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Sample records for wnt5a mrna level

  1. Amino acid limitation induces down-regulation of WNT5a at transcriptional level

    International Nuclear Information System (INIS)

    Wang Zuguang; Chen Hong

    2009-01-01

    An aberrant WNT signaling contributes to the development and progression of multiple cancers. WNT5a is one of the WNT signaling molecules. This study was designed to test the hypothesis that amino acid deprivation induces changes in the WNT signaling pathway in colon cancer cells. Results showed that targets of the amino acid response pathway, ATF3 and p21, were induced in the human colon cancer cell line SW480 during amino acid limitation. There was a significant decrease in the WNT5a mRNA level following amino acid deprivation. The down-regulation of WNT5a mRNA by amino acid deprivation is not due to mRNA destabilization. There is a reduction of nuclear β-catenin protein level by amino acid limitation. Under amino acid limitation, phosphorylation of ERK1/2 was increased and the blockage of ERK1/2 by the inhibitor U0126 partially restored WNT5a mRNA level. In conclusion, amino acid limitation in colon cancer cells induces phosphorylation of ERK1/2, which then down-regulates WNT5a expression.

  2. WNT2B2 mRNA, up-regulated in primary gastric cancer, is a positive regulator of the WNT- beta-catenin-TCF signaling pathway.

    Science.gov (United States)

    Katoh, M; Kirikoshi, H; Terasaki, H; Shiokawa, K

    2001-12-21

    Genetic alterations of WNT signaling molecules lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway. We have previously cloned and characterized WNT2B/WNT13 gene on human chromosome 1p13, which is homologous to proto-oncogene WNT2 on human chromosome 7q31. WNT2B1 and WNT2B2 mRNAs, generated from the WNT2B gene due to alternative splicing of the alternative promoter type, encode almost identical polypeptides with divergence in the N-terminal region. WNT2B2 mRNA rather than WNT2B1 mRNA is preferentially expressed in NT2 cells with the potential of neuronal differentiation. Here, we describe our investigations of expression of WNT2B mRNAs in various types of human primary cancer. Matched tumor/normal expression array analysis revealed that WNT2B mRNAs were significantly up-regulated in 2 of 8 cases of primary gastric cancer. WNT2B2 mRNA rather than WNT2B1 mRNA was found to be preferentially up-regulated in a case of primary gastric cancer (signet ring cell carcinoma). Function of WNT2B1 mRNA and that of WNT2B2 mRNA were investigated by using Xenopus axis duplication assay. Injection of synthetic WNT2B1 mRNA into the ventral marginal zone of fertilized Xenopus eggs at the 4-cell stage did not induce axis duplication. In contrast, ventral injection of synthetic WNT2B2 mRNA induced axis duplication in 90% of embryos (complete axis duplication, 24%). These results strongly suggest that WNT2B2 up-regulation in some cases of gastric cancer might lead to carcinogenesis through activation of the beta-catenin-TCF signaling pathway.

  3. Dynamic Wnt5a expression in murine hair follicle cycle and its inhibitory effects on follicular.

    Science.gov (United States)

    Fang, De-Ren; Lv, Zhong-Fa; Qiao, Gang

    2014-04-01

    To analyze the dynamic expression of Wnt family member 5A (Wingless-type MMTV integration Wnt site family, member 5a) in murine hair cycle and its inhibitory effects on follicle in vivo. Situ hybridization in full-thickness skin was used to observe the change of mouse protein expression in different growth stages, and Ad-Wnt5a was injected after defeathering to observe the hair follicle growth in vivo. The Wnt5a mRNA was expressed at birth, and was firstly increased then decreased along with the progress of the hair cycle. It reached the peak in advanced stage of growth cycle (P<0.05). Rhoa and β-catenin expression levels were significantly decreased in three groups. Rac2 expression was significantly up-regulated, and the expression level of Wnt5a, Shh and Frizzled2 was increased, but less significantly than group 2. The expression of Wnt5a mRNA is consistent with change of murine follicle cycle, and has obvious inhibitory effects on the growth of hair follicle in vivo, indicating that it is antagonistic to Wnts pathway and interferes the growth of follicle together. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

  4. Wnt5a is associated with cigarette smoke-related lung carcinogenesis via protein kinase C.

    Science.gov (United States)

