNTs, indicating regulation of the Wnt/β-catenin pathway modulators to activate the pathway. Consequently, the β-catenin signaling activity is enhanced by the MNTs as well as cell differentiation in terms of osteogenesis-related gene expressions and alkaline phosphatase and collagen products. On the smooth surface, exogenous Wnt3a stimulates β-catenin signaling and cell differentiation while exogenous Dkk1 attenuates the enhancement by the MNTs. The results explicitly demonstrate that the implant topography regulates the product of the Wnt/β-catenin pathway modulators from the cells and in turn activates the cell Wnt/β-catenin pathway promoting osteoblast differentiation. PMID:22889483

  1. WNT5A inhibits human dental papilla cell proliferation and migration

    International Nuclear Information System (INIS)

    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.

  2. WNT5A inhibits human dental papilla cell proliferation and migration

    Energy Technology Data Exchange (ETDEWEB)

    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.

  3. Loss of PKCδ Induces Prostate Cancer Resistance to Paclitaxel through Activation of Wnt/β-Catenin Pathway and Mcl-1 Accumulation.

    Science.gov (United States)

    Flores, M Luz; Castilla, Carolina; Gasca, Jessica; Medina, Rafael; Pérez-Valderrama, Begoña; Romero, Francisco; Japón, Miguel A; Sáez, Carmen

    2016-07-01

    Prostate cancer is the leading cause of cancer-related death among men in developed countries. Although castration therapy is initially effective, prostate cancers progress to hormone-refractory disease and in this case taxane-based chemotherapy is widely used. Castration-resistant prostate cancer cells often develop resistance to chemotherapy agents and the search for new therapeutic strategies is necessary. In this article, we demonstrate that PKCδ silencing favors mitotic arrest after paclitaxel treatment in PC3 and LNCaP cells; however, this is associated with resistance to paclitaxel-induced apoptosis. In prostate cancer cells, PKCδ seems to exert a proapoptotic role, acting as a negative regulator of the canonical Wnt/β-catenin pathway. PKCδ silencing induces activation of Wnt/β-catenin pathway and the expression of its target genes, including Aurora kinase A, which is involved in activation of Akt and both factors play a key role in GSK3β inactivation and consequently in the stabilization of β-catenin and antiapoptotic protein Mcl-1. We also show that combined treatments with paclitaxel and Wnt/β-catenin or Akt inhibitors improve the apoptotic response to paclitaxel, even in the absence of PKCδ. Finally, we observe that high Gleason score prostate tumors lose PKCδ expression and this correlates with higher activation of β-catenin, inactivation of GSK3β, and higher levels of Aurora kinase A and Mcl-1 proteins. These findings suggest that targeting Wnt/β-catenin or Akt pathways may increase the efficacy of taxane chemotherapy in advanced human prostate cancers that have lost PKCδ expression. Mol Cancer Ther; 15(7); 1713-25. ©2016 AACR.

  4. The epigenetically regulated effects of Wnt antagonists on the expression of genes in the apoptosis pathway in human bladder cancer cell line (T24).

    Science.gov (United States)

    Varol, Nuray; Konac, Ece; Onen, Ilke Hacer; Gurocak, Serhat; Alp, Ebru; Yilmaz, Akin; Menevse, Sevda; Sozen, Sinan

    2014-07-01

    The epigenetic suppression of Wnt antagonists (sFRPs, DKKs, and WIF-1) causes the activation of both β-catenin and target genes, which play an important role in cell proliferation, metastasis, and angiogenesis. This study is aimed to investigate, on transcriptional and protein levels, the synergic effects of unaccompanied and/or combined use of 5-aza-2'-deoxycytidine (DAC, 5-aza-dC), trichostatin A (TSA), and gemcitabine+cisplatin chemotherapeutic agents on the apoptotic pathway of human bladder cancer cell line T24. The anti-tumor effects of gemcitabine (0-500 nM), cisplatin (0-10 μM), DAC (10 μM), and TSA (300 nM) alone and/or together on T24 cells were determined by WST-1. ELISA method was used to analyze the effects of unaccompanied and combined use of gemcitabine+cisplatin, DAC, and TSA on cell proliferation and determine the cytotoxic and apoptotic dosages at the level of H3 histone acetylation. Methylation-specific PCR was used to evaluate methylation profiles of Wnt antagonist gene (WIF-1). In the case of unaccompanied and/or combined use of specified drugs, the variations in the expression levels of CTNNB1, GSK3β, c-MYC, CCND1, CASP-3, CASP-8, CASP-9, BCL2L1, and WIF-1 genes were determined by quantitative real-time PCR. Our results indicate that through inhibition of DNA methylation, expression of β-catenin and Wnt antagonist re-activation and expressions of canonical Wnt/β-catenin pathway target genes, c-myc and cyclin D1 (CCND1), have decreased. In addition, DAC, TSA, and gemcitabine+cisplatin combination caused an increase in GSK3β mRNA levels, which in turn significantly decreased CCND1 mRNA levels. Moreover, BCL2L1, an anti-apoptotic gene, was downregulated significantly. Meanwhile, both CASP-3 mRNA and active caspase-3 protein levels increased with respect to control (p<0.01). The results revealed that use of quadruplicate gemcitabine+cisplatin+DAC+TSA combination led to a reduced inhibition of canonical Wnt/β-catenin pathway and reduced

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

    Science.gov (United States)

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

    2016-09-21

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

  6. Cross-talk between TGF-β/Smad pathway and Wnt/β-catenin pathway in pathological scar formation.

    Science.gov (United States)

    Sun, Qiang; Guo, Shu; Wang, Chen-Chao; Sun, Xu; Wang, Di; Xu, Nan; Jin, Shi-Feng; Li, Ke-Zhu

    2015-01-01

    TGF-β1 is a key factor in the process of wound healing, which is regulated by TGF-β/Smad pathway. We previously demonstrated that TGF-β1 contributed to pathological scar formation. And previous studies also suggested Wnt/β-catenin pathway might be involved in wound healing. However, their role and relation in pathological scar formation remains not very clear. For evaluating TGF-β1 and β-catenin, key factors of the two signal pathways, immunohistochemistry, western blot analysis and RT-PCR were used. Simultaneously, immunohistochemistry were used to evaluate Smad2, Smad3 and Wnt-1, which were also the important factors. We found that they all significantly accumulated in pathological scars compared with normal skins (Pscar formation. Meanwhile, β-catenin expression showed a tendency to increase first and then decrease under the influence of different concentrations of TGF-β1 (Pscar formation (both synergy and antagonism).

  7. Activation of the wnt/β-Catenin Signaling Pathway in Polymyositis, Dermatomyositis and Duchenne Muscular Dystrophy

    Science.gov (United States)

    Liu, Fuchen; Liang, Zonglai; Xu, Jingwen; Li, Wei; Zhao, Dandan; Zhao, Yuying

    2016-01-01

    Background and Purpose The wnt/β-catenin signaling pathway plays a critical role in embryonic development and adult-tissue homeostasis. Recent investigations implicate the importance of wnt/β-catenin signaling in normal wound healing and its sustained activation being associated with fibrogenesis. We investigated the immunolocalization and activation of wnt/β-catenin in polymyositis (PM), dermatomyositis (DM), and Duchenne muscular dystrophy (DMD). Methods Immunofluorescence staining and Western blot analysis of β-catenin were performed in muscle specimens from 6 PM, 8 DM, and 6 DMD subjects. The β-catenin/Tcf4 DNA-binding activity in muscle was studied using an electrophoretic mobility shift assay (EMSA), and serum wnt/β-catenin/Tcf transcriptional activity was measured using a luciferase reporter gene assay. Results Immunoreactivity for β-catenin was found in the cytoplasm and nuclei of muscle fibers in PM, DM, and DMD. The protein level of β-catenin was elevated, and EMSA analysis confirmed the activation of wnt/β-catenin signaling. The transcriptional activities of β-catenin/Tcf in the circulation were increased in patients with PM, DM, and DMD, especially in those with interstitial lung disease, and these transcriptional activities decreased when PM or DM patients exhibited obvious clinical improvements. Conclusions Our findings indicate that wnt/β-catenin signaling is activated in PM, DM, and DMD. Its activation in muscle tissue and the circulation may play a role in modulating muscle regeneration and be at least partly involved in the process of muscle and pulmonary fibrosis. PMID:27165423

  8. Capsaicin inhibits the Wnt/β-catenin signaling pathway by down-regulating PP2A.

    Science.gov (United States)

    Park, Dong-Seok; Yoon, Gang-Ho; Lee, Hyun-Shik; Choi, Sun-Cheol

    2016-09-01

    Xenopus embryo serves as an ideal model for teratogenesis assays to examine the effects of any substances on the cellular processes critical for early development and adult tissue homeostasis. In our chemical library screening with frog embryo, capsaicin was found to repress the Wnt/β-catenin signaling. Depending on the stages at which embryos became exposed to capsaicin, it could disrupt formation of dorsal or posterior body axis of embryo, which is associated with inhibition of maternal or zygotic Wnt signal in early development. In agreement with these phenotypes, capsaicin suppressed the expression of Wnt target genes such as Siamois and Chordin in the organizer region of embryo and in Wnt signals-stimulated tissue explants. In addition, the cellular level of β-catenin, a key component of Wnt pathway, was down-regulated in capsaicin-treated embryonic cells. Unlike wild-type β-catenin, its non-phosphorylatable mutant in which serine and threonine residues phosphorylated by GSK3 are substituted with alanine was not destabilized by capsaicin, indicative of the effect of this chemical on the phosphorylation status of β-catenin. In support of this, capsaicin up-regulated the level of GSK3- or CK1-phosphorylated β-catenin, concomitantly lowering that of its de-phosphorylated version. Notably, capsaicin augmented the phosphorylation of a phosphatase, PP2A at tyrosine 307, suggesting its repression of the enzymatic activity of the phosphatase. Furthermore, capsaicin still enhanced β-catenin phosphorylation in cells treated with a GSK3 inhibitor, LiCl but not in those treated with a phosphatase inhibitor, okadaic acid. Together, these results indicate that capsaicin inhibits the patterning of the dorso-ventral and anterior-posterior body axes of embryo by repressing PP2A and thereby down-regulating the Wnt/β-catenin signaling. PMID:27318088

  9. Circadian disruption accelerates tumor growth and angio/stromagenesis through a Wnt signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yoshihiro Yasuniwa

    Full Text Available Epidemiologic studies show a high incidence of cancer in shift workers, suggesting a possible relationship between circadian rhythms and tumorigenesis. However, the precise molecular mechanism played by circadian rhythms in tumor progression is not known. To identify the possible mechanisms underlying tumor progression related to circadian rhythms, we set up nude mouse xenograft models. HeLa cells were injected in nude mice and nude mice were moved to two different cases, one case is exposed to a 24-hour light cycle (L/L, the other is a more "normal" 12-hour light/dark cycle (L/D. We found a significant increase in tumor volume in the L/L group compared with the L/D group. In addition, tumor microvessels and stroma were strongly increased in L/L mice. Although there was a hypervascularization in L/L tumors, there was no associated increase in the production of vascular endothelial cell growth factor (VEGF. DNA microarray analysis showed enhanced expression of WNT10A, and our subsequent study revealed that WNT10A stimulates the growth of both microvascular endothelial cells and fibroblasts in tumors from light-stressed mice, along with marked increases in angio/stromagenesis. Only the tumor stroma stained positive for WNT10A and WNT10A is also highly expressed in keloid dermal fibroblasts but not in normal dermal fibroblasts indicated that WNT10A may be a novel angio/stromagenic growth factor. These findings suggest that circadian disruption induces the progression of malignant tumors via a Wnt signaling pathway.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Expression analysis of eight amphioxus genes involved in the Wnt/β-catenin signaling pathway

    Science.gov (United States)

    WANG, Jing; LI, Guang; QIAN, Guang-Hui; HUA, Jun-Hao; WANG, Yi-Quan

    2016-01-01

    The Wnt/β-catenin signaling pathway plays a crucial role in the embryonic development of metazoans. Although the pathway has been studied extensively in many model animals, its function in amphioxus, the most primitive chordate, remains largely uncharacterized. To obtain basic data for functional analysis, we identified and isolated seven genes (Lrp5/6, Dvl, APC, CkIα, CkIδ, Gsk3β, and Gro) of the Wnt/β-catenin signaling pathway from the amphioxus (Branchiostoma floridae) genome. Phylogenetic analysis revealed that amphioxus had fewer members of each gene family than that found in vertebrates. Whole-mount in situ hybridization showed that the genes were maternally expressed and broadly distributed throughout the whole embryo at the cleavage and blastula stages. Among them, Dvl was expressed asymmetrically towards the animal pole, while the others were evenly distributed in all blastomeres. At the mid-gastrula stage, the genes were specifically expressed in the primitive endomesoderm, but displayed different patterns. When the embryo developed into the neurula stage, the gene expressions were mainly detected in either paraxial somites or the tail bud. With the development of the embryo, the expression levels further decreased gradually and remained only in some pharyngeal regions or the tail bud at the larva stage. Our results suggest that the Wnt/β-catenin pathway might be involved in amphioxus somite formation and posterior growth, but not in endomesoderm specification. PMID:27265651

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

    Science.gov (United States)

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

    2016-01-01

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

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

    Directory of Open Access Journals (Sweden)

    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.

  14. Wnt signaling pathway pharmacogenetics in non-small cell lung cancer.

    Science.gov (United States)

    Stewart, D J; Chang, D W; Ye, Y; Spitz, M; Lu, C; Shu, X; Wampfler, J A; Marks, R S; Garces, Y I; Yang, P; Wu, X

    2014-12-01

    Wingless-type protein (Wnt)/β-catenin pathway alterations in non-small cell lung cancer (NSCLC) are associated with poor prognosis and resistance. In 598 stage III-IV NSCLC patients receiving platinum-based chemotherapy at the MD Anderson Cancer Center (MDACC), we correlated survival with 441 host single-nucleotide polymorphisms (SNPs) in 50 Wnt pathway genes. We then assessed the most significant SNPs in 240 Mayo Clinic patients receiving platinum-based chemotherapy for advanced NSCLC, 127 MDACC patients receiving platinum-based adjuvant chemotherapy and 340 early stage MDACC patients undergoing surgery alone (cohorts 2-4). In multivariate analysis, survival correlates with SNPs for AXIN2 (rs11868547 and rs4541111, of which rs11868547 was assessed in cohorts 2-4), Wnt-5B (rs12819505), CXXC4 (rs4413407) and WIF-1 (rs10878232). Median survival was 19.7, 15.6 and 10.7 months for patients with 1, 2 and 3-5 unfavorable genotypes, respectively (P=3.8 × 10(-9)). Survival tree analysis classified patients into two groups (median survival time 11.3 vs 17.3 months, P=4.7 × 10(-8)). None of the SNPs achieved significance in cohorts 2-4; however, there was a trend in the same direction as cohort 1 for 3 of the SNPs. Using online databases, we found rs10878232 displayed expression quantitative trait loci correlation with the expression of LEMD3, a neighboring gene previously associated with NSCLC survival. In conclusion, results from cohort 1 provide further evidence for an important role for Wnt in NSCLC. Investigation of Wnt inhibitors in advanced NSCLC would be reasonable. Lack of an SNP association with outcome in cohorts 2-4 could be due to low statistical power, impact of patient heterogeneity or false-positive observations in cohort 1. PMID:24980784

  15. Activation and Inhibition of The Wnt3A Signaling Pathway in Buffalo (Bubalus bubalis Embryonic Stem Cells: Effects of WNT3A, Bio and Dkk1

    Directory of Open Access Journals (Sweden)

    Mohammad Zandi

    2015-07-01

    Full Text Available Background: This research studies the effects of activation and inhibition of Wnt3A signaling pathway in buffalo (Bubalus bubalis embryonic stem (ES cell-like cells. Materials and Methods: To carry on this experimental study, the effects of activation and inhibition of Wnt3A signaling in buffalo ES cell-like cells were examined using Bio (0.5 mM combined with WNT3A (200 ng/ml, as an activator, and Dickkopf-1 (Dkk1, 250 ng/ml, as an inhibitor, of the pathway. ES cells were cultured up to three weeks in ES cell medium without fibroblast growth factor-2 (FGF-2 and leukemia inhibitory factor (LIF, but in the presence of Bio, WNT3A, Bio+WNT3A and Dkk1. The effects of these supplements were measured on the mean area of ES cell colonies and on the expression levels of a number of important genes related to pluripotency (Oct4, Nanog, Sox2 and c-Myc and the Wnt pathway (β-catenin. ES cell colonies cultured in ES cell medium that contained optimized quantities of LIF and FGF-2 were used as the control. Data were collected for week-1 and week-3 treated cultures. In addition, WNT3A-transfected ES cells were compared with the respective mock-transfected colonies, either alone or in combination with Dkk1 for expression of β-catenin and the pluripotency-related genes. Data were analyzed by ANOVA, and statistical significance was accepted at P<0.05. Results: Among various examined concentrations of Bio (0.5-5 mM, the optimum effect was observed at the 0.5 mM dose as indicated by colony area and expressions of pluripotency- related genes at both weeks-1 and -3 culture periods. At this concentration,the expressions of Nanog, Oct3/4, Sox2, c-Myc and β-catenin genes were nonsignificantly higher compared to the controls. Expressions of these genes were highest in the Bio+WNT3A treated group, followed by the WNT3A and Bio-supplemented groups, and lowest in the Dkk1-treated group. The WNT-transfected colonies showed higher expressions compared to both mock and Dkk1

  16. AMP-activated protein kinase (AMPK) cross-talks with canonical Wnt signaling via phosphorylation of β-catenin at Ser 552

    International Nuclear Information System (INIS)

    AMP-activated protein kinase (AMPK) is a key regulator of energy metabolism; its activity is regulated by a plethora of physiological conditions, exercises and many anti-diabetic drugs. Recent studies show that AMPK involves in cell differentiation but the underlying mechanism remains undefined. Wingless Int-1 (Wnt)/β-catenin signaling pathway regulates the differentiation of mesenchymal stem cells through enhancing β-catenin/T-cell transcription factor 1 (TCF) mediated transcription. The objective of this study was to determine whether AMPK cross-talks with Wnt/β-catenin signaling through phosphorylation of β-catenin. C3H10T1/2 mesenchymal cells were used. Chemical inhibition of AMPK and the expression of a dominant negative AMPK decreased phosphorylation of β-catenin at Ser 552. The β-catenin/TCF mediated transcription was correlated with AMPK activity. In vitro, pure AMPK phosphorylated β-catenin at Ser 552 and the mutation of Ser 552 to Ala prevented such phosphorylation, which was further confirmed using [γ-32P]ATP autoradiography. In conclusion, AMPK phosphorylates β-catenin at Ser 552, which stabilizes β-catenin, enhances β-catenin/TCF mediated transcription, expanding AMPK from regulation of energy metabolism to cell differentiation and development via cross-talking with the Wnt/β-catenin signaling pathway.

  17. Dickkopf-related protein 1 inhibits the WNT signaling pathway and improves pig oocyte maturation.

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    Lee D Spate

    Full Text Available The ability to mature oocytes in vitro provides a tool for creating embryos by parthenogenesis, fertilization, and cloning. Unfortunately the quality of oocytes matured in vitro falls behind that of in vivo matured oocytes. To address this difference, transcriptional profiling by deep sequencing was conducted on pig oocytes that were either matured in vitro or in vivo. Alignment of over 18 million reads identified 1,316 transcripts that were differentially represented. One pathway that was overrepresented in the oocytes matured in vitro was for Wingless-type MMTV integration site (WNT signaling. In an attempt to inhibit the WNT pathway, Dickkopf-related protein 1 was added to the in vitro maturation medium. Addition of Dickkopf-related protein 1 improved the percentage of oocytes that matured to the metaphase II stage, increased the number of nuclei in the resulting blastocyst stage embryos, and reduced the amount of disheveled segment polarity protein 1 protein in oocytes. It is concluded that transcriptional profiling is a powerful method for detecting differences between in vitro and in vivo matured oocytes, and that the WNT signaling pathway is important for proper oocyte maturation.

  18. Signal Transduction Pathways of EMT Induced by TGF-β, SHH, and WNT and Their Crosstalks

    Science.gov (United States)

    Zhang, Jingyu; Tian, Xiao-Jun; Xing, Jianhua

    2016-01-01

    Epithelial-to-mesenchymal transition (EMT) is a key step in development, wound healing, and cancer development. It involves cooperation of signaling pathways, such as transformation growth factor-β (TGF-β), Sonic Hedgehog (SHH), and WNT pathways. These signaling pathways crosstalk to each other and converge to key transcription factors (e.g., SNAIL1) to initialize and maintain the process of EMT. The functional roles of multi-signaling pathway crosstalks in EMT are sophisticated and, thus, remain to be explored. In this review, we focused on three major signal transduction pathways that promote or regulate EMT in carcinoma. We discussed the network structures, and provided a brief overview of the current therapy strategies and drug development targeted to these three signal transduction pathways. Finally, we highlighted systems biology approaches that can accelerate the process of deconstructing complex networks and drug discovery. PMID:27043642

  19. 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.

  20. Signal Transduction Pathways of EMT Induced by TGF-β, SHH, and WNT and Their Crosstalks

    Directory of Open Access Journals (Sweden)

    Jingyu Zhang

    2016-03-01

    Full Text Available Epithelial-to-mesenchymal transition (EMT is a key step in development, wound healing, and cancer development. It involves cooperation of signaling pathways, such as transformation growth factor-β (TGF-β, Sonic Hedgehog (SHH, and WNT pathways. These signaling pathways crosstalk to each other and converge to key transcription factors (e.g., SNAIL1 to initialize and maintain the process of EMT. The functional roles of multi-signaling pathway crosstalks in EMT are sophisticated and, thus, remain to be explored. In this review, we focused on three major signal transduction pathways that promote or regulate EMT in carcinoma. We discussed the network structures, and provided a brief overview of the current therapy strategies and drug development targeted to these three signal transduction pathways. Finally, we highlighted systems biology approaches that can accelerate the process of deconstructing complex networks and drug discovery.

  1. 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

  2. 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

    Directory of Open Access Journals (Sweden)

    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.

  3. Genome-wide network analysis of Wnt signaling in three pediatric cancers

    Science.gov (United States)

    Bao, Ju; Lee, Ho-Jin; Zheng, Jie J.

    2013-10-01

    Genomic structural alteration is common in pediatric cancers, and analysis of data generated by the Pediatric Cancer Genome Project reveals such tumor-related alterations in many Wnt signaling-associated genes. Most pediatric cancers are thought to arise within developing tissues that undergo substantial expansion during early organ formation, growth and maturation, and Wnt signaling plays an important role in this development. We examined three pediatric tumors--medullobastoma, early T-cell precursor acute lymphoblastic leukemia, and retinoblastoma--that show multiple genomic structural variations within Wnt signaling pathways. We mathematically modeled this pathway to investigate the effects of cancer-related structural variations on Wnt signaling. Surprisingly, we found that an outcome measure of canonical Wnt signaling was consistently similar in matched cancer cells and normal cells, even in the context of different cancers, different mutations, and different Wnt-related genes. Our results suggest that the cancer cells maintain a normal level of Wnt signaling by developing multiple mutations.

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

    International Nuclear Information System (INIS)

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

  5. Heterogeneity between triple negative breast cancer cells due to differential activation of Wnt and PI3K/AKT pathways.

    Science.gov (United States)

    Martínez-Revollar, Gabriela; Garay, Erika; Martin-Tapia, Dolores; Nava, Porfirio; Huerta, Miriam; Lopez-Bayghen, Esther; Meraz-Cruz, Noemí; Segovia, José; González-Mariscal, Lorenza

    2015-11-15

    The lack of a successful treatment for triple-negative breast cancer demands the study of the heterogeneity of cells that constitute these tumors. With this aim, two clones from triple negative breast MDA-MB-231 cancer cells were isolated: One with fibroblast-like appearance (F) and another with semi-epithelial (SE) morphology. Cells of the F clone have a higher migration and tumorigenesis capacity than SE cells, suggesting that these cells are in a more advanced stage of epithelial to mesenchymal transformation. In agreement, F cells have a diminished expression of the tight junction proteins claudins 1 and 4, and an increased content of β-catenin. The latter is due to an augmented activity of the canonical Wnt route and of the EGFR/PI3K/mTORC2/AKT pathway favoring the cytoplasmic accumulation of β-catenin and its transcriptional activity. In addition, F cells display increased phosphorylation of β-catenin at Tyr654 by Src. These changes favor in F cells, the over-expression of Snail that promotes EMT. Finally, we observe that both F and SE cells display markers of cancer stem cells, which are more abundant in the F clone.

  6. Roles of noncanonical Wnt/PCP pathway genes in neuronal migration and neurulation in zebrafish.

    Science.gov (United States)

    Wada, Hironori; Okamoto, Hitoshi

    2009-03-01

    Noncanonical Wnt/planar cell polarity (PCP) pathways regulate oriented cell movement during development in both Drosophila and vertebrates. Recent studies have revealed similarities and differences between these pathways in the tissues on which they act. In zebrafish, PCP pathway genes regulate the directional migration of a specific population of motor neurons in the hindbrain, as well as morphogenesis of the neuroepithelium. In the present review, neuronal and neuroepithelial defects in zebrafish PCP pathway mutants are compared, and the possible cellular and molecular mechanisms underlying these phenotypes are discussed. Future analyses of zebrafish PCP mutants will reveal the general mechanisms underlying the development of the neuroepithelium and provide novel insights into both conserved and diverse functions of PCP pathway genes in vertebrate development.

  7. Wnt5a Increases the Glycolytic Rate and the Activity of the Pentose Phosphate Pathway in Cortical Neurons

    Science.gov (United States)

    Cisternas, Pedro; Salazar, Paulina; Silva-Álvarez, Carmen; Barros, L. Felipe

    2016-01-01

    In the last few years, several reports have proposed that Wnt signaling is a general metabolic regulator, suggesting a role for this pathway in the control of metabolic flux. Wnt signaling is critical for several neuronal functions, but little is known about the correlation between this pathway and energy metabolism. The brain has a high demand for glucose, which is mainly used for energy production. Neurons use energy for highly specific processes that require a high energy level, such as maintaining the electrical potential and synthesizing neurotransmitters. Moreover, an important metabolic impairment has been described in all neurodegenerative disorders. Despite the key role of glucose metabolism in the brain, little is known about the cellular pathways involved in regulating this process. We report here that Wnt5a induces an increase in glucose uptake and glycolytic rate and an increase in the activity of the pentose phosphate pathway; the effects of Wnt5a require the intracellular generation of nitric oxide. Our data suggest that Wnt signaling stimulates neuronal glucose metabolism, an effect that could be important for the reported neuroprotective role of Wnt signaling in neurodegenerative disorders. PMID:27688915

  8. Identification of genes regulated by Wnt/β-catenin pathway and involved in apoptosis via microarray analysis

    International Nuclear Information System (INIS)

    Wnt/β-catenin pathway has critical roles in development and oncogenesis. Although significant progress has been made in understanding the downstream signaling cascade of this pathway, little is known regarding Wnt/β-catenin pathway modification of the cellular apoptosis. To identify potential genes regulated by Wnt/β-catenin pathway and involved in apoptosis, we used a stably integrated, inducible RNA interference (RNAi) vector to specific inhibit the expression and the transcriptional activity of β-catenin in HeLa cells. Meanwhile, we designed an oligonucleotide microarray covering 1384 apoptosis-related genes. Using oligonucleotide microarrays, a series of differential expression of genes was identified and further confirmed by RT-PCR. Stably integrated inducible RNAi vector could effectively suppress β-catenin expression and the transcriptional activity of β-catenin/TCF. Meanwhile, depletion of β-catenin in this manner made the cells more sensitive to apoptosis. 130 genes involved in some important cell-apoptotic pathways, such as PTEN-PI3K-AKT pathway, NF-κB pathway and p53 pathway, showed significant alteration in their expression level after the knockdown of β-catenin. Coupling RNAi knockdown with microarray and RT-PCR analyses proves to be a versatile strategy for identifying genes regulated by Wnt/β-catenin pathway and for a better understanding the role of this pathway in apoptosis. Some of the identified β-catenin/TCF directed or indirected target genes may represent excellent targets to limit tumor growth

  9. Knockdown of TC-1 enhances radiosensitivity of non-small cell lung cancer via the Wnt/β-catenin pathway

    Directory of Open Access Journals (Sweden)

    Dapeng Wu

    2016-04-01

    Full Text Available Thyroid cancer 1 (TC-1, C8ofr4 is widely expressed in vertebrates and associated with many kinds of tumors. Previous studies indicated that TC-1 functions as a positive regulator in the Wnt/β-catenin signaling pathway in non-small cell lung cancer (NSCLC. However, its exact role and regulation mechanism in radiosensitivity of NSCLC are still unclear. The expression level of TC-1 was measured by qRT-PCR and western blot in NSCLC cell lines. Proliferation and apoptosis of NSCLC cells in response to TC-1 knockdown or/and radiation were determined by MTT assay and flow cytometry, respectively. The activation of the Wnt/β-catenin signaling pathway was further examined by western blot in vitro and in vivo. Compared to TC-1 siRNA or radiotherapy alone, TC-1 silencing combined with radiation inhibited cell proliferation and induced apoptosis in NSCLC cell lines by inactivating of the Wnt/β-catenin signaling pathway. Furthermore, inhibition of the Wnt/β-catenin signaling pathway by XAV939, a Wnt/β-catenin signaling inhibitor, contributed to proliferation inhibition and apoptosis induction in NSCLC A549 cells. Combinative treatment of A549 xenografts with TC-1 siRNA and radiation caused significant tumor regression and inactivation of the Wnt/β-catenin signaling pathway relative to TC-1 siRNA or radiotherapy alone. The results from in vitro and in vivo studies indicated that TC-1 silencing sensitized NSCLC cell lines to radiotherapy through the Wnt/β-catenin signaling pathway.

  10. Bilobalide induces neuronal differentiation of P19 embryonic carcinoma cells via activating Wnt/β-catenin pathway.

    Science.gov (United States)

    Liu, Mei; Guo, Jingjing; Wang, Juan; Zhang, Luyong; Pang, Tao; Liao, Hong

    2014-08-01

    Bilobalide, a natural product extracted from Ginkgo biloba leaf, is known to exhibit a number of pharmacological activities. So far, whether it could affect embryonic stem cell differentiation is still unknown. The main aim of this study was to investigate the effect of bilobalide on P19 embryonic carcinoma cells differentiation and the underlying mechanisms. Our results showed that bilobalide induced P19 cells differentiation into neurons in a concentration- and time-dependent manner. We also found that bilobalide promoted neuronal differentiation through activation of Wnt/β-catenin signaling pathway. Exposure to bilobalide increased inactive GSK-3β phosphorylation, further induced the nuclear accumulation of β-catenin, and also up-regulated the expression of Wnt ligands Wnt1 and Wnt7a. Neuronal differentiation induced by bilobalide was totally abolished by XAV939, an inhibitor of Wnt/β-catenin pathway. These results revealed a novel role of bilobalide in neuronal differentiation from P19 embryonic cells acting through Wnt/β-catenin signaling pathway, which would provide a better insight into the beneficial effects of bilobalide in brain diseases.

  11. Transcriptional Analysis of Vitiligo Skin Reveals the Alteration of WNT Pathway: A Promising Target for Repigmenting Vitiligo Patients.

    Science.gov (United States)

    Regazzetti, Claire; Joly, Florence; Marty, Carine; Rivier, Michel; Mehul, Bruno; Reiniche, Pascale; Mounier, Carine; Rival, Yves; Piwnica, David; Cavalié, Marine; Chignon-Sicard, Bérengère; Ballotti, Robert; Voegel, Johannes; Passeron, Thierry

    2015-12-01

    Vitiligo affects 1% of the worldwide population. Halting disease progression and repigmenting the lesional skin represent the two faces of therapeutic challenge in vitiligo. We performed transcriptome analysis on lesional, perilesional, and non-depigmented skin from vitiligo patients and on matched skin from healthy subjects. We found a significant increase in CXCL10 in non-depigmented and perilesional vitiligo skin compared with levels in healthy control skin; however, neither CXCL10 nor other immune factors were deregulated in depigmented vitiligo skin. Interestingly, the WNT pathway, which is involved in melanocyte differentiation, was altered specifically in vitiligo skin. We demonstrated that oxidative stress decreases WNT expression/activation in keratinocytes and melanocytes. We developed an ex vivo skin model and confirmed the decrease activation of the WNT pathway in human skin subjected to oxidative stress. Finally, using pharmacological agents that activate the WNT pathway, we treated ex vivo depigmented skin from vitiligo patients and successfully induced differentiation of resident stem cells into pre-melanocytes. Our results shed light on the previously unrecognized role of decreased WNT activation in the prevention of melanocyte differentiation in depigmented vitiligo skin. Furthermore, these results support further clinical exploration of WNT agonists to repigment vitiligo lesions.

  12. 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

  13. Influence of Five Potential Anticancer Drugs on Wnt Pathway and Cell Survival in Human Biliary Tract Cancer Cells

    Directory of Open Access Journals (Sweden)

    Julia WACHTER, Daniel NEUREITER, Beate ALINGER, Martin PICHLER, Julia FUEREDER, Christian OBERDANNER, Pietro Di FAZIO, Matthias OCKER, Frieder BERR, Tobias KIESSLICH

    2012-01-01

    Full Text Available Background: The role of Wnt signalling in carcinogenesis suggests compounds targeting this pathway as potential anti-cancer drugs. Several studies report activation of Wnt signalling in biliary tract cancer (BTC thus rendering Wnt inhibitory drugs as potential candidates for targeted therapy of this highly chemoresistant disease.Methods: In this study we analysed five compounds with suggested inhibitory effects on Wnt signalling (DMAT, FH535, myricetin, quercetin, and TBB for their cytotoxic efficiency, mode of cell death, time- and cell line-dependent characteristics as well as their effects on Wnt pathway activity in nine different BTC cell lines.Results: Exposure of cancer cells to different concentrations of the compounds results in a clear dose-dependent reduction of viability for all drugs in the order FH535 > DMAT > TBB > myricetin > quercetin. The first three substances show high cytotoxicity in all tested cell lines, cause a direct cytotoxic effect by induction of apoptosis and inhibit pathway-specific signal transduction in a Wnt transcription factor reporter activity assay. Selected target genes such as growth-promoting cyclin D1 and the cell cycle progression inhibitor p27 are down- and up-regulated after treatment, respectively.Conclusions: Taken together, these data demonstrate that the small molecular weight inhibitors DMAT, F535 and TBB have a considerable cytotoxic and possibly Wnt-specific effect on BTC cell lines in vitro. Further in vivo investigation of these drugs as well as of new Wnt inhibitors may provide a promising approach for targeted therapy of this difficult-to-treat tumour.

  14. Wnt-10b promotes differentiation of skin epithelial cells in vitro

    International Nuclear Information System (INIS)

    To evaluate the role of Wnt-10b in epithelial differentiation, we investigated the effects of Wnt-10b on adult mouse-derived primary skin epithelial cells (MPSEC). Recombinant Wnt-10b protein (rWnt-10b) was prepared using a gene engineering technique and MPSEC were cultured in its presence, which resulted in morphological changes from cuboidal to spindle-shaped and inhibited their proliferation. Further, involvement of the canonical Wnt signal pathway was also observed. MPSEC treated with rWnt-10b showed characteristics of the hair shaft and inner root sheath of the hair follicle, in results of Ayoub Shklar staining and immunocytochemistry. Further, the cells expressed mRNA for differentiated epithelial cells, including keratin 1, keratin 2, loricrin, mHa5, and mHb5, in association with a decreased expression of the basal cell marker keratin 5. These results suggest that Wnt-10b promotes the differentiation of MPSEC

  15. Common Genetic Variants in Wnt Signaling Pathway Genes as Potential Prognostic Biomarkers for Colorectal Cancer

    OpenAIRE

    Wen-Chien Ting; Lu-Min Chen; Jiunn-Bey Pao; Ying-Pi Yang; Bang-Jau You; Ta-Yuan Chang; Yu-Hsuan Lan; Hong-Zin Lee; Bo-Ying Bao

    2013-01-01

    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 overa...

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

    Science.gov (United States)

    MacLean, Adam L; Harrington, Heather A; Stumpf, Michael P H; Byrne, Helen M

    2016-01-01

    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. PMID:26677193

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

    Directory of Open Access Journals (Sweden)

    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.

  18. Dibenzocyclooctadiene lignans, gomisins J and N inhibit the Wnt/{beta}-catenin signaling pathway in HCT116 cells

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Kyungsu; Lee, Kyung-Mi; Yoo, Ji-Hye; Lee, Hee Ju [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); Kim, Chul Young [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of); College of Pharmacy, Hanyang University, Ansan 426-791 (Korea, Republic of); Nho, Chu Won, E-mail: cwnho@kist.re.kr [Functional Food Center, Korea Institute of Science and Technology, Gangneung 210-340 (Korea, Republic of)

    2012-11-16

    Graphical abstract: Schematic diagram of the possible molecular mechanism underlying the inhibition of the Wnt/{beta}-catenin signaling pathway and the induction of G0/G1-phase arrest by gomisins J and N, derived from the fruits of S. chinensis, in HCT116 human colon cancer cells. Highlights: Black-Right-Pointing-Pointer Gomisins J and N inhibited Wnt/{beta}-catenin signaling pathway in HCT116 cells. Black-Right-Pointing-Pointer Gomisins J and N disrupted the binding of {beta}-catenin to specific DNA sequences, TBE. Black-Right-Pointing-Pointer Gomisins J and N inhibited the HCT116 cell proliferation through G0/G1 phase arrest. Black-Right-Pointing-Pointer Gomisins J and N inhibited the expression of Cyc D1, a Wnt/{beta}-catenin target gene. -- Abstract: Here, we report that gomisin J and gomisin N, dibenzocyclooctadiene type lignans isolated from Schisandra chinensis, inhibit Wnt/{beta}-catenin signaling in HCT116 cells. Gomisins J and N appear to inhibit Wnt/{beta}-catenin signaling by disrupting the interaction between {beta}-catenin and its specific target DNA sequences (TCF binding elements, TBE) rather than by altering the expression of the {beta}-catenin protein. Gomisins J and N inhibit HCT116 cell proliferation by arresting the cell cycle at the G0/G1 phase. The G0/G1 phase arrest induced by gomisins J and N appears to be caused by a decrease in the expression of Cyclin D1, a representative target gene of the Wnt/{beta}-catenin signaling pathway, as well as Cdk2, Cdk4, and E2F-1. Therefore, gomisins J and N, the novel Wnt/{beta}-catenin inhibitors discovered in this study, may serve as potential agents for the prevention and treatment of human colorectal cancers.

  19. 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.

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

    Science.gov (United States)

    Ting, Wen-Chien; Chen, Lu-Min; Pao, Jiunn-Bey; Yang, Ying-Pi; You, Bang-Jau; Chang, Ta-Yuan; Lan, Yu-Hsuan; Lee, Hong-Zin; Bao, Bo-Ying

    2013-01-01

    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. PMID:23405266

  1. XEDAR activates the non-canonical NF-κB pathway

    Energy Technology Data Exchange (ETDEWEB)

    Verhelst, Kelly, E-mail: Kelly.Verhelst@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Gardam, Sandra, E-mail: s.gardam@garvan.org.au [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Borghi, Alice, E-mail: Alice.Borghi@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Kreike, Marja, E-mail: Marja.Kreike@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Carpentier, Isabelle, E-mail: Isabelle.Carpentier@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium); Beyaert, Rudi, E-mail: Rudi.Beyaert@irc.VIB-UGent.be [Inflammation Research Center, Unit of Molecular Signal Transduction in Inflammation, VIB, Ghent (Belgium); Department of Biomedical Molecular Biology, Ghent University, Ghent (Belgium)

    2015-09-18

    Members of the tumor necrosis factor receptor (TNFR) superfamily are involved in a number of physiological and pathological responses by activating a wide variety of intracellular signaling pathways. The X-linked ectodermal dysplasia receptor (XEDAR; also known as EDA2R or TNFRSF27) is a member of the TNFR superfamily that is highly expressed in ectodermal derivatives during embryonic development and binds to ectodysplasin-A2 (EDA-A2), a member of the TNF family that is encoded by the anhidrotic ectodermal dysplasia (EDA) gene. Although XEDAR was first described in the year 2000, its function and molecular mechanism of action is still largely unclear. XEDAR has been reported to activate canonical nuclear factor κB (NF-κB) signaling and mitogen-activated protein (MAP) kinases. Here we report that XEDAR is also able to trigger the non-canonical NF-κB pathway, characterized by the processing of p100 (NF-κB2) into p52, followed by nuclear translocation of p52 and RelB. We provide evidence that XEDAR-induced p100 processing relies on the binding of XEDAR to TRAF3 and TRAF6, and requires the kinase activity of NIK and IKKα. We also show that XEDAR stimulation results in NIK accumulation and that p100 processing is negatively regulated by TRAF3, cIAP1 and A20. - Highlights: • XEDAR activates the non-canonical NF-κB pathway. • XEDAR-induced processing of p100 depends on XEDAR interaction with TRAF3 and TRAF6. • XEDAR-induced processing of p100 depends on NIK and IKKα activity. • Overexpression of XEDAR leads to NIK accumulation. • XEDAR-induced processing of p100 is negatively regulated by TRAF3 cIAP1 and A20.

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

    Science.gov (United States)

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

    2016-01-01

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

  3. Wnt/β-catenin signaling pathway is active in pancreatic development of rat embryo

    Institute of Scientific and Technical Information of China (English)

    Qi-Ming Wang; Ye Zhang; Kai-Ming Yang; Hong-Ying Zhou; Hui-Jun Yang

    2006-01-01

    AIM: To elucidate the role of Wnt/β-catenin signaling pathway in pancreatic development of rat embryo.METHODS: The mRNAs of β-catenin, APC, cyclin D1 genes were amplified by means of semiquantitative reverse transcription polymerase chain reaction (RTPCR) from embryonic pancreas in different periods and normal pancreas of rat, respectively. Protein expression of these genes in embryonic pancreas of E14.5-E18.5was examined by immunohistochemical method.RESULTS: In embryonic pancreas of E14.5, the transcript amplification of β-catenin and cyclinD1 genes was detected. In embryonic pancreas of E18.5, the transcription levels of β-catenin and cyclinD1 genes became much higher than in other periods. But in adult rat pancreas the transcription of cyclinD1 gene could not be observed. Only until E18.5, the transcript amplification of mRNA of APC gene could be detected.Surprisingly, the transcription level of APC gene became much higher in adult rat pancreas than in embryonic pancreas. By means of immunohistochemical staining,identical results were obtained to the above by RP-PCR,except for β-catenin protein in adult rat pancreas.CONCLUSION: Active Wnt/β-catenin signaling occursin rat embryonic pancreas and is probably important for pancreatic development and organ formation.