    Whang, Young Mi; Jo, Ukhyun; Sung, Jae Sook; Ju, Hyun Jung; Kim, Hyun Kyung; Park, Kyong Hwa; Lee, Jong Won; Koh, In Song; Kim, Yeul Hong

    2013-01-01

    Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE) cells (NHBE, BEAS-2B, 1799, 1198 and 1170I) at different malignant stages established by exposure to cigarette smoke condensate (CSC). Abnormal up-regulation of Wnt5a mRNA and proteins was detected in CSC-exposed transformed 1198 and tumorigenic 1170I cells as compared with other non-CSC exposed HBE cells. Tumor tissues obtained from smokers showed higher Wnt5a expressions than matched normal tissues. In non-CSC exposed 1799 cells, treatment of recombinant Wnt5a caused the activations of PKC and Akt, and the blockage of Wnt5a and PKC significantly decreased the viabilities of CSC-transformed 1198 cells expressing high levels of Wnt5a. This reduced cell survival rate was associated with increased apoptosis via the down-regulation of Bcl2 and the induction of cleaved poly ADP-ribose polymerase. Moreover, CSC-treated 1799 cells showed induction of Wnt5a expression and enhanced colony-forming capacity. The CSC-induced colony forming efficiency was suppressed by the co-incubation with a PKC inhibitor. In conclusion, these results suggest that cigarette smoke induces Wnt5a-coupled PKC activity during lung carcinogenesis, which causes Akt activity and anti-apoptosis in lung cancer. Therefore, current study provides novel clues for the crucial role of Wnt5a in the smoking-related lung carcinogenesis.

  5. Wnt5a is associated with cigarette smoke-related lung carcinogenesis via protein kinase C.

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    Young Mi Whang

    Full Text Available Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE cells (NHBE, BEAS-2B, 1799, 1198 and 1170I at different malignant stages established by exposure to cigarette smoke condensate (CSC. Abnormal up-regulation of Wnt5a mRNA and proteins was detected in CSC-exposed transformed 1198 and tumorigenic 1170I cells as compared with other non-CSC exposed HBE cells. Tumor tissues obtained from smokers showed higher Wnt5a expressions than matched normal tissues. In non-CSC exposed 1799 cells, treatment of recombinant Wnt5a caused the activations of PKC and Akt, and the blockage of Wnt5a and PKC significantly decreased the viabilities of CSC-transformed 1198 cells expressing high levels of Wnt5a. This reduced cell survival rate was associated with increased apoptosis via the down-regulation of Bcl2 and the induction of cleaved poly ADP-ribose polymerase. Moreover, CSC-treated 1799 cells showed induction of Wnt5a expression and enhanced colony-forming capacity. The CSC-induced colony forming efficiency was suppressed by the co-incubation with a PKC inhibitor. In conclusion, these results suggest that cigarette smoke induces Wnt5a-coupled PKC activity during lung carcinogenesis, which causes Akt activity and anti-apoptosis in lung cancer. Therefore, current study provides novel clues for the crucial role of Wnt5a in the smoking-related lung carcinogenesis.

  6. Wnt5a Signaling in Cancer

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    Marwa S. Asem

    2016-08-01

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

  7. Unterschiede und Gemeinsamkeiten der nicht-kanonischen Wnt-Liganden Wnt5a und Wnt11

    OpenAIRE

    Wallkamm, Veronika

    2014-01-01

    Die nicht-kanonischen Zweige des Wnt-Signalnetzwerkes sind Regulatoren der konvergenten Extension während der Xenopus Gastrulation. Dabei übernehmen die nicht-kanonischen Wnt-Liganden Wnt5a und Wnt11 nicht-redundante Aufgaben.

  8. 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.

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

    International Nuclear Information System (INIS)

    Sakisaka, Yukihiko; Tsuchiya, Masahiro; Nakamura, Takashi; Tamura, Masato; Shimauchi, Hidetoshi; Nemoto, Eiji

    2015-01-01

    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

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

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

    2015-08-01

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

  11. 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)

    Ozeki, Nobuaki; Hase, Naoko; Hiyama, Taiki; Yamaguchi, Hideyuki; Kawai, Rie; Kondo, Ayami; Nakata, Kazuhiko; Mogi, Makio

    2014-01-01

    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

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

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    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.