  4. Functional interaction of TCF4 with ATF5 to regulate the Wnt signaling pathway

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Wnt signaling directs cell-fate choices during embryonic development and tissue tumorigenesis. T cell factor 4 (TCF4) plays a pivotal role in the Wnt signaling pathway. We demonstrate that a specific protein-protein interaction occurs between TCF4 and ATF5 (activating transcription factor 5) -- a new member of cAMP response element binding protein (CREB) with the yeast two-hybrid system. The N-terminal and DNA binding domain of TCF4 (TCF4ND, 1-495 aa) and the C-terminal spanning bZIP domain of ATF5 (162-282 aa) were found to be responsible for the interaction, and the C-terminal of ATF5 (ATF5/C) showed a much stronger interaction with TCF4ND than the full-length of ATF5 by detecting the ?-gal activity. Furthermore, overexpression of ATF5/C enhanced transcriptional activation by TCF4 proteins in luciferase assay by transient transfection. Taken together, these data suggest that ATF5 may function as a co-activator to potentiate the ability of TCF4 to activate transcription.

  5. WNT-pathway components as predictive markers useful for diagnosis, prevention and therapy in inflammatory bowel disease and sporadic colorectal cancer

    OpenAIRE

    Serafino, Annalucia; Moroni, Noemi; Zonfrillo, Manuela; Andreola, Federica; Mercuri, Luana; Nicotera, Giuseppe; Nunziata, Joseph; Ricci, Riccardo; Antinori, Armando; Rasi, Guido; Pierimarchi, Pasquale

    2014-01-01

    The key role of the Wnt/β-catenin signaling in colorectal cancer (CRC) insurgence and progression is now recognized and several therapeutic strategies targeting this pathway are currently in developing. Wnt/β-catenin signaling not only dominates the early stages of sporadic colorectal cancer (SCC), but could also represent the connection between inflammatory bowel diseases (IBD) and increased risk of developing SCC. The knowledge on the sequential molecular events of Wnt-signaling cascade in ...

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Institute of Scientific and Technical Information of China (English)

    Kai Gao; Yan-song Wang; Ya-jiang Yuan; Zhang-hui Wan; Tian-chen Yao; Hai-hong Li; Pei-fu Tang; Xi-fan Mei

    2015-01-01

    The Wnt/β-catenin signaling pathway plays a crucial role in neural development, axonal guid-ance, 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 intraper-itoneally injecting spinal cord injured rats with rapamycin over 2 days. Western blot analysis and immunolfuorescence staining were used to detect the expression levels ofβ-catenin protein, ca-spase-3 protein and brain-derived neurotrophic factor protein, components of the Wnt/β-catenin signaling pathway. Rapamycin increased the levels ofβ-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 ifndings suggest that the neuroprotective effect of rapamycin intervention is me-diated through activation of the Wnt/β-catenin signaling pathway after spinal cord injury.

  8. Gpr48 deficiency induces polycystic kidney lesions and renal fibrosis in mice by activating Wnt signal pathway.

    Directory of Open Access Journals (Sweden)

    Yongyan Dang

    Full Text Available G protein-coupled receptor 48 (Gpr48/Lgr4 is essential to regulate the development of multiple tissues in mice. The notion that Gpr48 functions in renal development prompted us to investigate the relation between Gpr48 and renal diseases. Using a Gpr48 knockout mice model, we observed that 66.7% Gpr48 null mice developed polycystic lesions in the kidney, while no cysts were observed in the kidneys of wild-type mice. Polycystic kidney disease 1 (PKD1 and PKD2 expressions were also markedly decreased in the Gpr48 knockout mice. Abnormal expressions of exra-cellular matrix protein lead to the progression of polycystic kidney disease and the formation of renal fibrosis in the Gpr48 null mice. The expressions of several Wnt molecules and its receptors were increased and marked β-catenin nuclear accumulation was observed in the Gpr48 null mice. The inhibitors of Wnt/β-catenin signal pathway such as GSK3β and axin2 were loss of function. The Wnt/PCP signaling pathway is also activated in Gpr48 null mice. However, TGF-β expression and phosphorylated Smad2/3 levels were not altered. Collectively, our results showed that Gpr48 null mice are at a greater risk of suffering from polycystic lesions and renal fibrosis. Moreover, the formation of polycystic lesions and renal fibrosis induced by Gpr48 deficiency involves the activation of Wnt signaling pathway but not the TGF-β/Smad pathway.

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  11. 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

  12. Effect of micro-nano-hybrid structured hydroxyapatite bioceramics on osteogenic and cementogenic differentiation of human periodontal ligament stem cell via Wnt signaling pathway

    Directory of Open Access Journals (Sweden)

    Mao LX

    2015-11-01

    -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.Keywords: surface topography, periodontal ligament stem cells, Wnt signaling pathway, bioceramics, periodontal reconstruction

  13. MicroRNA-214 controls skin and hair follicle development by modulating the activity of the Wnt pathway.

    Science.gov (United States)

    Ahmed, Mohammed I; Alam, Majid; Emelianov, Vladimir U; Poterlowicz, Krzysztof; Patel, Ankit; Sharov, Andrey A; Mardaryev, Andrei N; Botchkareva, Natalia V

    2014-11-24

    Skin development is governed by complex programs of gene activation and silencing, including microRNA-dependent modulation of gene expression. Here, we show that miR-214 regulates skin morphogenesis and hair follicle (HF) cycling by targeting β-catenin, a key component of the Wnt signaling pathway. miR-214 exhibits differential expression patterns in the skin epithelium, and its inducible overexpression in keratinocytes inhibited proliferation, which resulted in formation of fewer HFs with decreased hair bulb size and thinner hair production. The inhibitory effects of miR-214 on HF development and cycling were associated with altered activities of multiple signaling pathways, including decreased expression of key Wnt signaling mediators β-catenin and Lef-1, and were rescued by treatment with pharmacological Wnt activators. Finally, we identify β-catenin as one of the conserved miR-214 targets in keratinocytes. These data provide an important foundation for further analyses of miR-214 as a key regulator of Wnt pathway activity and stem cell functions during normal tissue homeostasis, regeneration, and aging.

  14. MicroRNA-214 controls skin and hair follicle development by modulating the activity of the Wnt pathway.

    Science.gov (United States)

    Ahmed, Mohammed I; Alam, Majid; Emelianov, Vladimir U; Poterlowicz, Krzysztof; Patel, Ankit; Sharov, Andrey A; Mardaryev, Andrei N; Botchkareva, Natalia V

    2014-11-24

    Skin development is governed by complex programs of gene activation and silencing, including microRNA-dependent modulation of gene expression. Here, we show that miR-214 regulates skin morphogenesis and hair follicle (HF) cycling by targeting β-catenin, a key component of the Wnt signaling pathway. miR-214 exhibits differential expression patterns in the skin epithelium, and its inducible overexpression in keratinocytes inhibited proliferation, which resulted in formation of fewer HFs with decreased hair bulb size and thinner hair production. The inhibitory effects of miR-214 on HF development and cycling were associated with altered activities of multiple signaling pathways, including decreased expression of key Wnt signaling mediators β-catenin and Lef-1, and were rescued by treatment with pharmacological Wnt activators. Finally, we identify β-catenin as one of the conserved miR-214 targets in keratinocytes. These data provide an important foundation for further analyses of miR-214 as a key regulator of Wnt pathway activity and stem cell functions during normal tissue homeostasis, regeneration, and aging. PMID:25422376

  15. Promoting neurogenesis via Wnt/β-catenin signaling pathway accounts for the neurorestorative effects of morroniside against cerebral ischemia injury.

    Science.gov (United States)

    Sun, Fang-Ling; Wang, Wen; Zuo, Wei; Xue, Jin-Long; Xu, Jing-dong; Ai, Hou-Xi; Zhang, Li; Wang, Xiao-Min; Ji, Xun-Ming

    2014-09-01

    Ischemic stroke is a leading cause of mortality and permanent disability in adults worldwide. Neurogenesis triggered by ischemia in the adult mammalian brain may provide insights into stroke treatment. Morroniside is an active component of sarcocarp of C. officinalis that have shown neuroprotective effects. The aim of the present study is to test whether morroniside promotes neurogenesis via Wnt/β-catenin signaling pathway for brain recovery in a rat model of focal cerebral ischemia. Morroniside was administered intragastrically once daily at the concentrations of 30, 90 and 270 mg/kg for 7 days post-ischemia. Neurological functions were detected by Ludmila Belayev score tests. Endogenous neural stem cells responses were investigated with immunofluorescence staining of Ki-67 and Nestin to identify the neurogenesis in the subventricular zone (SVZ). The expression of proteins involved in and related to Wnt/β-catenin signaling pathway was detected by western blotting analysis. Morroniside significantly promoted neurogenesis for brain recovery 7 days post-ischemia. Increased expression of Wnt 3a, β-catenin and T-cell transcription factor-4 (Tcf-4), along with activation of downstream transcription factors Pax6 and neurogenin2 (Ngn2), indicated that the neurorestorative effects of morroniside may be associated with Wnt/β-catenin signaling pathway. These data provide support for understanding the mechanisms of morroniside in neurorestorative effects and suggest a potential new strategy for ischemic stroke treatment. PMID:24876057

  16. 1,25-Vitamin-D3 Promotes Cardiac Differentiation through Modulation of the Wnt Signaling Pathway

    OpenAIRE

    Hlaing, Su M.; Garcia, Leah A.; Contreras, Jaime R.; Norris, Keith C.; Ferrini, Monica G.; Artaza, Jorge N.

    2014-01-01

    Cardiovascular disease (CV) remains the leading cause of death worldwide. Low levels of vitamin D are associated with high risk of myocardial infarction, even after controlling for factors associated with coronary artery disease. A growing body of evidence suggests that vitamin D plays an important role in CV related signaling pathways. However, little is known about the molecular mechanism by which vitamin D modulates cardiac development. The Wnt signaling pathway plays a pivotal role in tis...

  17. The Wnt/β-catenin signaling pathway is involved in the antitumor effect of fulvestrant on rat prolactinoma MMQ cells.

    Science.gov (United States)

    Cao, Lei; Gao, Hua; Li, Ping; Gui, Songbai; Zhang, Yazhuo

    2014-06-01

    Although an antiestrogen treatment for estrogen-dependent diseases, such as breast cancers, has been reported, the effect of this endocrine therapy on prolactinomas and its possible mechanism are unclear. This study investigates the antitumor effect of fulvestrant, which is a new estrogen receptor antagonist, on rat prolactinoma MMQ cells and the possible roles of the Wnt/β-catenin signaling pathway that is involved in this antitumor effect. To investigate the antitumor effect of fulvestrant, the effects of exposure to gradient doses of fulvestrant (0, 0.04, 1, 25, and 625 nM) on the proliferation of cells and the secretion of prolactin (PRL) were studied. Then, the expression levels of the Wnt/β-catenin signaling pathway-related proteins β-catenin and Wnt inhibitory factor-1 (WIF-1) were measured to investigate their possible roles in the antitumor effect of fulvestrant. The cells were also treated with decitabine (10 μM) to investigate the epigenetic mechanism of WIF-1 expression. The proliferation of MMQ cells and the secretion of PRL were suppressed by fulvestrant in a dose-dependent manner (up to 57.0 ± 3.9 % and 51.2 ± 4.9 %, respectively). β-Catenin expression was downregulated and was positively correlated with ER-α expression (PWIF-1 expression was upregulated and was negatively correlated with ER-α expression (PWIF-1 expression was upregulated via the hypomethylation of the promoter by decitabine, and cellular proliferation was correspondingly suppressed (37.8 ± 4.3 %). Antitumor effect of fulvestrant was partially disrupted by SB 216763 via activation of the Wnt/β-catenin pathway. In conclusion, through the Wnt/β-catenin signaling pathway, fulvestrant can suppress the proliferation of MMQ cells and the secretion of PRL. PMID:24643679

  18. Blocking the Wnt/β-Catenin Pathway by Lentivirus-Mediated Short Hairpin RNA Targeting β-Catenin Gene Suppresses Silica-Induced Lung Fibrosis in Mice

    OpenAIRE

    Xin Wang; Wujing Dai; Yanrang Wang; Qing Gu; Deyi Yang; Ming Zhang

    2015-01-01

    Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. While the pathogenesis of silicosis is not clearly understood, the Wnt/β-catenin signaling pathway is thought to play a major role in lung fibrosis. To explore the role of Wnt/β-catenin pathway in silicosis, we blocked Wnt/β-catenin pathway both in silica-treated MLE-12 cells (a mouse pulmonary epithelial cell line) and in a mouse silicosis model by using a lentiviral vector expressing a short ha...

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

    Directory of Open Access Journals (Sweden)

    Zhao Yu

    2012-09-01

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

  20. 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.

  1. BMP-2-enhanced chondrogenesis involves p38 MAPK-mediated down-regulation of Wnt-7a pathway.

    Science.gov (United States)

    Jin, Eun-Jung; Lee, Sun-Young; Choi, Young-Ae; Jung, Jae-Chang; Bang, Ok-Sun; Kang, Shin-Sung

    2006-12-31

    The bone morphogenetic protein (BMP) family has been implicated in control of cartilage development. Here, we demonstrate that BMP-2 promotes chondrogenesis by activating p38 mitogen-activated protein kinase (MAPK), which in turn downregulates Wnt-7a/b-catenin signaling responsible for proteasomal degradation of Sox9. Exposure of mesenchymal cells to BMP-2 resulted in upregulation of Sox9 protein and a concomitant decrease in the level of b-catenin protein and Wnt-7a signaling. In agreement with this, the interaction of Sox9 with b-catenin was inhibited in the presence of BMP-2. Inhibition of the p38 MAPK pathway using a dominant negative mutant led to sustained Wnt-7a signaling and decreased Sox9 expression, with consequent inhibition of precartilage condensation and chondrogenic differentiation. Moreover, overexpression of b-catenin caused degradation of Sox9 via the ubiquitin/26S proteasome pathway. Our results collectively indicate that the increase in Sox9 protein resulting from downregulation of b-catenin/Wnt-7a signaling is mediated by p38 MAPK during BMP-2 induced chondrogenesis in chick wing bud mesenchymal cells. PMID:17202865

  2. Wnt, Frizzled, and sFRP gene expression patterns during gastrulation in the starfish Patiria (Asterina) pectinifera.

    Science.gov (United States)

    Kawai, Narudo; Kuraishi, Ritsu; Kaneko, Hiroyuki

    2016-05-01

    By the initial phase of gastrulation, Wnt pathway regulation mediates endomesoderm specification and establishes the animal-vegetal axis, thereby leading to proper gastrulation in starfish. To provide insight into the ancestral mechanism regulating deuterostome gastrulation, we identified the gene expression patterns of Wnt, Frizzled (Fz), and secreted frizzled-related protein (sFRP) family genes, which play a role in the initial stage of the Wnt pathway, in starfish Patiria (Asterina) pectinifera embryos using whole mount in situ hybridization. We identified ten Wnt, four Fz, and two sFRP paralogues. From the hatching blastula to the late gastrula stage, the majority of the Wnt genes and both Fz5/8 and sFRP1/5 were expressed in the posterior and anterior half of the embryo, respectively. Wnt8, Fz1, and Fz4 showed restricted expression in the lateral ectoderm. On the other hand, several genes were expressed de novo in the restricted domain of the archenteron at the late gastrula stage. These results suggest that the canonical and/or non-canonical Wnt pathway might implicate endomesoderm specification, anterior-posterior axis establishment, anterior-posterior patterning, and archenteron morphogenesis in the developmental context of starfish embryos. From comparison with the expression patterns observed in Patria miniata, we consider that the Wnt pathway is conserved among starfishes.

  3. Involvement of Wnt, Eda and Shh at defined stages of sweat gland development.

    Science.gov (United States)

    Cui, Chang-Yi; Yin, Mingzhu; Sima, Jian; Childress, Victoria; Michel, Marc; Piao, Yulan; Schlessinger, David

    2014-10-01

    To maintain body temperature, sweat glands develop from embryonic ectoderm by a poorly defined mechanism. We demonstrate a temporal cascade of regulation during mouse sweat gland formation. Sweat gland induction failed completely when canonical Wnt signaling was blocked in skin epithelium, and was accompanied by sharp downregulation of downstream Wnt, Eda and Shh pathway genes. The Wnt antagonist Dkk4 appeared to inhibit this induction: Dkk4 was sharply downregulated in β-catenin-ablated mice, indicating that it is induced by Wnt/β-catenin; however, its overexpression repressed Wnt target genes and significantly reduced gland numbers. Eda signaling succeeded Wnt. Wnt signaling was still active and nascent sweat gland pre-germs were still seen in Eda-null mice, but the pre-germs failed to develop further and the downstream Shh pathway was not activated. When Wnt and Eda were intact but Shh was ablated, germ induction and subsequent duct formation occurred normally, but the final stage of secretory coil formation failed. Thus, sweat gland development shows a relay of regulatory steps initiated by Wnt/β-catenin - itself modulated by Dkk4 - with subsequent participation of Eda and Shh pathways. PMID:25249463

  4. CAFET algorithm reveals Wnt/PCP signature in lung squamous cell carcinoma.

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    Yue Hu

    Full Text Available We analyzed the gene expression patterns of 138 Non-Small Cell Lung Cancer (NSCLC samples and developed a new algorithm called Coverage Analysis with Fisher's Exact Test (CAFET to identify molecular pathways that are differentially activated in squamous cell carcinoma (SCC and adenocarcinoma (AC subtypes. Analysis of the lung cancer samples demonstrated hierarchical clustering according to the histological subtype and revealed a strong enrichment for the Wnt signaling pathway components in the cluster consisting predominantly of SCC samples. The specific gene expression pattern observed correlated with enhanced activation of the Wnt Planar Cell Polarity (PCP pathway and inhibition of the canonical Wnt signaling branch. Further real time RT-PCR follow-up with additional primary tumor samples and lung cancer cell lines confirmed enrichment of Wnt/PCP pathway associated genes in the SCC subtype. Dysregulation of the canonical Wnt pathway, characterized by increased levels of β-catenin and epigenetic silencing of negative regulators, has been reported in adenocarcinoma of the lung. Our results suggest that SCC and AC utilize different branches of the Wnt pathway during oncogenesis.

  5. Effect of tripterygium glycosides on Wnt/Frizzled signaling pathway in imiquimod-induced psoriasis-like mice

    Institute of Scientific and Technical Information of China (English)

    Xiu-Qing Liu; Zhuo-Cheng Li; Wen-Zhong Wu

    2016-01-01

    ABSTRACT Objective:To study the effect of tripterygium glycosides on Wnt/Frizzled signaling pathway in imiquimod-induced psoriasis-like mice.Methods:BALB/c female mice were selected as research objects and randomly divided into control group, model group and intervention group, model group and intervention group established the models of imiquimod-induced psoriasis-like mice, and intervention group received intragastric administration of tripterygium glycosides after establishment of models. Psoriasis lesion tissue was collected to detect the contents of Wnt/Frizzled signal molecules and downstream related molecules.Results:Wnt5a, Frizzled2, Frizzled3, Frizzled5, Frizzled6, NFAT, COX-2, VEGF, MIF, IFN-γ, IL-6, IL-17, IL-21, IL-23, JAK1, STAT3, Rsa, Raf, MEK, ERK1 and EKR2 contents in skin lesion tissue of model group were significantly higher than those of control group, cGMP and PKG contents were significantly lower than those of control group, and Frizzled4 content was not different from that of control group; Wnt5a, Frizzled2, Frizzled3, Frizzled5, Frizzled6, NFAT, COX-2, VEGF, MIF, IFN-γ, IL-6, IL-17, IL-21, IL-23, JAK1, STAT3, Rsa, Raf, MEK, ERK1 and EKR2 contents in skin lesion tissue of intervention group were significantly lower than those of model group, cGMP and PKG contents were significantly higher than those of model group, and Frizzled4 content was not different from that of model group.Conclusions:Tripterygium glycosides have inhibitory effect on the signaling pathway mediated by Wnt5a-Frizzled2/Frizzled3/Frizzled5/Frizzled6 in skin lesions of imiquimod-induced psoriasis-like mice.

  6. Wnt induction of chondrocyte hypertrophy through the Runx2 transcription factor.

    Science.gov (United States)

    Dong, Yu-Feng; Soung, Do Y; Schwarz, Edward M; O'Keefe, Regis J; Drissi, Hicham

    2006-07-01

    We investigated the molecular mechanisms underlying canonical Wnt-mediated regulation of chondrocyte hypertrophy using chick upper sternal chondrocytes. Replication competent avian sarcoma (RCAS) viral over-expression of Wnt8c and Wnt9a, upregulated type X collagen (col10a1) and Runx2 mRNA expression thereby inducing chondrocyte hypertrophy. Wnt8c and Wnt9a strongly inhibited mRNA levels of Sox9 and type II collagen (col2a1). Wnt8c further enhanced canonical bone morphogenetic proteins (BMP-2)-induced expression of Runx2 and col10a1 while Wnt8c and Wnt9a inhibited TGF-beta-induced expression of Sox9 and col2a1. Over-expression of beta-catenin mimics the effect of Wnt8c and Wnt9a by upregulating Runx2, col10a1, and alkaline phosphatase (AP) mRNA levels while it inhibits col2a1 transcription. Western blot analysis shows that Wnt8c and beta-catenin also induces Runx2 protein levels in chondrocytes. Thus, our results indicate that activation of the canonical beta-catenin Wnt signaling pathway induces chondrocyte hypertrophy and maturation. We further investigated the effects of beta-catenin-TCF/Lef on Runx2 promoter. Co-transfection of lymphoid enhancer factor (Lef1) and beta-catenin in chicken upper sternal chondrocytes together with deletion constructs of the Runx2 promoter shows that the proximal region spanning the first 128 base pairs of this promoter is responsible for the Wnt-mediated induction of Runx2. Mutation of the TCF/Lef binding site in the -128 fragment of the Runx2 promoter resulted in loss of its responsiveness to beta-catenin. Additionally, gel-shift assay analyses determined the DNA/protein interaction of the TCF/Lef binding sites on the Runx2 promoter. Finally, our site-directed mutagenesis data demonstrated that the Runx2 site on type X collagen promoter is required for canonical Wnt induction of col10a1. Altogether we demonstrate that Wnt/beta-catenin signaling is regulated by TGF-beta and BMP-2 in chick upper sternal chondrocytes, and mediates

  7. Stem cell signaling as a target for novel drug discovery: recent progress in the WNT and Hedgehog pathways

    Institute of Scientific and Technical Information of China (English)

    Songzhu Michael AN; Qiang Peter DING; Ling-song LI

    2013-01-01

    One of the most exciting fields in biomedical research over the past few years is stem cell biology,and therapeutic application of stem cells to replace the diseased or damaged tissues is also an active area in development.Although stem cell therapy has a number of technical challenges and regulatory hurdles to overcome,the use of stem cells as tools in drug discovery supported by mature technologies and established regulatory paths is expected to generate more immediate returns.In particular,the targeting of stem cell signaling pathways is opening up a new avenue for drug discovery.Aberrations in these pathways result in various diseases,including cancer,fibrosis and degenerative diseases.A number of drug targets in stem cell signaling pathways have been identified.Among them,WNT and Hedgehog are two most important signaling pathways,which are the focus of this review.A hedgehog pathway inhibitor,vismodegib (Erivedge),has recently been approved by the US FDA for the treatment of skin cancer,while several drug candidates for the WNT pathway are entering clinical trials.We have discovered that the stem cell signaling pathways respond to traditional Chinese medicines.Substances isolated from herbal medicine may act specifically on components of stem cell signaling pathways with high affinities.As many of these events can be explained through molecular interactions,these phenomena suggest that discovery of stem cell-targeting drugs from natural products may prove to be highly successful.

  8. hcrcn81 promotes cell proliferation through Wnt signaling pathway in colorectal cancer.

    Science.gov (United States)

    Chen, Yao; Jiang, Tingting; Shi, Lihong; He, Kunyan

    2016-01-01

    The objective of the study was to investigate the role of hcrcn81 gene in Wnt/β-catenin signaling pathway related to human colorectal cancer. A total of 30 pairs of human colorectal cancer tissues with control normal tissues were analyzed by qRT-PCR. The proliferation, apoptosis, cell cycle, cell colony and metastasis of LS174T(-hcrcn81), HCT116(-hcrcn81), LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) cells were tested, of which hcrcn81 was knockdown in LS174T, HCT116 cells and hcrcn81 was overexpressed in LoVo, SMMC-7721 cells. Besides, the mRNA and protein levels of hcrcn81, β-catenin, c-Myc, cyclinD1, GSK-3β and survivin in colon cancer cell lines were evaluated by qRT-PCR and western blot. The mRNA levels of β-catenin and Survivin were up-regulated in 76.7 % (23/30) and 63.3 % (19/30) of the tumor samples, respectively. hcrcn81 and GSK-3β mRNA expression levels were down-regulated in 20/30 (66.7 %) and 21/30 (70.0 %) of the tumor samples as compared to the adjacent normal tissues, respectively. Furthermore, in LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) cells, the mRNA and protein levels of β-catenin, c-Myc, cyclinD1 and Survivin were up-regulated, whereas those of GSK-3 were down-regulated. In LS174T(-hcrcn81) and HCT116(-hcrcn81) cells, the mRNA levels of β-catenin, c-Myc, cyclinD1 and Survivin were down-regulated, whereas GSK-3βmRNA was up-regulated. Cell proliferation in LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) groups was significantly enhanced (P LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) groups was significantly higher than that in the control groups (P LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) cells were significantly higher than that in the control groups (P LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) groups were significantly lower than that in the control groups (P LoVo(+hcrcn81) and SMMC-7721(+hcrcn81) groups than that in the control group (P < 0.05). hcrcn81 might promote carcinogenesis and progression through regulation of the Wnt/β-catenin signaling

  9. Association of Wnt signaling pathway genetic variants in gallbladder cancer susceptibility and survival.

    Science.gov (United States)

    Yadav, Anu; Gupta, Annapurna; Yadav, Saurabh; Rastogi, Neeraj; Agrawal, Sushma; Kumar, Ashok; Kumar, Vijay; Misra, Sanjeev; Mittal, Balraj

    2016-06-01

    Gallbladder cancer (GBC) is the most common malignancy of the biliary tract with adverse prognosis and poor survival. Wnt signaling plays an important role in embryonic development and regeneration of tissues in all the species. Deregulation of expression and mutations in this pathway may lead to disease state such as cancer. In this study, we assessed the association of common germline variants of Wnt pathway genes (SFRP2, SFRP4, DKK2, DKK3, WISP3, APC, β-catenin, AXIN-2, GLI-1) to evaluate their contribution in predisposition to GBC and treatment outcomes. The study included 564 GBC patients and 250 controls. Out of 564, 200 patients were followed up for treatment response and survival. Tumor response (RECIST 1.1) was recorded in 116 patients undergoing non-adjuvant chemotherapy (NACT). Survival was assessed by Kaplan-Meier curve and Cox-proportional hazard regression. Single locus analysis showed significant association of SFRP4 rs1802073G > T [p value = 0.0001], DKK2 rs17037102C > T [p value = 0.0001], DKK3 rs3206824C > T [p value = 0.012], APC rs4595552 A/T [p value = 0.021], APC rs11954856G > T [p value = 0.047], AXIN-2 rs4791171C > T [p value = 0.001], β-catenin rs4135385A > G [p value = 0.031], and GLI-1 rs222826C > G [p value = 0.001] with increased risk of GBC. Gene-gene interaction using GMDR analysis predicted APC rs11954856 and AXIN2 rs4791171 as significant in conferring GBC susceptibility. Cox-proportional hazard model showed GLI-1 rs2228226 CG/GG and AXIN-2 rs4791171 TT genotype higher hazard ratio. In recursive partitioning, AXIN-2 rs4791171 TT genotype showed higher mortality and hazard. Most of studied genetic variants influence GBC susceptibility. APC rs11954856, GLI-1 rs2228226, and AXIN-2 rs4791171 were found to be associated with poor survival in advanced GBC patients. PMID:26715268

  10. Wnt5a regulates midbrain dopaminergic axon growth and guidance.

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    Brette D Blakely

    Full Text Available During development, precise temporal and spatial gradients are responsible for guiding axons to their appropriate targets. Within the developing ventral midbrain (VM the cues that guide dopaminergic (DA axons to their forebrain targets remain to be fully elucidated. Wnts are morphogens that have been identified as axon guidance molecules. Several Wnts are expressed in the VM where they regulate the birth of DA neurons. Here, we describe that a precise temporo-spatial expression of Wnt5a accompanies the development of nigrostriatal projections by VM DA neurons. In mice at E11.5, Wnt5a is expressed in the VM where it was found to promote DA neurite and axonal growth in VM primary cultures. By E14.5, when DA axons are approaching their striatal target, Wnt5a causes DA neurite retraction in primary cultures. Co-culture of VM explants with Wnt5a-overexpressing cell aggregates revealed that Wnt5a is capable of repelling DA neurites. Antagonism experiments revealed that the effects of Wnt5a are mediated by the Frizzled receptors and by the small GTPase, Rac1 (a component of the non-canonical Wnt planar cell polarity pathway. Moreover, the effects were specific as they could be blocked by Wnt5a antibody, sFRPs and RYK-Fc. The importance of Wnt5a in DA axon morphogenesis was further verified in Wnt5a-/- mice, where fasciculation of the medial forebrain bundle (MFB as well as the density of DA neurites in the MFB and striatal terminals were disrupted. Thus, our results identify a novel role of Wnt5a in DA axon growth and guidance.

  11. MicroRNA-214 controls skin and hair follicle development by modulating the activity of the Wnt pathway

    OpenAIRE

    Ahmed, Mohammed I.; Alam, Majid; Emelianov, Vladimir U.; Poterlowicz, Krzysztof; Patel, Ankit; Sharov, Andrey A.; Mardaryev, Andrei N.; Botchkareva, Natalia V.

    2014-01-01

    Skin development is governed by complex programs of gene activation and silencing, including microRNA-dependent modulation of gene expression. Here, we show that miR-214 regulates skin morphogenesis and hair follicle (HF) cycling by targeting β-catenin, a key component of the Wnt signaling pathway. miR-214 exhibits differential expression patterns in the skin epithelium, and its inducible overexpression in keratinocytes inhibited proliferation, which resulted in formation of fewer HFs with de...

  12. Wnt/β-catenin信号通路在胚胎着床和发育中的作用%Role of Wnt/β-catenin Signaling Pathway in Embryo Implantation and Development

    Institute of Scientific and Technical Information of China (English)

    谢宝国; 朱伟杰

    2013-01-01

    Wnt/β-catenin信号通路作为经典的Wnt信号转导通路参与调控细胞增殖、凋亡和分化等多种生物学过程.在胚胎着床和发育过程中,Wnt/β-catenin信号通路失活或其受体、配体的异常表达均可引起胚胎着床失败、器官分化异常、发育畸形甚至死亡.%Wnt/β-catenin signaling pathway is one of the classical Wnt signaling pathways involved in a variety of biological processes,such as cell proliferation,apoptosis and differentiation.Under physiological conditions,this pathway plays a role on embryonic implantation and development by improving cell proliferation and differentiation.On the other hand,the inactivation of Wnt/β-catenin signaling pathway or abnormal expressions of its receptors and ligands can cause implantation failure,organ maldifferentiation,embryonic malformation and even death.

  13. Mesenchymal Stem Cells Increase Hippocampal Neurogenesis and Neuronal Differentiation by Enhancing the Wnt Signaling Pathway in an Alzheimer's Disease Model.

    Science.gov (United States)

    Oh, Se Hee; Kim, Ha Na; Park, Hyun-Jung; Shin, Jin Young; Lee, Phil Hyu

    2015-01-01

    Neurogenesis in the subgranular zone of the hippocampal dentate gyrus may act as an endogenous repair mechanism in Alzheimer's disease (AD), and the Wnt signaling pathway has been suggested to closely modulate neurogenesis in amyloid-β (Aβ)-related AD models. The present study investigated whether mesenchymal stem cells (MSCs) would modulate hippocampal neurogenesis via modulation of the Wnt signaling pathway in a model of AD. In Aβ-treated neuronal progenitor cells (NPCs), the coculture with MSCs increased significantly the expression of Ki-67, GFAP, SOX2, nestin, and HuD compared to Aβ treatment alone. In addition, MSC treatment in Aβ-treated NPCs enhanced the expression of β-catenin and Ngn1 compared to Aβ treatment alone. MSC treatment in Aβ-treated animals significantly increased the number of BrdU-ir cells in the hippocampus at 2 and 4 weeks compared to Aβ treatment alone. In addition, quantitative analysis showed that the number of BrdU and HuD double-positive cells in the dentate gyrus was significantly higher in the MSC-treated group than in controls or after Aβ treatment alone. These results demonstrate that MSC administration significantly augments hippocampal neurogenesis and enhances the differentiation of NPCs into mature neurons in AD models by augmenting the Wnt signaling pathway. The use of MSCs to modulate endogenous adult neurogenesis may have a significant impact on future strategies for AD treatment.

  14. Calycosin-7-O-β-d-glucopyranoside stimulates osteoblast differentiation through regulating the BMP/WNT signaling pathways

    Directory of Open Access Journals (Sweden)

    Jing Jian

    2015-09-01

    Full Text Available The isoflavone calycosin-7-O-β-d-glucopyranoside (CG is a principal constituent of Astragalus membranaceus (AR and has been reported to inhibit osteoclast development in vitro and bone loss in vivo. The aim of this study was to investigate the osteogenic effects of CG and its underlying mechanism in ST2 cells. The results show that exposure of cells to CG in osteogenic differentiation medium increases ALP activity, osteocalcin (Ocal mRNA expression and the osteoblastic mineralization process. Mechanistically, CG treatment increased the expression of bone morphogenetic protein 2 (BMP-2, p-Smad 1/5/8, β-catenin and Runx2, all of which are regulators of the BMP- or wingless-type MMTV integration site family (WNT/β-catenin-signaling pathways. Moreover, the osteogenic effects of CG were inhibited by Noggin and DKK-1 which are classical inhibitors of the BMP and WNT/β-catenin-signaling pathways, respectively. Taken together, the results indicate that CG promotes the osteoblastic differentiation of ST2 cells through regulating the BMP/WNT signaling pathways. On this basis, CG may be a useful lead compound for improving the treatment of bone-decreasing diseases and enhancing bone regeneration.

  15. WNT16B is a new marker of cellular senescence that regulates p53 activity and the phosphoinositide 3-kinase/AKT pathway.

    Science.gov (United States)

    Binet, Romuald; Ythier, Damien; Robles, Ana I; Collado, Manuel; Larrieu, Delphine; Fonti, Claire; Brambilla, Elisabeth; Brambilla, Christian; Serrano, Manuel; Harris, Curtis C; Pedeux, Rémy

    2009-12-15

    Senescence is a tumor suppression mechanism that is induced by several stimuli, including oncogenic signaling and telomere shortening, and controlled by the p53/p21(WAF1) signaling pathway. Recently, a critical role for secreted factors has emerged, suggesting that extracellular signals are necessary for the onset and maintenance of senescence. Conversely, factors secreted by senescent cells may promote tumor growth. By using expression profiling techniques, we searched for secreted factors that were overexpressed in fibroblasts undergoing replicative senescence. We identified WNT16B, a member of the WNT family of secreted proteins. We found that WNT16B is overexpressed in cells undergoing stress-induced premature senescence and oncogene-induced senescence in both MRC5 cell line and the in vivo murine model of K-Ras(V12)-induced senescence. By small interfering RNA experiments, we observed that both p53 and WNT16B are necessary for the onset of replicative senescence. WNT16B expression is required for the full transcriptional activation of p21(WAF1). Moreover, WNT16B regulates activation of the phosphoinositide 3-kinase (PI3K)/AKT pathway. Overall, we identified WNT16B as a new marker of senescence that regulates p53 activity and the PI3K/AKT pathway and is necessary for the onset of replicative senescence.

  16. Matrix metalloproteinase-10 regulates stemness of ovarian cancer stem-like cells by activation of canonical Wnt signaling and can be a target of chemotherapy-resistant ovarian cancer

    Science.gov (United States)

    Mariya, Tasuku; Hirohashi, Yoshihiko; Torigoe, Toshihiko; Tabuchi, Yuta; Asano, Takuya; Saijo, Hiroshi; Kuroda, Takafumi; Yasuda, Kazuyo; Mizuuchi, Masahito; Saito, Tsuyoshi; Sato, Noriyuki

    2016-01-01

    Epithelial ovarian cancer (EOC) is one of the most lethal cancers in females. Cancer stem-like cells (CSCs)/cancer-initiating cells (CICs) have been reported to be origin of primary and recurrent cancers and to be resistant to several treatments. In this study, we identified matrix metalloproteinase-10 (MMP10) is expressed in CSCs/CICs of EOC. An immunohistochemical study revealed that a high expression level of MMP10 is a marker for poor prognosis and platinum resistance in multivariate analysis. MMP10 gene overexpression experiments and MMP10 gene knockdown experiments using siRNAs revealed that MMP10 has a role in the maintenance of CSCs/CICs in EOC and resistance to platinum reagent. Furthermore, MMP10 activate canonical Wnt signaling by inhibiting noncanonical Wnt signaling ligand Wnt5a. Therefore, MMP10 is a novel marker for CSCs/CICs in EOC and that targeting MMP10 is a novel promising approach for chemotherapy-resistant CSCs/CICs in EOC. PMID:27072580

  17. CAV1 promotes HCC cell progression and metastasis through Wnt/β-catenin pathway.

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    Hongxiu Yu

    Full Text Available Caveolin-1 (CAV1 has significant roles in many primary tumors and metastasis, despite the fact that malignant cells from different cancer types have different profiles of CAV1 expression. There is little information concerning CAV1 expression and role in hepatocellular carcinoma (HCC progresion and metastasis. The role of CAV1 in HCC progression was explored in this study. We reported that CAV1 was overexpressed in highly invasive HCC cell lines compared with poorly invasive ones. The immunohistochemical staining was obviously stronger in metastatic HCC samples than in the non-metastatic specimens via tissue microarrays. Furthermore, CAV1 overexpression enhanced HCC cell invasiveness in vitro, and promoted tumorigenicity and lung metastasis in vivo. By contrast, CAV1 stable knockdown markedly reduced these malignant behaviors. Importantly, we found that CAV1 could induce EMT process through Wnt/β-catenin pathway to promote HCC metastasis. We also identify MMP-7 as a novel downstream target of CAV1. We have determined that CAV1 acts as a mediator between hyperactive ERK1/2 signaling and regulation of MMP-7 transcription. Together, these studies mechanistically show a previously unrecognized interplay between CAV1, EMT, ERK1/2 and MMP-7 that is likely significant in the progression of HCC toward metastasis.

  18. Mutations in components of the Wnt signaling pathway in gastric cancer

    Institute of Scientific and Technical Information of China (English)

    Kai-Feng Pan; Wan-Guo Liu; Lian Zhang; Wei-Cheng You; You-Yong Lu

    2008-01-01

    AIM:To explore the contribution of AXIN1,AXIN2 and beta-catenin,components of Wnt signaling pathway,to the carcinogenesis of gastric cancer(GC),we examined AXIN1,AXIN2 exon7 and CTNNB1(encoding betacatenin) exon3 mutations in 70 GCs.METHODS:The presence of mutations was identified by polymerase chain reaction(PCR)-based denaturing high-performance liquid chromatography and direct DNA sequencing.Beta-catenin expression was detected by immunohistochemical analysis.RESULTS:Among the 70 GCs,5(7.1%)had mutations in one or two of these three components.A frameshift mutation(1 bp deletion)in exon7 of AXIN2 was found in one case.Four cases,including the case with a mutation in AXIN2,had frameshift mutations and missense mutations in AXIN1.Five single nucleotide polymorphisms (SNPs),334 C>T,874 C>T,1396 G>A,1690 C>T and 1942 T>G,were identified in AXTN1.A frameshift mutation(27 bp deletion) spanning exon3 of CTNNB1 was observed in one case.All four cases with mutations in AXIN1 and AXIN2 showed nuclear betacatenin expression.CONCLUSION:These data indicate that the mutations in AXIN1 and AXIN2 may contribute to gastric carcinogenesis.

  19. Macrophage Activation in Pediatric Nonalcoholic Fatty Liver Disease (NAFLD Correlates with Hepatic Progenitor Cell Response via Wnt3a Pathway.

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    Guido Carpino

    Full Text Available Non-alcoholic fatty liver disease is one of the most important causes of liver-related morbidity in children. In non-alcoholic fatty liver disease, the activation of liver resident macrophage pool is a central event in the progression of liver injury. The aims of the present study were to evaluate the polarization of liver macrophages and the possible role of Wnt3a production by macrophages in hepatic progenitor cell response in the progression of pediatric non-alcoholic fatty liver disease. 32 children with biopsy-proven non-alcoholic fatty liver disease were included. 20 out of 32 patients were treated with docosahexaenoic acid for 18 months and biopsies at the baseline and after 18 months were included. Hepatic progenitor cell activation, macrophage subsets and Wnt/β-catenin pathway were evaluated by immunohistochemistry and immunofluorescence. Our results indicated that in pediatric non-alcoholic fatty liver disease, pro-inflammatory macrophages were the predominant subset. Macrophage polarization was correlated with Non-alcoholic fatty liver disease Activity Score, ductular reaction, and portal fibrosis; docosahexaenoic acid treatment determined a macrophage polarization towards an anti-inflammatory phenotype in correlation with the reduction of serum inflammatory cytokines, with increased macrophage apoptosis, and with the up-regulation of macrophage Wnt3a expression; macrophage Wnt3a expression was correlated with β-catenin phosphorylation in hepatic progenitor cells and signs of commitment towards hepatocyte fate. In conclusion, macrophage polarization seems to have a key role in the progression of pediatric non-alcoholic fatty liver disease; the modulation of macrophage polarization could drive hepatic progenitor cell response by Wnt3a production.

  20. Macrophage Activation in Pediatric Nonalcoholic Fatty Liver Disease (NAFLD) Correlates with Hepatic Progenitor Cell Response via Wnt3a Pathway

    Science.gov (United States)

    Renzi, Anastasia; De Stefanis, Cristiano; Stronati, Laura; Franchitto, Antonio; Alisi, Anna; Onori, Paolo; De Vito, Rita; Alpini, Gianfranco; Gaudio, Eugenio

    2016-01-01

    Non-alcoholic fatty liver disease is one of the most important causes of liver-related morbidity in children. In non-alcoholic fatty liver disease, the activation of liver resident macrophage pool is a central event in the progression of liver injury. The aims of the present study were to evaluate the polarization of liver macrophages and the possible role of Wnt3a production by macrophages in hepatic progenitor cell response in the progression of pediatric non-alcoholic fatty liver disease. 32 children with biopsy-proven non-alcoholic fatty liver disease were included. 20 out of 32 patients were treated with docosahexaenoic acid for 18 months and biopsies at the baseline and after 18 months were included. Hepatic progenitor cell activation, macrophage subsets and Wnt/β-catenin pathway were evaluated by immunohistochemistry and immunofluorescence. Our results indicated that in pediatric non-alcoholic fatty liver disease, pro-inflammatory macrophages were the predominant subset. Macrophage polarization was correlated with Non-alcoholic fatty liver disease Activity Score, ductular reaction, and portal fibrosis; docosahexaenoic acid treatment determined a macrophage polarization towards an anti-inflammatory phenotype in correlation with the reduction of serum inflammatory cytokines, with increased macrophage apoptosis, and with the up-regulation of macrophage Wnt3a expression; macrophage Wnt3a expression was correlated with β-catenin phosphorylation in hepatic progenitor cells and signs of commitment towards hepatocyte fate. In conclusion, macrophage polarization seems to have a key role in the progression of pediatric non-alcoholic fatty liver disease; the modulation of macrophage polarization could drive hepatic progenitor cell response by Wnt3a production. PMID:27310371

  1. Wnt3a upregulates transforming growth factor-β-stimulated VEGF synthesis in osteoblasts.

    Science.gov (United States)

    Natsume, Hideo; Tokuda, Haruhiko; Matsushima-Nishiwaki, Rie; Kato, Kenji; Yamakawa, Kengo; Otsuka, Takanobu; Kozawa, Osamu

    2011-07-01

    It is recognized that Wnt3a affects bone metabolism via the canonical Wnt/β-catenin signalling pathway. We have previously shown that transforming growth factor-β (TGF-β) stimulates the synthesis of vascular endothelial growth factor (VEGF) via p44/p42 mitogen-activated protein (MAP) kinase, stress-activated protein kinase (SAPK)/c-Jun N-terminal kinase (JNK) and p38 MAP kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated the effect of Wnt3a on TGF-β-stimulated VEGF synthesis in these cells. Wnt3a, which alone had little effect on the VEGF levels, significantly enhanced the TGF-β-stimulated VEGF release. Lithium chloride and SB216763, inhibitors of glycogen synthase kinase 3β, markedly amplified the TGF-β-stimulated VEGF release. Wnt3a failed to affect the TGF-β-induced phosphorylation of Smad2, p44/p42 MAP kinase, p38 MAP kinase or SAPK/JNK. Wnt3a and lithium chloride strengthened the VEGF mRNA expression induced by TGF-β. These results strongly suggest that Wnt3a upregulates VEGF synthesis stimulated by TGF-β via activation of the canonical pathway in osteoblasts.

  2. Def6 Is Required for Convergent Extension Movements during Zebrafish Gastrulation Downstream of Wnt5b Signaling

    OpenAIRE

    Goudevenou, Katerina; Martin, Paul; Yeh, Yu-Jung; Jones, Peter; Sablitzky, Fred

    2011-01-01

    During gastrulation, convergent extension (CE) cell movements are regulated through the non-canonical Wnt signaling pathway. Wnt signaling results in downstream activation of Rho GTPases that in turn regulate actin cytoskeleton rearrangements essential for co-ordinated CE cell movement. Rho GTPases are bi-molecular switches that are inactive in their GDP-bound stage but can be activated to bind GTP through guanine nucleotide exchange factors (GEFs). Here we show that def6, a novel GEF, regula...

  3. Natural derivatives of curcumin attenuate the Wnt/beta-catenin pathway through down-regulation of the transcriptional coactivator p300.

    Science.gov (United States)

    Ryu, Min-Jung; Cho, Munju; Song, Jie-Young; Yun, Yeon-Sook; Choi, Il-Whan; Kim, Dong-Eun; Park, Byeoung-Soo; Oh, Sangtaek

    2008-12-26

    Curcumin, a component of turmeric (Curcuma longa), has been reported to suppress beta-catenin response transcription (CRT), which is aberrantly activated in colorectal cancer. However, the effects of its natural analogs (demethoxycurcumin [DMC] and bisdemethoxycurcumin [BDMC]) and metabolite (tetrahydrocurcumin [THC]) on the Wnt/beta-catenin pathway have not been investigated. Here, we show that DMC and BDMC suppressed CRT that was activated by Wnt3a conditioned-medium (Wnt3a-CM) without altering the level of intracellular beta-catenin, and inhibited the growth of various colon cancer cells, with comparable potency to curcumin. Additionally, DMC and BDMC down-regulated p300, which is a positive regulator of the Wnt/beta-catenin pathway. Notably, THC also inhibited CRT and cell proliferation, but to a much lesser degree than curcumin, DMC, or BDMC, indicating that the conjugated bonds in the central seven-carbon chain of curcuminoids are essential for the inhibition of Wnt/beta-catenin pathway and the anti-proliferative activity of curcuminoids. Thus, our findings suggest that curcumin derivatives inhibit the Wnt/beta-catenin pathway by decreasing the amount of the transcriptional coactivator p300.

  4. Natural derivatives of curcumin attenuate the Wnt/β-catenin pathway through down-regulation of the transcriptional coactivator p300

    International Nuclear Information System (INIS)

    Curcumin, a component of turmeric (Curcuma longa), has been reported to suppress β-catenin response transcription (CRT), which is aberrantly activated in colorectal cancer. However, the effects of its natural analogs (demethoxycurcumin [DMC] and bisdemethoxycurcumin [BDMC]) and metabolite (tetrahydrocurcumin [THC]) on the Wnt/β-catenin pathway have not been investigated. Here, we show that DMC and BDMC suppressed CRT that was activated by Wnt3a conditioned-medium (Wnt3a-CM) without altering the level of intracellular β-catenin, and inhibited the growth of various colon cancer cells, with comparable potency to curcumin. Additionally, DMC and BDMC down-regulated p300, which is a positive regulator of the Wnt/β-catenin pathway. Notably, THC also inhibited CRT and cell proliferation, but to a much lesser degree than curcumin, DMC, or BDMC, indicating that the conjugated bonds in the central seven-carbon chain of curcuminoids are essential for the inhibition of Wnt/β-catenin pathway and the anti-proliferative activity of curcuminoids. Thus, our findings suggest that curcumin derivatives inhibit the Wnt/β-catenin pathway by decreasing the amount of the transcriptional coactivator p300.

  5. 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.

  6. Wnt signaling in the regulation of adult hippocampal neurogenesis

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    Lorena eVarela-Nallar

    2013-06-01

    Full Text Available In the adult brain new neurons are continuously generated mainly in two regions, the subventricular zone of the lateral ventricles and the subgranular zone (SGZ in the hippocampal dentate gyrus. In the SGZ, radial neural stem cells give rise to granule cells that integrate into the hippocampal circuitry and are relevant for the plasticity of the hippocampus. Loss of neurogenesis impairs learning and memory, suggesting that this process is important for adult hippocampal function. Adult neurogenesis is tightly regulated by multiple signaling pathways, including the canonical Wnt/beta-catenin pathway. This pathway plays important roles during the development of neuronal circuits and in the adult brain it modulates synaptic transmission and plasticity. Here, we review current knowledge on the regulation of adult hippocampal neurogenesis by the Wnt/beta-catenin signaling cascade and the potential mechanisms involved in this regulation. Also we discuss the evidence supporting that the canonical Wnt pathway is part of the signaling mechanisms involved in the regulation of neurogenesis in different physiological conditions. Finally, some unsolved questions regarding the Wnt-mediated regulation of neurogenesis are discussed.

  7. Identification of Wnt Pathway Target Genes Regulating the Division and Differentiation of Larval Seam Cells and Vulval Precursor Cells in Caenorhabditis elegans.

    Science.gov (United States)

    Gorrepati, Lakshmi; Krause, Michael W; Chen, Weiping; Brodigan, Thomas M; Correa-Mendez, Margarita; Eisenmann, David M

    2015-06-05

    The evolutionarily conserved Wnt/β-catenin signaling pathway plays a fundamental role during metazoan development, regulating numerous processes including cell fate specification, cell migration, and stem cell renewal. Wnt ligand binding leads to stabilization of the transcriptional effector β-catenin and upregulation of target gene expression to mediate a cellular response. During larval development of the nematode Caenorhabditis elegans, Wnt/β-catenin pathways act in fate specification of two hypodermal cell types, the ventral vulval precursor cells (VPCs) and the lateral seam cells. Because little is known about targets of the Wnt signaling pathways acting during larval VPC and seam cell differentiation, we sought to identify genes regulated by Wnt signaling in these two hypodermal cell types. We conditionally activated Wnt signaling in larval animals and performed cell type-specific "mRNA tagging" to enrich for VPC and seam cell-specific mRNAs, and then used microarray analysis to examine gene expression compared to control animals. Two hundred thirty-nine genes activated in response to Wnt signaling were identified, and we characterized 50 genes further. The majority of these genes are expressed in seam and/or vulval lineages during normal development, and reduction of function for nine genes caused defects in the proper division, fate specification, fate execution, or differentiation of seam cells and vulval cells. Therefore, the combination of these techniques was successful at identifying potential cell type-specific Wnt pathway target genes from a small number of cells and at increasing our knowledge of the specification and behavior of these C. elegans larval hypodermal cells.

  8. 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.

  9. WNT5A inhibits metastasis and alters splicing of Cd44 in breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Wen Jiang

    Full Text Available Wnt5a is a non-canonical signaling Wnt. Low expression of WNT5A is correlated with poor prognosis in breast cancer patients. The highly invasive breast cancer cell lines, MDA-MB-231 and 4T1, express very low levels of WNT5A. To determine if enhanced expression of WNT5A would affect metastatic behavior, we generated WNT5A expressing cells from the 4T1 and MDA-MB-231 parental cell lines. WNT5A expressing cells demonstrated cobblestone morphology and reduced in vitro migration relative to controls. Cell growth was not altered. Metastasis to the lung via tail vein injection was reduced in the 4T1-WNT5A expressing cells relative to 4T1-vector controls. To determine the mechanism of WNT5A action on metastasis, we performed microarray and whole-transcriptome sequence analysis (RNA-seq to compare gene expression in 4T1-WNT5A and 4T1-vector cells. Analysis indicated highly significant alterations in expression of genes associated with cellular movement. Down-regulation of a subset of these genes, Mmp13, Nos2, Il1a, Cxcl2, and Lamb3, in WNT5A expressing cells was verified by semi-quantitative RT-PCR. Significant differences in transcript splicing were also detected in cell movement associated genes including Cd44. Cd44 is an adhesion molecule with a complex genome structure. Variable exon usage is associated with metastatic phenotype. Alternative spicing of Cd44 in WNT5A expressing cells was confirmed using RT-PCR. We conclude that WNT5A inhibits metastasis through down-regulation of multiple cell movement pathways by regulating transcript levels and splicing of key genes like Cd44.

  10. Nicotine deteriorates the osteogenic differentiation of periodontal ligament stem cells through α7 nicotinic acetylcholine receptor regulating Wnt pathway.

    Directory of Open Access Journals (Sweden)

    Zhifei Zhou

    Full Text Available AIMS: Cigarette smoking is one of the high risk factors of adult chronic periodontitis and nicotine is the well established toxic substance in cigarette. However, the mechanism of nicotine induced periodontitis is still unknown. Here we studied whether nicotine impaired the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs through activating α7 nicotinic acetylcholine receptor (α7 nAChR. METHODS: hPDLSCs with multi differentiation potential and surface makers for mesenchymal stem cells were harvested by limiting dilution technique. The level of mineralized nodule formation was assessed by alizarin red S staining. Expression level of ostegenic related genes and proteins were detected by real-time PCR and western blot analysis. The expression of α7 nAChR and its downstream signaling pathway were examined by western blot. The role of the receptor and related signaling pathway in nicotine impairing the osteogenic potential of hPDLSCs were also studied in different levels. RESULTS: Nicotine deteriorated the ostegenic differentiation of hPDLSCs in a dose dependent manner. Activation of α7 nAChR by nicotine treatment activated wnt/β-catenin signaling pathway, leading to osteogenic deficiency of hPDLSCs. Blockage of α7 nAChR and wnt pathway inhibitor treatment rescued nicotine induced osteogenic differentiation deficiency. CONCLUSIONS: These data suggested that nicotine activated α7 nAChR expressed on PDLSCs and further activated wnt signaling downstream, thus deteriorating the osteogenic potential of PDLSCs. The impairment of osteogenic differentiation of PDLSCs by nicotine might lead to cigarette smoking related periodontitis.

  11. A Canonical Correlation Analysis of AIDS Restriction Genes and Metabolic Pathways Identifies Purine Metabolism as a Key Cooperator

    Directory of Open Access Journals (Sweden)

    Hanhui Ye

    2016-01-01

    Full Text Available Human immunodeficiency virus causes a severe disease in humans, referred to as immune deficiency syndrome. Studies on the interaction between host genetic factors and the virus have revealed dozens of genes that impact diverse processes in the AIDS disease. To resolve more genetic factors related to AIDS, a canonical correlation analysis was used to determine the correlation between AIDS restriction and metabolic pathway gene expression. The results show that HIV-1 postentry cellular viral cofactors from AIDS restriction genes are coexpressed in human transcriptome microarray datasets. Further, the purine metabolism pathway comprises novel host factors that are coexpressed with AIDS restriction genes. Using a canonical correlation analysis for expression is a reliable approach to exploring the mechanism underlying AIDS.

  12. Loss of FTO antagonises Wnt signaling and leads to developmental defects associated with ciliopathies.

    Directory of Open Access Journals (Sweden)

    Daniel P S Osborn

    Full Text Available Common intronic variants in the Human fat mass and obesity-associated gene (FTO are found to be associated with an increased risk of obesity. Overexpression of FTO correlates with increased food intake and obesity, whilst loss-of-function results in lethality and severe developmental defects. Despite intense scientific discussions around the role of FTO in energy metabolism, the function of FTO during development remains undefined. Here, we show that loss of Fto leads to developmental defects such as growth retardation, craniofacial dysmorphism and aberrant neural crest cells migration in Zebrafish. We find that the important developmental pathway, Wnt, is compromised in the absence of FTO, both in vivo (zebrafish and in vitro (Fto(-/- MEFs and HEK293T. Canonical Wnt signalling is down regulated by abrogated β-Catenin translocation to the nucleus whilst non-canonical Wnt/Ca(2+ pathway is activated via its key signal mediators CaMKII and PKCδ. Moreover, we demonstrate that loss of Fto results in short, absent or disorganised cilia leading to situs inversus, renal cystogenesis, neural crest cell defects and microcephaly in Zebrafish. Congruently, Fto knockout mice display aberrant tissue specific cilia. These data identify FTO as a protein-regulator of the balanced activation between canonical and non-canonical branches of the Wnt pathway. Furthermore, we present the first evidence that FTO plays a role in development and cilia formation/function.

  13. CaSR function in the intestine: Hormone secretion, electrolyte absorption and secretion, paracrine non-canonical Wnt signaling and colonic crypt cell proliferation.

    Science.gov (United States)

    Macleod, R John

    2013-06-01

    Expression and function of the CaSR have been shown in some mammalian taste buds and basal cells of the esophagus. Signaling cascades responsible for CaSR-mediated stimulation of H(+)-K(+)-ATPase on human parietal cells have been defined. Transgenic mice and reductionistic cell culture models have shown that the CaSR promotes gastrin secretion from G cells, cholecystokinin (CCK) secretion from duodenal I cells and BMP-2 secretion from sub-epithelial myofibroblasts. In addition, the CaSR mediates a novel paracrine relationship between myofibroblasts and overlying epithelial cells in the colon. Thus, CaSR activators stimulate secretion of Wnt5a from myofibroblasts and expression of the Wnt5a receptor Ror2 in epithelial cells. CaSR-mediated Wnt5a/Ror2 engagement stimulates epithelial differentiation and reduces expression of the receptor for tumor necrosis factor (TNFR1). CaSR activators also modulate intestinal motility, inhibit Cl(-) secretion and stimulate Na(+) absorption in both the small intestine and colon. Colonic epithelia from conditional and global CaSR knockout mice exhibit increased proliferation with increased Wnt/β-catenin signaling, demonstrating that the CaSR negatively modulates colonic epithelial growth.

  14. Daple is a novel non-receptor GEF required for trimeric G protein activation in Wnt signaling.

    Science.gov (United States)

    Aznar, Nicolas; Midde, Krishna K; Dunkel, Ying; Lopez-Sanchez, Inmaculada; Pavlova, Yelena; Marivin, Arthur; Barbazán, Jorge; Murray, Fiona; Nitsche, Ulrich; Janssen, Klaus-Peter; Willert, Karl; Goel, Ajay; Abal, Miguel; Garcia-Marcos, Mikel; Ghosh, Pradipta

    2015-01-01

    Wnt signaling is essential for tissue homeostasis and its dysregulation causes cancer. Wnt ligands trigger signaling by activating Frizzled receptors (FZDRs), which belong to the G-protein coupled receptor superfamily. However, the mechanisms of G protein activation in Wnt signaling remain controversial. In this study, we demonstrate that FZDRs activate G proteins and trigger non-canonical Wnt signaling via the Dishevelled-binding protein, Daple. Daple contains a Gα-binding and activating (GBA) motif, which activates Gαi proteins and an adjacent domain that directly binds FZDRs, thereby linking Wnt stimulation to G protein activation. This triggers non-canonical Wnt responses, that is, suppresses the β-catenin/TCF/LEF pathway and tumorigenesis, but enhances PI3K-Akt and Rac1 signals and tumor cell invasiveness. In colorectal cancers, Daple is suppressed during adenoma-to-carcinoma transformation and expressed later in metastasized tumor cells. Thus, Daple activates Gαi and enhances non-canonical Wnt signaling by FZDRs, and its dysregulation can impact both tumor initiation and progression to metastasis. PMID:26126266

  15. Blocking the Wnt/β-Catenin Pathway by Lentivirus-Mediated Short Hairpin RNA Targeting β-Catenin Gene Suppresses Silica-Induced Lung Fibrosis in Mice

    Directory of Open Access Journals (Sweden)

    Xin Wang

    2015-09-01

    Full Text Available Silicosis is a form of occupational lung disease caused by inhalation of crystalline silica dust. While the pathogenesis of silicosis is not clearly understood, the Wnt/β-catenin signaling pathway is thought to play a major role in lung fibrosis. To explore the role of Wnt/β-catenin pathway in silicosis, we blocked Wnt/β-catenin pathway both in silica-treated MLE-12 cells (a mouse pulmonary epithelial cell line and in a mouse silicosis model by using a lentiviral vector expressing a short hairpin RNA silencing β-catenin (Lv-shβ-catenin. In vitro, Lv-shβ-catenin significantly decreased the expression of β-catenin, MMP2 and MMP9, and secretion of TGF-β1. In vivo, intratracheal treatment with Lv-shβ-catenin significantly reduced expression of β-catenin in the lung and levels of TGF-β1 in bronchoalveolar lavage fluid, and notably attenuated pulmonary fibrosis as evidenced by hydroxyproline content and collagen I\\III synthesis in silica-administered mice. These results indicate that blockade of the Wnt/β-catenin pathway can prevent the development of silica-induced lung fibrosis. Thus Wnt/β-catenin pathway may be a target in prevention and treatment of silicosis.

  16. 肺癌干细胞Wnt信号通路的研究进展%The Research Progress about Wnt Pathway of Lung Cancer Stem Cells

    Institute of Scientific and Technical Information of China (English)

    李小江; 贾英杰; 张文治; 张莹; 李宝乐; 黄敏娜; 包芳芳; 吴建国; 娄怡

    2011-01-01

    Being the most critical signaling molecule in the Wnt pathway the Wnt/ β-catenin signaling pathway plays an important role in the maintenance of the cell proliferation and clone formation of lung cancer stem cells.Since it is closely related to the WNT pathway, the proliferation of lung cancer stem cells can be restrained by blocling the WNT pathway or influencing its key protein.Such method provides a new method for the treatment of lung cancer.By summarizing the state ofthe-art research of lung cancer stem cells and the Wnt pathway from 2005 to 2010, their relationship is investigated.%Wnt信号通路在维持肺癌干细胞的增殖和克隆形成方面发挥着重要作用,可通过影响其关键蛋白质抑制肺癌干细胞增殖,为肺癌的治疗提供新的路径.本文旨在通过总结2005年-2010年肺癌干细胞及Wnt通路的研究现状,探讨Wnt通路与肺癌干细胞的关系.

  17. Early planarian brain regeneration is independent of blastema polarity mediated by the Wnt/β-catenin pathway.

    Science.gov (United States)

    Iglesias, Marta; Almuedo-Castillo, Maria; Aboobaker, A Aziz; Saló, Emili

    2011-10-01

    Analysis of anteroposterior (AP) axis specification in regenerating planarian flatworms has shown that Wnt/β-catenin signaling is required for posterior specification and that the FGF-like receptor molecule nou-darake (ndk) may be involved in restricting brain regeneration to anterior regions. The relationship between re-establishment of AP identity and correct morphogenesis of the brain is, however, still poorly understood. Here we report the characterization of two axin paralogs in the planarian Schmidtea mediterranea. Although Axins are well known negative regulators of Wnt/β-catenin signaling, no role in AP specification has previously been reported for axin genes in planarians. We show that silencing of Smed-axin genes by RNA interference (RNAi) results in two-tailed planarians, a phenotype previously reported after silencing of Smed-APC-1, another β-catenin inhibitor. More strikingly, we show for the first time that while early brain formation at anterior wounds remains unaffected, subsequent development of the brain is blocked in the two-tailed planarians generated after silencing of Smed-axin genes and Smed-APC-1. These findings suggest that the mechanisms underlying early brain formation can be uncoupled from the specification of AP identity by the Wnt/β-catenin pathway. Finally, the posterior expansion of the brain observed following Smed-ndk RNAi is enhanced by silencing Smed-APC-1, revealing an indirect relationship between the FGFR/Ndk and Wnt/β-catenin signaling systems in establishing the posterior limits of brain differentiation. PMID:21806978

  18. Genomic imbalances in esophageal carcinoma cell lines involve Wnt pathway genes

    Institute of Scientific and Technical Information of China (English)

    Jacqueline Brown; Hannelie Bothma; Robin Veale; Pascale Willem

    2011-01-01

    AIM: To identify molecular markers shared across South African esophageal squamous cell carcinoma (ESCC) cell lines using cytogenetics, fluorescence in situ hybridization (FISH) and single nucleotide polymorphism (SNP) array copy number analysis. METHODS: We used conventional cytogenetics, FISH, and multicolor FISH to characterize the chromosomal rearrangements of five ESCC cell lines established in South Africa. The whole genome copy number profile was established from 250K SNP arrays, and data was analyzed with the CNAT 4.0 and GISTIC software. RESULTS: We detected common translocation breakpoints involving chromosomes 1p11-12 and 3p11.2, the latter correlated with the deletion, or interruption of the EPHA3 gene. The most significant amplifications involved the following chromosomal regions and genes: 11q13.3 ( CCND1, FGF3, FGF4, FGF19, MYEOV), 8q24.21( C-MYC, FAM84B), 11q22.1-q22.3 ( BIRC2, BIRC3), 5p15.2 ( CTNND2), 3q11.2-q12.2 ( MINA) and 18p11.32 ( TYMS, YES1). The significant deletions included 1p31.2-p31.1 ( CTH, GADD45α, DIRAS3), 2q22.1 ( LRP1B), 3p12.1-p14.2 ( FHIT), 4q22.1-q32.1 ( CASP6, SMAD1), 8p23.2-q11.1 ( BNIP3L) and 18q21.1-q21.2 ( SMAD4, DCC). The 3p11.2 translocation breakpoint was shared across four cell lines, supporting a role for genes involved at this site, in particular, the EPHA3 gene which has previously been reported to be deleted in ESCC. CONCLUSION: The finding that a significant number of genes that were amplified (FGF3 , FGF4 , FGF19 , CCND1 and C-MYC ) or deleted (SFRP2 gene) are involved in the Wnt and fibroblast growth factor signaling pathways, suggests that these pathways may be activated in these cell lines.

  19. Wnt signaling and c-Myc in intestinal epithelium

    OpenAIRE

    Muncan, V.

    2007-01-01

    constantly produce cells from a stem cell reservoir that give rise to proliferating transit amplifying cells, which subsequently differentiate and are positioned in their proper compartments. This process has to be under stringent control to ensure life-long tissue homeostasis. It has now become clear that the same signaling pathways that are important during embryonic development control selfreneving tissues. Canonical Wnt signaling plays a key role in regulating intestinal tissue homeostasi...

  20. Wnt signaling in cardiovascular physiology.

    Science.gov (United States)

    Marinou, K; Christodoulides, C; Antoniades, C; Koutsilieris, M

    2012-12-01

    Wnt signaling pathways play a key role in cardiac development, angiogenesis, and cardiac hypertrophy; emerging evidence suggests that they are also involved in the pathophysiology of atherosclerosis. Specifically, an important role for Wnts has been described in the regulation of endothelial inflammation, vascular calcification, and mesenchymal stem cell differentiation. Wnt signaling also induces monocyte adhesion to endothelial cells and is crucial for the regulation of vascular smooth-muscle cell (VSMC) behavior. We discuss how the Wnt pathways are implicated in vascular biology and outline the role of Wnt signaling in atherosclerosis. Dissecting Wnt pathways involved in atherogenesis and cardiovascular disease may provide crucial insights into novel mechanisms with therapeutic potential for atherosclerosis.

  1. Chondroprotective effects of palmatine on osteoarthritis in vivo and in vitro: A possible mechanism of inhibiting the Wnt/β-catenin and Hedgehog signaling pathways.

    Science.gov (United States)

    Zhou, Xindie; Lin, Xiaolong; Xiong, Yan; Jiang, Lifeng; Li, Weijun; Li, Jin; Wu, Lidong

    2016-05-01

    The present study aimed to investigate the effect of palmatine (Pal) in a rabbit osteoarthritis (OA) model in vivo and rabbit interleukin-1β (IL-1β)-stimulated chondrocytes in vitro. Appropriate concentrations of Pal were identified by the MTT assay and used to preincubate IL-1β-induced chondrocytes, as well as an activator or inhibitor of Wnt and Hedgehog signaling pathways. Matrix metalloproteinase (MMP)-1, 3, and 13; tissue inhibitor of metalloproteinase (TIMP)-1; collagenase II; aggrecan; and the related molecules of the Wnt/β-catenin and Hedgehog signaling pathways were investigated. Protein expression was detected by Western blot analysis and messenger RNA (mRNA) expression was examined by PCR analysis. Pal (0.3 mL, 100 mg/L) was injected into rabbit knee joints and histological examination, immunohistochemistry, and Mankin scoring of the articular cartilage were performed. Pal (10-100 mg/L) had no effect on chondrocyte viability, decreased the expression of the MMPs, and increased the synthesis of TIMP-1whereas collagenase II and aggrecan were inhibited by IL-1β. When the activator (Licl) and inhibitor (DKK-1) of the Wnt/β-catenin signaling pathway as well as the inhibitor (cyclopamine) of the Hedgehog signaling pathway were added, the Wnt/β-catenin signaling pathway was less inhibited by Pal, and a similar inhibitory effect of cyclopamine on the Hedgehog signaling pathway was evident. Additionally, Pal enhanced the effect of cyclopamine. The histological examination, immunohistochemistry and Mankin scoring also demonstrated the protective effect of Pal, and the inhibition of the Wnt and Hedgehog signaling pathways by Pal. Pal may be useful in the treatment of OA, in which its effect is likely mediated via the Wnt/β-catenin and Hedgehog signaling pathways. PMID:26945831

  2. Trichosanthin suppresses the proliferation of glioma cells by inhibiting LGR5 expression and the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Miao, Junjie; Jiang, Yilin; Wang, Dongliang; Zhou, Jingru; Fan, Cungang; Jiao, Feng; Liu, Bo; Zhang, Jun; Wang, Yangshuo; Zhang, Qingjun

    2015-12-01

    Studies have indicated that trichosanthin (TCS), a bioactive protein extracted and purified from the tuberous root of Trichosanthes kirilowii (a well‑known traditional Chinese medicinal plant), produces antitumor effects on various types of cancer cells. However, the effects of TCS on glioma cells are poorly understood. The objective of this study was to investigate the antitumor effects of TCS on the U87 and U251 cell lines. The in vitro effects of TCS on these two cell lines were determined using a Cell Counting Kit‑8 (CCK‑8) assay, Annexin V‑FITC staining, DAPI staining, Transwell assays, terminal deoxynucleotidyl transferase‑mediated dUTP nick end‑labeling (TUNEL) assays, 5,5',6,6'‑tetrachloro‑1,1',3,3'‑tetraethyl‑imidacarbocyanine iodide (JC‑1) staining and western blotting, which was utilized to assess the expression of leucine‑rich repeat‑containing G protein‑coupled receptor 5 (LGR5) and key proteins in the Wnt/β‑catenin signaling pathway. Our data indicated that TCS inhibited the proliferation of glioma cells in a dose‑ and time‑dependent manner and played a role in inhibiting glioma cell invasion and migration. Additional investigation revealed that the expression levels of LGR5 and of key proteins in the Wnt/β‑catenin signaling pathway were markedly decreased after TCS treatment. The results suggest that TCS may induce apoptosis in glioma cells by targeting LGR5 and repressing the Wnt/β‑catenin signaling pathway. In the future, in vivo experiments should be conducted to examine the potential use of this compound as a novel therapeutic agent for gliomas.

  3. Neuroprotective Role of Novel Triazine Derivatives by Activating Wnt/β Catenin Signaling Pathway in Rodent Models of Alzheimer's Disease.

    Science.gov (United States)

    Sinha, Anshuman; Tamboli, Riyaj S; Seth, Brashket; Kanhed, Ashish M; Tiwari, Shashi Kant; Agarwal, Swati; Nair, Saumya; Giridhar, Rajani; Chaturvedi, Rajnish Kumar; Yadav, Mange Ram

    2015-08-01

    It has been reported in the literature that cholinesterase inhibitors provide protection in Alzheimer's disease (AD). Recent reports have implicated triazine derivatives as cholinesterase inhibitors. These findings led us to investigate anti-cholinestrase property of some novel triazine derivatives synthesized in this laboratory. In vitro cholinesterase inhibition assay was performed using Ellman method. The potent compounds screened out from in vitro assay were further evaluated using scopolamine-induced amnesic mice model. Further, in vitro reactive oxygen species (ROS) scavenging and anti-apoptotic property of the potent compounds were demonstrated against Aβ1-42-induced neurotoxicity in rat hippocampal cells. Their neuroprotective role was assessed using Aβ1-42-induced Alzheimer's-like phenotype in rats. Further, the role of compounds on the activation of the Wnt/β-catenin pathway was studied. The results showed that the chosen compounds are having protective effect in Alzheimer's-like condition; the ex vivo results advocated their anti-cholinestrase and anti-oxidant activities. Treatment with TRZ-15 and TRZ-20 showed neuroprotective ability of the compounds as evidenced from the improved cognitive ability in the animals, and decrease in Aβ1-42 burden and cytochrome c and cleaved caspase-3 levels in the brain. This study also demonstrates positive involvement of the novel triazine derivatives in the Wnt/β-catenin pathway. Immunoblot and immunofluorescence data suggested that ratio of pGSK3/GSK3 and β-catenin got dramatically improved after treatment with TRZ-15 and TRZ-20. TRZ-15 and TRZ-20 showed neuroprotection in scopolamine-induced amnesic mice and Aβ1-42-induced Alzheimer's rat model and also activate the Wnt/β-catenin signaling pathway. These findings conclude that TRZ-15 and TRZ-20 could be a therapeutic approach to treat AD.

  4. Dissecting the PCP pathway: one or more pathways?: Does a separate Wnt-Fz-Rho pathway drive morphogenesis?

    Science.gov (United States)

    Lapébie, Pascal; Borchiellini, Carole; Houliston, Evelyn

    2011-10-01

    Planar cell polarity (PCP), the alignment of cells within 2D tissue planes, involves a set of core molecular regulators highly conserved between animals and cell types. These include the transmembrane proteins Frizzled (Fz) and VanGogh and the cytoplasmic regulators Dishevelled (Dsh) and Prickle. It is widely accepted that this core forms part of a 'PCP pathway' for signal transduction, which can affect cell morphology through activation of an evolutionary ancient regulatory module involving Rho family GTPases and Myosin II, and/or the JNK kinase cascade. We have re-examined the evidence for interactions between the proposed PCP pathway components, and question the placing of the cell morphology regulators in the same pathway as the PCP core. While Fz and Dsh are clearly involved in both PCP and Rho-based cell morphology regulation, available evidence cannot currently discriminate whether these processes are linked mechanistically by a shared Fz/Dsh population, or pass by two distinct pathways.

  5. 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.

  6. 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

    influence on the Wnt signaling-related genes and progression of colorectal cancer. Although several inflammatory signaling pathways, including TNF-α, have been reported to promote Wnt/β-catenin activity and development of cancer, the underlying molecular mechanisms remain unclear. The aim was to investigate...... that these are involved in the TNF-α-dependent downregulation of CDX2. Furthermore, TNF-α-mediated downregulation of CDX2 was found to significantly decrease the mRNA levels of adenomatous polyposis coli (APC), axis inhibition protein 2 (AXIN2) and glycogen synthase kinase-3 beta (GSK3β), whereas the mRNA levels of Wnt...... 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...

  7. Calcitonin gene-related peptide promotes the expression of osteoblastic genes and activates the WNT signal transduction pathway in bone marrow stromal stem cells

    Science.gov (United States)

    ZHOU, RI; YUAN, ZHI; LIU, JIERONG; LIU, JIAN

    2016-01-01

    Calcitonin gene-related peptide (CGRP) is known to induce osteoblastic differentiation and alkaline phosphatase activity in bone marrow stromal stem cells (BMSCs). However, it has remained elusive whether this effect is mediated by CGRP receptors directly or whether other signaling pathways are involved. The present study assessed the possible involvement of the Wnt/β-catenin signaling pathway in the activation of CGRP signaling during the differentiation of BMSCs. First, the differentiation of BMSCs was induced in vitro and the expression of CGRP receptors was examined by western blot analysis. The effects of exogenous CGRP and LiCl, a stimulator of the Wnt/β-catenin signaling pathway, on the osteoblastic differentiation of BMSCs were assessed; furthermore, the expression of mRNA and proteins involved in the Wnt/β-catenin signaling pathway was assessed using quantitative PCR and western blot analyses. The results revealed that CGRP receptors were expressed throughout the differentiation of BMSCs, at days 7 and 14. Incubation with CGRP and LiCl led to the upregulation of the expression of osteoblastic genes associated with the Wnt/β-catenin pathway, including the mRNA of c-myc, cyclin D1, Lef1, Tcf7 and β-catenin as well as β-catenin protein. However, the upregulation of these genes and β-catenin protein was inhibited by CGRP receptor antagonist or secreted frizzled-related protein, an antagonist of the Wnt/β-catenin pathway. The results of the present study therefore suggested that the Wnt/β-catenin signaling pathway may be involved in CGRP- and LiCl-promoted osteoblastic differentiation of BMSCs. PMID:27082317

  8. Autocrine stimulation of osteoblast activity by Wnt5a in response to TNF-α in human mesenchymal stem cells

    Energy Technology Data Exchange (ETDEWEB)

    Briolay, A. [ICBMS, UMR CNRS 5246, University of Lyon 1, Bâtiment Raulin, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Lencel, P. [Physiopathology of Inflammatory Bone Diseases, EA4490, ULCO. Quai Masset, Bassin Napoléon BP120, 62327 Boulogne/Mer (France); Bessueille, L. [ICBMS, UMR CNRS 5246, University of Lyon 1, Bâtiment Raulin, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Caverzasio, J. [Service of Bone Diseases, Department of Internal Medicine Specialties, University Hospital of Geneva, CH-1211 Geneva 14 (Switzerland); Buchet, R. [ICBMS, UMR CNRS 5246, University of Lyon 1, Bâtiment Raulin, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France); Magne, D., E-mail: david.magne@univ-lyon1.fr [ICBMS, UMR CNRS 5246, University of Lyon 1, Bâtiment Raulin, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex (France)

    2013-01-18

    Highlights: ► Ankylosing spondylitis (AS) leads to bone fusions and ankylosis. ► TNF-α stimulates osteoblasts through growth factors in AS. ► We compare the involvement of canonical vs non-canonical Wnt signaling. ► Canonical Wnt signaling is not involved in TNF-α effects in differentiating hMSCs. ► TNF-α stimulates osteoblasts through Wnt5a autocrine secretion in hMSCs. -- Abstract: Although anti-tumor necrosis factor (TNF)-α treatments efficiently block inflammation in ankylosing spondylitis (AS), they are inefficient to prevent excessive bone formation. In AS, ossification seems more prone to develop in sites where inflammation has resolved following anti-TNF therapy, suggesting that TNF-α indirectly stimulates ossification. In this context, our objectives were to determine and compare the involvement of Wnt proteins, which are potent growth factors of bone formation, in the effects of TNF-α on osteoblast function. In human mesenchymal stem cells (MSCs), TNF-α significantly increased the levels of Wnt10b and Wnt5a. Associated with this effect, TNF-α stimulated tissue-non specific alkaline phosphatase (TNAP) and mineralization. This effect was mimicked by activation of the canonical β-catenin pathway with either anti-Dkk1 antibodies, lithium chloride (LiCl) or SB216763. TNF-α reduced, and activation of β-catenin had little effect on expression of osteocalcin, a late marker of osteoblast differentiation. Surprisingly, TNF-α failed to stabilize β-catenin and Dkk1 did not inhibit TNF-α effects. In fact, Dkk1 expression was also enhanced in response to TNF-α, perhaps explaining why canonical signaling by Wnt10b was not activated by TNF-α. However, we found that Wnt5a also stimulated TNAP in MSCs cultured in osteogenic conditions, and increased the levels of inflammatory markers such as COX-2. Interestingly, treatment with anti-Wnt5a antibodies reduced endogenous TNAP expression and activity. Collectively, these data suggest that increased

  9. Orphan nuclear receptor TLX activates Wnt/β-catenin signalling to stimulate neural stem cell proliferation and self-renewal

    OpenAIRE

    Qu, Qiuhao; Sun, Guoqiang; Li, Wenwu; Yang, Su; Ye, Peng; Zhao, Chunnian; Yu, Ruth T.; Gage, Fred H; Evans, Ronald M; Shi, Yanhong

    2009-01-01

    The nuclear receptor TLX (also known as NR2E1) is essential for adult neural stem cell self-renewal; however, the molecular mechanisms involved remain elusive. Here we show that TLX activates the canonical Wnt/β-catenin pathway in adult mouse neural stem cells. Furthermore, we demonstrate that Wnt/β-catenin signalling is important in the proliferation and self-renewal of adult neural stem cells in the presence of epidermal growth factor and fibroblast growth factor. Wnt7a and active β-catenin...

  10. 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.

  11. Functional Selectivity of CB2 Cannabinoid Receptor Ligands at a Canonical and Noncanonical Pathway.

    Science.gov (United States)

    Dhopeshwarkar, Amey; Mackie, Ken

    2016-08-01

    The CB2 cannabinoid receptor (CB2) remains a tantalizing, but unrealized therapeutic target. CB2 receptor ligands belong to varied structural classes and display extreme functional selectivity. Here, we have screened diverse CB2 receptor ligands at canonical (inhibition of adenylyl cyclase) and noncanonical (arrestin recruitment) pathways. The nonclassic cannabinoid (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]-trans-4-(3-hydroxypropyl)cyclohexanol (CP55940) was the most potent agonist for both pathways, while the classic cannabinoid ligand (6aR,10aR)-3-(1,1-Dimethylbutyl)-6a,7,10,10a-tetrahydro-6,6,9-trimethyl-6H-dibenzo[b,d]pyran JWH133) was the most efficacious agonist among all the ligands profiled in cyclase assays. In the cyclase assay, other classic cannabinoids showed little [(-)-trans-Δ(9)-tetrahydrocannabinol and (-)-(6aR,7,10,10aR)-tetrahydro-6,6,9-trimethyl-3-(1-methyl-1-phenylethyl)-6H-dibenzo[b,d]pyran-1-ol] (KM233) to no efficacy [(6aR,10aR)-1-methoxy-6,6,9-trimethyl-3-(2-methyloctan-2-yl)-6a,7,10,10a-tetrahydrobenzo[c]chromene(L759633) and (6aR,10aR)-3-(1,1-dimethylheptyl)-6a,7,8,9,10,10a-hexahydro-1-methoxy-6,6-dimethyl-9-methylene-6H-dibenzo[b,d]pyran]L759656. Most aminoalkylindoles, including [(3R)-​2,​3-​dihydro-​5-​methyl-​3-​(4-​morpholinylmethyl)pyrrolo[1,​2,​3-​de]-​1,​4-​benzoxazin-​6-​yl]-​1-​naphthalenyl-​methanone,​ monomethanesulfonate (WIN55212-2), were moderate efficacy agonists. The cannabilactone 3-(1,1-dimethyl-heptyl)-1-hydroxy-9-methoxy-benzo(c)chromen-6-one (AM1710) was equiefficacious to CP55940 to inhibit adenylyl cyclase, albeit with lower potency. In the arrestin recruitment assays, all classic cannabinoid ligands failed to recruit arrestins, indicating a bias toward G-protein coupling for this class of compound. All aminoalkylindoles tested, except for WIN55212-2 and (1-​pentyl-​1H-​indol-​3-​yl)(2,​2,​3,​3-​tetramethylcyclopropyl)-​methanone (UR144), failed

  12. Secreted and transmembrane wnt inhibitors and activators.

    Science.gov (United States)

    Cruciat, Cristina-Maria; Niehrs, Christof

    2013-03-01

    Signaling by the Wnt family of secreted glycoproteins plays important roles in embryonic development and adult homeostasis. Wnt signaling is modulated by a number of evolutionarily conserved inhibitors and activators. Wnt inhibitors belong to small protein families, including sFRP, Dkk, WIF, Wise/SOST, Cerberus, IGFBP, Shisa, Waif1, APCDD1, and Tiki1. Their common feature is to antagonize Wnt signaling by preventing ligand-receptor interactions or Wnt receptor maturation. Conversely, the Wnt activators, R-spondin and Norrin, promote Wnt signaling by binding to Wnt receptors or releasing a Wnt-inhibitory step. With few exceptions, these antagonists and agonists are not pure Wnt modulators, but also affect additional signaling pathways, such as TGF-β and FGF signaling. Here we discuss their interactions with Wnt ligands and Wnt receptors, their role in developmental processes, as well as their implication in disease. PMID:23085770

  13. Negative feedback regulation of Wnt4 signaling by EAF1 and EAF2/U19.

    Directory of Open Access Journals (Sweden)

    Xiaoyang Wan

    Full Text Available Previous studies indicated that EAF (ELL-associated factor family members, EAF1 and EAF2/U19, play a role in cancer and embryogenesis. For example, EAF2/U19 may serve as a tumor suppressor in prostate cancer. At the same time, EAF2/U19 is a downstream factor in the non-canonical Wnt 4 signaling pathway required for eye development in Xenopus laevis, and along with EAF1, contributes to convergence and extension movements in zebrafish embryos through Wnt maintenance. Here, we used zebrafish embryos and mammalian cells to show that both EAF1 and EAF2/U19 were up-regulated by Wnt4 (Wnt4a. Furthermore, we found that EAF1 and EAF2/U19 suppressed Wnt4 expression by directly binding to the Wnt4 promoter as seen in chromatin immunoprecipitation assays. These findings indicate that an auto-regulatory negative feedback loop occurs between Wnt4 and the EAF family, which is conserved between zebrafish and mammalian. The rescue experiments in zebrafish embryos showed that early embryonic development required the maintenance of the appropriate levels of Wnt4a through the feedback loop. Others have demonstrated that the tumor suppressors p63, p73 and WT1 positively regulate Wnt4 expression while p21 has the opposite effect, suggesting that maintenance of appropriate Wnt4 expression may also be critical for adult tissue homeostasis and prevention against tumor initiation. Thus, the auto-regulatory negative feedback loop that controls expression of Wnt4 and EAF proteins may play an important role in both embryonic development and tumor suppression. Our findings provide the first convincing line of evidence that EAF and Wnt4 form an auto-regulatory negative feedback loop in vivo.