  13. Heterotrimeric G protein-dependent WNT-5A signaling to ERK1/2 mediates distinct aspects of microglia proinflammatory transformation

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    Halleskog Carina

    2012-05-01

    Full Text Available Abstract Background WNT-5A signaling in the central nervous system is important for morphogenesis, neurogenesis and establishment of functional connectivity; the source of WNT-5A and its importance for cellular communication in the adult brain, however, are mainly unknown. We have previously investigated the inflammatory effects of WNT/β-catenin signaling in microglia in Alzheimer's disease. WNT-5A, however, generally recruits β-catenin-independent signaling. Thus, we aim here to characterize the role of WNT-5A and downstream signaling pathways for the inflammatory transformation of the brain's macrophages, the microglia. Methods Mouse brain sections were used for immunohistochemistry. Primary isolated microglia and astrocytes were employed to characterize the WNT-induced inflammatory transformation and underlying intracellular signaling pathways by immunoblotting, quantitative mRNA analysis, proliferation and invasion assays. Further, measurements of G protein activation by [γ-35 S]GTP binding, examination of calcium fluxes and cyclic AMP production were used to define intracellular signaling pathways. Results Astrocytes in the adult mouse brain express high levels of WNT-5A, which could serve as a novel astroglia-microglia communication pathway. The WNT-5A-induced proinflammatory microglia response is characterized by increased expression of inducible nitric oxide synthase, cyclooxygenase-2, cytokines, chemokines, enhanced invasive capacity and proliferation. Mapping of intracellular transduction pathways reveals that WNT-5A activates heterotrimeric Gi/o proteins to reduce cyclic AMP levels and to activate a Gi/o protein/phospholipase C/calcium-dependent protein kinase/extracellular signal-regulated kinase 1/2 (ERK1/2 axis. We show further that WNT-5A-induced ERK1/2 signaling is responsible for distinct aspects of the proinflammatory transformation, such as matrix metalloprotease 9/13 expression, invasion and proliferation. Conclusions

  14. Wnt-β-Catenin Signaling Promotes the Maturation of Mast Cells

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    Tomoko Yamaguchi

    2016-01-01

    Full Text Available Mast cells play an important role in the pathogenesis of allergic diseases. Immature mast cells migrate into peripheral tissues from the bone marrow and undergo complete maturation. Interestingly, mast cells have characteristics similar to hematopoietic stem cells (HSCs, such as self-renewal and c-kit expression. In HSCs, Wnt signaling is involved in their maintenance and differentiation. On the other hand, the relation between Wnt signaling and mast cell differentiation is poorly understood. To study whether Wnt signals play a role in the maturation of mast cells, we studied the effect of Wnt proteins on mast cell maturation of bone marrow-derived mast cells (BMMCs. The expression levels of CD81 protein and histidine decarboxylase mRNA and activity of mast cell-specific protease were all elevated in BMMCs treated with Wnt5a. In addition, Wnt5a induced the expression of Axin2 and TCF mRNA in BMMCs. These results showed that Wnt5a could promote the maturation of mast cells via the canonical Wnt signaling pathway and provide important insights into the molecular mechanisms underlying the differentiation of mast cells.

  15. Non-canonical Wnt signaling through Wnt5a/b and a novel Wnt11 gene, Wnt11b, regulates cell migration during avian gastrulation

    OpenAIRE

    Hardy, Katharine M.; Garriock, Robert J.; Yatskievych, Tatiana A.; D'Agostino, Susan L.; Antin, Parker B.; Krieg, Paul A.

    2008-01-01

    Knowledge of the molecular mechanisms regulating cell ingression, epithelial-mesenchymal transition and migration movements during amniote gastrulation is steadily improving. In the frog and fish embryo, Wnt5 and Wnt11 ligands are expressed around the blastopore and play an important role in regulating cell movements associated with gastrulation. In the chicken embryo, although Wnt5a and Wnt5b are expressed in the primitive streak, the known Wnt11 gene is expressed in paraxial and intermediat...

  16. Wnt Signaling Alteration in the Spinal Cord of Amyotrophic Lateral Sclerosis Transgenic Mice: Special Focus on Frizzled-5 Cellular Expression Pattern.