  14. MicroRNA-17-5p-activated Wnt/β-catenin pathway contributes to the progression of liver fibrosis

    OpenAIRE

    Yu, Fujun; Lu, Zhongqiu; HUANG, KATE; Wang, Xiaodong; Xu, Ziqiang; Chen, Bicheng; Dong, Peihong; Zheng, Jianjian

    2015-01-01

    Aberrant Wnt/β-catenin pathway contributes to the development of liver fibrosis. MicroRNAs (MiRNAs) are found to act as regulators of the activation of hepatic stellate cell (HSC) in liver fibrosis. However, whether miRNAs activate Wnt/β-catenin pathway in activated HSCs during liver fibrosis is largely unknown. In this study, we found that Salvianolic acid B (Sal B) treatment significantly inhibited liver fibrosis in CCl4-treated rats, HSC-T6 cells and rat primary HSCs, resulting in the supp...

  15. Distinct Effect of TCF4 on the NFκB Pathway in Human Primary Chondrocytes and the C20/A4 Chondrocyte Cell Line

    NARCIS (Netherlands)

    Landman, E.B.M.; Periyasamy, P.C.; Blitterswijk, van C.A.; Post, J.N.; Karperien, M.

    2014-01-01

    Objective: Previous studies indicated a difference in crosstalk between canonical WNT pathway and nuclear factor-κB (NFκB) signaling in human and animal chondrocytes. To assess whether the differences found were dependent on cell types used, we tested the effect of WNT modulation on NFκB signaling i

  16. DNA methyltransferase inhibitor-mediated apoptosis in the Wnt/β-catenin signal pathway in a renal cell carcinoma cell line.

    Science.gov (United States)

    Konac, Ece; Varol, Nuray; Yilmaz, Akin; Menevse, Sevda; Sozen, Sinan

    2013-09-01

    The Wnt signaling pathway is activated in most cancer types when Wnt antagonist genes are inactivated. Glycogen synthase kinase 3 (GSK3β) is an important regulator of the Wnt/β-catenin signaling pathway. The mechanisms underlying GSK3β regulation of neoplastic transformation and tumor development are unclear. Studies have raised the possibility that the Wnt signaling pathway may be implicated in renal cell carcinoma (RCC). Therefore, in the present study, we hypothesize that the expression and methylation status of the secreted frizzled-related protein 2 (sFRP2) gene, one of the secreted antagonists that bind Wnt protein, and re-expression of this gene with the demethylation agent (5-aza-2'-deoxycytidine; DAC) may induce apoptosis in RCC cells. To test this hypothesis, we investigated the relationship among epigenetic inactivation of sFRP2 and p-GSK3β (Ser9) and other Wnt antagonists (sFRP1, DKK3, WIF-1) and apoptotic factors (Bax and Caspase3) as well as the anti-apoptotic factor BCL2. Our results indicate that DAC-mediated inhibition of DNA methylation led to a re-activation of sFRP2 expression and increased expression levels of the Wnt antagonists and apoptotic factors. In contrast, the level of β-catenin (CTNNB1) expression decreased. The p-GSK3β (Ser9) protein level in Caki-2 cells was significantly down-regulated, while the DNA fragmentation rate increased after treatment with 5 μM DAC at 96 h. Our data show that sFRP2 functions as a tumor suppressor gene in RCC and that its restoration may offer a new therapeutic approach for the treatment of RCC. Moreover, our study draws attention to the regulatory features of epigenetic molecules and analyses their underlying molecular mechanisms of action and their potential use in clinical practice. PMID:23975733

  17. HOTAIR, a prognostic factor in esophageal squamous cell carcinoma, inhibits WIF-1 expression and activates Wnt pathway.

    Science.gov (United States)

    Ge, Xiao-Song; Ma, Hua-Juan; Zheng, Xiao-Hui; Ruan, Hong-Lian; Liao, Xiao-Yu; Xue, Wen-Qiong; Chen, Yuan-Bin; Zhang, Ying; Jia, Wei-Hua

    2013-12-01

    Long non-coding RNAs (LncRNAs) have been recently found to be pervasively transcribed in the genome and critical regulators of the epigenome. HOTAIR, as a well-known LncRNA, has been found to play important roles in several tumors. Herein, the clinical application value and biological functions of HOTAIR were focused and explored in esophageal squamous cell carcinoma (ESCC). It was found that there was a great upregulation of HOTAIR in ESCC compared to their adjacent normal esophageal tissues. Meanwhile, patients with high HOTAIR expression have a significantly poorer prognosis than those with low expression. Moreover, HOTAIR was further validated to promote migration and invasion of ESCC cells in vitro. Then some specific molecules with great significance were investigated after HOTAIR overexpression using microarray and quantitative real time-polymerase chain reaction (qPCR). WIF-1 playing an important role in Wnt/β-catenin signaling pathway was selected and further tested by immunehistochemistry. Generally, inverse correlation between HOTAIR and WIF-1 expression was demonstrated both in ESCC cells and tissues. Mechanistically, HOTAIR directly decreased WIF-1 expression by promoting its histone H3K27 methylation in the promoter region and then activated the Wnt/β-catenin signaling pathway. This newly identified HOTAIR/WIF-1 axis clarified the molecular mechanism of ESCC cell metastasis and represented a novel therapeutic target in patients with ESCC. PMID:24118380

  18. 5-Azacytidine suppresses the proliferation of pancreatic cancer cells by inhibiting the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Zhang, H; Zhou, W C; Li, X; Meng, W B; Zhang, L; Zhu, X L; Zhu, K X; Bai, Z T; Yan, J; Liu, T; Xu, X C; Li, Y M

    2014-01-01

    5-Azacytidine has been shown to be an effective anti-pancreatic cancer drug, but the mechanism remains unknown. In the current study, we explored the effect of 5-azacytidine on abnormal activation of the Wnt-β-catenin signaling pathway in pancreatic cancer cells. The human pancreatic cancer cell line Bxpc-3 was treated with different concentrations of 5-azacytidine for various times. The proliferation and early apoptosis of the cells were evaluated using the CCK8 method and flow cytometry, respectively. mRNA and protein expression of β-catenin, c-myc, and cyclinD1 were detected using real-time fluorescent quantitative polymerase chain reaction and Western blot analysis, respectively. The proliferation of Bxpc-3 cells was suppressed by 5-azacytidine. The early apoptosis of the cells was significantly enhanced over time and with increasing drug concentrations. The expression of β-catenin, c-myc, and cyclinD1 were down-regulated, showing significant differences between different concentrations and treatment times (P < 0.05). 5-Azacytidine suppressed the proliferation of pancreatic cancer cells by inhibiting the Wnt/β-catenin signaling pathway, particularly the expression of β-catenin, c-myc, and cyclinD1. This study may provide a new potential strategy for diagnosing and treating pancreatic cancer. PMID:25061731

  19. Targeting the interaction of Aurora kinases and SIRT1 mediated by Wnt signaling pathway in colorectal cancer: A critical review.

    Science.gov (United States)

    Subramaniyan, Boopathi; Jagadeesan, Kaviya; Ramakrishnan, Sabitha; Mathan, Ganeshan

    2016-08-01

    The Aurora kinases belong to the family of serine/threonine kinase, a central regulator of mitosis and their expression increased during G2/M phase. It is classified into Aurora A, B and C, each has distinct roles in cellular processes, which includes regulation of spindle assembly, function of centrosomes, cytoskeleton and cytokinesis. During cancer growth, their rapid increase makes most attractive marker for cancer treatment at present. However Aurora A kinase is known to be a marker for cancer therapy, the most important serine/threonine kinase of Aurora B kinase involvement in cancer is still inadequate. Subsequently, the recent findings revealed that the class III histone deacetylase of SIRT1 is a key regulator to activate Aurora kinases from S phase damaged DNA through Wnt signaling pathway. Even if both Aurora A kinase and SIRT1 serve as a marker for cancer therapy, the present review reveals it is interaction in Wnt signaling pathway that solely for colorectal cancer. PMID:27470380

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

    Institute of Scientific and Technical Information of China (English)

    Yuan-HuiWang; Zhen-Hua Zhou

    2016-01-01

    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 andβ-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 andβ-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.

  1. 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

  2. Loss of WIF-1 and Wnt5a expression is related to aggressiveness of sporadic breast cancer in Tunisian patients.

    Science.gov (United States)

    Trifa, Fatma; Karray-Chouayekh, Sondes; Jmal, Emna; Jmaa, Zeineb Ben; Khabir, Abdelmajid; Sellami-Boudawara, Tahia; Frikha, Mounir; Daoud, Jamel; Mokdad-Gargouri, Raja

    2013-06-01

    Activation of the Wnt/β-catenin signaling pathway is common in various human cancers. The aim of this study was to investigate the expression of 2 members of the Wnt family (WIF-1 and Wnt5a) in sporadic and hereditary breast cancer tissues. WIF-1, is a secreted antagonist that binds Wnt ligands, and therefore inhibits the canonical Wnt/β-catenin pathway. Wnt5a is one of the members of the noncanonical Wnt family that mainly acts through calcium signaling pathway. The expression of WIF-1 was analyzed by methylation-specific PCR and RT-PCR, and the level of Wnt5a ligand was quantified by RT-QPCR in breast cancer tissues. Methylation of WIF-1 was detected in 71.3 % and 81.8 % of sporadic and hereditary cases, respectively. Aberrant methylation of WIF-1 was associated with advanced TNM stage and triple negative cases in sporadic breast carcinoma (p=0.001 and p=0.037, respectively). In hereditary cases, methylation of WIF-1 correlated with age at diagnosis (p=0.027) and p53 status (p=0.035). Regarding patients' survival, WIF-1 methylated promoter conferred a reduced overall survival rate, and particularly in a group of patients with advanced TNM stage (p log rank=0.006). Furthermore, aberrant CpG methylation of the WIF-1 promoter was significantly associated with transcriptional silencing of this tumor suppressor gene in sporadic breast cancer tissues (p=0.036). On the other hand, in sporadic tumor tissues, the level of Wnt5a mRNA was significantly lower compared to normal tissues (p=0.031) and lower still in those showing more aggressive behavior, suggesting that Wnt5a, a ligand involved in the noncanonical Wnt/β-catenin pathway, could act as a tumor suppressor gene in breast cancer. PMID:23417837

  3. Selective modulation of Wnt ligands and their receptors in adipose tissue by chronic hyperadiponectinemia.

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    Nobuhiko Wada

    Full Text Available BACKGROUND: Adiponectin-transgenic mice had many small adipocytes in both subcutaneous and visceral adipose tissues, and showed higher sensitivity to insulin, longer life span, and reduced chronic inflammation. We hypothesized that adiponectin regulates Wnt signaling in adipocytes and thereby modulates adipocyte proliferation and chronic inflammation in adipose tissue. MATERIALS AND METHODS: We examined the expression of all Wnt ligands and their receptors and the activity of Wnt signaling pathways in visceral adipose tissue from wild-type mice and two lines of adiponectin-transgenic mice. The effects of adiponectin were also investigated in cultured 3T3-L1 cells. RESULTS: The Wnt5b, Wnt6, Frizzled 6 (Fzd6, and Fzd9 genes were up-regulated in both lines of transgenic mice, whereas Wnt1, Wnt2, Wnt5a, Wnt9b, Wnt10b, Wnt11, Fzd1, Fzd2, Fzd4, Fzd7, and the Fzd coreceptor low-density-lipoprotein receptor-related protein 6 (Lrp6 were reduced. There was no difference in total β-catenin levels in whole-cell extracts, non-phospho-β-catenin levels in nuclear extracts, or mRNA levels of β-catenin target genes, indicating that hyperadiponectinemia did not affect canonical Wnt signaling. In contrast, phosphorylated calcium/calmodulin-dependent kinase II (p-CaMKII and phosphorylated Jun N-terminal kinase (p-JNK were markedly reduced in adipose tissue from the transgenic mice. The adipose tissue of the transgenic mice consisted of many small cells and had increased expression of adiponectin, whereas cyclooxygenase-2 expression was reduced. Wnt5b expression was elevated in preadipocytes of the transgenic mice and decreased in diet-induced obese mice, suggesting a role in adipocyte differentiation. Some Wnt genes, Fzd genes, and p-CaMKII protein were down-regulated in 3T3-L1 cells cultured with a high concentration of adiponectin. CONCLUSION: Chronic hyperadiponectinemia selectively modulated the expression of Wnt ligands, Fzd receptors and LRP coreceptors

  4. Aquaporin 3 protects against lumbar intervertebral disc degeneration via the Wnt/β-catenin pathway.

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    Xie, Huanxin; Jing, Yongbin; Xia, Jingjun; Wang, Xintao; You, Changcheng; Yan, Jinglong

    2016-03-01

    Previous studies have demonstrated that the expression of aquaporin 3 (AQP3), a water channel which promotes glycerol permeability and water transport across cell membranes, is reduced in degenerative lumbar intervertebral disc (IVD) tissues. However, the role of AQP3 in the pathogenesis of IVD degeneration has not recieved much scholarly attention. The objective of the present study was to investigate the effect of AQP3 on cell proliferation and extracellular matrix (ECM) degradation in human nucleus pulposus cells (hNPCs) using gain-of-function and loss-of-function experiments, and to determine whether Wnt/β-catenin signaling is involved in the effect of AQP3 on IVD degeneration. hNPCs were transfected with the AQP3-pcDNA3.1 plasmid or AQP3 siRNA to overexpress or suppress AQP3. An MTT assay was performed to determine cell proliferation, and we found that AQP3 promoted hNPC proliferation. The expression of aggrecan, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)4 and ADAMTS5 was detected using western blot analysis, to examine the effect of AQP3 on ECM degradation in hNPCs. The results revealed that AQP3 inhibited ECM degradation in hNPCs. In addition, we found that Wnt/β-catenin signaling was suppressed by AQP3. However, the effect of AQP3 on hNPC proliferation and ECM degradation was reversed by treatment with lithium chloride, a known activator of Wnt/β‑catenin signaling. In conclusion, using in vitro and in vivo tests, we have reported for the first time, to the best of our knowledge, that AQP3 exerts protective effects against IVD degeneration, and these are effected, at least partially, through the inhibition of Wnt/β-catenin signaling. PMID:26820815

  5. Wnt Signaling in Cell Motility and Invasion: Drawing Parallels between Development and Cancer.

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    Sedgwick, Alanna E; D'Souza-Schorey, Crislyn

    2016-01-01

    The importance of canonical and non-canonical Wnt signal transduction cascades in embryonic development and tissue homeostasis is well recognized. The aberrant activation of these pathways in the adult leads to abnormal cellular behaviors, and tumor progression is frequently a consequence. Here we discuss recent findings and analogies between Wnt signaling in developmental processes and tumor progression, with a particular focus on cell motility and matrix invasion and highlight the roles of the ARF (ADP-Ribosylation Factor) and Rho-family small GTP-binding proteins. Wnt-regulated signal transduction from cell surface receptors, signaling endosomes and/or extracellular vesicles has the potential to profoundly influence cell movement, matrix degradation and paracrine signaling in both development and disease. PMID:27589803

  6. Wnt Signaling in Cell Motility and Invasion: Drawing Parallels between Development and Cancer

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    Alanna E. Sedgwick

    2016-08-01

    Full Text Available The importance of canonical and non-canonical Wnt signal transduction cascades in embryonic development and tissue homeostasis is well recognized. The aberrant activation of these pathways in the adult leads to abnormal cellular behaviors, and tumor progression is frequently a consequence. Here we discuss recent findings and analogies between Wnt signaling in developmental processes and tumor progression, with a particular focus on cell motility and matrix invasion and highlight the roles of the ARF (ADP-Ribosylation Factor and Rho-family small GTP-binding proteins. Wnt-regulated signal transduction from cell surface receptors, signaling endosomes and/or extracellular vesicles has the potential to profoundly influence cell movement, matrix degradation and paracrine signaling in both development and disease.

  7. Does Wnt/β-catenin pathway contribute to the stability of DNMT1 expression in urological cancer cell lines?

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    Varol, Nuray; Konac, Ece; Bilen, Cenk Y

    2015-05-01

    DNA methylation is considered as one of the most important epigenetic mechanisms and it is catalyzed by DNA methyltransferases (DNMTs). DNMT1 abundance has been frequently seen in urogenital system tumors but the reasons for this abundance are not well understood. We aimed to look into the effects of Wnt/β-catenin signaling pathway on overexpression of DNMT1 and aberrant expression of UHRF1 and HAUSP which are responsible for stability of DNMT1 at transcriptional and protein levels in urogenital cancers. In this context, firstly, Wnt/β-catenin signaling pathway was activated by using SB216763 which is a glycogen synthase kinase-3 (GSK3) β inhibitor. Cell proliferation levels in bladder cancer cells, renal cell carcinoma, and prostate cancer cells treated with GSK3β inhibitor (SB216763) were detected by WST-1 reagent. WIF-1 gene methylation profile was determined by methylation-specific PCR (MSP); expression levels of target genes β-catenin and WIF-1 by real-time PCR; and protein levels of β-catenin, DNMT1, pGSK3β(Ser9), HAUSP, and UHRF1 by Western Blot. Our results indicated that treatment with SB216763 caused an increased cell proliferation at low dose. mRNA levels of β-catenin increased after treatment with SB216273 and protein levels of pGSK3β(Ser9), β-catenin, and DNMT1 increased in comparison to control. HAUSP and UHRF1 were either up-regulated or down-regulated at the same doses depending on the type of cancer. Also, we showed that protein levels of DNMT1, β-catenin, HAUSP, and UHRF1 decreased after re-expression of WIF-1 following treatment with DAC. In Caki-2 cells, β-catenin pathway might have accounted for the stability of DNMT1 expression, whereas such relation is not valid for T24 and PC3 cells. Our findings may offer a new approach for determination of molecular effects of Wnt/β-catenin signal pathway on DNMT1. This may allow us to identify new molecular targets for the treatment of urogenital cancers. PMID:25349215

  8. 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.

  9. NMDA受体的活化调节原代皮层神经元的Wnt/β-catenin信号通路%NMDA Receptor Activation Regulates Wnt/β-catenin Signaling Pathway in Primary Cortical Neurons

    Institute of Scientific and Technical Information of China (English)

    彭彦茜; 万仙子; 李屹晨; 李莎莎; 张薇; Tang Shaojun; 钟翎

    2012-01-01

    Wnt signaling has a key role in regulation of synaptic formation and function in the brain. Gluta-mate, which is the mainly excitatory transmitter, binds the glutamic acid receptor to regulate the activity of many signaling pathways. To determine the effect of NMDA receptor activation on Wnt/p-catenin signaling, primary cortical C57 mouse neurons were treated with 10 umol/L MSG and 50 umol/L NMDA and the components of Wnt/ p-catenin signaling were analyzed by Western blot or immunofluorescent experiments. We found that NMDA receptor activation not only increased the p-Ser9-GSK-3p to inhibit its activity but also caused an increase of intracellu-lar P-catenin and induced its translocation into nuclei, thereby up-regulated the downstream gene expression. These results suggest that NMDA receptors activation up-regulates Wnt/p-catenin signaling in primary cortical cultured neurons.%经典的Wnt/β-catenin信号通路在中枢神经系统突触形成和功能中发挥重要的调节作用.作为兴奋性神经递质的谷氨酸,与其受体结合,参与许多信号调节活动.为了探讨NMDA受体活化对Wnt/βcatenin信号通路的作用,该文利用18d的C57小鼠胚胎培养皮层神经元(离体10 d),用10 μmol/L谷氨酸钠(monosodium glutamate,MSG)和50 μmol/L N-甲基-D-天冬氨酸(NMDA)处理细胞,通过蛋白免疫印迹技术或者细胞免疫荧光染色分析Wnt/β-catenin信号通路关键成员.结果发现,NMDA受体的活化能使GSK-3β的Ser9位磷酸化水平增加,活性被抑制,胞浆内β-catenin蛋白降解减少,入核增加,激活下游基因表达.这些结果提示,NMDA受体激活能够上调Wnt/β-catenin信号通路.

  10. Canonical pathways, networks and transcriptional factor regulation by clinical strains of Mycobacterium tuberculosis in pulmonary alveolar epithelial cells.

    Science.gov (United States)

    Mvubu, Nontobeko E; Pillay, Balakrishna; Gamieldien, Junaid; Bishai, William; Pillay, Manormoney

    2016-03-01

    Limited knowledge exists on pathways, networks and transcriptional factors regulated within epithelial cells by diverse Mycobacterium tuberculosis genotypes. This study aimed to elucidate these mechanisms induced in A549 epithelial cells by dominant clinical strains in KwaZulu-Natal, South Africa. RNA for sequencing was extracted from epithelial cells at 48 h post-infection with 5 strains at a multiplicity of infection of approximately 10:1. Bioinformatics analysis performed with the RNA-Seq Tuxedo pipeline identified differentially expressed genes. Changes in pathways, networks and transcriptional factors were identified using Ingenuity Pathway Analysis (IPA). The interferon signalling and hepatic fibrosis/hepatic stellate cell activation pathways were among the top 5 canonical pathways in all strains. Hierarchical clustering for enrichment of cholesterol biosynthesis and immune associated pathways revealed similar patterns for Beijing and Unique; F15/LAM4/KZN and F11; and, F28 and H37Rv strains, respectively. However, the induction of top scoring networks varied among the strains. Among the transcriptional factors, only EHL, IRF7, PML, STAT1, STAT2 and VDR were induced by all clinical strains. Activation of the different pathways, networks and transcriptional factors revealed in the current study may be an underlying mechanism that results in the differential host response by clinical strains of M. tuberculosis. PMID:26980499

  11. Lens regeneration from the cornea requires suppression of Wnt/β-catenin signaling.

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    Hamilton, Paul W; Sun, Yu; Henry, Jonathan J

    2016-04-01

    The frog, Xenopus laevis, possesses a high capacity to regenerate various larval tissues, including the lens, which is capable of complete regeneration from the cornea epithelium. However, the molecular signaling mechanisms of cornea-lens regeneration are not fully understood. Previous work has implicated the involvement of the Wnt signaling pathway, but molecular studies have been very limited. Iris-derived lens regeneration in the newt (Wolffian lens regeneration) has shown a necessity for active Wnt signaling in order to regenerate a new lens. Here we provide evidence that the Wnt signaling pathway plays a different role in the context of cornea-lens regeneration in Xenopus. We examined the expression of frizzled receptors and wnt ligands in the frog cornea epithelium. Numerous frizzled receptors (fzd1, fzd2, fzd3, fzd4, fzd6, fzd7, fzd8, and fzd10) and wnt ligands (wnt2b.a, wnt3a, wnt4, wnt5a, wnt5b, wnt6, wnt7b, wnt10a, wnt11, and wnt11b) are expressed in the cornea epithelium, demonstrating that this tissue is transcribing many of the ligands and receptors of the Wnt signaling pathway. When compared to flank epithelium, which is lens regeneration incompetent, only wnt11 and wnt11b are different (present only in the cornea epithelium), identifying them as potential regulators of cornea-lens regeneration. To detect changes in canonical Wnt/β-catenin signaling occurring within the cornea epithelium, axin2 expression was measured over the course of regeneration. axin2 is a well-established reporter of active Wnt/β-catenin signaling, and its expression shows a significant decrease at 24 h post-lentectomy. This decrease recovers to normal endogenous levels by 48 h. To test whether this signaling decrease was necessary for lens regeneration to occur, regenerating eyes were treated with either 6-bromoindirubin-3'-oxime (BIO) or 1-azakenpaullone - both activators of Wnt signaling - resulting in a significant reduction in the percentage of cases with successful

  12. R-spondin 3 regulates dorsoventral and anteroposterior patterning by antagonizing Wnt/β-catenin signaling in zebrafish embryos.

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    Xiaozhi Rong

    Full Text Available The Wnt/β-catenin or canonical Wnt signaling pathway plays fundamental roles in early development and in maintaining adult tissue homeostasis. R-spondin 3 (Rspo3 is a secreted protein that has been implicated in activating the Wnt/β-catenin signaling in amphibians and mammals. Here we report that zebrafish Rspo3 plays a negative role in regulating the zygotic Wnt/β-catenin signaling. Zebrafish Rspo3 has a unique domain structure. It contains a third furin-like (FU3 domain. This FU3 is present in other four ray-finned fish species studied but not in elephant shark. In zebrafish, rspo3 mRNA is maternally deposited and has a ubiquitous expression in early embryonic stages. After 12 hpf, its expression becomes tissue-specific. Forced expression of rspo3 promotes dorsoanterior patterning and increases the expression of dorsal and anterior marker genes. Knockdown of rspo3 increases ventral-posterior development and stimulates ventral and posterior marker genes expression. Forced expression of rspo3 abolishes exogenous Wnt3a action and reduces the endogenous Wnt signaling activity. Knockdown of rspo3 results in increased Wnt/β-catenin signaling activity. Further analyses indicate that Rspo3 does not promote maternal Wnt signaling. Human RSPO3 has similar action when tested in zebrafish embryos. These results suggest that Rspo3 regulates dorsoventral and anteroposterior patterning by negatively regulating the zygotic Wnt/β-catenin signaling in zebrafish embryos.

  13. Lipopolysaccharide-induced activation of NF-{kappa}B non-canonical pathway requires BCL10 serine 138 and NIK phosphorylations

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    Bhattacharyya, Sumit; Borthakur, Alip; Dudeja, Pradeep K. [Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, IL 60612-7227 (United States); Tobacman, Joanne K., E-mail: jkt@uic.edu [Department of Medicine, University of Illinois at Chicago and Jesse Brown VA Medical Center, Chicago, IL 60612-7227 (United States)

    2010-11-15

    Background and aims: B-cell lymphoma/leukemia (BCL)-10 and reactive oxygen species mediate two pathways of NF-{kappa}B (RelA) activation by lipopolysaccharide (LPS) in human colonic epithelial cells. The pathway for LPS activation of RelB by the non-canonical pathway (RelB) in non-myeloid cells was not yet reported, but important for understanding the range of potential microbial LPS-induced effects in inflammatory bowel disease. Methods: Experiments were performed in human colonic epithelial cells and in mouse embryonic fibroblasts deficient in components of the IkappaB kinase (IKK) signalosome, in order to detect mediators of the non-canonical pathway of NF-{kappa}B activation, including nuclear RelB and p52 and phospho- and total NF-{kappa}B inducing kinase (NIK). BCL10 was silenced by siRNA and effects of mutations of specific phosphorylation sites of BCL10 (Ser138Gly and Ser218Gly) were determined. Results: By the non-canonical pathway, LPS exposure increased nuclear RelB and p52, and phospho-NIK, with no change in total NIK. Phosphorylation of BCL10 serine 138 was required for NIK phosphorylation, since mutation of this residue eliminated the increases in phospho-NIK and nuclear RelB and p52. Mutations of either serine 138 or serine 218 reduced RelA, p50, and phospho-I{kappa}B{alpha} of the canonical pathway. Effects of LPS stimulation and BCL10 silencing on NIK phosphorylation were demonstrated in confocal images. Conclusions: LPS induces activation of both canonical and non-canonical pathways of NF-{kappa}B in human colonic epithelial cells, and the non-canonical pathway requires phosphorylations of BCL10 (serine 138) and NIK. These findings demonstrate the important role of BCL10 in mediating LPS-induced inflammation in human colonic epithelial cells and may open new avenues for therapeutic interventions.

  14. Effects of Simulated Microgravity on Wnt/β-catenin Pathway in Osteocytes%模拟微重力效应对骨细胞Wnt/β-catenin通路的影响

    Institute of Scientific and Technical Information of China (English)

    梁萌; 杨肖; 樊瑜波; 孙联文

    2014-01-01

    Objective To explore the effects of simulated microgravity on the activity of Wnt/β-catenin signaling pathway in osteocytes for clarifying the occurance mechanism of bone lose induced by microgravity.Methods MLO-Y4 osteocytes were divided into two groups:simulated microgravity group and control group.Cells were cultured with rotation to simulate microgravity.RT-PCR and Western blot were used to examine components of gene and protein expression level related to Wnt/β-catenin signaling pathway.Results The results of simulated microgravity group to be compared with control group:the mRNA' s expression of Cyclin D1 and Lef-1 was significantly decreased (P < 0.05),but of CX43 and SOST was significantly increased (P < 0.05),as well as the expression of Wnt3a,Lrp5 and β-catenin had no significant difference; Moreover,the protein' s expression of β-catenin,Cyclin D1 and CX43 was significantly decreased (P < 0.05),but of Lef-1 and Sclerostin was significantly increased (P <0.05),as well as the expression of Wnt3a,Lrp5/6 and CX43 had no significant difference.Conclusion The activity of Wnt/β-catenin signaling pathway declines in osteocytes under simulated microgravity.%目的 探究模拟微重力效应对骨细胞Wnt/β-catenin信号通路活性的影响,以阐明微重力导致骨质丢失的发生机制.方法 将骨细胞MLO-Y4分为两组:模拟微重力组和静置对照组.细胞旋转培养以模拟微重力效应,利用RT-PCR和Western blot法检测细胞Wnt/β-catenin信号通路相关组分的基因和蛋白表达水平.结果 RT-PCR结果显示,模拟微重力组的Cyclin D1和Lef-1 mRNA水平显著低于对照组(P<0.05),CX43和抑制剂SOST的mRNA水平显著高于对照组(P<0.05),而两组的Wnt3a、Lrp5和β-catenin的mRNA水平无显著性差异.Western blot结果显示,模拟微重力组的β-catenin和Cyclin D1的蛋白表达水平显著低于对照组(P<0.05),Lef-1和抑制剂SOST蛋白质的表达水平显著高于对照组(P<0

  15. Diverse roles for Wnt7a in ventral midbrain neurogenesis and dopaminergic axon morphogenesis.

    Science.gov (United States)

    Fernando, Chathurini V; Kele, Julianna; Bye, Christopher R; Niclis, Jonathan C; Alsanie, Walaa; Blakely, Brette D; Stenman, Jan; Turner, Brad J; Parish, Clare L

    2014-09-01

    During development of the central nervous system, trophic, together with genetic, cues dictate the balance between cellular proliferation and differentiation. Subsequent to the birth of new neurons, additional intrinsic and extrinsic signals regulate the connectivity of these cells. While a number of regulators of ventral midbrain (VM) neurogenesis and dopaminergic (DA) axon guidance are known, we identify a number of novel roles for the secreted glycoprotein, Wnt7a, in this context. We demonstrate a temporal and spatial expression of Wnt7a in the VM, indicative of roles in neurogenesis, differentiation, and axonal growth and guidance. In primary VM cultures, and validated in Wnt7a-deficient mice, we show that the early expression within the VM is important for regulating VM progenitor proliferation, cell cycle progression, and cell survival, thereby dictating the number of midbrain Nurr1 precursors and DA neurons. During early development of the midbrain DA pathways, Wnt7a promotes axonal elongation and repels DA neurites out of the midbrain. Later, Wnt7a expression in the VM midline suggests a role in preventing axonal crossing while expression in regions flanking the medial forebrain bundle (thalamus and hypothalamus) ensured appropriate trajectory of DA axons en route to their forebrain targets. We show that the effects of Wnt7a in VM development are mediated, at least in part, by the β-catenin/canonical pathways. Together, these findings identify Wnt7a as a new regulator of VM neurogenesis and DA axon growth and guidance.

  16. Ricinine: a pyridone alkaloid from Ricinus communis that activates the Wnt signaling pathway through casein kinase 1α.

    Science.gov (United States)

    Ohishi, Kensuke; Toume, Kazufumi; Arai, Midori A; Sadhu, Samir K; Ahmed, Firoj; Mizoguchi, Takamasa; Itoh, Motoyuki; Ishibashi, Masami

    2014-09-01

    Wnt signaling plays important roles in proliferation, differentiation, development of cells, and various diseases. Activity-guided fractionation of the MeOH extract of the Ricinus communis stem led to the isolation of four compounds (1-4). The TCF/β-catenin transcription activities of 1 and 3 were 2.2 and 2.5 fold higher at 20 and 30μM, respectively. Cells treated with ricinine (1) had higher β-catenin and lower of p-β-catenin (ser 33, 37, 45, Thr 41) protein levels, whereas glycogen synthase kinase 3β (GSK3β) and casein kinase 1α (CK1α) protein levels remained unchanged. Cells treated with pyrvinium, an activator of CK1α, had lower β-catenin levels. However, the combined treatment of pyrvinium and 1 led to higher β-catenin levels than those in cells treated with pyrvinium alone, which suggested that 1 inhibited CK1α activity. Furthermore, 1 increased β-catenin protein levels in zebrafish embryos. These results indicated that 1 activated the Wnt signaling pathway by inhibiting CK1α.

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

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    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.

  18. A possible zebrafish model of polycystic kidney disease: knockdown of wnt5a causes cysts in zebrafish kidneys.

    Science.gov (United States)

    Huang, Liwei; Xiao, An; Wecker, Andrea; McBride, Daniel A; Choi, Soo Young; Zhou, Weibin; Lipschutz, Joshua H

    2014-12-02

    Polycystic kidney disease (PKD) is one of the most common causes of end-stage kidney disease, a devastating disease for which there is no cure. The molecular mechanisms leading to cyst formation in PKD remain somewhat unclear, but many genes are thought to be involved. Wnt5a is a non-canonical glycoprotein that regulates a wide range of developmental processes. Wnt5a works through the planar cell polarity (PCP) pathway that regulates oriented cell division during renal tubular cell elongation. Defects of the PCP pathway have been found to cause kidney cyst formation. Our paper describes a method for developing a zebrafish cystic kidney disease model by knockdown of the wnt5a gene with wnt5a antisense morpholino (MO) oligonucleotides. Tg(wt1b:GFP) transgenic zebrafish were used to visualize kidney structure and kidney cysts following wnt5a knockdown. Two distinct antisense MOs (AUG - and splice-site) were used and both resulted in curly tail down phenotype and cyst formation after wnt5a knockdown. Injection of mouse Wnt5a mRNA, resistant to the MOs due to a difference in primary base pair structure, rescued the abnormal phenotype, demonstrating that the phenotype was not due to "off-target" effects of the morpholino. This work supports the validity of using a zebrafish model to study wnt5a function in the kidney.

  19. Wnt5a signaling is a substantial constituent in bone morphogenetic protein-2-mediated osteoblastogenesis.

    Science.gov (United States)

    Nemoto, Eiji; Ebe, Yukari; Kanaya, Sousuke; Tsuchiya, Masahiro; Nakamura, Takashi; Tamura, Masato; Shimauchi, Hidetoshi

    2012-06-15

    Wnts are secreted glycoproteins that mediate developmental and post-developmental physiology by regulating cellular processes including proliferation, differentiation, and apoptosis through β-catenin-dependent canonical and β-catenin-independent noncanonical pathway. It has been reported that Wnt5a activates noncanonical Wnt signaling through receptor tyrosine kinase-like orphan receptor 2 (Ror2). Although it appears that Wnt5a/Ror2 signaling supports normal bone physiology, the biological significance of noncanonical Wnts in osteogenesis is essentially unknown. In this study, we identified expression of Wnt5a in osteoblasts in the ossification zone of the tibial growth plate as well as bone marrow of the rat tibia as assessed by immunohistochemistry. In addition, we show that osteoblastic differentiation mediated by BMP-2 is associated with increased expression of Wnt5a and Ror2 using cultured pre-osteoblasts, MC3T3-E1 cells. Silencing gene expression of Wnt5a and Ror2 in MC3T3-E1 cells results in suppression of BMP-2-mediated osteoblastic differentiation, suggesting that Wnt5a and Ror2 signaling are of substantial importance for BMP-2-mediated osteoblastic differentiation. BMP-2 stimulation induced phosphorylation of Smad1/5/8 in a similar fashion in both siWnt5a-treated cells and control cells, suggesting that Wnt5a was dispensable for the phosphorylation of Smads by BMP-2. Taken together, our results suggest that Wnt5a/Ror2 signaling appears to be involved in BMP-2-mediated osteoblast differentiation in a Smad independent pathway.

  20. The NAV2 homolog Sickie regulates F-actin-mediated axonal growth in Drosophila mushroom body neurons via the non-canonical Rac-Cofilin pathway.

    Science.gov (United States)

    Abe, Takashi; Yamazaki, Daisuke; Murakami, Satoshi; Hiroi, Makoto; Nitta, Yohei; Maeyama, Yuko; Tabata, Tetsuya

    2014-12-01

    The Rac-Cofilin pathway is essential for cytoskeletal remodeling to control axonal development. Rac signals through the canonical Rac-Pak-LIMK pathway to suppress Cofilin-dependent axonal growth and through a Pak-independent non-canonical pathway to promote outgrowth. Whether this non-canonical pathway converges to promote Cofilin-dependent F-actin reorganization in axonal growth remains elusive. We demonstrate that Sickie, a homolog of the human microtubule-associated protein neuron navigator 2, cell-autonomously regulates axonal growth of Drosophila mushroom body (MB) neurons via the non-canonical pathway. Sickie was prominently expressed in the newborn F-actin-rich axons of MB neurons. A sickie mutant exhibited axonal growth defects, and its phenotypes were rescued by exogenous expression of Sickie. We observed phenotypic similarities and genetic interactions among sickie and Rac-Cofilin signaling components. Using the MARCM technique, distinct F-actin and phospho-Cofilin patterns were detected in developing axons mutant for sickie and Rac-Cofilin signaling regulators. The upregulation of Cofilin function alleviated the axonal defect of the sickie mutant. Epistasis analyses revealed that Sickie suppresses the LIMK overexpression phenotype and is required for Pak-independent Rac1 and Slingshot phosphatase to counteract LIMK. We propose that Sickie regulates F-actin-mediated axonal growth via the non-canonical Rac-Cofilin pathway in a Slingshot-dependent manner.

  1. Aberrant Wnt Signaling in Leukemia.

    Science.gov (United States)

    Staal, Frank J T; Famili, Farbod; Garcia Perez, Laura; Pike-Overzet, Karin

    2016-01-01

    The Wnt signaling pathway is essential in the development and homeostasis of blood and immune cells, but its exact role is still controversial and is the subject of intense research. The malignant counterpart of normal hematopoietic cells, leukemic (stem) cells, have hijacked the Wnt pathway for their self-renewal and proliferation. Here we review the multiple ways dysregulated Wnt signaling can contribute to leukemogenesis, both cell autonomously as well as by changes in the microenvironment. PMID:27571104

  2. Genome-wide pathway analysis of memory impairment in the Alzheimer's Disease Neuroimaging Initiative (ADNI) cohort implicates gene candidates, canonical pathways, and networks.

    Science.gov (United States)

    Ramanan, Vijay K; Kim, Sungeun; Holohan, Kelly; Shen, Li; Nho, Kwangsik; Risacher, Shannon L; Foroud, Tatiana M; Mukherjee, Shubhabrata; Crane, Paul K; Aisen, Paul S; Petersen, Ronald C; Weiner, Michael W; Saykin, Andrew J

    2012-12-01

    Memory deficits are prominent features of mild cognitive impairment (MCI) and Alzheimer's disease (AD). The genetic architecture underlying these memory deficits likely involves the combined effects of multiple genetic variants operative within numerous biological pathways. In order to identify functional pathways associated with memory impairment, we performed a pathway enrichment analysis on genome-wide association data from 742 Alzheimer's Disease Neuroimaging Initiative (ADNI) participants. A composite measure of memory was generated as the phenotype for this analysis by applying modern psychometric theory to item-level data from the ADNI neuropsychological test battery. Using the GSA-SNP software tool, we identified 27 canonical, expertly-curated pathways with enrichment (FDR-corrected p-value consolidation, such as neurotransmitter receptor-mediated calcium signaling and long-term potentiation, were highly represented among the enriched pathways. In addition, pathways related to cell adhesion, neuronal differentiation and guided outgrowth, and glucose- and inflammation-related signaling were also enriched. Among genes that were highly-represented in these enriched pathways, we found indications of coordinated relationships, including one large gene set that is subject to regulation by the SP1 transcription factor, and another set that displays co-localized expression in normal brain tissue along with known AD risk genes. These results 1) demonstrate that psychometrically-derived composite memory scores are an effective phenotype for genetic investigations of memory impairment and 2) highlight the promise of pathway analysis in elucidating key mechanistic targets for future studies and for therapeutic interventions. PMID:22865056

  3. Resveratrol inhibits breast cancer stem-like cells and induces autophagy via suppressing Wnt/β-catenin signaling pathway.

    Directory of Open Access Journals (Sweden)

    Yujie Fu

    Full Text Available Resveratrol, a natural polyphenolic compound, is abundantly found in plant foods and has been extensively studied for its anti-cancer properties. Given the important role of CSCs (Cancer Stem Cells in breast tumorigenesis and progression, it is worth investigating the effects of resveratrol on CSCs. The article is an attempt to investigate the effects of resveratrol on breast CSCs. Resveratrol significantly inhibits the proliferation of BCSCs (breast cancer stem-like cells isolated from MCF-7 and SUM159, and decreased the percentage of BCSCs population, consequently reduced the size and number of mammospheres in non-adherent spherical clusters. Accordingly, the injection of resveratrol (100 mg/kg/d in NOD/SCID (nonobese diabetic/severe combined immunodeficient mice effectively inhibited the growth of xenograft tumors and reduced BCSC population in tumor cells. After the reimplantation of primary tumor cells into the secondary mice for 30 d, all 6 control inoculations produced tumors, while tumor cells derived from resveratrol-treated mice only caused 1 tumor of 6 inoculations. Further studies by TEM (Transmission electron microscopy analysis, GFP-LC3-II puncta formation assay and western blot for LC3-II, Beclin1 and Atg 7, showed that resveratrol induces autophagy in BCSCs. Moreover, resveratrol suppresses Wnt/β-catenin signaling pathway in BCSCs; over-expression of β-catenin by transfecting the plasmid markedly reduced resveratrol-induced cytotoxicity and autophagy in BCSCs. Our findings indicated that resveratrol inhibits BCSCs and induces autophagy via suppressing Wnt/β-catenin signaling pathway.

  4. Wnt5a signaling is a substantial constituent in bone morphogenetic protein-2-mediated osteoblastogenesis

    Energy Technology Data Exchange (ETDEWEB)

    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); Ebe, Yukari; Kanaya, Sousuke [Department of Periodontology and Endodontology, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Tsuchiya, Masahiro [Department of Aging and Geriatric Dentistry, Tohoku University Graduate School of Dentistry, Sendai 980-8575 (Japan); Nakamura, Takashi [Department of Pediatric 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)

    2012-06-15

    Highlights: Black-Right-Pointing-Pointer Wnt5a is identified in osteoblasts in tibial growth plate and bone marrow. Black-Right-Pointing-Pointer Osteoblastic differentiation is associated with increased expression of Wnt5a/Ror2. Black-Right-Pointing-Pointer Wnt5a/Ror2 signaling is important for BMP-2-mediated osteoblastic differentiation. Black-Right-Pointing-Pointer Wnt5a/Ror2 operates independently of BMP-Smad pathway. -- Abstract: Wnts are secreted glycoproteins that mediate developmental and post-developmental physiology by regulating cellular processes including proliferation, differentiation, and apoptosis through {beta}-catenin-dependent canonical and {beta}-catenin-independent noncanonical pathway. It has been reported that Wnt5a activates noncanonical Wnt signaling through receptor tyrosine kinase-like orphan receptor 2 (Ror2). Although it appears that Wnt5a/Ror2 signaling supports normal bone physiology, the biological significance of noncanonical Wnts in osteogenesis is essentially unknown. In this study, we identified expression of Wnt5a in osteoblasts in the ossification zone of the tibial growth plate as well as bone marrow of the rat tibia as assessed by immunohistochemistry. In addition, we show that osteoblastic differentiation mediated by BMP-2 is associated with increased expression of Wnt5a and Ror2 using cultured pre-osteoblasts, MC3T3-E1 cells. Silencing gene expression of Wnt5a and Ror2 in MC3T3-E1 cells results in suppression of BMP-2-mediated osteoblastic differentiation, suggesting that Wnt5a and Ror2 signaling are of substantial importance for BMP-2-mediated osteoblastic differentiation. BMP-2 stimulation induced phosphorylation of Smad1/5/8 in a similar fashion in both siWnt5a-treated cells and control cells, suggesting that Wnt5a was dispensable for the phosphorylation of Smads by BMP-2. Taken together, our results suggest that Wnt5a/Ror2 signaling appears to be involved in BMP-2-mediated osteoblast differentiation in a Smad independent

  5. Wnt5a signaling is a substantial constituent in bone morphogenetic protein-2-mediated osteoblastogenesis

    International Nuclear Information System (INIS)

    Highlights: ► Wnt5a is identified in osteoblasts in tibial growth plate and bone marrow. ► Osteoblastic differentiation is associated with increased expression of Wnt5a/Ror2. ► Wnt5a/Ror2 signaling is important for BMP-2-mediated osteoblastic differentiation. ► Wnt5a/Ror2 operates independently of BMP-Smad pathway. -- Abstract: Wnts are secreted glycoproteins that mediate developmental and post-developmental physiology by regulating cellular processes including proliferation, differentiation, and apoptosis through β-catenin-dependent canonical and β-catenin-independent noncanonical pathway. It has been reported that Wnt5a activates noncanonical Wnt signaling through receptor tyrosine kinase-like orphan receptor 2 (Ror2). Although it appears that Wnt5a/Ror2 signaling supports normal bone physiology, the biological significance of noncanonical Wnts in osteogenesis is essentially unknown. In this study, we identified expression of Wnt5a in osteoblasts in the ossification zone of the tibial growth plate as well as bone marrow of the rat tibia as assessed by immunohistochemistry. In addition, we show that osteoblastic differentiation mediated by BMP-2 is associated with increased expression of Wnt5a and Ror2 using cultured pre-osteoblasts, MC3T3-E1 cells. Silencing gene expression of Wnt5a and Ror2 in MC3T3-E1 cells results in suppression of BMP-2-mediated osteoblastic differentiation, suggesting that Wnt5a and Ror2 signaling are of substantial importance for BMP-2-mediated osteoblastic differentiation. BMP-2 stimulation induced phosphorylation of Smad1/5/8 in a similar fashion in both siWnt5a-treated cells and control cells, suggesting that Wnt5a was dispensable for the phosphorylation of Smads by BMP-2. Taken together, our results suggest that Wnt5a/Ror2 signaling appears to be involved in BMP-2-mediated osteoblast differentiation in a Smad independent pathway.

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

    Directory of Open Access Journals (Sweden)

    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.

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

    Directory of Open Access Journals (Sweden)

    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.

  8. The WNT/β-catenin pathway is involved in the anti-adipogenic activity of cerebrosides from the sea cucumber Cucumaria frondosa.

    Science.gov (United States)

    Xu, Hui; Wang, Fei; Wang, Jingfeng; Xu, Jie; Wang, Yuming; Xue, Changhu

    2015-07-01

    Both adipocyte hypertrophy and hyperplasia lead to obesity. Here, we isolated cerebrosides from the sea cucumber Cucumaria frondosa (CFC) and examined its anti-adipogenic activity in vitro. CFC inhibited the lipid accumulation of 3T3-L1 cells and suppressed PPARγ and C/EBPα expressions, proving its anti-adipogenic activity. Furthermore, CFC suppressed lipogenesis in mature adipocytes. The WNT/β-catenin pathway acts as an anti-adipogenic factor. CFC enhanced β-catenin expression, promoted its nuclear translocation and up-regulated the expression of CCND1 and c-myc, two target genes of β-catenin. Moreover, after cells were treated with the β-catenin inhibitor 21H7, β-catenin nuclear translocation and transcription activity can be recovered by CFC. These findings suggested that CFC promoted the activation of the WNT/β-catenin pathway. Besides, CFC enhanced the expressions of Fz1, LRP5 and LRP6, while it had no effect on the expressions of Wnt10b and GSK3β. These findings indicated that CFC exhibits anti-adipogenic activity through enhancing the activation of the WNT/β-catenin pathway, which was mediated by FZ and LRPs. PMID:26091058

  9. ET-1 Promotes Differentiation of Periodontal Ligament Stem Cells into Osteoblasts through ETR, MAPK, and Wnt/β-Catenin Signaling Pathways under Inflammatory Microenvironment

    Directory of Open Access Journals (Sweden)

    Li Liang

    2016-01-01

    Full Text Available Periodontitis is a kind of chronic inflammatory disease that affects the tooth-supporting tissues. ET-1 is related to periodontitis and involved in the regulation of cytokines, but the mechanisms remain unclear. The aim of this study is to investigate how ET-1 affects proinflammatory cytokine expression and differentiation in human periodontal ligament stem cells (PDLSCs. PDLSCs were isolated from the periodontal ligament tissues of periodontitis patients and then treated with ET-1 (1, 10, or 100 nM for 12 h, 24 h, or 72 h. The osteogenic potential of PDLSCs was tested using ALP staining. TNF-α, IL-1β, and IL-6 levels were evaluated by ELISA and western blot. Runx2, OCN, and COL1 mRNA and western levels were detected by RT-PCR and western blot, respectively. To examine the signaling pathways and molecular mechanisms involved in ET-1-mediated cytokine expression and osteogenic differentiation, ETR pathway, MAPKs pathway, Wnt/β-catenin pathway, and Wnt/Ca2+ pathway were detected by RT-PCR and western blot, respectively. ET-1 promoted differentiation of PDLSCs into osteoblasts by increasing secretion of TNF-α, IL-1β, and IL-6 in a dose- and time-dependent manner. ET-1 also increased expression of Runx2, OCN, and COL1. ET-1 promotes differentiation of PDLSCs into osteoblasts through ETR, MAPK, and Wnt/β-catenin signaling pathways under inflammatory microenvironment.

  10. Identification, mechanism of action, and antitumor activity of a small molecule inhibitor of hippo, TGF-β, and Wnt signaling pathways.

    Science.gov (United States)

    Basu, Dipanjan; Lettan, Robert; Damodaran, Krishnan; Strellec, Susan; Reyes-Mugica, Miguel; Rebbaa, Abdelhadi

    2014-06-01

    Embryonic signaling pathways, in particular those mediated by Wnt and TGF-β, are known to play key roles in tumor progression through the induction of epithelial-mesenchymal transition (EMT). Their simultaneous targeting could therefore represent a desirable anticancer strategy. On the basis of recent findings that both Wnt and TGF-β-associated pathways are regulated by Hippo signaling in mammalian cells, we reasoned that targeting the latter would be more effective in inhibiting EMT. In a search for such inhibitors, we identified a small molecule (C19) with remarkable inhibitory activity not only against Hippo, but also against Wnt and TGF-β pathways. C19 inhibited cancer cell migration, proliferation, and resistance to doxorubicin in vitro, and exerted strong antitumor activity in a mouse tumor model. Mechanistically, C19 induced GSK3-β-mediated degradation of the Hippo transducer TAZ, through activation of the Hippo kinases Mst/Lats and the tumor suppressor kinase AMPK upstream of the degradation complex. Overall, this study identified C19 as a multi-EMT pathway inhibitor with a unique mechanism of action. The findings that both AMPK and Mst/Lats mediate the antitumor activity of C19 shed light on a potential cross-talk between metabolic and organ size control pathways in regulating cancer progression. By simultaneously targeting these two pathways, C19 may represent a new type of agents to suppress cancer progression and/or its recurrence. PMID:24694946

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

    Directory of Open Access Journals (Sweden)

    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.

  12. Wnt信号通路影响肺癌干细胞机制的研究进展%Research progress of Wnt pathway on lung cancer stem cells

    Institute of Scientific and Technical Information of China (English)

    李小江; 贾英杰; 张文治; 张莹; 娄怡

    2012-01-01

    By studying a total of 31 papers searched with lung cancer stem cells and Wnt pathway as key words in Medline, Pubtned and CNKI databases from 2001 to 2011, we found that the Wnt pathway played its role in cell through the following three channels : Wnt classical signaling pathway, Wnt-Ca2 + pathway and the Wnt-cell plane polarization. As the most critical signaling molecule in the Wnt pathway,the Wnt/-catenin signaling pathway plays an important role in maintaining the cell proliferation and clone formation of lung cancer stem cells, which can restrain the proliferation of lung cancer stem cells by influencing key protein. It provides a new method in the treatment of lung cancer.%检索2001年至2011年Medline、PubMed及CNKI期刊全文数据库检索系统与Wnt信号通路及肺癌干细胞相关的中、英文文献发现,Wnt信号主要通过Wnt经典信号传导途径、Wnt-Ca2+途径、Wnt-细胞平面极化途径在细胞中起作用.作为Wnt信号通路中最关键的通道传递分子,Wnt/β-catenin信号通路在维持肺癌干细胞的增殖和克隆形成方面发挥着重要作用,通过对关键蛋白的影响抑制肺癌干细胞增殖,为肺癌的治疗提供了新路径.

  13. Wnt/β-catenin-signaling and the formation of Müller glia-derived progenitors in the chick retina.

    Science.gov (United States)

    Gallina, Donika; Palazzo, Isabella; Steffenson, Lillia; Todd, Levi; Fischer, Andy J

    2016-09-01

    Müller glia can be stimulated to de-differentiate, proliferate, and form Müller glia-derived progenitor cells (MGPCs) that are capable of producing retinal neurons. The signaling pathways that influence the de-differentiation of mature Müller glia and proliferation of MGPCs may include the Wnt-pathway. The purpose of this study was to investigate how Wnt-signaling influences the formation of MGPCs in the chick retina in vivo. In NMDA-damaged retinas where MGPCs are known to form, we find dynamic changes in retinal levels of potential readouts of Wnt-signaling, including dkk1, dkk3, axin2, c-myc, tcf-1, and cd44. We find accumulations of nuclear β-catenin in MGPCs that peaks at 3 days and rapidly declines by 5 days after NMDA-treatment. Inhibition of Wnt-signaling with XAV939 in damaged retinas suppressed the formation of MGPCs, increased expression of ascl1a and decreased hes5, but had no effect upon the differentiation of progeny produced by MGPCs. Activation of Wnt-signaling, with GSK3β-inhibitors, in the absence of retinal damage, failed to stimulate the formation of MGPCs, whereas activation of Wnt-signaling in damaged retinas stimulated the formation of MGPCs. In the absence of retinal damage, FGF2/MAPK-signaling stimulated the formation of MGPCs by activating a signaling network that includes Wnt/β-catenin. In FGF2-treated retinas, inhibition of Wnt-signaling reduced numbers of proliferating MGPCs, whereas activation of Wnt-signaling failed to influence the formation of proliferating MGPCs. Our findings indicate that Wnt-signaling is part of a network initiated by FGF2/MAPK or retinal damage, and activation of canonical Wnt-signaling is required for the formation of proliferating MGPCs. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 983-1002, 2016. PMID:26663639

  14. Involvement of WNT/β-catenin signaling in the treatment of osteoporosis.

    Science.gov (United States)

    Rossini, Maurizio; Gatti, Davide; Adami, Silvano

    2013-08-01

    Osteoblast differentiation is predominantly regulated by the WNT/β-catenin signaling (canonical WNT pathway), which, together with bone morphogenetic proteins, acts as the master regulator of osteogenesis. The recent characterization of the canonical WNT pathway in the regulation of bone modeling and remodeling provided important insights for our understanding of the pathophysiology of a number of conditions and of the mechanism of action of hormones or drugs with important effect on bone metabolism. This review is mainly focused on the growing therapeutic implications of these new findings. WNT/β-catenin signaling plays a key role in bone tissue by determining the differentiation of stem cells into mature osteoblasts rather than into chondrocytes and adipocytes. Its regulation is predominantly driven by the production of two WNT signaling antagonists: sclerostin (SOST) and Dickkopf-related protein 1 (DKK1). The most proximate regulator of SOST expression by osteocytes and its serum levels is bone mechanical load. SOST expression is increased with advancing age, by glucocorticoid treatment and during treatment with antiresorptive agents such as bisphosphonates and denosumab, while it is decreased by parathyroid hormone excess or administration of estrogens. Correlation between DKK1 serum levels and bone formation in various pathological conditions or during osteoporosis treatment has been reported. Inhibitors of the negative regulators of WNT/β-catenin signaling ("inhibiting the endogenous inhibitors") are potential candidates for the prevention and treatment of bone loss. Inactivating monoclonal antibodies against SOST appears to be the most attractive strategy because SOST is the only component of the WNT pathway expressed almost exclusively by osteocytes.

  15. Developmental Plasticity Is Bound by Pluripotency and the Fgf and Wnt Signaling Pathways

    Directory of Open Access Journals (Sweden)

    Samantha A. Morris

    2012-10-01

    Full Text Available Plasticity is a well-known feature of mammalian development, and yet very little is known about its underlying mechanism. Here, we establish a model system to examine the extent and limitations of developmental plasticity in living mouse embryos. We show that halved embryos follow the same strict clock of developmental transitions as intact embryos, but their potential is not equal. We have determined that unless a minimum of four pluripotent cells is established before implantation, development will arrest. This failure can be rescued by modulating Fgf and Wnt signaling to enhance pluripotent cell number, allowing the generation of monozygotic twins, which is an otherwise rare phenomenon. Knowledge of the minimum pluripotent-cell number required for development to birth, as well as the different potentials of blastomeres, allowed us to establish a protocol for splitting an embryo into one part that develops to adulthood and another that provides embryonic stem cells for that individual.

  16. Developmental plasticity is bound by pluripotency and the Fgf and Wnt signaling pathways.

    Science.gov (United States)

    Morris, Samantha A; Guo, Yu; Zernicka-Goetz, Magdalena

    2012-10-25

    Plasticity is a well-known feature of mammalian development, and yet very little is known about its underlying mechanism. Here, we establish a model system to examine the extent and limitations of developmental plasticity in living mouse embryos. We show that halved embryos follow the same strict clock of developmental transitions as intact embryos, but their potential is not equal. We have determined that unless a minimum of four pluripotent cells is established before implantation, development will arrest. This failure can be rescued by modulating Fgf and Wnt signaling to enhance pluripotent cell number, allowing the generation of monozygotic twins, which is an otherwise rare phenomenon. Knowledge of the minimum pluripotent-cell number required for development to birth, as well as the different potentials of blastomeres, allowed us to establish a protocol for splitting an embryo into one part that develops to adulthood and another that provides embryonic stem cells for that individual.

  17. The Wnt11 Signaling Pathway in Potential Cellular EMT and Osteochondral Differentiation Progression in Nephrolithiasis Formation

    Directory of Open Access Journals (Sweden)

    Deng He

    2015-07-01

    Full Text Available The molecular events leading to nephrolithiasis are extremely complex. Previous studies demonstrated that calcium and transforming growth factor-β1 (TGF-β1 may participate in the pathogenesis of stone formation, but the explicit mechanism has not been defined. Using a self-created genetic hypercalciuric stone-forming (GHS rat model, we observed that the increased level of serous/uric TGF-β1 and elevated intracellular calcium in primary renal tubular epithelial cells (PRECs was associated with nephrolithiasis progression in vivo. In the setting of high calcium plus high TGF-β1 in vitro, PRECs showed great potential epithelial to mesenchymal transition (EMT progression and osteochondral differentiation properties, representing the multifarious increased mesenchymal and osteochondral phenotypes (Zeb1, Snail1, Col2A1, OPN, Sox9, Runx2 and decreased epithelial phenotypes (E-cadherin, CK19 bythe detection of mRNAs and corresponding proteins. Moreover, TGF-β-dependent Wnt11 knockdown and L-type Ca2+ channel blocker could greatly reverse EMT progression and osteochondral differentiation in PRECs. TGF-β1 alone could effectively promote EMT, but it had no effect on osteochondral differentiation in NRK cells (Rat kidney epithelial cell line. Stimulation with Ca2+ alone did not accelerate differentiation of NRK. Co-incubation of extracellular Ca2+ and TGF-β1 synergistically promotes EMT and osteochondral differentiation in NRK control cells. Our data supplied a novel view that the pathogenesis of calcium stone development may be associated with synergic effects of TGF-β1 and Ca2+, which promote EMT and osteochondral differentiation via Wnt11 and the L-type calcium channel.

  18. Wnt-10b secreted from lymphocytes promotes differentiation of skin epithelial cells

    International Nuclear Information System (INIS)

    Wnt-10b was originally isolated from lymphoid tissue and is known to be involved in a wide range of biological actions, while recently it was found to be expressed early in the development of hair follicles. However, few studies have been conducted concerning the role of Wnt-10b with the differentiation of skin epithelial cells. To evaluate its role in epithelial differentiation, we purified Wnt-10b from the supernatant of a concanavalin A-stimulated lymphocyte culture using an affinity column and investigated its effects on the differentiation of adult mouse-derived primary skin epithelial cells (MPSEC). MPSEC cultured with Wnt-10b showed morphological changes from cuboidal to spindle-shaped with inhibited proliferation, and also obtained characteristics of the hair shaft and inner root sheath of the hair follicle, represented by red-colored Ayoub Shklar staining, and reactions to AE-13 and AE-15 as seen with immunocytology. Further, RT-PCR analysis demonstrated the expression of mRNA for keratin 1, keratin 2, loricrin, mHa5, and mHb5, in association with a decreased expression of the basal cell marker keratin 5, in Wnt-10b-treated MPSEC. In addition, involvement of the canonical Wnt signal pathway was demonstrated by a TCF reporter (pTOPFLASH) assay. These results suggest that Wnt-10b promotes the differentiation of MPSEC and may play an important role in hair follicle development by promoting differentiation of epithelial cells

  19. Wnt/β-catenin signaling in melanoma: Preclinical rationale and novel therapeutic insights.

    Science.gov (United States)

    Xue, Gongda; Romano, Emanuela; Massi, Daniela; Mandalà, Mario

    2016-09-01

    WNT signaling regulates embryonic development and tissue homeostasis in the adult stage. Evolutionarily, activation of the WNT pathway is triggered by a large family of cytokines and activates a broad spectrum of downstream targets through two independent branches mediated by β-catenin (defined as canonical pathway) or PLC and small GTPase (defined as non-canonical pathway), respectively. Recent studies revealed the crucial role of WNT in the maintenance of cell metabolism and stemness as well as its deregulation in tumourigenesis and malignant transformation through oncogenic reprogramming, which contributes to cancer cell proliferation and differentiation, survival, stress response and resistance. In addition, multiple functional mutations discovered in human tumours have been reported to cause malignancy, indicating this pathway as a novel therapeutic target in oncology. Notably, emerging data highlights its involvement in the crosstalk between immune and cancer cells. However, contradictory effects have been also observed in different pre-clinical models when strategic(???) inhibitors are tested. In this review, we address the multifaceted regulatory mechanisms of WNT signaling in cancer, with a particular focus on current melanoma therapy, which has witnessed dramatic improvement in the last five years. PMID:27395773

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

    Science.gov (United States)

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

    2016-07-01

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

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

    Science.gov (United States)

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

    2016-07-01

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

  2. 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.

  3. Wnt Signaling Pathway in Central Nervous System Diseases%Wnt信号通路和中枢神经系统疾病的研究进展

    Institute of Scientific and Technical Information of China (English)

    马义辉(综述); 周杰; 荔志云(审校)

    2014-01-01

    Wnt信号通路作为多细胞真核生物中的重要信号通路,不仅参与神经干细胞的增殖、分化、轴突形成等过程,还调控突触发生、突触囊泡循环等生理过程。最近的研究还证实,Wnt信号通路在血管再生、血管重塑和血脑屏障的形成等生理过程中也发挥着重要作用。近年来的研究证实, Wnt信号通路在脑卒中、阿尔兹海默症和帕金森病等中枢神经系统疾病中发挥着重要的作用。因此,探讨Wnt信号通路与神经系统疾病的病理生理机制和治疗的关系有重要意义。%As an important pathway in multicellular eukaryotes,Wnt signaling pathway not only involves in the proliferation,differentiation and neurite formation process of neural stem cells,but also regulates synap-togenesis,synaptic vesicle recycling,and other physiological processes. Recent studies also confirm that,Wnt signaling pathway plays an important role in angiogenesis,vascular remodeling and formation of blood-brain barrier and other important physiological processes. Recent studies have demonstrated that Wnt signaling pathway plays an important role in stroke,Alzheimer's disease and Parkinson's disease and other central nerv-ous system diseases. So discussing the relationship of the Wnt signaling pathway with the neurological disor-ders’ pathogenesis and treatment has an important significance.

  4. IQGAP1 functions as a modulator of dishevelled nuclear localization in Wnt signaling.

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    Toshiyasu Goto

    Full Text Available Dishevelled (DVL is a central factor in the Wnt signaling pathway, which is highly conserved among various organisms. DVL plays important roles in transcriptional activation in the nucleus, but the molecular mechanisms underlying their nuclear localization remain unclear. In the present study, we identified IQGAP1 as a regulator of DVL function. In Xenopus embryos, depletion of IQGAP1 reduced Wnt-induced nuclear accumulation of DVL, and expression of Wnt target genes during early embryogenesis. The domains in DVL and IQGAP1 that mediated their interaction are also required for their nuclear localization. Endogenous expression of Wnt target genes was reduced by depletion of IQGAP1 during early embryogenesis, but notably not by depletion of other IQGAP family genes. Moreover, expression of Wnt target genes caused by depletion of endogenous IQGAP1 could be rescued by expression of wild-type IQGAP1, but not IQGAP1 deleting DVL binding region. These results provide the first evidence that IQGAP1 functions as a modulator in the canonical Wnt signaling pathway.

  5. Treadmill exercise ameliorates Alzheimer disease-associated memory loss through the Wnt signaling pathway in the streptozotocin-induced diabetic rats.

    Science.gov (United States)

    Kim, Dae-Young; Jung, Sun-Young; Kim, Kijeong; Kim, Chang-Ju

    2016-08-01

    Diabetes mellitus is considered as a risk factor for Alzheimer disease. The aim of the present study was to evaluate the possibility whether treadmill exercise ameliorates Alzheimer disease-associated memory loss in the diabetes mellitus. For this study, the effects of treadmill exercise on short-term memory and spatial learning ability in relation with Wnt signaling pathway were evaluated using the streptozotocin (STZ)-induced diabetic rats. Diabetes was induced by intraperitoneal injection of STZ. Step-down avoidance task and 8-arm radial maze test were performed for the memory function. Immunohistochemistry for 5-bro-mo-2'-deoxyridine (BrdU) and doublecortin (DCX) and Western blot for Wnt3 and glycogen synthase kinase-3β (GSK-3β) were conducted. The rats in the exercise groups were made to run on the treadmill for 30 min per one day, 5 times a week, during 12 weeks. In the present results, short-term memory and spatial learning ability were deteriorated by induction of diabetes. Treadmill exercise improved short-term memory and spatial learning ability in the diabetic rats. The numbers of BrdU-positive and DCX-positive cells in the hippocampal dentate gyrus were decreased by induction of diabetes. Treadmill exercise increased these numbers in the diabetic rats. Wnt3 expression in the hippocampus was decreased and GSK-3β expression in the hippocampus was increased by induction of diabetes. Treadmill exercise increased Wnt3 expression and suppressed GSK-3β expression in the diabetic rats. The present study suggests that treadmill exercise alleviates Alzheimer disease-associated memory loss by increasing neurogenesis through activating Wnt signaling pathway in the diabetic rats. PMID:27656623

  6. Wnt/β-catenin signaling mediates the senescence of bone marrow-mesenchymal stem cells from systemic lupus erythematosus patients through the p53/p21 pathway.

    Science.gov (United States)

    Gu, Zhifeng; Tan, Wei; Feng, Guijuan; Meng, Yan; Shen, Biyu; Liu, Hong; Cheng, Chun

    2014-02-01

    Recent studies have shown that allogeneic bone marrow (BM)-mesenchymal stem cell transplantation (MSCT) appears to be effective in systemic lupus erythematosus (SLE) patients and lupus-prone mice, contrary to studies in syngeneic BM-MSCT. These studies indicated that the abnormalities of BM-MSCs may be involved in the pathogenesis of SLE. Our studies and other previous studies have revealed that BM-MSCs from SLE patients exhibited early signs of senescence, such as flattened morphology, slow proliferation, increased senescence-associated β-galactosidase (SA-β-gal) activity, and so on. However, the mechanisms by which these cells senescences were still unclear. Previous studies have demonstrated that Wnt/β-catenin signaling plays an important role in stem cell senescence. In the current study, we investigated whether Wnt/β-catenin signaling mediates the senescence of BM-MSCs from SLE patients. We have found that Wnt/β-catenin signaling and the p53/p21 pathway were significantly hyperactivated in senescent SLE BM-MSCs. Treatment with 100 ng/mL Dickkopf-1 (DKK1), a Wnt/β-catenin signaling inhibitor or β-catenin siRNA for 48 h could reverse the senescent features of SLE BM-MSCs. Additionally, the expression levels of p53 and p21 were reduced in treated-SLE BM-MSCs compared with the untreated group. In summary, our study indicated that Wnt/β-catenin signaling may play a critical role in the senescence of SLE BM-MSCs through the p53/p21 pathway.

  7. Circular RNA-ITCH Suppresses Lung Cancer Proliferation via Inhibiting the Wnt/β-Catenin Pathway

    Science.gov (United States)

    Wan, Li; Zhang, Lin; Fan, Kai; Cheng, Zai-Xing; Sun, Quan-Chao

    2016-01-01

    As a special form of noncoding RNAs, circular RNAs (circRNAs) played important roles in regulating cancer progression mainly by functioning as miRNA sponge. While the function of circular RNA-ITCH (cir-ITCH) in lung cancer is still less reported, in this study, we firstly detected the expression of cir-ITCH in tumor tissues and paired adjacent noncancer tissues of 78 patients with lung cancer using a TaqMan-based quantitative real-time PCR (qRT-PCR). The results showed that the expression of cir-ITCH was significantly decreased in lung cancer tissues. In cellular studies, cir-ITCH was also enhanced in different lung cancer cell lines, A549 and NIC-H460. Ectopic expression of cir-ITCH markedly elevated its parental cancer-suppressive gene, ITCH, expression and inhibited proliferation of lung cancer cells. Molecular analysis further revealed that cir-ITCH acted as sponge of oncogenic miR-7 and miR-214 to enhance ITCH expression and thus suppressed the activation of Wnt/β-catenin signaling. Altogether, our results suggested that cir-ITCH may play an inhibitory role in lung cancer progression by enhancing its parental gene, ITCH, expression. PMID:27642589

  8. 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

  9. 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

    International Nuclear Information System (INIS)

    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. 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. 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. 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. NCT00256334

  10. An Lmx1b-miR135a2 regulatory circuit modulates Wnt1/Wnt signaling and determines the size of the midbrain dopaminergic progenitor pool.

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    Angela Anderegg

    Full Text Available MicroRNAs regulate gene expression in diverse physiological scenarios. Their role in the control of morphogen related signaling pathways has been less studied, particularly in the context of embryonic Central Nervous System (CNS development. Here, we uncover a role for microRNAs in limiting the spatiotemporal range of morphogen expression and function. Wnt1 is a key morphogen in the embryonic midbrain, and directs proliferation, survival, patterning and neurogenesis. We reveal an autoregulatory negative feedback loop between the transcription factor Lmx1b and a newly characterized microRNA, miR135a2, which modulates the extent of Wnt1/Wnt signaling and the size of the dopamine progenitor domain. Conditional gain of function studies reveal that Lmx1b promotes Wnt1/Wnt signaling, and thereby increases midbrain size and dopamine progenitor allocation. Conditional removal of Lmx1b has the opposite effect, in that expansion of the dopamine progenitor domain is severely compromised. Next, we provide evidence that microRNAs are involved in restricting dopamine progenitor allocation. Conditional loss of Dicer1 in embryonic stem cells (ESCs results in expanded Lmx1a/b+ progenitors. In contrast, forced elevation of miR135a2 during an early window in vivo phenocopies the Lmx1b conditional knockout. When En1::Cre, but not Shh::Cre or Nes::Cre, is used for recombination, the expansion of Lmx1a/b+ progenitors is selectively reduced. Bioinformatics and luciferase assay data suggests that miR135a2 targets Lmx1b and many genes in the Wnt signaling pathway, including Ccnd1, Gsk3b, and Tcf7l2. Consistent with this, we demonstrate that this mutant displays reductions in the size of the Lmx1b/Wnt1 domain and range of canonical Wnt signaling. We posit that microRNA modulation of the Lmx1b/Wnt axis in the early midbrain/isthmus could determine midbrain size and allocation of dopamine progenitors. Since canonical Wnt activity has recently been recognized as a key

  11. MicroRNA-185 is a novel tumor suppressor by negatively modulating the Wnt/β-catenin pathway in human colorectal cancer

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    W Dong-xu

    2015-01-01

    Full Text Available OBJECTIVE: The deregulation of microRNA-185 (miR-185 has been showed to be associated with many cancers and act as a tumor suppressor in many types of human malignancies. We hence tried to find out its role in human colorectal cancer (CRC. MATERIALS AND METHODS: miR-185 expression was investigated by real-time quantitative polymerase chain reaction. We carried out transfections to overexpress or knockdown of miR-185 by mimics or inhibitor, respectively. Functional study like cell counting kit-8 assay was performed to evaluate the proliferation. For addressing the impact of miR-185 on Wnt/β-catenin signaling, we further applied luciferase reporter assay and Western blotting for specific proteins in this pathway. RESULTS: miR-185 was decreased in CRC cell lines when compared with corresponding control cell line. We also proved that its overexpression in LoVo cells could remarkably suppress cell proliferation whereas knocked it down in SW480 cells has the opposite effect in vitro. Mechanically, we demonstrated that miR-185 could suppress the Wnt/β-catenin signaling and modulate the transcription and translation level of downstream molecules of this pathway, including MYC and CCND1. CONCLUSION: Taken together, these results suggested that miR-185 exerts its tumor suppressor activities probably through a negative modulation of the Wnt/β-catenin pathway.

  12. Crosstalk of Hippo/YAP and Wnt/β-catenin pathways%Hippo/YAP和Wnt/β-catenin通路的对话

    Institute of Scientific and Technical Information of China (English)

    许飞; 张进; 马端

    2014-01-01

    Hippo/YAP通路和Wnt/β-catenin通路是在细胞的生长分化、组织器官形成以及成体干细胞的维持等方面都起着重要作用的两条信号通路.在哺乳动物细胞中,Wnt/β-catenin通路通过一系列胞质蛋白的相互作用,使β-catenin蛋白在胞质内累积,进而入核传递生长刺激信号.Hippo/YAP通路通过激酶级联反应磷酸化YAP/TAZ,使其滞留在细胞质中,抑制了YAP/TAZ的转录活性,从而限制细胞的生长增殖,诱导细胞凋亡.这两条通路的异常调控往往会导致肿瘤的发生.近年来越来越多的研究证实,Hippo/YAP和Wnt/β-catenin在很多方面相互影响,共同参与组织生长和胚胎发育的调控.研究这两个通路在肿瘤发生过程中的转导和调控以及它们相互作用的机制,有助于为肿瘤的防治提供新的思路与策略.文章对这两条通路的协同作用及其分子机制进行了综述.

  13. The Wnt/Planar Cell Polarity Pathway Component Vangl2 Induces Synapse Formation through Direct Control of N-Cadherin

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    Tadahiro Nagaoka

    2014-03-01

    Full Text Available Although regulators of the Wnt/planar cell polarity (PCP pathway are widely expressed in vertebrate nervous systems, their roles at synapses are unknown. Here, we show that Vangl2 is a postsynaptic factor crucial for synaptogenesis and that it coprecipitates with N-cadherin and PSD-95 from synapse-rich brain extracts. Vangl2 directly binds N-cadherin and enhances its internalization in a Rab5-dependent manner. This physical and functional interaction is suppressed by β-catenin, which binds the same intracellular region of N-cadherin as Vangl2. In hippocampal neurons expressing reduced Vangl2 levels, dendritic spine formation as well as synaptic marker clustering is significantly impaired. Furthermore, Prickle2, another postsynaptic PCP component, inhibits the N-cadherin-Vangl2 interaction and is required for normal spine formation. These results demonstrate direct control of classic cadherin by PCP factors; this control may play a central role in the precise formation and maturation of cell-cell adhesions at the synapse.

  14. Dark Aberrant Crypt Foci with activated Wnt pathway are related to tumorigenesis in the colon of AOM-treated rat

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    Lin Chen

    2008-08-01

    Full Text Available Abstract Background To evaluate the relationship between Aberrant Crypt Foci (ACF and tumorigenesis, we observed the sequential development from ACF to tumor in the colon of azoxymethane-exposed wistar rats. Methods Sixty wistar rats were sacrificed at different time points after exposure to azoxymethane and the colons were stained with methylene blue for stereomicroscopic analysis. Results We found two types of early lesions: classic ACF and dark ACF. Dark ACF were characterized by dark blue staining, mildly enlarged or small compressed crypts that are not elevated from the surrounding epithelium. Large dark ACF and nascent tumors displayed the same surface morphology. Furthermore, dark ACF grew significantly faster than classic ACF and showed dysplasia without hyperplasia. In contrast, classic ACF showed hyperplasia without dysplasia. Dark ACF has significant higher expression rate of β-catenin (100% and MMP-7 (81.82% compared with the expression of β-catenin and MMP-7 in classic ACF (4.84% and 7.87%, respectively. Conclusion Our data indicated that dark ACF is closely related to tumorigenesis while classic ACF is not. Furthermore, Wnt signal pathway was activated during the early period of dark ACF.

  15. TIPE2 Inhibits Hypoxia-Induced Wnt/β-Catenin Pathway Activation and EMT in Glioma Cells.

    Science.gov (United States)

    Liu, Zhi-Jun; Liu, Hong-Lin; Zhou, Hai-Cun; Wang, Gui-Cong

    2016-01-01

    Hypoxia-induced epithelial-to-mesenchymal transition (EMT) could facilitate tumor progression. TIPE2, the tumor necrosis factor-α (TNF-α)-induced protein 8-like 2 (also known as TNFAIP8L2), is a member of the TNF-α-induced protein 8 (TNFAIP8, TIPE) family and has been involved in the development and progression of several tumors. However, the effects of TIPE2 on the EMT process in glioma cells and the underlying mechanisms of these effects have not been previously reported. In our study, we assessed the roles of TIPE2 in the EMT process in glioma cells in response to hypoxia. Our results indicated that TIPE2 expression was significantly decreased in human glioma cell lines. TIPE2 overexpression significantly inhibited hypoxia-induced migration and invasion, as well as suppressed the EMT process in glioma cells. Furthermore, TIPE2 overexpression prevented hypoxia-induced expression of β-catenin, cyclin D1, and c-myc in human glioma cells. In summary, these data suggest that TIPE2 overexpression inhibited hypoxia-induced Wnt/β-catenin pathway activation and EMT in glioma cells. PMID:27656836

  16. 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.

  17. 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.

  18. MiRNA-335 suppresses neuroblastoma cell invasiveness by direct targeting of multiple genes from the non-canonical TGF-β signalling pathway.

    Science.gov (United States)

    Lynch, Jennifer; Fay, Joanna; Meehan, Maria; Bryan, Kenneth; Watters, Karen M; Murphy, Derek M; Stallings, Raymond L

    2012-05-01

    Transforming growth factor-β (TGF-β) signaling regulates many diverse cellular activities through both canonical (SMAD-dependent) and non-canonical branches, which includes the mitogen-activated protein kinase (MAPK), Rho-like guanosine triphosphatase and phosphatidylinositol-3-kinase/AKT pathways. Here, we demonstrate that miR-335 directly targets and downregulates genes in the TGF-β non-canonical pathways, including the Rho-associated coiled-coil containing protein (ROCK1) and MAPK1, resulting in reduced phosphorylation of downstream pathway members. Specifically, inhibition of ROCK1 and MAPK1 reduces phosphorylation levels of the motor protein myosin light chain (MLC) leading to a significant inhibition of the invasive and migratory potential of neuroblastoma cells. Additionally, miR-335 targets the leucine-rich alpha-2-glycoprotein 1 (LRG1) messenger RNA, which similarly results in a significant reduction in the phosphorylation status of MLC and a decrease in neuroblastoma cell migration and invasion. Thus, we link LRG1 to the migratory machinery of the cell, altering its activity presumably by exerting its effect within the non-canonical TGF-β pathway. Moreover, we demonstrate that the MYCN transcription factor, whose coding sequence is highly amplified in a particularly clinically aggressive neuroblastoma tumor subtype, directly binds to a region immediately upstream of the miR-335 transcriptional start site, resulting in transcriptional repression. We conclude that MYCN contributes to neuroblastoma cell migration and invasion, by directly downregulating miR-335, resulting in the upregulation of the TGF-β signaling pathway members ROCK1, MAPK1 and putative member LRG1, which positively promote this process. Our results provide novel insight into the direct regulation of TGF-β non-canonical signaling by miR-335, which in turn is downregulated by MYCN.

  19. IL-1β stimulation of CCD-18co myofibroblasts enhances repair of epithelial monolayers through Wnt-5a.

    Science.gov (United States)

    Raymond, Meera; Marchbank, Tania; Moyer, Mary P; Playford, Raymond J; Sanderson, Ian R; Kruidenier, Laurens

    2012-12-01

    Subepithelial myofibroblasts are involved in the initiation and coordination of intestinal epithelial repair, but the molecular signaling pathways are largely unknown. The cellular adaptations that occur during repair range from dedifferentiation and migration to proliferation and redifferentiation, in a way that is strongly reminiscent of normal crypt-to-villus epithelial maturation. We therefore hypothesized that Wnt/β-catenin signaling may have a pivotal role in intestinal epithelial wound repair. We used the established scratch wound method in Caco-2 cells and in nontransformed NCM460 cells to monitor the effects of IL-1β-stimulated colonic myofibroblasts (CCD-18co) on intestinal epithelial repair, with immunoblotting and immunodepletion to examine the conditioned media. Conditioned media from IL-1β-stimulated, but not -untreated, myofibroblasts increased Caco-2 wound closure twofold over 24 h. IL-1β-stimulated myofibroblasts downregulated the differentiation marker sucrase-isomaltase in the Caco-2 cells, whereas the proliferation marker c-myc was upregulated. Array expression profiling identified Wnt-5a as the Wnt-related gene that was most upregulated (28-fold) by IL-1β stimulation of CCDs. Recombinant Wnt-5a enhanced proliferation of Caco-2 and NCM460 cells. In scratch assays, it increased migration of the leading edge in both cell lines. Wnt-5a immunodepletion of the IL-1β-CCD conditioned media abrogated the ability to enhance the repair. Wnt-5a often acts through a noncanonical signal transduction pathway. Further experiments supported this pathway in epithelial wound healing: IL-1β-CCD-mediated repair was not affected by the addition of the canonical Wnt antagonist Dickkopf-1. Furthermore, media from stimulated myofibroblasts (but not Wnt-5a-depleted media) increased c-jun in Caco-2 cell nuclear extracts. Myofibroblast-mediated noncanonical Wnt-5a signaling is therefore important in the dedifferentiation and migration stages of epithelial wound

  20. Wnt signaling regulates multipolar-to-bipolar transition of migrating neurons in the cerebral cortex.

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    Boitard, Michael; Bocchi, Riccardo; Egervari, Kristof; Petrenko, Volodymyr; Viale, Beatrice; Gremaud, Stéphane; Zgraggen, Eloisa; Salmon, Patrick; Kiss, Jozsef Z

    2015-03-01

    The precise timing of pyramidal cell migration from the ventricular germinal zone to the cortical plate is essential for establishing cortical layers, and migration errors can lead to neurodevelopmental disorders underlying psychiatric and neurological diseases. Here, we report that Wnt canonical as well as non-canonical signaling is active in pyramidal precursors during radial migration. We demonstrate using constitutive and conditional genetic strategies that transient downregulation of canonical Wnt/β-catenin signaling during the multipolar stage plays a critical role in polarizing and orienting cells for radial migration. In addition, we show that reduced canonical Wnt signaling is triggered cell autonomously by time-dependent expression of Wnt5A and activation of non-canonical signaling. We identify ephrin-B1 as a canonical Wnt-signaling-regulated target in control of the multipolar-to-bipolar switch. These findings highlight the critical role of Wnt signaling activity in neuronal positioning during cortical development. PMID:25732825

  1. Wnt/β-catenin signaling induces the aging of mesenchymal stem cells through the DNA damage response and the p53/p21 pathway.

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    Da-yong Zhang

    Full Text Available Recent studies have demonstrated the importance of cellular extrinsic factors in the aging of adult stem cells. However, the effects of an aged cell-extrinsic environment on mesenchymal stem cell (MSC aging and the factors involved remain unclear. In the current study, we examine the effects of old rat serum (ORS on the aging of MSCs, and explore the effects and mechanisms of Wnt/β-catenin signaling on MSC aging induced by ORS treatment. Senescence-associated changes in the cells are examined with SA-β-galactosidase staining and ROS staining. The proliferation ability is detected by MTT assay. The surviving and apoptotic cells are determined using AO/EB staining. The results suggest that ORS promotes MSC senescence and reduces the proliferation and survival of cells. The immunofluorescence staining shows that the expression of β-catenin increases in MSCs of old rats. To identify the effects of Wnt/β-catenin signaling on MSC aging induced with ORS, the expression of β-catenin, GSK-3β, and c-myc are detected. The results show that the Wnt/β-catenin signaling in the cells is activated after ORS treatment. Then we examine the aging, proliferation, and survival of MSCs after modulating Wnt/β-catenin signaling. The results indicate that the senescence and dysfunction of MSCs in the medium containing ORS is reversed by the Wnt/β-catenin signaling inhibitor DKK1 or by β-catenin siRNA. Moreover, the expression of γ-H2A.X, a molecular marker of DNA damage response, p16(INK4a, p53, and p21 is increased in senescent MSCs induced with ORS, and is also reversed by DKK1 or by β-catenin siRNA. In summary, our study indicates the Wnt/β-catenin signaling may play a critical role in MSC aging induced by the serum of aged animals and suggests that the DNA damage response and p53/p21 pathway may be the main mediators of MSC aging induced by excessive activation of Wnt/β-catenin signaling.

  2. Wnt/β-catenin信号通路在糖尿病创面难愈中的作用%Role of Wnt/β-catenin signaling pathway in impaired wound healing of diabetes mellitus

    Institute of Scientific and Technical Information of China (English)

    孙晓磊; 何延政; 刘勇; 石镁虹; 钟武; 曾宏; 杨辉; 施森; 周翔宇; 聂丽霞

    2011-01-01

    Objective To investigate the role of Wnt/β-catenin signaling pathway in impaired wound healing of diabetes mellitus.Methods The back skin defect was produced in rats with type1diabetes.All of these rats were divided into normal group, diabetes group, lithium chloride group, and epidermal growth factor (EGF) group.The back wound healing and β-catenin expression were observed.Results There were no signs of infection in the wound of rats after injury.Compared with diabetic group, the wound healing time was shorter,wound healing rate was higher, wound cavity volume was smaller, granulation tissue was more mature, and β-catenin positive cell rate was higher in normal group, lithium chloride group, and EGF group(P<0.05 or P<0.01).Conclusions Wnt/beta-catenin signaling pathway is involved in the process of wound healing in diabetic rats.%目的 探讨Wnt/β-catenin信号途径在糖尿病创面难愈中的作用.方法 在1型糖尿病大鼠制作背部皮肤缺损,分为对照组、糖尿病组、氯化锂组和表皮生长因子(EGF)组,观察背部创面愈合情况及β-catenin表达变化.结果 伤后各组大鼠创面未见感染征象.对照组、氯化锂组及EGF组大鼠与糖尿病组大鼠相比,创面愈合时间短,创面愈合率高,伤腔容积缩小显著,肉芽组织成熟,且β-catenin阳性细胞率高,差异有统计学意义(P<0.05或P<0.01).结论 Wnt/β-catenin信号通路参与了糖尿病大鼠创面愈合过程.

  3. Involvement of periostin-sclerostin-Wnt/β-catenin signaling pathway in the prevention of neurectomy-induced bone loss by naringin.

    Science.gov (United States)

    Lv, Jianwei; Sun, Xiaolei; Ma, Jianxiong; Ma, Xinlong; Xing, Guosheng; Wang, Ying; Sun, Lei; Wang, Jianbao; Li, Fengbo; Li, Yanjun

    2015-12-25

    Periostin has an essential role in mechanotransduction in bone. Naringin, a natural flavonoid, has been evidenced for its osteoprotective role in osteoporosis, while its mechanism is far from clear. Here we show that down-regulation of periostin, and up-regulation of its downstream sclerostin and inactivation of Wnt/β-catenin signaling were implicated in neurectomy-induced bone loss. Naringin could up-regulate periostin and prevent neurectomy-induced deterioration of BMD, trabecular microstructure and bone mechanical characteristics. In conclusion, naringin could prevent progress of disuse osteoporosis in rats, which may be mediated by increased periostin expression and subsequently inhibition of sclerostin and activation of Wnt/β-catenin signaling pathways. PMID:26541456

  4. Wnt5a Signals through DVL1 to Repress Ribosomal DNA Transcription by RNA Polymerase I

    Science.gov (United States)

    Dass, Randall A.; Sarshad, Aishe A.; Feenstra, Jennifer M.; Kaur, Amanpreet; Pietras, Kristian; Serra, Rosa; Blanchard, Scott C.; Percipalle, Piergiorgio; Brown, Anthony M. C.; Vincent, C. Theresa

    2016-01-01

    Ribosome biogenesis is essential for cell growth and proliferation and is commonly elevated in cancer. Accordingly, numerous oncogene and tumor suppressor signaling pathways target rRNA synthesis. In breast cancer, non-canonical Wnt signaling by Wnt5a has been reported to antagonize tumor growth. Here, we show that Wnt5a rapidly represses rDNA gene transcription in breast cancer cells and generates a chromatin state with reduced transcription of rDNA by RNA polymerase I (Pol I). These effects were specifically dependent on Dishevelled1 (DVL1), which accumulates in nucleolar organizer regions (NORs) and binds to rDNA regions of the chromosome. Upon DVL1 binding, the Pol I transcription activator and deacetylase Sirtuin 7 (SIRT7) releases from rDNA loci, concomitant with disassembly of Pol I transcription machinery at the rDNA promoter. These findings reveal that Wnt5a signals through DVL1 to suppress rRNA transcription. This provides a novel mechanism for how Wnt5a exerts tumor suppressive effects and why disruption of Wnt5a signaling enhances mammary tumor growth in vivo. PMID:27500936

  5. The Wnt secretion protein Evi/Gpr177 promotes glioma tumourigenesis.

    Science.gov (United States)

    Augustin, Iris; Goidts, Violaine; Bongers, Angelika; Kerr, Grainne; Vollert, Gordon; Radlwimmer, Bernhard; Hartmann, Christian; Herold-Mende, Christel; Reifenberger, Guido; von Deimling, Andreas; Boutros, Michael

    2012-01-01

    Malignant astrocytomas are highly aggressive brain tumours with poor prognosis. While a number of structural genomic changes and dysregulation of signalling pathways in gliomas have been described, the identification of biomarkers and druggable targets remains an important task for novel diagnostic and therapeutic approaches. Here, we show that the Wnt-specific secretory protein Evi (also known as GPR177/Wntless/Sprinter) is overexpressed in astrocytic gliomas. Evi/Wls is a core Wnt signalling component and a specific regulator of pan-Wnt protein secretion, affecting both canonical and non-canonical signalling. We demonstrate that its depletion in glioma and glioma-derived stem-like cells led to decreased cell proliferation and apoptosis. Furthermore, Evi/Wls silencing in glioma cells reduced cell migration and the capacity to form tumours in vivo. We further show that Evi/Wls overexpression is sufficient to promote downstream Wnt signalling. Taken together, our study identifies Evi/Wls as an essential regulator of glioma tumourigenesis, identifying a pathway-specific protein trafficking factor as an oncogene and offering novel therapeutic options to interfere with the aberrant regulation of growth factors at the site of production.

  6. Wnt signaling in form deprivation myopia of the mice retina.

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    Mingming Ma

    Full Text Available BACKGROUND: The canonical Wnt signaling pathway plays important roles in cellular proliferation and differentiation, axonal outgrowth, cellular maintenance in retinas. Here we test the hypothesis that elements of the Wnt signaling pathway are involved in the regulation of eye growth and prevention of myopia, in the mouse form-deprivation myopia model. METHODOLOGY/PRINCIPAL FINDINGS: (1 One hundred twenty-five C57BL/6 mice were randomly distributed into form-deprivation myopia and control groups. Form-deprivation myopia (FDM was induced by suturing the right eyelid, while the control group received no treatment. After 1, 2, and 4 weeks of treatment, eyes were assessed in vivo by cycloplegic retinoscopic refraction and axial length measurement by photography or A-scan ultrasonography. Levels of retinal Wnt2b, Fzd5 and β-catenin mRNA and protein were evaluated using RT-PCR and western blotting, respectively. (2 Another 96 mice were divided into three groups: control, drugs-only, and drugs+FDM (by diffuser. Experimentally treated eyes in the last two groups received intravitreal injections of vehicle or the proteins, DKK-1 (Wnt-pathway antagonist or Norrin (Wnt-pathway agonist, once every three days, for 4 injections total. Axial length and retinoscopic refraction were measured on the 14th day of form deprivation. Following form-deprivation for 1, 2, and 4 weeks, FDM eyes had a relatively myopic refractive error, compared with contralateral eyes. There were no significant differences in refractive error between right and left eye in control group. The amounts of Wnt2b, Fzd5 and β-catenin mRNA and protein were significantly greater in form-deprived myopia eyes than in control eyes.DKK-1 (antagonist reduced the myopic shift in refractive error and increase in axial elongation, whereas Norrin had the opposite effect in FDM eyes. CONCLUSIONS/SIGNIFICANCE: Our studies provide the first evidence that the Wnt2b signaling pathway may play a role in the

  7. Emerging roles of microRNAs in the Wnt signaling network.

    Science.gov (United States)

    Schepeler, Troels

    2013-01-01

    The Wnt signaling network is known to regulate many cellular processes and is of crucial importance during development and in pathological conditions, including cancer. Small noncoding RNAs from the microRNA family (miRNAs) are important elements in the post-transcriptional control of gene expression. In this work, I review the cross talk between miRNAs and the canonical Wnt signaling pathway in various biological processes with particular emphasis on carcinogenesis. Because alterations of miRNA activity and aberrant Wnt signaling are each intimately linked to tumor biology, deciphering the complex interplay between these two regulatory modules is essential to advance our understanding of the integrated functions of miRNAs in signal transduction cascades and develop rational treatment regimens against cancer. PMID:23614621

  8. Wnt5a regulates growth, patterning, and odontoblast differentiation of developing mouse tooth

    OpenAIRE

    Lin, Minkui; Li, Lu; Liu, Chao; Hongbing LIU; He, Fenglei; Yan, Fuhua; Zhang, Yanding; Chen, Yiping

    2011-01-01

    Wnt/β-catenin signaling is essential for tooth development beyond the bud stage, but little is known about the role of non-canonical Wnt signaling in odontogenesis. Here we compared the expression of Wnt5a, a representative of noncanonical Wnts, with that of Ror2, the Wnt5a receptor for non-canonical signaling, in the developing tooth, and analyzed tooth phenotype in Wnt5a mutants. Wnt5a deficient mice exhibit retarded tooth development beginning from E16.5, leading to the formation of smalle...

  9. Both the caspase CSP-1 and a caspase-independent pathway promote programmed cell death in parallel to the canonical pathway for apoptosis in Caenorhabditis elegans.

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    Daniel P Denning

    Full Text Available Caspases are cysteine proteases that can drive apoptosis in metazoans and have critical functions in the elimination of cells during development, the maintenance of tissue homeostasis, and responses to cellular damage. Although a growing body of research suggests that programmed cell death can occur in the absence of caspases, mammalian studies of caspase-independent apoptosis are confounded by the existence of at least seven caspase homologs that can function redundantly to promote cell death. Caspase-independent programmed cell death is also thought to occur in the invertebrate nematode Caenorhabditis elegans. The C. elegans genome contains four caspase genes (ced-3, csp-1, csp-2, and csp-3, of which only ced-3 has been demonstrated to promote apoptosis. Here, we show that CSP-1 is a pro-apoptotic caspase that promotes programmed cell death in a subset of cells fated to die during C. elegans embryogenesis. csp-1 is expressed robustly in late pachytene nuclei of the germline and is required maternally for its role in embryonic programmed cell deaths. Unlike CED-3, CSP-1 is not regulated by the APAF-1 homolog CED-4 or the BCL-2 homolog CED-9, revealing that csp-1 functions independently of the canonical genetic pathway for apoptosis. Previously we demonstrated that embryos lacking all four caspases can eliminate cells through an extrusion mechanism and that these cells are apoptotic. Extruded cells differ from cells that normally undergo programmed cell death not only by being extruded but also by not being engulfed by neighboring cells. In this study, we identify in csp-3; csp-1; csp-2 ced-3 quadruple mutants apoptotic cell corpses that fully resemble wild-type cell corpses: these caspase-deficient cell corpses are morphologically apoptotic, are not extruded, and are internalized by engulfing cells. We conclude that both caspase-dependent and caspase-independent pathways promote apoptotic programmed cell death and the phagocytosis of cell

  10. TWEAK activates the non-canonical NFkappaB pathway in murine renal tubular cells: modulation of CCL21.

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    Ana B Sanz

    Full Text Available TWEAK is a member of the TNF superfamily of cytokines that contribute to kidney tubulointerstitial injury. It has previously been reported that TWEAK induces transient nuclear translocation of RelA and expression of RelA-dependent cytokines in renal tubular cells. Additionally, TWEAK induced long-lasting NFkappaB activation suggestive of engagement of the non-canonical NFkappaB pathway. We now explore TWEAK-induced activation of NFkappaB2 and RelB, as well as expression of CCL21, a T-cell chemotactic factor, in cultured murine tubular epithelial cells and in healthy kidneys in vivo. In cultured tubular cells, TWEAK and TNFalpha activated different DNA-binding NFkappaB complexes. TWEAK-induced sustained NFkappaB activation was associated with NFkappaB2 p100 processing to p52 via proteasome and nuclear translocation and DNA-binding of p52 and RelB. TWEAK, but not TNFalpha used as control, induced a delayed increase in CCL21a mRNA (3.5+/-1.22-fold over control and CCL21 protein (2.5+/-0.8-fold over control, which was prevented by inhibition of the proteasome, or siRNA targeting of NIK or RelB, but not by RelA inhibition with parthenolide. A second NFkappaB2-dependent chemokine, CCL19, was upregulates by TWEAK, but not by TNFalpha. However, both cytokines promoted chemokine RANTES expression (3-fold mRNA at 24 h. In vivo, TWEAK induced nuclear NFkappaB2 and RelB translocation and CCL21a mRNA (1.5+/-0.3-fold over control and CCL21 protein (1.6+/-0.5-fold over control expression in normal kidney. Increased tubular nuclear RelB and tubular CCL21 expression in acute kidney injury were decreased by neutralization (2+/-0.9 vs 1.3+/-0.6-fold over healthy control or deficiency of TWEAK (2+/-0.9 vs 0.8+/-0.6-fold over healthy control. Moreover, anti-TWEAK treatment prevented the recruitment of T cells to the kidney in this model (4.1+/-1.4 vs 1.8+/-1-fold over healthy control. Our results thus identify TWEAK as a regulator of non-canonical NFkappa

  11. 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

  12. LGR5 regulates pro-survival MEK/ERK and proliferative Wnt/β-catenin signalling in neuroblastoma.

    Science.gov (United States)

    Vieira, Gabriella Cunha; Chockalingam, S; Melegh, Zsombor; Greenhough, Alexander; Malik, Sally; Szemes, Marianna; Park, Ji Hyun; Kaidi, Abderrahmane; Zhou, Li; Catchpoole, Daniel; Morgan, Rhys; Bates, David O; Gabb, Peter David; Malik, Karim

    2015-11-24

    LGR5 is a marker of normal and cancer stem cells in various tissues where it functions as a receptor for R-spondins and increases canonical Wnt signalling amplitude. Here we report that LGR5 is also highly expressed in a subset of high grade neuroblastomas. Neuroblastoma is a clinically heterogenous paediatric cancer comprising a high proportion of poor prognosis cases (~40%) which are frequently lethal. Unlike many cancers, Wnt pathway mutations are not apparent in neuroblastoma, although previous microarray analyses have implicated deregulated Wnt signalling in high-risk neuroblastoma. We demonstrate that LGR5 facilitates high Wnt signalling in neuroblastoma cell lines treated with Wnt3a and R-spondins, with SK-N-BE(2)-C, SK-N-NAS and SH-SY5Y cell-lines all displaying strong Wnt induction. These lines represent MYCN-amplified, NRAS and ALK mutant neuroblastoma subtypes respectively. Wnt3a/R-Spondin treatment also promoted nuclear translocation of β-catenin, increased proliferation and activation of Wnt target genes. Strikingly, short-interfering RNA mediated knockdown of LGR5 induces dramatic Wnt-independent apoptosis in all three cell-lines, accompanied by greatly diminished phosphorylation of mitogen/extracellular signal-regulated kinases (MEK1/2) and extracellular signal-regulated kinases (ERK1/2), and an increase of BimEL, an apoptosis facilitator downstream of ERK. Akt signalling is also decreased by a Rictor dependent, PDK1-independent mechanism. LGR5 expression is cell cycle regulated and LGR5 depletion triggers G1 cell-cycle arrest, increased p27 and decreased phosphorylated retinoblastoma protein. Our study therefore characterises new cancer-associated pathways regulated by LGR5, and suggest that targeting of LGR5 may be of therapeutic benefit for neuroblastomas with diverse etiologies, as well as other cancers expressing high LGR5.

  13. Expression of osterix Is Regulated by FGF and Wnt/β-Catenin Signalling during Osteoblast Differentiation.

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    Katharina Felber

    Full Text Available Osteoblast differentiation from mesenchymal cells is regulated by multiple signalling pathways. Here we have analysed the roles of Fibroblast Growth Factor (FGF and canonical Wingless-type MMTV integration site (Wnt/β-Catenin signalling pathways on zebrafish osteogenesis. We have used transgenic and chemical interference approaches to manipulate these pathways and have found that both pathways are required for osteoblast differentiation in vivo. Our analysis of bone markers suggests that these pathways act at the same stage of differentiation to initiate expression of the osteoblast master regulatory gene osterix (osx. We use two independent approaches that suggest that osx is a direct target of these pathways. Firstly, we manipulate signalling and show that osx gene expression responds with similar kinetics to that of known transcriptional targets of the FGF and Wnt pathways. Secondly, we have performed ChIP with transcription factors for both pathways and our data suggest that a genomic region in the first intron of osx mediates transcriptional activation. Based upon these data, we propose that FGF and Wnt/β-Catenin pathways act in part by directing transcription of osx to promote osteoblast differentiation at sites of bone formation.

  14. Heterogeneous gene expression changes in colorectal cancer cells share the WNT pathway in response to growth suppression by APHS-mediated COX-2 inhibition

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    Bostjan Humar

    2008-06-01

    Full Text Available Bostjan Humar1, Les McNoe1, Anita Dunbier1, Rosemary Heathcott1, Antony W Braithwaite2, Anthony E Reeve11Cancer Genetics Laboratory, Department of Biochemistry; University of Otago, Dunedin, Aotearoa New Zealand; 2Children's Medical Research Institute, Wintworthbill, NSW, AustraliaAbstract: Cyclooxygenase-2 (COX-2, the prostaglandin (PG-synthesizing enzyme overexpressed in colorectal cancer (CRC, has pleiotropic, cancer-promoting effects. COX-2inhibitors (CIBs interfere with many cancer-associated processes and show promising antineoplastic activity, however, a common mechanism of CIB action has not yet been established. We therefore investigated by microarray the global response towards the CIB APHS at a dose significantly inhibiting the growth of three COX-2-positive CRC but not of two COX-2-negative cell lines. None of the genes significantly (p = 0.005 affected by APHS were common to all three cell lines and 83% of the altered pathways were cell line-specific. Quantitative polymerase chain reaction (QPCR on selected pathways confirmed cell line-specific expression alterations induced by APHS. A low stringency data analysis approach using BRB array tools coupled with QPCR, however, identified small expression changes shared by all COX-2-positive cell lines in genes related to the WNT pathway, the key driver of colonic carcinogenesis. Our data indicates a substantial cell line-specificity of APHS-induced expression alterations in CRC cells and helps to explain the divergent effects reported for CIBs. Further, the shared inhibition of the WNT pathway by APHS suggests one potential common mechanism behind the antineoplastic effects of COX-2 inhibition.Keywords: antineoplastic drugs, cell lines, colon cancer, COX-2 inhibitors, DNA arrays, WNT factors

  15. Berberine acts as a natural inhibitor of Wnt/β-catenin signaling--identification of more active 13-arylalkyl derivatives.

    Science.gov (United States)

    Albring, Kai Frederik; Weidemüller, Julia; Mittag, Sonnhild; Weiske, Jörg; Friedrich, Karlheinz; Geroni, M Cristina; Lombardi, Paolo; Huber, Otmar

    2013-01-01

    Aberrant activation of the canonical Wnt/β-catenin signaling pathway has been reported for numerous tumors of different origins. In most cases, mutations in components of the Wnt signaling pathway or in β-catenin itself were detected which ultimately induce a genetic program that promotes cell proliferation and attenuates apoptosis. Thus, targeting of Wnt/β-catenin signaling is of specific therapeutic interest. Herein, we investigated the plant-derived isoquinoline alkaloid berberine, which has been reported to have anticancer activity, and synthetic 13-arylalkyl derivatives thereof for their effects on Wnt/β-catenin signaling. Berberine did not show major effects on viability of HEK-293 embryonic kidney and HCT116 colon carcinoma cells and was not toxic in concentrations up to 20 µM. Berberine inhibited β-catenin transcriptional activity and attenuated anchorage-independent growth. As a result of berberine treatment, cellular levels of active β-catenin were reduced concomitant with an increase in the expression of E-cadherin. However, in unstimulated cells, the effects on β-catenin levels were low. A screen of synthetic 13-arylalkyl berberine derivatives identified compounds exhibiting activities superior to those of the naturally occurring parent substance with more than 100-fold lower EC50 values for Wnt-repression. Thus, berberine and its synthetic derivatives represent potential therapeutic agents to inhibit Wnt/β-catenin signaling in tumorigenesis.

  16. Dact2 represses PITX2 transcriptional activation and cell proliferation through Wnt/beta-catenin signaling during odontogenesis.

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    Xiao Li

    Full Text Available Dact proteins belong to the Dapper/Frodo protein family and function as cytoplasmic attenuators in Wnt and TGFβ signaling. Previous studies show that Dact1 is a potent Wnt signaling inhibitor by promoting degradation of β-catenin. We report a new mechanism for Dact2 function as an inhibitor of the canonical Wnt signaling pathway by interacting with PITX2. PITX2 is a downstream transcription factor in Wnt/β-catenin signaling, and PITX2 synergizes with Lef-1 to activate downstream genes. Immunohistochemistry verified the expression of Dact2 in the tooth epithelium, which correlated with Pitx2 epithelial expression. Dact2 loss of function and PITX2 gain of function studies reveal a feedback mechanism for controlling Dact2 expression. Pitx2 endogenously activates Dact2 expression and Dact2 feeds back to repress Pitx2 transcriptional activity. A Topflash reporter system was employed showing PITX2 activation of Wnt signaling, which is attenuated by Dact2. Transient transfections demonstrate the inhibitory effect of Dact2 on critical dental epithelial differentiation factors during tooth development. Dact2 significantly inhibits PITX2 activation of the Dlx2 and amelogenin promoters. Multiple lines of evidence conclude the inhibition is achieved by the physical interaction between Dact2 and Pitx2 proteins. The loss of function of Dact2 also reveals increased cell proliferation due to up-regulated Wnt downstream genes, cyclinD1 and cyclinD2. In summary, we have identified a novel role for Dact2 as an inhibitor of the canonical Wnt pathway in embryonic tooth development through its regulation of cell proliferation and differentiation.

  17. The antidepressant roles of Wnt2 and Wnt3 in stress-induced depression-like behaviors

    Science.gov (United States)

    Zhou, W-J; Xu, N; Kong, L; Sun, S-C; Xu, X-F; Jia, M-Z; Wang, Y; Chen, Z-Y

    2016-01-01

    Wnts-related signaling pathways have been reported to play roles in the pathogenesis of stress-induced depression-like behaviors. However, there is relatively few direct evidence to indicate the effect of Wnt ligands on this process. Here, we investigated the role of Wnts in mediating chronic restraint stress (CRS)-induced depression-like behaviors. We found that CRS induced a significant decrease in the expression of Wnt2 and Wnt3 in the ventral hippocampus (VH) but not in the dorsal hippocampus. Knocking down Wnt2 or Wnt3 in the VH led to impaired Wnt/β-catenin signaling, neurogenesis deficits and depression-like behaviors. In contrast, overexpression of Wnt2 or Wnt3 reversed CRS-induced depression-like behaviors. Moreover, Wnt2 and Wnt3 activated cAMP response element-binding protein (CREB) and there was CREB-dependent positive feedback between Wnt2 and Wnt3. Finally, fluoxetine treatment increased Wnt2 and Wnt3 levels in the VH and knocking down Wnt2 or Wnt3 abolished the antidepressant effect of fluoxetine. Taken together, our study indicates essential roles for Wnt2 and Wnt3 in CRS-induced depression-like behaviors and antidepressant. PMID:27622936

  18. WNT-5A and WNT-5B modulate calcium homeostasis in airway smooth muscle

    NARCIS (Netherlands)

    Koopmans, Tim; Kumawat, Kudleer; Van Den Berge, Maarten; Hoffmann, Roland; Halayko, Andrew J.; Gosens, Reinoud

    2014-01-01

    Rationale Airway hyperresponsiveness is a common feature of asthma explained in part by an excessive contractile response of the airway smooth muscle (ASM). The underlying mechanisms are complex and in need of study. WNT-5A and WNT-5B, two members of the WNT signaling pathway, may be of significance

  19. Role of Wnt signal pathway in osteoblasts:bone-forming or bone-resorbing?%Wnt信号通路在成骨细胞中的作用:成骨还是破骨?

    Institute of Scientific and Technical Information of China (English)

    刘艳玲; 李方兵; 赵曦

    2014-01-01

    BACKGROUND:Wnt signal pathway is involved in the regulation of bone marrow mesenchymal stem cells differentiating into osteoblasts, promotes osteoblasts proliferation and differentiation, inhibits programmed death of osteoblasts, and indirectly affects the function of osteoclasts. OBJECTIVE:To summarize the relationship between Wnt/β-catenin signal pathway and bone disease. METHODS:A computer-based online search was performed to find papers published between January 2000 and January 2014 in CNKI database and Elsevier database. The key words were“Wnt/β-catenin, osteoblasts, bone marrow mesenchymal stem cells, osteoarthritis, chondrocytes”in Chinese. Documents concerning the effects of Wnt/β-catenin signal pathway on osteoblasts and bone disease were included. RESULTS AND CONCLUSION:Wnt signaling pathway is consisted of Wnt/β-catenin signal pathway (Wnt typical signal pathway), Wnt/Ca2+signal pathway and Wnt/planar cellpolarity signal pathway. Wnt signaling pathway is one of the most important regulatory systems that plays a key role in modulating the differentiation, proliferation and programmed celldeath of osteoblasts, osteoclasts and chondrocytes. The role of Wnt signal pathway in patients with rheumatoid arthritis is mediated by osteoblasts. The inhibitory factor of Wnt signal pathway in osteoblasts is upregulated, which reduces the ratio of osteoprotegerin/receptor activating factor ligand, promotes the osteoclasts differentiation and immaturation. The researches addressing the components and effect of Wnt signal pathway are important for the special treatment of bone diseases and the prevention of osteoporosis or other bone diseases.%背景:研究表明,Wnt 信号通路参与调节骨髓间充质干细胞向成骨细胞分化,促进成骨细胞增殖和分化,抑制成骨细胞的程序性死亡,间接影响破骨细胞的功能。  目的:分析Wnt/β-连环蛋白信号通路与骨疾病的关系。  方法:通过

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

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    Jonas Ungerbäck

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

  1. The negative regulators of Wnt pathway-DACH1, DKK1, and WIF1 are methylated in oral and oropharyngeal cancer and WIF1 methylation predicts shorter survival.

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    Paluszczak, Jarosław; Sarbak, Joanna; Kostrzewska-Poczekaj, Magdalena; Kiwerska, Katarzyna; Jarmuż-Szymczak, Małgorzata; Grenman, Reidar; Mielcarek-Kuchta, Daniela; Baer-Dubowska, Wanda

    2015-04-01

    The deregulation of Wnt signaling has recently emerged as one of the drivers of head and neck cancers. This is frequently related to the methylation of several antagonists of this pathway. This study aimed at the assessment of the profile of methylation of Wnt pathway antagonists and the determination of the prognostic value of the methylation of selected genes in oral carcinomas. The methylation of DACH1, DKK1, LKB1, PPP2R2B, RUNX3, SFRP2, and WIF-1 was analyzed in 16 oral squamous cell carcinoma cell lines using the methylation-specific polymerase chain reaction. The methylation of selected genes was further analyzed in tumor sections from 43 primary oral carcinoma patients. The analysis of oral carcinoma cell lines showed very frequent methylation of SFRP2 and WIF-1 and also a less frequent methylation of DACH1 and DKK1. On the other hand, RUNX3 was methylated only in one cell line, while LKB1 and PPP2R2B were not methylated in any of the cell lines. The biallelic methylation of DKK1 correlated with the low level of expression of this gene. Further evaluation of the methylation of DACH1, DKK1, and WIF1 in a clinical patient group confirmed the frequent methylation of WIF1 and intermediate or low frequency of methylation of DACH1 or DKK1, respectively. Importantly, the methylation of WIF-1 correlated with shorter survival in oral cancer patients. Overall, the methylation of the antagonists of Wnt pathway is frequently detected in oral squamous cell carcinomas. The methylation of WIF1 may be considered a prognostic marker in oral cancers. PMID:25487617

  2. Alterations of β-catenin and Tcf-4 instead of GSK-3β contribute to activation of Wnt pathway in hepatocellular carcinoma

    Institute of Scientific and Technical Information of China (English)

    CUI Jian 崔健; ZHOU Xinda 周信达; LIU Yinkun 刘银坤; TANG Zhaoyou 汤钊猷; Mahmoud Romeih

    2003-01-01

    Objective The goal of this study is to investigate the inappropriate activation of Wnt pathway in the hepatocarcinogenesis.Methods We analyzed the alterations of three key components of Wnt pathway, β-catenin, glycogen synthase kinase 3β (GSK-3β) and T cell factor 4 (Tcf-4), in 34 samples of hepatocellular carcinoma (HCC) and paracancerous normal liver by immunohistochemistry, polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP), direct sequencing, semi-quantitative reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization.Results We found 61.8% (21/34) of all the HCCs examined showed an abnormal β-catenin protein accumulation in the cytoplasm or nuclei. RT-PCR-SSCP and direct sequencing showed that β-catenin exon 3 mutations existed in 44.1% (15/34) of the HCCs. No mutations of GSK-3β or Tcf-4 were detected in HCCs. Moreover, mRNA of β-catenin and Tcf-4 but not GSK-3β was found to be over expressed in HCCs. On analyzing the relationship between alterations of β-catenin or Tcf-4 and C-myc or Cyclin D1 expression, we found that the mutations of β-catenin as well as over expression of β-catenin or Tcf-4 gene were independently correlated with C-myc gene over expression in HCCs.Conclusions Our present findings strongly suggest mutations of β-catenin as well as over expression of β-catenin and Tcf-4 gene activate the Wnt pathway in HCC independently with the target gene most likely to be C-myc.

  3. Hydrogen Sulfide Inhibits Transforming Growth Factor-β1-Induced EMT via Wnt/Catenin Pathway.

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    Lin Guo

    Full Text Available Hydrogen sulfide (H2S has anti-fibrotic potential in lung, kidney and other organs. The exogenous H2S is released from sodium hydrosulfide (NaHS and can influence the renal fibrosis by blocking the differentiation of quiescent renal fibroblasts to myofibroblasts. But whether H2S affects renal epithelial-to-mesenchymal transition (EMT and the underlying mechanisms remain unknown. Our study is aimed at investigating the in vitro effects of H2S on transforming growth factor-β1 (TGF-β1-induced EMT in renal tubular epithelial cells (HK-2 cells and the associated mechanisms. The induced EMT is assessed by Western blotting analysis on the expressions of α-SMA, E-cadherin and fibronectin. HK-2 cells were treated with NaHS before incubating with TGF-β1 to investigate its effect on EMT and the related molecular mechanism. Results demonstrated that NaHS decreased the expression of α-SMA and fibronectin, and increased the expression of E-cadherin. NaHS reduced the expression of TGF-β receptor type I (TβR I and TGF-β receptor type II (TβR II. In addition, NaHS attenuated TGF-β1-induced increase of β-catenin expression and ERK phosphorylation. Moreover, it inhibited the TGF-β1-induced nuclear translocation of ββ-catenin. These effects of NaHS on fibronectin, E-cadherin and TβR I were abolished by the ERK inhibitor U0126 or β-catenin inhibitor XAV939, or β-catenin siRNA interference. We get the conclusion that NaHS attenuated TGF-β1-induced EMT in HK-2 cells through both ERK-dependent and β-catenin-dependent pathways.

  4. Hydrogen Sulfide Inhibits Transforming Growth Factor-β1-Induced EMT via Wnt/Catenin Pathway

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    Tao, Jie; Lan, Zhen; Hei, Hongya; Tian, Lulu; Pan, Wanma; Wang, Li; Zhang, Xuemei

    2016-01-01

    Hydrogen sulfide (H2S) has anti-fibrotic potential in lung, kidney and other organs. The exogenous H2S is released from sodium hydrosulfide (NaHS) and can influence the renal fibrosis by blocking the differentiation of quiescent renal fibroblasts to myofibroblasts. But whether H2S affects renal epithelial-to-mesenchymal transition (EMT) and the underlying mechanisms remain unknown. Our study is aimed at investigating the in vitro effects of H2S on transforming growth factor-β1 (TGF-β1)-induced EMT in renal tubular epithelial cells (HK-2 cells) and the associated mechanisms. The induced EMT is assessed by Western blotting analysis on the expressions of α-SMA, E-cadherin and fibronectin. HK-2 cells were treated with NaHS before incubating with TGF-β1 to investigate its effect on EMT and the related molecular mechanism. Results demonstrated that NaHS decreased the expression of α-SMA and fibronectin, and increased the expression of E-cadherin. NaHS reduced the expression of TGF-β receptor type I (TβR I) and TGF-β receptor type II (TβR II). In addition, NaHS attenuated TGF-β1-induced increase of β-catenin expression and ERK phosphorylation. Moreover, it inhibited the TGF-β1-induced nuclear translocation of ββ-catenin. These effects of NaHS on fibronectin, E-cadherin and TβR I were abolished by the ERK inhibitor U0126 or β-catenin inhibitor XAV939, or β-catenin siRNA interference. We get the conclusion that NaHS attenuated TGF-β1-induced EMT in HK-2 cells through both ERK-dependent and β-catenin-dependent pathways. PMID:26760502

  5. Pentoxifylline Inhibits WNT Signalling in β-Cateninhigh Patient-Derived Melanoma Cell Populations

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    Talar, Beata; Gajos-Michniewicz, Anna; Talar, Marcin; Chouaib, Salem; Czyz, Malgorzata

    2016-01-01

    Background The heterogeneity of melanoma needs to be addressed and combination therapies seem to be necessary to overcome intrinsic and acquired resistance to newly developed immunotherapies and targeted therapies. Although the role of WNT/β-catenin pathway in melanoma was early demonstrated, its contribution to the lack of the melanoma patient response to treatment was only recently recognized. Using patient-derived melanoma cell populations, we investigated the influence of pentoxifylline on melanoma cells with either high or low expression of β-catenin. Findings Our results indicate that pentoxifylline inhibits the activity of the canonical WNT pathway in melanoma cell populations with high basal activity of this signalling. This is supported by lowered overall activity of transcription factors TCF/LEF and reduced nuclear localisation of active β-catenin. Moreover, treatment of β-cateninhigh melanoma cell populations with pentoxifylline induces downregulation of genes that are targets of the WNT/β-catenin pathway including connective tissue growth factor (CTGF) and microphthalmia-associated transcription factor (MITF-M), a melanocyte- and melanoma cell-specific regulator. Conclusions These results suggest that pentoxifylline, a drug approved by the FDA in the treatment of peripheral arterial disease, might be tested in a subset of melanoma patients with elevated activity of β-catenin. This pharmaceutical might be tested as an adjuvant drug in combination therapies when the response to immunotherapy is prevented by high activity of the WNT/β-catenin pathway. PMID:27351373

  6. Pentoxifylline Inhibits WNT Signalling in β-Cateninhigh Patient-Derived Melanoma Cell Populations.

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    Beata Talar

    Full Text Available The heterogeneity of melanoma needs to be addressed and combination therapies seem to be necessary to overcome intrinsic and acquired resistance to newly developed immunotherapies and targeted therapies. Although the role of WNT/β-catenin pathway in melanoma was early demonstrated, its contribution to the lack of the melanoma patient response to treatment was only recently recognized. Using patient-derived melanoma cell populations, we investigated the influence of pentoxifylline on melanoma cells with either high or low expression of β-catenin.Our results indicate that pentoxifylline inhibits the activity of the canonical WNT pathway in melanoma cell populations with high basal activity of this signalling. This is supported by lowered overall activity of transcription factors TCF/LEF and reduced nuclear localisation of active β-catenin. Moreover, treatment of β-cateninhigh melanoma cell populations with pentoxifylline induces downregulation of genes that are targets of the WNT/β-catenin pathway including connective tissue growth factor (CTGF and microphthalmia-associated transcription factor (MITF-M, a melanocyte- and melanoma cell-specific regulator.These results suggest that pentoxifylline, a drug approved by the FDA in the treatment of peripheral arterial disease, might be tested in a subset of melanoma patients with elevated activity of β-catenin. This pharmaceutical might be tested as an adjuvant drug in combination therapies when the response to immunotherapy is prevented by high activity of the WNT/β-catenin pathway.

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

    Institute of Scientific and Technical Information of China (English)

    Yue-Ying Pan; Yan Deng; Sheng Xie; Zhi-Hua Wang; Yu Wang; Jie Ren; Hui-Guo Liu

    2016-01-01

    Background:Cognitive impairment is a severe complication caused by obstructive sleep apnea (OSA).The mechanisms of causation are still unclear.The Wnt/β-catenin signaling pathway is involved in cognition,and abnormalities in it are implicated in neurological disorders.Here,we explored the Wnt/β-catenin signaling pathway abnormalities caused by chronic intermittent hypoxia (CIH),the most characteristic pathophysiological component of OSA.Methods:We divided 32 4-week-old male C57/BL mice into four groups of eight each:a CIH + normal saline (NS) group,CIH + LiC1 group,sham CIH + NS group,and a sham CIH + LiC1 group.The spatial learning performance of each group was assessed by using the Morris water maze (MWM).Protein expressions of glycogen synthase kinase-3β (GSK-3β) and β-catenin in the hippocampus were examined using the Western blotting test.EdU labeling and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling staining methods were used,respectively,to determine the proliferation and apoptosis of neurons in the hippocampal dentate gyrus region.Results:Mice exposed to CIH showed impaired spatial learning performance in the MWM,including increased mean escape latencies to reach the target platform,decreased mean times passing through the target platform and mean duration in the target quadrant.The GSK-3β activity increased,and expression of β-catenin decreased significantly in the hippocampus of the CIH-exposed mice.Besides,CIH significantly increased hippocampal neuronal apoptosis,with an elevated apoptosis index.Meanwhile,LiCl decreased the activity of GSK-3β and increased the expression of β-catenin and partially reversed the spatial memory deficits in MWM and the apoptosis caused by CIH.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

  8. 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

  9. Wnt Signaling in Cancer Stem Cell Biology.

    Science.gov (United States)

    de Sousa E Melo, Felipe; Vermeulen, Louis

    2016-06-27

    Aberrant regulation of Wnt signaling is a common theme seen across many tumor types. Decades of research have unraveled the epigenetic and genetic alterations that result in elevated Wnt pathway activity. More recently, it has become apparent that Wnt signaling levels identify stem-like tumor cells that are responsible for fueling tumor growth. As therapeutic targeting of these tumor stem cells is an intense area of investigation, a concise understanding on how Wnt activity relates to cancer stem cell traits is needed. This review attempts at summarizing the intricacies between Wnt signaling and cancer stem cell biology with a special emphasis on colorectal cancer.

  10. Wnt Signaling in Cancer Stem Cell Biology

    Science.gov (United States)

    de Sousa e Melo, Felipe; Vermeulen, Louis

    2016-01-01

    Aberrant regulation of Wnt signaling is a common theme seen across many tumor types. Decades of research have unraveled the epigenetic and genetic alterations that result in elevated Wnt pathway activity. More recently, it has become apparent that Wnt signaling levels identify stem-like tumor cells that are responsible for fueling tumor growth. As therapeutic targeting of these tumor stem cells is an intense area of investigation, a concise understanding on how Wnt activity relates to cancer stem cell traits is needed. This review attempts at summarizing the intricacies between Wnt signaling and cancer stem cell biology with a special emphasis on colorectal cancer. PMID:27355964

  11. WNT/β-Catenin Signaling Is Required for Integration of CD24+ Renal Progenitor Cells into Glycerol-Damaged Adult Renal Tubules

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    Zhao Zhang

    2015-01-01

    Full Text Available During development, nephron progenitor cells (NPC are induced to differentiate by WNT9b signals from the ureteric bud. Although nephrogenesis ends in the perinatal period, acute kidney injury (AKI elicits repopulation of damaged nephrons. Interestingly, embryonic NPC infused into adult mice with AKI are incorporated into regenerating tubules. Since WNT/β-catenin signaling is crucial for primary nephrogenesis, we reasoned that it might also be needed for the endogenous repair mechanism and for integration of exogenous NPC. When we examined glycerol-induced AKI in adult mice bearing a β-catenin/TCF reporter transgene, endogenous tubular cells reexpressed the NPC marker, CD24, and showed widespread β-catenin/TCF signaling. We isolated CD24+ cells from E15 kidneys of mice with the canonical WNT signaling reporter. 40% of cells responded to WNT3a in vitro and when infused into glycerol-injured adult, the cells exhibited β-catenin/TCF reporter activity when integrated into damaged tubules. When embryonic CD24+ cells were treated with a β-catenin/TCF pathway inhibitor (IWR-1 prior to infusion into glycerol-injured mice, tubular integration of cells was sharply reduced. Thus, the endogenous canonical β-catenin/TCF pathway is reactivated during recovery from AKI and is required for integration of exogenous embryonic renal progenitor cells into damaged tubules. These events appear to recapitulate the WNT-dependent inductive process which drives primary nephrogenesis.

  12. Wnt signaling in gut development and homeostasis

    NARCIS (Netherlands)

    Gregorieff, A.

    2006-01-01

    The Wnt pathway controls diverse biological processes during embryonic development. In the adult, Wnts maintain the balance between cell division and cell specialisation in tissues such as the hemapoetic system, skin, and the intestine. Genetic modifications which activate the Wnt pathway are also c

  13. Canonical BMP Signaling Pathway And Mammalian Lung Development%经典BMP信号通路与哺乳动物肺器官发育

    Institute of Scientific and Technical Information of China (English)

    肖爱平; 滕鸿琦; 李小兵; 张明凤

    2012-01-01

      肺器官发育是上皮和间充质相互作用的过程,由多条信号通路共同调控。已知经典BMP信号通路调控了细胞的增殖、凋亡及分化过程,对哺乳动物肺器官形态发生极为重要。在小鼠等模式生物上研究发现,它参与了哺乳动物肺器官发育的调控过程。本文综合了近年来经典BMP信号通路成员在哺乳动物肺器官发育过程中的表达变化、作用功能及表达异常可能诱发的肺部疾病,以期为研究经典BMP信号通路调控人类肺器官发育的分子机制及相关肺部疾病的诊治奠定基础。%  Lung development is a consequence of interaction between epithelium and mesenchyme,which is regulated by several sig-naling pathways. It is well known that the canonical BMP signal pathway plays an important role in the regulation of cell proliferation, apoptosis and differentiation. They are also found to play pivotal roles in morphogenesis of mammalian lung. Recent studies on model organisms,such as mouse and rat,verified that the canonical BMP signal pathway participated in the regulation of mammalian lung development. This review has summarized the main recent research findings on the role of canonical BMP signaling components in the regulation of mammalian lung development. The gene expression and function in all members of canonical BMP signaling pathway, and the possible lung diseases induced by abnormal expression of canonical BMP signaling components during the mammalian lung development were emphasized to state. It’s anticipated to provide valuable information for further illustration of the molecular mecha-nisms of BMP signals in the regulation of human lung development,as well as will be in favor of finding the way to diagnose and cure human lung diseases.

  14. Functional Effects of WNT1-Inducible Signaling Pathway Protein-1 on Bronchial Smooth Muscle Cell Migration and Proliferation in OVA-Induced Airway Remodeling.

    Science.gov (United States)

    Yang, Mingjin; Du, Yuejun; Xu, Zhibo; Jiang, Youfan

    2016-02-01

    Upregulation of WISP1 has been demonstrated in lung remodeling. Moreover, it has been recently found that some signaling components of WNT pathway can activate GSK3β signaling to mediate remodeling of airway smooth muscle (ASM) in asthma. Therefore, we hypothesized that WISP1, a signaling molecule downstream of the WNT signaling pathway, is involved in PI3K/GSK3β signaling to mediate ASM remodeling in asthma. Our results showed that WISP1 depletion partly suppressed OVA-induced ASM hypertrophy in vivo. In vitro, WISP1 could induce hBSMC hypertrophy and proliferation, accompanied by upregulation of levels of PI3K, p-Akt, p-GSK3β, and its own expression. TGF-β treatment could increase expression of PI3K, p-Akt, p-GSK3β, and WISP1. SH-5 treatment could partly suppress TGF-β-induced hypertrophy and proliferation of hBSMC, and depress expression of p-GSK3β and WISP1. In conclusion, WISP1 may be a potential inducer of ASM proliferation and hypertrophy in asthma. The pro-remodeling effect of WISP1 is likely due to be involved in PI3K-GSK3β-dependent noncanonical TGF-β signaling. PMID:26242865

  15. Wnt trafficking: new insights into Wnt maturation, secretion and spreading.

    Science.gov (United States)

    Port, Fillip; Basler, Konrad

    2010-10-01

    Proteins of the Wnt family are secreted signaling molecules that regulate multiple processes in animal development and control tissue homeostasis in the adult. Wnts spread over considerable distances to regulate gene expression in cells located at distant sites. Paradoxically, Wnts are poorly mobile because of their posttranslational modification with lipids. Recent evidence suggests that several pathways exist that are capable of transforming hydrophobic, insoluble Wnts into long-range signaling molecules. Furthermore, the discovery of Wntless as a protein specifically required for the secretion of Wnt suggests that Wnt trafficking through the secretory pathway is already under special scrutiny. Here, we review recent data on the molecular machinery that controls Wnt secretion and discuss how Wnts can be mobilized for long-range signaling. PMID:20477987

  16. Differentiation of the brain vasculature: the answer came blowing by the Wnt

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    Plate Karl H

    2010-01-01

    Full Text Available Abstract Vascularization of the vertebrate brain takes place during embryonic development from a preformed perineural vascular plexus. As a consequence of the intimate contact with neuroectodermal cells the vessels, which are entering the brain exclusively via sprouting angiogenesis, acquire and maintain unique barrier properties known as the blood-brain barrier (BBB. The endothelial BBB depends upon the close association of endothelial cells with pericytes, astrocytes, neurons and microglia, which are summarized in the term neuro-vascular unit. Although it is known since decades that the CNS tissue provides the cues for BBB induction and differentiation in endothelial cells, the molecular mechanism remained obscure. Only recently, the canonical Wnt/β-catenin pathway and the Wnt7a/7b growth factors have been implicated in brain angiogenesis on the one hand and in BBB induction on the other. This breakthrough in understanding the differentiation of the brain vasculature prompted us to review these findings embedded in the emerging concepts of Wnt signaling in the vasculature. In particular, interactions with other pathways that are crucial for vascular development such as VEGF, Notch, angiopoietins and Sonic hedgehog are discussed. Finally, we considered the potential role of the Wnt pathway in vascular brain pathologies in which BBB function is hampered, as for example in glioma, stroke and Alzheimer's disease.

  17. Plakophilin-1, a Novel Wnt Signaling Regulator, Is Critical for Tooth Development and Ameloblast Differentiation.

    Science.gov (United States)

    Miyazaki, Kanako; Yoshizaki, Keigo; Arai, Chieko; Yamada, Aya; Saito, Kan; Ishikawa, Masaki; Xue, Han; Funada, Keita; Haruyama, Naoto; Yamada, Yoshihiko; Fukumoto, Satoshi; Takahashi, Ichiro

    2016-01-01

    Tooth morphogenesis is initiated by reciprocal interactions between the ectoderm and neural crest-derived mesenchyme, and the Wnt signaling pathway is involved in this process. We found that Plakophilin (PKP)1, which is associated with diseases such as ectodermal dysplasia/skin fragility syndrome, was highly expressed in teeth and skin, and was upregulated during tooth development. We hypothesized that PKP1 regulates Wnt signaling via its armadillo repeat domain in a manner similar to β-catenin. To determine its role in tooth development, we performed Pkp1 knockdown experiments using ex vivo organ cultures and cell cultures. Loss of Pkp1 reduced the size of tooth germs and inhibited dental epithelial cell proliferation, which was stimulated by Wnt3a. Furthermore, transfected PKP1-emerald green fluorescent protein was translocated from the plasma membrane to the nucleus upon stimulation with Wnt3a and LiCl, which required the PKP1 N terminus (amino acids 161 to 270). Localization of PKP1, which is known as an adhesion-related desmosome component, shifted to the plasma membrane during ameloblast differentiation. In addition, Pkp1 knockdown disrupted the localization of Zona occludens 1 in tight junctions and inhibited ameloblast differentiation; the two proteins were shown to directly interact by immunoprecipitation. These results implicate the participation of PKP1 in early tooth morphogenesis as an effector of canonical Wnt signaling that controls ameloblast differentiation via regulation of the cell adhesion complex. PMID:27015268

  18. Plakophilin-1, a Novel Wnt Signaling Regulator, Is Critical for Tooth Development and Ameloblast Differentiation.

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    Kanako Miyazaki

    Full Text Available Tooth morphogenesis is initiated by reciprocal interactions between the ectoderm and neural crest-derived mesenchyme, and the Wnt signaling pathway is involved in this process. We found that Plakophilin (PKP1, which is associated with diseases such as ectodermal dysplasia/skin fragility syndrome, was highly expressed in teeth and skin, and was upregulated during tooth development. We hypothesized that PKP1 regulates Wnt signaling via its armadillo repeat domain in a manner similar to β-catenin. To determine its role in tooth development, we performed Pkp1 knockdown experiments using ex vivo organ cultures and cell cultures. Loss of Pkp1 reduced the size of tooth germs and inhibited dental epithelial cell proliferation, which was stimulated by Wnt3a. Furthermore, transfected PKP1-emerald green fluorescent protein was translocated from the plasma membrane to the nucleus upon stimulation with Wnt3a and LiCl, which required the PKP1 N terminus (amino acids 161 to 270. Localization of PKP1, which is known as an adhesion-related desmosome component, shifted to the plasma membrane during ameloblast differentiation. In addition, Pkp1 knockdown disrupted the localization of Zona occludens 1 in tight junctions and inhibited ameloblast differentiation; the two proteins were shown to directly interact by immunoprecipitation. These results implicate the participation of PKP1 in early tooth morphogenesis as an effector of canonical Wnt signaling that controls ameloblast differentiation via regulation of the cell adhesion complex.

  19. Wnt signaling: the good and the bad

    Institute of Scientific and Technical Information of China (English)

    Xi Chen; Jun Yang; Paul M Evans; Chunming Liu

    2008-01-01

    Since the first Wnt gene was identified in 1982,the functions and mechanisms of Wnt signaling have been extensively studied.Wnt signaling is conserved from invertebrates to vertebrates and regulates early embryonic development as well as the homeostasis of adult tissues.In addition,both embryonic stem cells and adult stem cells are regulated by Wnt signaling.Deregulation of Wnt signaling is associated with many human diseases,particularly cancers.In this review,we will discuss in detail the functions of many components involved in the Wnt signal transduction pathway.Then,we will explore what is known about the role of Wnt signaling in stem cells and cancers.

  20. Downregulation of sFRP-2 by epigenetic silencing activates the β-catenin/Wnt signaling pathway in esophageal basaloid squamous cell carcinoma.

    Science.gov (United States)

    Saito, Tsuyoshi; Mitomi, Hiroyuki; Imamhasan, Abdukadir; Hayashi, Takuo; Mitani, Keiko; Takahashi, Michiko; Kajiyama, Yoshiaki; Yao, Takashi

    2014-02-01

    Basaloid squamous cell carcinoma (BSCC) of the esophagus is a rare variant of typical squamous cell carcinoma (SCC) associated with poor survival. A characteristic feature is nuclear accumulation of β-catenin, without a mutation of the gene. We studied the methylation status of Wnt antagonist genes, such as secreted frizzled-related protein (sFRP) gene family members, Wnt inhibitory factor-1 (WIF-1), Dickkopf-1 (Dkk-1), and human Dapper protein-1 (HDPR-1), and alterations of the APC, Axin1, and Axin2 genes in 30 cases of esophageal BSCC. β-catenin and sFRP (sFRP-1, sFRP-2, sFRP-4, sFRP-5) protein expression was examined by immunohistochemistry. APC, Axin1, and Axin2 gene mutations were detected in 3, 2, and 2 cases, respectively, and 6 cases (20 %) harbored at least 1 alteration in these genes. Methylation of the sFRP-2 promoter region was observed in all cases, and methylation was frequent in sFRP-1 and sFRP-5, but infrequent in Dkk-1, WIF-1, sFRP-4, and HDPR-1. sFRP-2 expression was almost completely absent in 25 cases (83 %), consistent with the methylation status. Nuclear accumulation of β-catenin was observed in all cases. sFRP-5 expression was associated with a low nuclear β-catenin labeling index. These results show that sFRP-2 is a target gene of hypermethylation in esophageal BSCC and suggest that sFRP-2 might contribute to BSCC tumorigenesis through the Wnt/β-catenin signaling pathway. PMID:24464051

  1. Tyrosine phosphorylation of transcriptional coactivator WW-domain binding protein 2 regulates estrogen receptor α function in breast cancer via the Wnt pathway.

    Science.gov (United States)

    Lim, Shen Kiat; Orhant-Prioux, Magali; Toy, Weiyi; Tan, Kah Yap; Lim, Yoon Pin

    2011-09-01

    WW-binding protein 2 (WBP2) has been demonstrated in different studies to be a tyrosine kinase substrate, to activate estrogen receptor α (ERα)/progesterone receptor (PR) transcription, and to play a role in breast cancer. However, the role of WBP2 tyrosine phosphorylation in regulating ERα function and breast cancer biology is unknown. Here, we established WBP2 as a tyrosine phosphorylation target of estrogen signaling via EGFR crosstalk. Using dominant-negative, constitutively active mutants, RNAi, and pharmacological studies, we demonstrated that phosphorylation of WBP2 at Tyr192 and Tyr231 could be regulated by c-Src and c-Yes kinases. We further showed that abrogating WBP2 phosphorylation impaired >60% of ERα reporter activity, putatively by blocking nuclear entry of WBP2 and its interaction with ERα. Compared to vector control, overexpression of WBP2 and its phospho-mimic mutant in MCF7 cells resulted in larger tumors in mice, induced loss of cell-cell adhesion, and enhanced cell proliferation, anchorage-independent growth, migration, and invasion in both estrogen-dependent and -independent manners, events of which could be substantially abolished by overexpression of the phosphorylation-defective mutant. Hormone independence of cells expressing WBP2 phospho-mimic mutant was associated with heightened ERα and Wnt reporter activities. Wnt/β-catenin inhibitor FH535 blocked phospho-WBP2-mediated cancer cell growth more pronouncedly than tamoxifen and fulvestrant, in part by reducing the expression of ERα. Wnt pathway is likely to be a critical component in WBP2-mediated breast cancer biology.

  2. Disruption of kif3a results in defective osteoblastic differentiation in dental mesenchymal stem/precursor cells via the Wnt signaling pathway.

    Science.gov (United States)

    Jiang, Sicong; Chen, Guoqing; Feng, Lian; Jiang, Zongting; Yu, Mei; Bao, Jinku; Tian, Weidong

    2016-09-01

    The anterograde intraflagellar transport motor protein, kif3a, regulates the integrity of primary cilia and various cellular functions, however, the role of kif3a in dental mesenchymal stem/precursor cell differentiation remains to be fully elucidated. In the present study, the expression of kif3a was knocked down in human dental follicle cells (hDFCs) and human dental pulp cells (hDPCs) using short hairpin RNA. The results of subsequent immunofluorescence revealed that knocking down kif3a resulted in the loss of primary cilia, which led to impairment of substantial mineralization and expression of the differentiation‑associated markers, including alkaline phosphatase, Runt‑related transcription factor 2, dentin matrix protein 1 and dentin sialophosphoprotein in the hDFCs and hDPCs. The results of reverse transcription‑quantitative polymerase chain reaction and western blot analyses showed that the expression levels of Wnt3a‑mediated active β‑catenin and lymphoid enhancer‑binding factor 1 were attenuated, whereas the expression of phosphorylated glycogen synthase kinase 3β was enhanced, in the kif3a‑knockdown cells. In addition, exogenous Wnt3a partially rescued osteoblastic differentiation in the hDFCs and hDPCs. These results demonstrated that inhibition of kif3a in the hDFCs and hDPCs disrupted primary cilia formation and/or function, and indicated that kif3a is important in the differentiation of hDFCs and hDPCs through the Wnt pathway. These findings not only enhance current understanding of tooth development and diseases of tooth mineralization, but also indicate possible strategies to regulate mineralization during tooth repair and regeneration. PMID:27432616

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

    Energy Technology Data Exchange (ETDEWEB)

    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.

  4. Thyroid hormone activates Wnt/β-catenin signaling involved in adult epithelial development during intestinal remodeling in Xenopus laevis.

    Science.gov (United States)

    Hasebe, Takashi; Fujimoto, Kenta; Kajita, Mitsuko; Ishizuya-Oka, Atsuko

    2016-08-01

    During amphibian intestinal remodeling, thyroid hormone (TH) induces some larval epithelial cells to dedifferentiate into adult stem cells, which newly generate the absorptive epithelium analogous to the mammalian epithelium. To clarify molecular mechanisms underlying adult epithelial development, we here focus on TH response genes that are associated with the canonical Wnt pathway. Our quantitative reverse transcription plus polymerase chain reaction and immunohistochemical analyses indicate that all of the genes examined, including β-catenin, c-Myc and secreted frizzle-related protein 2 (SFRP2), are up-regulated in Xenopus laevis intestine during both natural and TH-induced metamorphosis. Moreover, immunoreactivity for nuclear β-catenin becomes detectable in adult stem cells from the start of their appearance and then increases in intensity in adult epithelial primordia derived from the stem cells, which actively proliferate and coexpress Wnt target genes c-Myc and LGR5. These expression profiles strongly suggest the involvement of the canonical Wnt pathway in the maintenance and/or proliferation of adult stem/progenitor cells. More importantly, by using organ cultures of the tadpole intestine, we have experimentally shown that the addition of exogenous SFRP2 protein to the culture medium promotes cell proliferation of the adult epithelial primordia, whereas inhibition of endogenous SFRP2 by its antibody suppresses their proliferation. The inhibition of SFRP2 suppresses larval epithelial changes in shape from simple columnar to stem-cell-like roundish cells, resulting in the failure of epithelial dedifferentiation. Thus, TH-up-regulated SFRP2 in the postembryonic intestine promotes adult stem cell development, possibly by acting as an agonist of both canonical and non-canonical Wnt signaling. PMID:27068920

  5. CUX1/Wnt signaling regulates Epithelial Mesenchymal Transition in EBV infected epithelial cells

    International Nuclear Information System (INIS)

    Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGFβ1-mediated lytic phase. EBV lytic reactivation by TGFβ1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM181552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.

  6. CUX1/Wnt signaling regulates Epithelial Mesenchymal Transition in EBV infected epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Malizia, Andrea P.; Lacey, Noreen [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland); Walls, Dermot [School of Biotechnology, Dublin City University. Dublin, 9. Ireland (Ireland); Egan, Jim J. [Advanced Lung Disease and Lung Transplant Program, Mater Misericordiae University Hospital. 44, Eccles Street. Dublin, 7. Ireland (Ireland); Doran, Peter P., E-mail: peter.doran@ucd.ie [Clinical Research Centre, School of Medicine and Medical Science, University College Dublin. 21, Nelson Street. Dublin, 7. Ireland (Ireland)

    2009-07-01

    Idiopathic pulmonary fibrosis (IPF) is a refractory and lethal interstitial lung disease characterized by alveolar epithelial cells apoptosis, fibroblast proliferation and extra-cellular matrix protein deposition. EBV, localised to alveolar epithelial cells of pulmonary fibrosis patients is associated with a poor prognosis. A strategy based on microarray-differential gene expression analysis to identify molecular drivers of EBV-associated lung fibrosis was utilized. Alveolar epithelial cells were infected with EBV to identify genes whose expression was altered following TGF{beta}1-mediated lytic phase. EBV lytic reactivation by TGF{beta}1 drives a selective alteration in CUX1 variant (a) (NCBI accession number NM{sub 1}81552) expression, inducing activation of non-canonical Wnt pathway mediators, implicating it in Epithelial Mesenchymal Transition (EMT), the molecular event underpinning scar production in tissue fibrosis. The role of EBV in EMT can be attenuated by antiviral strategies and inhibition of Wnt signaling by using All-Trans Retinoic Acids (ATRA). Activation of non-canonical Wnt signaling pathway by EBV in epithelial cells suggests a novel mechanism of EMT via CUX1 signaling. These data present a framework for further description of the link between infectious agents and fibrosis, a significant disease burden.

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

    International Nuclear Information System (INIS)

    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

  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. Vascular Calcification in Chronic Kidney Disease is Induced by Bone Morphogenetic Protein-2 via a Mechanism Involving the Wnt/β-Catenin Pathway

    Directory of Open Access Journals (Sweden)

    Shu Rong

    2014-11-01

    Full Text Available Background: Vascular calcification (VC, in which vascular smooth muscle cells (VSMCs undergo a phenotypic transformation into osteoblast-like cells, is one of the emergent risk factors for the accelerated atherosclerosis process characteristic of chronic kidney disease (CKD. Phosphate is an important regulator of VC. Methods: The expression of different smooth muscle cell or osteogenesis markers in response to high concentrations of phosphate or exogenous bone morphogenetic protein 2 (BMP-2 was examined by qRT-PCR and western blotting in rat VSMCs. Osteocalcin secretion was measured by radioimmunoassay. Differentiation and calcification of VSMCs were examined by alkaline phosphatase (ALP activity assay and Alizarin staining. Short hairpin RNA-mediated silencing of β-catenin was performed to examine the involvement of Wnt/β-catenin signaling in VSMC calcification and osteoblastic differentiation induced by high phosphate or BMP-2. Apoptosis was determined by TUNEL assay and immunofluorescence imaging. Results: BMP-2 serum levels were significantly higher in CKD patients than in controls. High phosphate concentrations and BMP-2 induced VSMC apoptosis and upregulated the expression of β-catenin, Msx2, Runx2 and the phosphate cotransporter Pit1, whereas a BMP-2 neutralization antibody reversed these effects. Knockdown of β-catenin abolished the effect of high phosphate and BMP-2 on VSMC apoptosis and calcification. Conclusions: BMP-2 plays a crucial role in calcium deposition in VSMCs and VC in CKD patients via a mechanism involving the Wnt/β-catenin pathway.

  10. MUC4 is negatively regulated through the Wnt/β-catenin pathway via the Notch effector Hath1 in colorectal cancer.

    Science.gov (United States)

    Pai, Priya; Rachagani, Satyanarayana; Dhawan, Punita; Sheinin, Yuri M; Macha, Muzafar A; Qazi, Asif Khurshid; Chugh, Seema; Ponnusamy, Moorthy P; Mallya, Kavita; Pothuraju, Ramesh; Batra, Surinder K

    2016-05-01

    MUC4 is a transmembrane mucin lining the normal colonic epithelium. The aberrant/de novo over-expression of MUC4 is well documented in malignancies of the pancreas, ovary and breast. However, studies have reported the loss of MUC4 expression in the majority of colorectal cancers (CRCs). A MUC4 promoter analysis showed the presence of three putative TCF/LEF sites, implying a possible regulation by the Wnt/β-catenin pathway, which has been shown to drive CRC progression. Thus, the objective of our study was to determine whether MUC4 is regulated by β-catenin in CRC. We first knocked down (KD) β-catenin in three CRC cell lines; LS180, HCT-8 and HCT116, which resulted in increased MUC4 transcript and MUC4 protein. Additionally, the overexpression of stabilized mutant β-catenin in LS180 and HCT-8 resulted in a decrease in MUC4 expression. Immunohistochemistry (IHC) of mouse colon tissue harboring tubular adenomas and high grade dysplasia showed dramatically reduced Muc4 in lesions relative to adjacent normal tissue, with increased cytosolic/nuclear β-catenin. Luciferase assays with the complete MUC4 promoter construct p3778 showed increased MUC4 promoter luciferase activity in the absence of β-catenin (KD). Mutation of all three putative TCF/LEF sites showed that MUC4 promoter luciferase activity was increased relative to the un-mutated promoter. Interestingly, it was observed that MUC4 expressing CRC cell lines also expressed high levels of Hath1, a transcription factor repressed by both active Wnt/β-catenin and Notch signaling. The KD of β-catenin and/or treatment with a Notch γ-secretase inhibitor, Dibenzazepine (DBZ) resulted in increased Hath1 and MUC4 in LS180, HCT-8 and HCT116. Furthermore, overexpression of Hath1 in HCT-8 and LS180 caused increased MUC4 transcript and MUC4 protein. Taken together, our results indicate that the Wnt/β-catenin pathway suppresses the Notch pathway effector Hath1, resulting in reduced MUC4 in CRC. PMID:27551331

  11. Helicobacter pylori upregulates Nanog and Oct4 via Wnt/β-catenin signaling pathway to promote cancer stem cell-like properties in human gastric cancer.

    Science.gov (United States)

    Yong, Xin; Tang, Bo; Xiao, Yu-Feng; Xie, Rui; Qin, Yong; Luo, Gang; Hu, Chang-Jiang; Dong, Hui; Yang, Shi-Ming

    2016-05-01

    Helicobacter pylori (H. pylori) infection is considered a major risk factor for gastric cancer. CagA behaves as a major bacterial oncoprotein playing a key role in H. pylori-induced tumorigenesis. Cancer stem cells (CSCs) are believed to possess the ability to initiate tumorigenesis and promote progression. Although studies have suggested that cancer cells can exhibit CSC-like properties in the tumor microenvironment, it remains unclear whether H. pylori infection could induce the emergence of CSC-like properties in gastric cancer cells and, the underlying mechanism. Here, gastric cancer cells were co-cultured with a CagA-positive H. pylori strain or a CagA isogenic mutant strain. We found that H. pylori-infected gastric cancer cells exhibited CSC-like properties, including an increased expression of CSC specific surface markers CD44 and Lgr5, as well as that of Nanog, Oct4 and c-myc, which are known pluripotency genes, and an increased capacity for self-renewal, whereas these properties were not observed in the CagA isogenic mutant strain-infected cells. Further studies revealed that H. pylori activated Wnt/β-catenin signaling pathway in a CagA-dependent manner and that the activation of this pathway was dependent upon CagA-positive H. pylori-mediated phosphorylation of β-catenin at the C-terminal Ser675 and Ser552 residues in a c-met- and/or Akt-dependent manner. We further demonstrated that this activation was responsible for H. pylori-induced CSC-like properties. Moreover, we found the promoter activity of Nanog and Oct4 were upregulated, and β-catenin was observed to bind to these promoters during H. pylori infection, while a Wnt/β-catenin inhibitor suppressed promoter activity and binding. Taken together, these results suggest that H. pylori upregulates Nanog and Oct4 via Wnt/β-catenin signaling pathway to promote CSC-like properties in gastric cancer cells.

  12. Wnt signaling activates Shh signaling in early postnatal intervertebral discs, and re-activates Shh signaling in old discs in the mouse.

    Directory of Open Access Journals (Sweden)

    Tamara Winkler

    Full Text Available Intervertebral discs (IVDs are strong fibrocartilaginous joints that connect adjacent vertebrae of the spine. As discs age they become prone to failure, with neurological consequences that are often severe. Surgical repair of discs treats the result of the disease, which affects as many as one in seven people, rather than its cause. An ideal solution would be to repair degenerating discs using the mechanisms of their normal differentiation. However, these mechanisms are poorly understood. Using the mouse as a model, we previously showed that Shh signaling produced by nucleus pulposus cells activates the expression of differentiation markers, and cell proliferation, in the postnatal IVD. In the present study, we show that canonical Wnt signaling is required for the expression of Shh signaling targets in the IVD. We also show that Shh and canonical Wnt signaling pathways are down-regulated in adult IVDs. Furthermore, this down-regulation is reversible, since re-activation of the Wnt or Shh pathways in older discs can re-activate molecular markers of the IVD that are lost with age. These data suggest that biological treatments targeting Wnt and Shh signaling pathways may be feasible as a therapeutic for degenerative disc disease.

  13. 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.

  14. Resveratrol inhibits invasion and metastasis of colorectal cancer cells via MALAT1 mediated Wnt/β-catenin signal pathway.

    Directory of Open Access Journals (Sweden)

    Qing Ji

    Full Text Available Resveratrol, extracted from Chinese herbal medicine Polygonum cuspidatum, is known to inhibit invasion and metastasis of human colorectal cancer (CRC, in which long non-coding Metastasis Associated Lung Adenocarcinoma Transcript 1 (RNA-MALAT1 also plays an important role. Using MALAT1 lentiviral shRNA and over-expression constructs in CRC derived cell lines, LoVo and HCT116, we demonstrated that the anti-tumor effects of resveratrol on CRC are through inhibiting Wnt/β-catenin signaling, thus the expression of its target genes such as c-Myc, MMP-7, as well as the expression of MALAT1. In detail, resveratrol down-regulates MALAT1, resulting in decreased nuclear localization of β-catenin thus attenuated Wnt/β-catenin signaling, which leads to the inhibition of CRC invasion and metastasis. This finding of ours surely provides important pre-clinical evidence supporting future use of resveratrol in prevention and treatment of CRC.

  15. 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

  16. Time-resolved Studies of IsdG Protein Identify Molecular Signposts along the Non-canonical Heme Oxygenase Pathway.

    Science.gov (United States)

    Streit, Bennett R; Kant, Ravi; Tokmina-Lukaszewska, Monika; Celis, Arianna I; Machovina, Melodie M; Skaar, Eric P; Bothner, Brian; DuBois, Jennifer L

    2016-01-01

    IsdGs are heme monooxygenases that break open the tetrapyrrole, releasing the iron, and thereby allowing bacteria expressing this protein to use heme as a nutritional iron source. Little is currently known about the mechanism by which IsdGs degrade heme, although the products differ from those generated by canonical heme oxygenases. A synthesis of time-resolved techniques, including in proteo mass spectrometry and conventional and stopped-flow UV/visible spectroscopy, was used in conjunction with analytical methods to define the reaction steps mediated by IsdG from Staphylococcus aureus and their time scales. An apparent meso-hydroxyheme (forming with k = 0.6 min(-1), pH 7.4, 10 mm ascorbate, 10 μm IsdG-heme, 22 °C) was identified as a likely common intermediate with the canonical heme oxygenases. Unlike heme oxygenases, this intermediate does not form with added H2O2 nor does it convert to verdoheme and CO. Rather, the next observable intermediates (k = 0.16 min(-1)) were a set of formyloxobilin isomers, similar to the mycobilin products of the IsdG homolog from Mycobacterium tuberculosis (MhuD). These converted in separate fast and slow phases to β-/δ-staphylobilin isomers and formaldehyde (CH2O). Controlled release of this unusual C1 product may support IsdG's dual role as both an oxygenase and a sensor of heme availability in S. aureus. PMID:26534961

  17. Excessive Wnt/beta-catenin signaling promotes midbrain floor plate neurogenesis, but results in vacillating dopamine progenitors.

    Science.gov (United States)

    Nouri, Navid; Patel, Meera J; Joksimovic, Milan; Poulin, Jean-Francois; Anderegg, Angela; Taketo, M Mark; Ma, Yong-Chao; Awatramani, Rajeshwar

    2015-09-01

    The floor plate (FP), a ventral midline structure of the developing neural tube, has differential neurogenic capabilities along the anterior-posterior axis. The midbrain FP, unlike the hindbrain and spinal cord floor plate, is highly neurogenic and produces midbrain dopaminergic (mDA) neurons. Canonical Wnt/beta-catenin signaling, at least in part, is thought to account for the difference in neurogenic capability. Removal of beta-catenin results in mDA progenitor specification defects as well as a profound reduction of neurogenesis. To examine the effects of excessive Wnt/beta-catenin signaling on mDA specification and neurogenesis, we have analyzed a model wherein beta-catenin is conditionally stabilized in the Shh+domain. Here, we show that the Foxa2+/Lmx1a+ domain is extended rostrally in mutant embryos, suggesting that canonical Wnt/beta-catenin signaling can drive FP expansion along the rostrocaudal axis. Although excess canonical Wnt/beta-catenin signaling generally promotes neurogenesis at midbrain levels, less tyrosine hydroxylase (Th)+, mDA neurons are generated, particularly impacting the Substantia Nigra pars compacta. This is likely because of improper progenitor specification. Excess canonical Wnt/beta-catenin signaling causes downregulation of net Lmx1b, Shh and Foxa2 levels in mDA progenitors. Moreover, these progenitors assume a mixed identity to that of Lmx1a+/Lmx1b+/Nkx6-1+/Neurog1+ progenitors. We also show by lineage tracing analysis that normally, Neurog1+ progenitors predominantly give rise to Pou4f1+ neurons, but not Th+ neurons. Accordingly, in the mutant embryos, Neurog1+ progenitors at the midline generate ectopic Pou4f1+ neurons at the expense of Th+ mDA neurons. Our study suggests that an optimal dose of Wnt/beta-catenin signaling is critical for proper establishment of the mDA progenitor character. Our findings will impact embryonic stem cell protocols that utilize Wnt pathway reagents to derive mDA neuron models and therapeutics for

  18. Cross-Talking Between PPAR and WNT Signaling and its Regulation in Mesenchymal Stem Cell Differentiation.

    Science.gov (United States)

    Xu, Chenyuan; Wang, Jing; Zhu, Tianjie; Shen, Yun; Tang, Xiaoshan; Fang, Li; Xu, Yuanzhi

    2016-01-01

    The pluripotent mesenchymal stem cells (MSC) are common precursors to adipocytes and osteoblasts. Large numbers of extracellular and intracellular signals and transcription factors moderate adipogenesis and osteoblastogenesis. Importantly, between adipogenic and osteogenic lineage commitment and differentiation, differentiation of MSCs into one lineage will inhibit their differentiation toward the other lineage. This balance is regulated by numerous signaling pathways. As we know, the peroxisome-proliferator-activated receptor-γ (PPAR-γ) and Wnt/β-catenin pathway are regarded as the master moderators of adipogenesis and osteogenesis. Moreover, governing the differentiation of MSCs to adipogenesis and osteoblastogenesis has significant implications in diverse areas of human health, from obesity to regenerative medicine to osteoporosis. Rivalry roles have been reported of the two pathways since the downstream products activated by Wnt-5a repress PPAR-γ transactivation through the H3K9 histone methyltransferase protein complexes. This review will discuss the inductive and inhibitive role of PPAR-γ in adipogenesis and osteoblastogenesis respectively, as well as the canonical Wnt/β-catenin pathway. PMID:26201865

  19. Delivery of the Porcupine Inhibitor WNT974 in Mice

    Science.gov (United States)

    Zhang, Li-shu; Lum, Lawrence

    2016-01-01

    We describe here a technique for delivering the porcupine inhibitor WNT974 (formerly LGK974) in mice. The protocol entails once-a-day oral delivery of WNT974 for up to 3 months at a concentration sufficient to achieve systemic Wnt pathway inhibition with limited toxicity as measured by weight change. This route of delivery enables extended durations of Wnt signaling inhibition in a mammalian model organism. PMID:27590157

  20. Delivery of the Porcupine Inhibitor WNT974 in Mice.

    Science.gov (United States)

    Zhang, Li-Shu; Lum, Lawrence

    2016-01-01

    We describe here a technique for delivering the porcupine inhibitor WNT974 (formerly LGK974) in mice. The protocol entails once-a-day oral delivery of WNT974 for up to 3 months at a concentration sufficient to achieve systemic Wnt pathway inhibition with limited toxicity as measured by weight change. This route of delivery enables extended durations of Wnt signaling inhibition in a mammalian model organism. PMID:27590157

  1. Wnt Lipidation and Modifiers in Intestinal Carcinogenesis and Cancer

    OpenAIRE

    Elke Kaemmerer; Nikolaus Gassler

    2016-01-01

    The wingless (Wnt) signaling is suggested as a fundamental hierarchical pathway in regulation of proliferation and differentiation of cells. The Wnt ligands are small proteins of about 40 kDa essentially for regulation and initiation of the Wnt activity. They are secreted proteins requiring acylation for activity in the Wnt signaling cascade and for functional interactivity with transmembrane proteins. Dual lipidation is important for posttranslational activation of the overwhelming number of...

  2. ALFY-Controlled DVL3 Autophagy Regulates Wnt Signaling, Determining Human Brain Size.

    Directory of Open Access Journals (Sweden)

    Rotem Kadir

    2016-03-01

    Full Text Available Primary microcephaly is a congenital neurodevelopmental disorder of reduced head circumference and brain volume, with fewer neurons in the cortex of the developing brain due to premature transition between symmetrical and asymmetrical cellular division of the neuronal stem cell layer during neurogenesis. We now show through linkage analysis and whole exome sequencing, that a dominant mutation in ALFY, encoding an autophagy scaffold protein, causes human primary microcephaly. We demonstrate the dominant effect of the mutation in drosophila: transgenic flies harboring the human mutant allele display small brain volume, recapitulating the disease phenotype. Moreover, eye-specific expression of human mutant ALFY causes rough eye phenotype. In molecular terms, we demonstrate that normally ALFY attenuates the canonical Wnt signaling pathway via autophagy-dependent removal specifically of aggregates of DVL3 and not of Dvl1 or Dvl2. Thus, autophagic attenuation of Wnt signaling through removal of Dvl3 aggregates by ALFY acts in determining human brain size.

  3. 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.

  4. Wnt inhibitory factor-1 functions as a tumor suppressor through modulating Wnt/β-catenin signaling in neuroblastoma

    OpenAIRE

    Zhang, Jiao; Zhou, Bin; Liu, Yinghua; Chen, Keling; Bao, Pingqian; Wang, Yi; Wang, Jiaxiang; Zhou, Zongguang; Sun, Xiao-Feng; Li, Yuan

    2014-01-01

    Neuroblastoma is the most common extracranial solid tumor in childhood and is associated with serious morbidity and mortality. The effective treatment of neuroblastoma remains one of the major challenges in pediatric oncology. The Wnt signaling pathway has been shown to play a significant role in the pathogenesis of adult and pediatric tumors. WIF-1 has been identified as an important Wnt antagonist which inhibits Wnt/β-catenin signaling by directly binding to Wnt proteins. However, the expre...

  5. Wnt signaling induces differentiation of progenitor cells in organotypic keratinocyte cultures

    Directory of Open Access Journals (Sweden)

    Liu Bob Y

    2007-02-01

    Full Text Available Abstract Background Interfollicular skin develops normally only when the activity of the progenitor cells in the basal layer is counterbalanced by the exit of cells into the suprabasal layers, where they differentiate and cornify to establish barrier function. Distinct stem and progenitor compartments have been demonstrated in hair follicles and sebaceous glands, but there are few data to describe the control of interfollicular progenitor cell activity. Wnt signaling has been shown to be an important growth-inducer of stem cell compartments in skin and many other tissues. Results Here, we test the effect of ectopic Wnt1 expression on the behavior of interfollicular progenitor cells in an organotypic culture model, and find that Wnt1 signaling inhibits their growth and promotes terminal differentiation. Conclusion These results are consistent with the phenotypes reported for transgenic mice engineered to have gain or loss of function of Wnt signaling in skin, which would recommend our culture model as an accurate one for molecular analysis. Since it is known that canonical ligands are expressed in skin, it is likely that this pathway normally regulates the balance of growth and differentiation, and suggests it could be important to pathogenesis.

  6. Age-related neuroinflammation and changes in AKT-GSK-3β and WNT/ β-CATENIN signaling in rat hippocampus.

    Science.gov (United States)

    Orellana, Ana Maria Marques; Vasconcelos, Andrea Rodrigues; Leite, Jacqueline Alves; de Sá Lima, Larissa; Andreotti, Diana Zukas; Munhoz, Carolina Demarchi; Kawamoto, Elisa Mitiko; Scavone, Cristoforo

    2015-12-01

    Aging is a multifactorial process associated with an increased susceptibility to neurodegenerative disorders which can be related to chronic inflammation. Chronic inflammation, however, can be characterized by the persistent elevated glucocorticoid (GCs) levels, activation of the proinflammatory transcription factor NF-кB, as well as an increase in cytokines. Interestingly, both NF-кB and cytokines can be even modulated by Glycogen Synthase Kinase 3 beta (GSK-3β) activity, which is a key protein that can intermediate inflammation and metabolism, once it has a critical role in AKT signaling pathway, and can also intermediate WNT/β-CATENIN signaling pathway. The aim of this study was to verify age-related changes in inflammatory status, as well as in the AKT and WNT signaling pathways. Results showed an age-related increase in neuroinflammation as indicated by NF-кB activation, TNF-α and GCs increased levels, a decrease in AKT activation and an increase in GSK-3β activity in both 12- and 24- month old animals. Aging also seems to induce a progressive decrease in canonical WNT/β-CATENIN signaling pathway once there is a decrease in DVL-2 levels and in the transcription of Axin2 gene. Little is known about the DVL-2 regulation as well as its roles in WNT signaling pathway, but for the first time it was suggested that DVL-2 expression can be changed along aging.

  7. Inhibition of CAY10404 on Wnt/β-catenin Signaling Pathway to Eliminate Multiple Myeloma Stem Cells%CAY10404靶向干预Wnt/β-catenin信号通路对多发性骨髓瘤干细胞清除作用的研究

    Institute of Scientific and Technical Information of China (English)

    杨烨; 顾春艳; 陆美龄; 王旻

    2013-01-01

    Wnt信号被认为是多发性骨髓瘤(MM)致癌作用的一个重要角色.为了观察Wnt/β-catenin信号通路在多发性骨髓瘤特别是多发性骨髓瘤干细胞中的表达及Wnt/β-catenin信号通路抑制剂CAY10404对多发性骨髓瘤的治疗作用,对13个多发性骨髓瘤患者的骨髓样本和多发性骨髓瘤细胞株中的Wnt/β-catenin相关基因的表达情况进行分析和运用Western-blot方法分析β-catenin蛋白在多发性骨髓瘤不同细胞亚群中的表达及COX2抑制剂CAY10404对β-catenin蛋白表达的抑制,通过体内外试验观察CAY1040对多发性骨髓瘤不同细胞亚群的增殖抑制作用.结果显示Wnt/β-catenin信号通路在多发性骨髓瘤病人样本CD138-/CD19+干细胞亚群中比CD138+细胞亚群表达显著增高(P<0.05);体内外试验显示CAY10404明显抑制多发性骨髓瘤干细胞亚群的增殖(P<0.05).该研究通过靶向干预Wnt/β-catenin信号通路,对治疗多发性骨髓瘤尤其是多发性骨髓瘤干细胞进行了探索.%Wnt/β-catenin signaling pathway is involved in multiple myeloma. In order to evaluate the function of Wnt/p-catenin signaling pathway in the multiple myeloma, 13 bone marrow samples from multiple myeloma patients and myeloma cell lines were analysed by micro-array, real-time PCR. Western blot was used to test the expression of β-catenin in these samples, especially in multiple myeloma stem cells. COX2 inhibitor,CAY10404 was used to evaluate the effect of inhibtion Wnt signaling on the myeloma progression both in vitro and in vivo. Results showed that Wnt/p-catenin signaling highly expressed in myeloma cells especially in myeloma stem cells(P <0. 05) and CAY10404 significantly inhibited proliferation of myeloma cells and tumorgenesis in Nod-Scid mice(P<0. 05). These findings provide a rationale for Wnt/β-catenin signaling pathway-based therapy in multiple myeloma, especially in multiple myeloma stem cells.

  8. Gold nanoparticles promote osteogenic differentiation in human adipose-derived mesenchymal stem cells through the Wnt/β-catenin signaling pathway

    Directory of Open Access Journals (Sweden)

    Choi SY

    2015-07-01

    Full Text Available Seon Young Choi,1 Min Seok Song,1 Pan Dong Ryu,1 Anh Thu Ngoc Lam,2 Sang-Woo Joo,2 So Yeong Lee1 1Laboratory of Veterinary Pharmacology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, 2Department of Chemistry, Soongsil University, Seoul, South Korea Abstract: Gold nanoparticles (AuNPs are attractive materials for use in biomedicine due to their physical properties. Increasing evidence suggests that several nanoparticles induce the differentiation of human mesenchymal stem cells into osteoblasts and adipocytes. In this study, we hypothesized that chitosan-conjugated AuNPs promote the osteogenic differentiation of human adipose-derived mesenchymal stem cells. For the evaluation of osteogenic differentiation, alizarin red staining, an alamarBlue® assay, and a quantitative real-time polymerase chain reaction analysis were performed. In order to examine specific signaling pathways, immunofluorescence and a western blotting assay were performed. Our results demonstrate that chitosan-conjugated AuNPs increase the deposition of calcium content and the expression of marker genes related to osteogenic differentiation in human adipose-derived mesenchymal stem cells at nontoxic concentrations. These results indicate that chitosan-conjugated AuNPs promote osteogenesis through the Wnt/β-catenin signaling pathway. Therefore, chitosan-conjugated AuNPs can be used as a reagent for promoting bone formation. Keywords: chitosan-conjugated gold nanoparticle, mineralization, nonphosphorylated beta-catenin

  9. Dietary chlorophyllin inhibits the canonical NF-κB signaling pathway and induces intrinsic apoptosis in a hamster model of oral oncogenesis.

    Science.gov (United States)

    Thiyagarajan, P; Senthil Murugan, R; Kavitha, K; Anitha, P; Prathiba, D; Nagini, S

    2012-03-01

    Chlorophyllin, a water-soluble, semi-synthetic derivative of the ubiquitous green pigment chlorophyll is shown to exert potent anticarcinogenic effects. In the present study, we investigated the chemopreventive effects of chlorophyllin on 7,12-dimethylbenz(a)anthracene (DMBA)-induced hamster buccal pouch (HBP) carcinogenesis by analyzing the expression of NF-κB family members and markers of intrinsic apoptosis. Dietary administration of chlorophyllin (4 mg/kg bw) suppressed the development of HBP carcinomas by inhibiting the canonical NF-κB signaling pathway by downregulating IKKβ, preventing the phosphorylation of IκB-α, and reducing the expression of nuclear NF-κB. Inactivation of NF-κB signaling by chlorophyllin was associated with the induction of intrinsic apoptosis as evidenced by modulation of Bcl-2 family proteins, enforced nuclear localization of survivin, upregulation of apoptogenic molecules, activation of caspases, and cleavage of PARP. The results of the present study demonstrate that chlorophyllin inhibits the development of DMBA-induced HBP carcinogenesis by targeting NF-κB and the intrinsic apoptotic pathway. Thus, dietary agents such as chlorophyllin that simultaneously target divergent pathways of cell survival and cell death are novel candidates for cancer chemoprevention. PMID:22210229

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

    Directory of Open Access Journals (Sweden)

    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.

  11. Stearoyl CoA Desaturase Is Required to Produce Active, Lipid-Modified Wnt Proteins

    Directory of Open Access Journals (Sweden)

    Jessica Rios-Esteves

    2013-09-01

    Full Text Available Wnt proteins contain palmitoleic acid, an unusual lipid modification. Production of an active Wnt signal requires the acyltransferase Porcupine and depends on the attachment of palmitoleic acid to Wnt. The source of this monounsaturated fatty acid has not been identified, and it is not known how Porcupine recognizes its substrate and whether desaturation occurs before or after fatty acid transfer to Wnt. Here, we show that stearoyl desaturase (SCD generates a monounsaturated fatty acid substrate that is then transferred by Porcupine to Wnt. Treatment of cells with SCD inhibitors blocked incorporation of palmitate analogs into Wnt3a and Wnt5a and reduced Wnt secretion as well as autocrine and paracrine Wnt signaling. The SCD inhibitor effects were rescued by exogenous addition of monounsaturated fatty acids. We propose that SCD is a key molecular player responsible for Wnt biogenesis and processing and that SCD inhibition provides an alternative mechanism for blocking Wnt pathway activation.

  12. Lipid-independent secretion of a Drosophila Wnt protein.

    Science.gov (United States)

    Ching, Wendy; Hang, Howard C; Nusse, Roel

    2008-06-20

    Wnt proteins comprise a large class of secreted signaling molecules with key roles during embryonic development and throughout adult life. Recently, much effort has been focused on understanding the factors that regulate Wnt signal production. For example, Porcupine and Wntless/Evi/Sprinter have been identified as being required in Wnt-producing cells for the processing and secretion of many Wnt proteins. Interestingly, in this study we find that WntD, a recently characterized Drosophila Wnt family member, does not require Porcupine or Wntless/Evi/Sprinter for its secretion or signaling activity. Because Porcupine is involved in post-translational lipid modification of Wnt proteins, we used a novel labeling method and mass spectrometry to ask whether WntD undergoes lipid modification and found that it does not. Although lipid modification is also hypothesized to be required for Wnt secretion, we find that WntD is secreted very efficiently. WntD secretion does, however, maintain a requirement for the secretory pathway component Rab1. Our results show that not all Wnt family members require lipid modification, Porcupine, or Wntless/Evi/Sprinter for secretion and suggest that different modes of secretion may exist for different Wnt proteins.

  13. Genome-wide identification of new Wnt/β-catenin target genes in the human genome using CART method

    Directory of Open Access Journals (Sweden)

    Inestrosa Nibaldo C

    2010-06-01

    genome. In particular, several of these genes represent a new group of transcriptional dependent targets of the canonical Wnt pathway. The functions of these genes indicate that they are involved in pathophysiology related to Alzheimer's disease or other brain disorders.

  14. IFNβ/TNFα synergism induces a non-canonical STAT2/IRF9-dependent pathway triggering a novel DUOX2 NADPH Oxidase-mediated airway antiviral response

    Institute of Scientific and Technical Information of China (English)

    Karin Fink; Lydie Martin; Esperance Mukawera; Stéfany Chartier; Xavier De Deken; Emmanuelle Brochiero; Fran(c)oise Miot

    2013-01-01

    Airway epithelial cells are key initial innate immune responders in the fight against respiratory viruses,primarily via the secretion of antiviral and proinflammatory cytokines that act in an autocrine/paracrine fashion to trigger the establishment of an antiviral state.It is currently thought that the early antiviral state in airway epithelial cells primarily relies on IFNβ secretion and the subsequent activation of the interferon-stimulated gene factor 3 (ISGF3) transcription factor complex,composed of STAT1,STAT2 and IRF9,which regulates the expression of a panoply of interferon-stimulated genes encoding proteins with antiviral activities.However,the specific pathways engaged by the synergistic action of different cytokines during viral infections,and the resulting physiological outcomes are still ill-defined.Here,we unveil a novel delayed antiviral response in the airways,which is initiated by the synergistic autocrine/paracrine action of IFNβ and TNFα,and signals through a non-canonical STAT2-and IRF9-dependent,but STAT1-independent cascade.This pathway ultimately leads to the late induction of the DUOX2 NADPH oxidase expression.Importantly,our study uncovers that the development of the antiviral state relies on DUOX2-dependent H2O2 production.Key antiviral pathways are often targeted by evasion strategies evolved by various pathogenic viruses.In this regard,the importance of the novel DUOX2-dependent antiviral pathway is further underlined by the observation that the human respiratory syncytial virus is able to subvert DUOX2 induction.

  15. Correlation of Alzheimer’s disease with Wnt signaling pathway and neural stem cells%阿尔茨海默病与Wnt信号通路及神经干细胞的关系***★

    Institute of Scientific and Technical Information of China (English)

    王薇; 张海廷; 王淑辉; 张拥波

    2013-01-01

      背景:阿尔茨海默病的病因涉及遗传、环境、免疫等多种因素和机制,大量研究表明Wnt信号通路与之密切相关,也有研究表明,Wnt信号通路对神经干细胞的增殖发挥着决定性作用。目的:对阿尔茨海默病的病理过程与Wnt 信号通路的关系以及 Wnt 信号通路与神经干细胞增殖分化进行综述,为阿尔茨海默病的治疗提供理论依据。方法:通过Pubmed数据库检索有关阿尔茨海默病病理过程与Wnt信号通路及Wnt信号通路与神经干细胞关联的相关文献,检索词为“Alzheimer’s disease、Wnt signaling pathway、NSCs、stem cel differentiation、amyloid-βprotein、Protein Tau”。纳入与阿尔茨海默病和Wnt信号通路相关的文献,排除重复性研究,保留50篇文献进行综述。结果与结论:目前通过神经干细胞移植来治疗以神经元的缺失为特征的神经退行性疾病已成为研究的热点,而如何调控神经干细胞向特定神经元分化成为了研究的难点,信号转导在神经干细胞的分化中起重要的作用,其中Wnt信号通路是调节神经干细胞增殖及分化的细胞外的重要因素。Wnt信号通路的失活可以促进阿尔茨海默病的病理过程,相反激活Wnt信号通路可以保护海马神经元,同时促进神经干细胞的分化,为阿尔茨海默病的治疗提供新的思路。%BACKGROUND:The pathological mechanism of Alzheimer’s disease involves inherited, environmental and immunological factors. Strong evidence exists that Wnt signaling pathway is closely related to the pathological process of Alzheimer’s disease. There is also evidence that Wnt signaling pathway plays a crucial effect on the proliferation of neural stem cel s. OBJECTIVE:To review the relationship between pathological process of Alzheimer’s disease and Wnt signaling pathway and effects of Wnt signaling on proliferation and differentiation of neural stem cel s

  16. TGFβ-mediated suppression of CD248 in non-cancer cells via canonical Smad-dependent signaling pathways is uncoupled in cancer cells

    International Nuclear Information System (INIS)

    CD248 is a cell surface glycoprotein, highly expressed by stromal cells and fibroblasts of tumors and inflammatory lesions, but virtually undetectable in healthy adult tissues. CD248 promotes tumorigenesis, while lack of CD248 in mice confers resistance to tumor growth. Mechanisms by which CD248 is downregulated are poorly understood, hindering the development of anti-cancer therapies. We sought to characterize the molecular mechanisms by which CD248 is downregulated by surveying its expression in different cells in response to cytokines and growth factors. Only transforming growth factor (TGFβ) suppressed CD248 protein and mRNA levels in cultured fibroblasts and vascular smooth muscle cells in a concentration- and time-dependent manner. TGFβ transcriptionally downregulated CD248 by signaling through canonical Smad2/3-dependent pathways, but not via mitogen activated protein kinases p38 or ERK1/2. Notably, cancer associated fibroblasts (CAF) and cancer cells were resistant to TGFβ mediated suppression of CD248. The findings indicate that decoupling of CD248 regulation by TGFβ may contribute to its tumor-promoting properties, and underline the importance of exploring the TGFβ-CD248 signaling pathway as a potential therapeutic target for early prevention of cancer and proliferative disorders

  17. Immunohistochemical study of hair follicle stem cells in regenerated hair follicles induced by Wnt10b

    Science.gov (United States)

    Zhang, Yiming; Xing, Yizhan; Guo, Haiying; Ma, Xiaogen; Li, Yuhong

    2016-01-01

    The regulation of the periodic regeneration of hair follicles is complicated. Although Wnt10b has been reported to induce hair follicle regeneration, the characteristics of induced hair follicles, especially the target cells of Wnt10b, have not yet been clearly elucidated. Thus, we systematically evaluated the expression and proliferation patterns of Wnt10b-induced hair follicles. We found that Wnt10b promoted the proliferation of hair follicle stem cells from 24 hours after AdWnt10b injection. Seventy-two hours after AdWnt10b injection, cells outside of bulge area began to proliferate. When the induced hair follicle entered full anagen, although the hair follicle stem cells were normal, canonical Wnt signaling was maintained in the hair precortex cells. Our results reveal that the target cells that overexpressed Wnt10b included hair follicle stem cells, hair precortex cells, and matrix cells.

  18. 鱼藤素可影响斑马鱼胚胎Wnt信号通路相关基因的表达*★%Deguelin regulates the expression of Wnt signaling pathway related genes in Zebrafish embryo

    Institute of Scientific and Technical Information of China (English)

    刘瑞瑾; 吴新荣

    2013-01-01

    BACKGROUND:Previous studies found that in different periods of early development of zebrafish, embryos treated with certain concentration of deguelin show varying degrees of developmental delay and abnormal phenotype. OBJECTIVE:To observe the effect of deguelin on expression of Wnt signaling pathway related genes in Zebrafish embryo during early embryo development. METHODS:Zebrafish embryos that incubated to the shield period were col ected and put into the 6-wel plate, 0.6μmol/L deguelin solution were added and treated in dark, and then cultured in the incubator under 28℃.Zebrafish em bryos treated with 0.1%dimethylsulfoxide solution were as control group, and cultured in the same conditions. At 6, 8, 10, 12, 14 and 24 hours after fertilization, phenotype of Zebrafish embryos was observed with upright fluorescence microscope. The expression levels of target genes before and after treatment were tested by quantitative real time PCR. RESULTS AND CONCLUSION:The embryos treated by deguelin on shield stage stop growing and stay at bud stage;the expressions of wnt9a, wnt10b, axin2 as wel as snail1b and Jnk2 related with Wnt signal were changed significantly, among them, the expression of wnt9a, wnt10b, axin2 and snail 1b were decreased, while the expression of Jnk2 was increased. Deguelin has a negative effect on Zebrafish in vivo Wnt signal.%  背景:前期研究发现,在斑马鱼早期发育的不同时期,经过一定浓度鱼藤素处理的胚胎表现出不同程度的发育延缓和表型异常。  目的:观察斑马鱼早期胚胎发育过程中鱼藤素对wnt信号通路相关基因表达的影响。  方法:收集孵育至shield期的斑马鱼胚胎于6孔板中,加入0.6μmol/L浓度的鱼藤素溶液,避光处理,28℃培养箱中孵养。用0.1%二甲基亚砜溶液作为对照组,相同条件培养。在受精后6,8,10,12,14,24 h时用正置荧光显微镜拍照观察鱼藤素处理后斑马鱼胚胎发育表

  19. Study on Oridonin for Antitumor Based on Restraining Wnt Signal Pathway in Breast Cancer MCF-7 Cells%基于Wnt信号通路抑制的冬凌草甲素抗乳腺癌研究

    Institute of Scientific and Technical Information of China (English)

    岳静; 陈如意; 洪姣; 贵志芳; 张婷; 任军; 许健

    2014-01-01

    [目的]探究冬凌草甲素对乳腺癌MCF-7细胞生长及Wnt信号通路的影响。[方法] MTT法检测冬凌草甲素对乳腺癌MCF-7细胞活度的影响,流式细胞术检测冬凌草甲素对乳腺癌MCF-7细胞周期、细胞凋亡的影响,免疫蛋白印记法检测冬凌草甲素对乳腺癌MCF-7细胞Wnt通路相关蛋白Wnt4、GSK3β和β-catenin表达的影响。[结果]冬凌草甲素对乳腺癌MCF-7细胞的增殖抑制作用呈时间依赖性、浓度依赖性;冬凌草甲素阻滞MCF-7细胞于G2/M期,且可诱导其凋亡;冬凌草甲素可下调Wnt4、GSK3β、β-catenin的表达。[结论]冬凌草甲素可抑制乳腺癌MCF-7细胞的增殖,且影响了Wnt信号通路。%Objective] To explore the effects of oridonin on the growth and Wnt signal pathway in MCF-7 cel s;. [Methods] Cel viability of MCF-7 cel s was evaluated by MTT assay. Cel cycle and apoptosis were measured by flow cytometry. Expression of the proteins related to Wnt signal pathway was detected by Western Blot. [Result] Oridonin inhibited the proliferation of MCF-7 cel s in a manner as dose- and time-dependence. MCF-7 cel s were arrested in G2/M by oridonin. The expressions of Wnt4, GSK3βandβ-catenin were down-regulated by oridonin. [Conclusion] Oridonin could inhibit the proliferation of MCF-7 cel s, and influence the Wnt signal pathway.

  20. Study on Oridonin for Antitumor Based on Restraining Wnt Signal Pathway in Breast Cancer MCF-7 Cells%基于Wnt信号通路抑制的冬凌草甲素抗乳腺癌研究

    Institute of Scientific and Technical Information of China (English)

    岳静; 陈如意; 洪姣; 贵志芳; 张婷; 任军; 许健

    2014-01-01

    Objective] To explore the effects of oridonin on the growth and Wnt signal pathway in MCF-7 cel s;. [Methods] Cel viability of MCF-7 cel s was evaluated by MTT assay. Cel cycle and apoptosis were measured by flow cytometry. Expression of the proteins related to Wnt signal pathway was detected by Western Blot. [Result] Oridonin inhibited the proliferation of MCF-7 cel s in a manner as dose- and time-dependence. MCF-7 cel s were arrested in G2/M by oridonin. The expressions of Wnt4, GSK3βandβ-catenin were down-regulated by oridonin. [Conclusion] Oridonin could inhibit the proliferation of MCF-7 cel s, and influence the Wnt signal pathway.%[目的]探究冬凌草甲素对乳腺癌MCF-7细胞生长及Wnt信号通路的影响。[方法] MTT法检测冬凌草甲素对乳腺癌MCF-7细胞活度的影响,流式细胞术检测冬凌草甲素对乳腺癌MCF-7细胞周期、细胞凋亡的影响,免疫蛋白印记法检测冬凌草甲素对乳腺癌MCF-7细胞Wnt通路相关蛋白Wnt4、GSK3β和β-catenin表达的影响。[结果]冬凌草甲素对乳腺癌MCF-7细胞的增殖抑制作用呈时间依赖性、浓度依赖性;冬凌草甲素阻滞MCF-7细胞于G2/M期,且可诱导其凋亡;冬凌草甲素可下调Wnt4、GSK3β、β-catenin的表达。[结论]冬凌草甲素可抑制乳腺癌MCF-7细胞的增殖,且影响了Wnt信号通路。

  1. The Wnt Signaling Antagonist Kremen1 is Required for Development of Thymic Architecture

    Directory of Open Access Journals (Sweden)

    Masako Osada

    2006-01-01

    Full Text Available Wnt signaling has been reported to regulate thymocyte proliferation and selection at several stages during T cell ontogeny, as well as the expression of FoxN1 in thymic epithelial cells (TECs. Kremen1 (Krm1 is a negative regulator of the canonical Wnt signaling pathway, and functions together with the secreted Wnt inhibitor Dickkopf (Dkk by competing for the lipoprotein receptor-related protein (LRP-6 co-receptor for Wnts. Here krm1 knockout mice were used to examine krm1 expression in the thymus and its function in thymocyte and TEC development. krm1 expression was detected in both cortical and medullary TEC subsets, as well as in immature thymocyte subsets, beginning at the CD25+CD44+ (DN2 stage and continuing until the CD4+CD8+(DP stage. Neonatal mice show elevated expression of krm1 in all TEC subsets. krm1− / − mice exhibit a severe defect in thymic cortical architecture, including large epithelial free regions. Much of the epithelial component remains at an immature Keratin 5+ (K5 Keratin 8+(K8 stage, with a loss of defined cortical and medullary regions. A TOPFlash assay revealed a 2-fold increase in canonical Wnt signaling in TEC lines derived from krm1− / − mice, when compared with krm1+ / + derived TEC lines. Fluorescence activated cell sorting (FACS analysis of dissociated thymus revealed a reduced frequency of both cortical (BP1+EpCAM+ and medullary (UEA-1+ EpCAMhi epithelial subsets, within the krm1− / − thymus. Surprisingly, no change in thymus size, total thymocyte number or the frequency of thymocyte subsets was detected in krm1− / − mice. However, our data suggest that a loss of Krm1 leads to a severe defect in thymic architecture. Taken together, this study revealed a new role for Krm1 in proper development of thymic epithelium.

  2. 20(S)-ginsenoside Rh2 inhibits the proliferation and induces the apoptosis of KG-1a cells through the Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Chen, Yi; Liu, Ze-Hong; Xia, Jing; Li, Xiao-Peng; Li, Ke-Qiong; Xiong, Wei; Li, Jing; Chen, Di-Long

    2016-07-01

    Previous research has shown that total saponins of Panax ginseng (TSPG) and other ginsenoside monomers inhibit the proliferation of leukemia cells. However, the effect has not been compared among them. Cell viability was determined by Cell Counting Kit-8 assay, and ultra-structural characteristics were observed under transmission electron microscopy. Cell cycle distribution and apoptosis were determined by flow cytometry (FCM). Real-time fluorescence quantitative‑PCR, western blotting and immunofluorescence were used to measure the expression of β-catenin, TCF4, cyclin D1 and NF-κBp65. β-catenin/TCF4 target gene transcription were observed by ChIP-PCR assay. We found that 20(S)-ginsenoside Rh2 [(S)Rh2] inhibited the proliferation of KG-1a cells more efficiently than the other monomers. Moreover, (S)Rh2 arrested KG-1a cells in the G0/G1 phase and induced apoptosis. In addition, the levels of β-catenin, TCF4, cyclin D1 mRNA and protein were decreased. The ChIP-PCR showed that (S)Rh2 downregulated the transcription of β-catenin/TCF4 target genes, such as cyclin D1 and c-myc. These results indicated that (S)Rh2 induced cell cycle arrest and apoptosis through the Wnt/β-catenin signaling pathway, demonstrating its potential as a chemotherapeutic agent for leukemia therapy. PMID:27121661

  3. Ubiquitin ligase HUWE1 regulates axon branching through the Wnt/β-catenin pathway in a Drosophila model for intellectual disability.

    Science.gov (United States)

    Vandewalle, Joke; Langen, Marion; Zschätzsch, Marlen; Zschaetzsch, Marlen; Nijhof, Bonnie; Kramer, Jamie M; Brems, Hilde; Bauters, Marijke; Lauwers, Elsa; Srahna, Mohammed; Marynen, Peter; Verstreken, Patrik; Schenck, Annette; Hassan, Bassem A; Froyen, Guy

    2013-01-01

    We recently reported that duplication of the E3 ubiquitin ligase HUWE1 results in intellectual disability (ID) in male patients. However, the underlying molecular mechanism remains unknown. We used Drosophila melanogaster as a model to investigate the effect of increased HUWE1 levels on the developing nervous system. Similar to the observed levels in patients we overexpressed the HUWE1 mRNA about 2-fold in the fly. The development of the mushroom body and neuromuscular junctions were not altered, and basal neurotransmission was unaffected. These data are in agreement with normal learning and memory in the courtship conditioning paradigm. However, a disturbed branching phenotype at the axon terminals of the dorsal cluster neurons (DCN) was detected. Interestingly, overexpression of HUWE1 was found to decrease the protein levels of dishevelled (dsh) by 50%. As dsh as well as Fz2 mutant flies showed the same disturbed DCN branching phenotype, and the constitutive active homolog of β-catenin, armadillo, could partially rescue this phenotype, our data strongly suggest that increased dosage of HUWE1 compromises the Wnt/β-catenin pathway possibly by enhancing the degradation of dsh.

  4. Ubiquitin ligase HUWE1 regulates axon branching through the Wnt/β-catenin pathway in a Drosophila model for intellectual disability.

    Directory of Open Access Journals (Sweden)

    Joke Vandewalle

    Full Text Available We recently reported that duplication of the E3 ubiquitin ligase HUWE1 results in intellectual disability (ID in male patients. However, the underlying molecular mechanism remains unknown. We used Drosophila melanogaster as a model to investigate the effect of increased HUWE1 levels on the developing nervous system. Similar to the observed levels in patients we overexpressed the HUWE1 mRNA about 2-fold in the fly. The development of the mushroom body and neuromuscular junctions were not altered, and basal neurotransmission was unaffected. These data are in agreement with normal learning and memory in the courtship conditioning paradigm. However, a disturbed branching phenotype at the axon terminals of the dorsal cluster neurons (DCN was detected. Interestingly, overexpression of HUWE1 was found to decrease the protein levels of dishevelled (dsh by 50%. As dsh as well as Fz2 mutant flies showed the same disturbed DCN branching phenotype, and the constitutive active homolog of β-catenin, armadillo, could partially rescue this phenotype, our data strongly suggest that increased dosage of HUWE1 compromises the Wnt/β-catenin pathway possibly by enhancing the degradation of dsh.

  5. Expression of Wnt and TGF-β pathway components and key adrenal transcription factors in adrenocortical tumors – association to carcinoma aggressiveness

    Science.gov (United States)

    Parviainen, Helka; Schrade, Anja; Kiiveri, Sanne; Prunskaite-Hyyryläinen, Renata; Haglund, Caj; Vainio, Seppo; Wilson, David B.; Arola, Johanna; Heikinheimo, Markku

    2013-01-01

    Factors controlling benign and malignant adrenocortical tumorigenesis are largely unknown, but several mouse models suggest an important role for inhibin-alpha (INHA). To show that findings in the mouse are relevant to human tumors and clinical outcome, we investigated the expression of signaling proteins and transcription factors involved in the regulation of INHA in human tumor samples. Thirty-one adrenocortical tumor samples, including 13 adrenocortical carcinomas (ACCs), were categorized according to Weiss score, hormonal profile, and patient survival data and analyzed using immunohistochemistry and RT-PCR. Expression of the TGF-β signaling mediator SMAD3 varied inversely with Weiss score, so that SMAD3 expression was lowest in the most malignant tumors. By contrast, SMAD2 expression was upregulated in most malignant tumors. Wnt pathway co-receptors LRP5 and LRP6 were predominantly expressed in benign adrenocortical tumors. In ACCs, expression of transcription factors GATA-6 and SF-1 correlated with that of their target gene INHA. Moreover, the diminished expression of GATA-6 and SF-1 in ACCs correlated with poor outcome. We conclude that the factors driving INHA expression are reduced in ACCs with poor outcome, implicating a role for INHAas a tumor suppressor in humans. PMID:23866946

  6. Expression of Wnt and TGF-β pathway components and key adrenal transcription factors in adrenocortical tumors: association to carcinoma aggressiveness.

    Science.gov (United States)

    Parviainen, Helka; Schrade, Anja; Kiiveri, Sanne; Prunskaite-Hyyryläinen, Renata; Haglund, Caj; Vainio, Seppo; Wilson, David B; Arola, Johanna; Heikinheimo, Markku

    2013-08-01

    Factors controlling benign and malignant adrenocortical tumorigenesis are largely unknown, but several mouse models suggest an important role for inhibin-alpha (INHA). To show that findings in the mouse are relevant to human tumors and clinical outcome, we investigated the expression of signaling proteins and transcription factors involved in the regulation of INHA in human tumor samples⋅ Thirty-one adrenocortical tumor samples, including 13 adrenocortical carcinomas (ACCs), were categorized according to Weiss score, hormonal profile, and patient survival data and analyzed using immunohistochemistry and RT-PCR. Expression of the TGF-β signaling mediator SMAD3 varied inversely with Weiss score, so that SMAD3 expression was lowest in the most malignant tumors. By contrast, SMAD2 expression was upregulated in most malignant tumors. Wnt pathway co-receptors LRP5 and LRP6 were predominantly expressed in benign adrenocortical tumors. In ACCs, expression of transcription factors GATA-6 and SF-1 correlated with that of their target gene INHA. Moreover, the diminished expression of GATA-6 and SF-1 in ACCs correlated with poor outcome. We conclude that the factors driving INHA expression are reduced in ACCs with poor outcome, implicating a role for INHA as a tumor suppressor in humans.

  7. 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. PMID:26420483

  8. Altered lung morphogenesis, epithelial cell differentiation and mechanics in mice deficient in the Wnt/β-catenin antagonist Chibby.

    Directory of Open Access Journals (Sweden)

    Damon Love

    Full Text Available The canonical Wnt/β-catenin pathway plays crucial roles in various aspects of lung morphogenesis and regeneration/repair. Here, we examined the lung phenotype and function in mice lacking the Wnt/β-catenin antagonist Chibby (Cby. In support of its inhibitory role in canonical Wnt signaling, expression of β-catenin target genes is elevated in the Cby(-/- lung. Notably, Cby protein is prominently associated with the centrosome/basal body microtubule structures in embryonic lung epithelial progenitor cells, and later enriches as discrete foci at the base of motile cilia in airway ciliated cells. At birth, Cby(-/- lungs are grossly normal but spontaneously develop alveolar airspace enlargement with reduced proliferation and abnormal differentiation of lung epithelial cells, resulting in altered pulmonary function. Consistent with the Cby expression pattern, airway ciliated cells exhibit a marked paucity of motile cilia with apparent failure of basal body docking. Moreover, we demonstrate that Cby is a direct downstream target for the master ciliogenesis transcription factor Foxj1. Collectively, our results demonstrate that Cby facilitates proper postnatal lung development and function.

  9. Inhibition of p300 histone acetyltransferase activity in palate mesenchyme cells attenuates Wnt signaling via aberrant E-cadherin expression.

    Science.gov (United States)

    Warner, Dennis R; Smith, Scott C; Smolenkova, Irina A; Pisano, M Michele; Greene, Robert M

    2016-03-01

    p300 is a multifunctional transcriptional coactivator that interacts with numerous transcription factors and exhibits protein/histone acetyltransferase activity. Loss of p300 function in humans and in mice leads to craniofacial defects. In this study, we demonstrated that inhibition of p300 histone acetyltransferase activity with the compound, C646, altered the expression of several genes, including Cdh1 (E-cadherin) in mouse maxillary mesenchyme cells, which are the cells that give rise to the secondary palate. The increased expression of plasma membrane-bound E-cadherin was associated with reduced cytosolic β-catenin, that led to attenuated signaling through the canonical Wnt pathway. Furthermore, C646 reduced both cell proliferation and the migratory ability of these cells. These results suggest that p300 histone acetyltransferase activity is critical for Wnt-dependent palate mesenchymal cell proliferation and migration, both processes that play a significant role in morphogenesis of the palate.

  10. Histone H3K27me3 demethylases KDM6A and KDM6B modulate definitive endoderm differentiation from human ESCs by regulating WNT signaling pathway

    Institute of Scientific and Technical Information of China (English)

    Wei Jiang; Jinzhao Wang; Yi Zhang

    2013-01-01

    Definitive endoderm differentiation is crucial for generating respiratory and gastrointestinal organs including pancreas and liver.However,whether epigenetic regulation contributes to this process is unknown.Here,we show that the H3K27me3 demethylases KDM6A and KDM6B play an important role in endoderm differentiation from human ESCs.Knockdown of KDM6A or KDM6B impairs endoderm differentiation,which can be rescued by sequential treatment with WNT agonist and antagonist.KDM6A and KDM6B contribute to the activation of WNT3 and DKK1 at different differentiation stages when WNT3 and DKK1 are required for mesendoderm and definitive endoderm differentiation,respectively.Our study not only uncovers an important role of the H3K27me3 demethylases in definitive endoderm differentiation,but also reveals that they achieve this through modulating the WNT signalingpathway.

  11. The WNT-less wonder: WNT-independent β-catenin signaling.

    Science.gov (United States)

    Aktary, Zackie; Bertrand, Juliette U; Larue, Lionel

    2016-09-01

    β-catenin is known as an Armadillo protein that regulates gene expression following WNT pathway activation. However, WNT-independent pathways also activate β-catenin. During the establishment of the melanocyte lineage, β-catenin plays an important role. In the context of physiopathology, β-catenin is activated genetically or transiently in various cancers, including melanoma, where it can be found in the nucleus of tumors. In this review, we discuss alternative pathways that activate β-catenin independent of WNTs and highlight what is known regarding these pathways in melanoma. We also discuss the role of β-catenin as a transcriptional regulator in various cell types, with emphasis on the different transcription factors it associates with independent of WNT induction. Finally, the role of WNT-independent β-catenin in melanocyte development and melanomagenesis is also discussed. PMID:27311806

  12. Norcantharidin blocks Wnt/β-catenin signaling via promoter demethylation of WIF-1 in glioma.

    Science.gov (United States)

    Xie, Dajiang; Xie, Jixi; Wan, Yingfeng; Ma, Li; Qi, Xuchen; Wang, Kun; Yang, Shuxu

    2016-04-01

    Glioma is one of the most common primary intracranial tumors, and the prognosis is poor even though much treatment management is employed. Wnt/β-catenin signaling has been reported to be associated with glioma. Norcantharidin (NCTD) is the demethylated analog of cantharidin isolated from blister beetles, and it is reported to possess anticancer activity but less nephrotoxicity than cantharidin. Accordingly, we aimed to investigate NCTD as an anti-neoplastic drug that inhibits the Wnt/β‑catenin pathway via promoter demethylation of Wnt inhibitory factor-1 (WIF-1) in glioma growth in vitro. In the present study, we report that NCTD inhibited cell proliferation, induced apoptosis and cell cycle arrest, and suppressed cell migration and invasion in vitro. Moreover, we observed that the expression levels of WIF-1 mRNA and protein in the NCTD-treated cells were increased significantly compared with these levels in the negative control (NC) cells. Promoter demethylation was observed in the NCTD‑treated cells. In contrast, aberrant methylation was observed in the NC cells. Additionally, more investigation revealed that NCTD suppressed activity of Wnt/β-catenin signaling and transcription of β-catenin/TCF-4. Furthermore, the expression of apoptosis-related proteins Bcl-2 and cleaved caspase-3 indicated significant cell apoptosis. We provide initial evidence that NCTD reactivates WIF-1 from a methylation state, and downregulates canonical Wnt/β-catenin signaling. Our findings revealed that NCTD is effective for glioma in vitro and may be a new therapeutic option in vivo. PMID:26781164

  13. WIF1, a Wnt pathway inhibitor, regulates SKP2 and c-myc expression leading to G1 arrest and growth inhibition ofhuman invasive urinary bladder cancer cells

    OpenAIRE

    Tang, Yaxiong; Simoneau, Anne R; Liao, Wu-Xiang; Yi, Guo; Hope, Christopher; Liu, Feng; Li, Shunqiang; Xie, Jun; Holcombe, Randall F; Jurnak, Frances A.; Mercola, Dan; Hoang, Bang H.; Zi, Xiaolin

    2009-01-01

    Epigenetic silencing of secreted wingless-type (Wnt) antagonists through hypermethylation is associated with tobacco smoking and with invasive bladder cancer. The secreted Wnt inhibitory factor-1 (WIF1) has shown consistent growth-inhibitory effect on various cancer cell lines. Therefore,we assessed the mechanisms of action of WIF1 by either restoring WIF1 expression in invasive bladder cancer cell lines (T24 and TSU-PR1) or using a recombinant protein containing functional WIF1 domain. Both ...

  14. The role of ibuprofen to Wnt signaling pathway and chondrocytes matrix metabolism in oste-oarthritis%布洛芬对兔骨关节炎模型 Wnt/β-catenin 信号通路和软骨细胞基质代谢的影响

    Institute of Scientific and Technical Information of China (English)

    刘洪彦; 郑毅

    2015-01-01

    Objective To study the metabolism how ibuprofen influence matrix metabolism of rabbit OA chondrocytes and the role of Wnt /β-catenin signaling pathway in this process .Methods Use a modified way of mechanical fixation to make rabbit OA mod -el,separation and extraction of rabbit knee OA chondrocytes and then culture in medium .MTT was used to select the dose of DMSO and ibuprofen.After that,the cultured chondroctyes were divided into nomral control group and ibuprofen group ,use ELISA and real-time PCR to detect the protein and gene expression of Wnt /β-catenin signaling pathway related factors including β-catenin,MMP-3,MMP-13,ADAMTS-4,collagen II,proteoglycan.Results There were no differences between normal group and ibuprofen group of Wnt /β-catenin signaling pathway related factors including β-catenin,MMP-3,MMP-13,ADAMTS-4,collagen II and proteoglycan .Conclusion In rabbit OA knee chondrocytes ,ibuprofen has no effect on matrix metabolism and Wnt /β-catenin signaling pathway.%目的:探讨布洛芬对兔骨关节炎(osteoarthritis,OA)模型膝关节软骨细胞基质代谢及 Wnt /β-catenin 信号通路的影响。方法采用改良伸直位固定法制作兔 OA 模型,分离提取兔 OA 模型膝关节软骨细胞进行培养。采用四唑盐比色法选择布洛芬和二甲基亚砜(DMSO)实验浓度。确定实验浓度后将软骨细胞分为 DMSO 组和布洛芬组,分别给予1%DMSO 和250μM 布洛芬干预48 h 后,采用 real-time PCR 法和 ELISA 方法检测软骨细胞 Wnt /β-catenin 相关因子(β-catenin、MMP-13、ADAMTS-4、II 型胶原和蛋白聚糖)mRNA 及蛋白的水平。结果DMSO 对照组和布洛芬组β-catenin、MMP-13、ADAMTS-4、II型胶原和蛋白聚糖的 mRNA 及蛋白水平比较,差异均无统计学意义(P >0.05)。结论兔 OA 模型膝关节软骨细胞中,布洛芬对 Wnt /β-catenin 信号通路和软骨细胞基质代谢无明显影响。

  15. TGF-β Prevents Phosphate-Induced Osteogenesis through Inhibition of BMP and Wnt/β-Catenin Pathways

    OpenAIRE

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

    2014-01-01

    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 ...

  16. Wnt Inhibitory Factor 1 (WIF-1) decreases tumorigenesis and metastasis in osteosarcoma

    OpenAIRE

    Rubin, Elyssa M.; Guo, Yi; Tu, Khoa; Xie, Jun; Zi, Xiaolin; Hoang, Bang H.

    2010-01-01

    It has been reported that the progression of osteosarcoma was closely associated with aberrant activation of canonical Wnt signaling. Wnt inhibitory factor-1 (WIF-1) is a secreted Wnt inhibitor whose role in human osteosarcoma remains unknown. In this study, WIF-1 expression in normal human osteoblast and osteosarcoma cell lines was determined by real-time RT-PCR, methylation-specific PCR (MSP), and Western blotting analysis. In addition, tissue array from patient samples was examined for WIF...

  17. Vitamin B6 nutritional status and cellular availability of pyridoxal 5'-phosphate govern the function of the transsulfuration pathway's canonical reactions and hydrogen sulfide production via side reactions.

    Science.gov (United States)

    Gregory, Jesse F; DeRatt, Barbara N; Rios-Avila, Luisa; Ralat, Maria; Stacpoole, Peter W

    2016-07-01

    The transsulfuration pathway (TS) acts in sulfur amino acid metabolism by contributing to the regulation of cellular homocysteine, cysteine production, and the generation of H2S for signaling functions. Regulation of TS pathway kinetics involves stimulation of cystathionine β-synthase (CBS) by S-adenosylmethionine (SAM) and oxidants such as H2O2, and by Michaelis-Menten principles whereby substrate concentrations affect reaction rates. Although pyridoxal phosphate (PLP) serves as coenzyme for both CBS and cystathionine γ-lyase (CSE), CSE exhibits much greater loss of activity than CBS during PLP insufficiency. Thus, cellular and plasma cystathionine concentrations increase in vitamin B6 deficiency mainly due to the bottleneck caused by reduced CSE activity. Because of the increase in cystathionine, the canonical production of cysteine (homocysteine → cystathionine → cysteine) is largely maintained even during vitamin B6 deficiency. Typical whole body transsulfuration flux in humans is 3-7 μmol/h per kg body weight. The in vivo kinetics of H2S production via side reactions of CBS and CSE in humans are unknown but they have been reported for cultured HepG2 cells. In these studies, cells exhibit a pronounced reduction in H2S production capacity and rates of lanthionine and homolanthionine synthesis in deficiency. In humans, plasma concentrations of lanthionine and homolanthionine exhibit little or no mean change due to 4-wk vitamin B6 restriction, nor do they respond to pyridoxine supplementation of subjects in chronically low-vitamin B6 status. Wide individual variation in responses of the H2S biomarkers to such perturbations of human vitamin B6 status suggests that the resulting modulation of H2S production may have physiological consequences in a subset of people. Supported by NIH grant DK072398. This paper refers to