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    Carlos González-Fernández

    Full Text Available Amyotrophic lateral sclerosis is a chronic neurodegenerative disease characterized by progressive paralysis due to degeneration of motor neurons by unknown causes. Recent evidence shows that Wnt signaling is involved in neurodegenerative processes, including Amyotrophic Lateral Sclerosis. However, to date, little is known regarding the expression of Wnt signaling components in this fatal condition. In the present study we used transgenic SOD1G93A mice to evaluate the expression of several Wnt signaling components, with special focus on Frizzled-5 cellular expression alteration along disease progression.Based on previous studies demonstrating the expression of Wnts and their transcriptional regulation during Amyotrophic lateral sclerosis development, we have analyzed the mRNA expression of several Wnt signaling components in the spinal cord of SOD1G93A transgenic mice at different stages of the disease by using real time quantitative PCR analysis. Strikingly, one of the molecules that seemed not to be altered at mRNA level, Frizzled-5, showed a clear up-regulation at late stages in neurons, as evidenced by immunofluorescence assays. Moreover, increased Frizzled-5 appears to correlate with a decrease in NeuN signal in these cells, suggesting a correlation between neuronal affectation and the increased expression of this receptor.Our data suggest the involvement of Wnt signaling pathways in the pathophysiology of Amyotrophic Lateral Sclerosis and, more specifically, the implication of Frizzled-5 receptor in the response of neuronal cells against neurodegeneration. Nevertheless, further experimental studies are needed to shed light on the specific role of Frizzled-5 and the emerging but increasing Wnt family of proteins research field as a potential target for this neuropathology.

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

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    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.

  18. Endothelial Dysfunction in Human Diabetes Is Mediated by Wnt5a-JNK Signaling.

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    Bretón-Romero, Rosa; Feng, Bihua; Holbrook, Monika; Farb, Melissa G; Fetterman, Jessica L; Linder, Erika A; Berk, Brittany D; Masaki, Nobuyuki; Weisbrod, Robert M; Inagaki, Elica; Gokce, Noyan; Fuster, Jose J; Walsh, Kenneth; Hamburg, Naomi M

    2016-03-01

    Endothelial dysfunction is linked to insulin resistance, inflammatory activation, and increased cardiovascular risk in diabetes mellitus; however, the mechanisms remain incompletely understood. Recent studies have identified proinflammatory signaling of wingless-type family member (Wnt) 5a through c-jun N-terminal kinase (JNK) as a regulator of metabolic dysfunction with potential relevance to vascular function. We sought to gain evidence that increased activation of Wnt5a-JNK signaling contributes to impaired endothelial function in patients with diabetes mellitus. We measured flow-mediated dilation of the brachial artery and characterized freshly isolated endothelial cells by protein expression, eNOS activation, and nitric oxide production in 85 subjects with type 2 diabetes mellitus (n=42) and age- and sex-matched nondiabetic controls (n=43) and in human aortic endothelial cells treated with Wnt5a. Endothelial cells from patients with diabetes mellitus displayed 1.3-fold higher Wnt5a levels (P=0.01) along with 1.4-fold higher JNK activation (P<0.01) without a difference in total JNK levels. Higher JNK activation was associated with lower flow-mediated dilation, consistent with endothelial dysfunction (r=0.53, P=0.02). Inhibition of Wnt5a and JNK signaling restored insulin and A23187-mediated eNOS activation and improved nitric oxide production in endothelial cells from patients with diabetes mellitus. In endothelial cells from nondiabetic controls, rWnt5a treatment inhibited eNOS activation replicating the diabetic endothelial phenotype. In human aortic endothelial cells, Wnt5a-induced impairment of eNOS activation and nitric oxide production was reversed by Wnt5a and JNK inhibition. Our findings demonstrate that noncanonical Wnt5a signaling and JNK activity contribute to vascular insulin resistance and endothelial dysfunction and may represent a novel therapeutic opportunity to protect the vasculature in patients with diabetes mellitus. © 2016 American Heart

  19. Selective enhancement of wnt4 expression by cyclic AMP-associated cooperation between rat central astrocytes and microglia

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    Ohnishi, Masatoshi; Urasaki, Tomoka; Ochiai, Hiroyuki; Matsuoka, Kohei; Takeo, Shin; Harada, Tomoki; Ohsugi, Yoshihito; Inoue, Atsuko

    2015-01-01

    The wnt protein family has important members involved in cell differentiation, proliferation and plasticity expression; however, little is known about its biosynthesis processes. On the other hand, an increase in the intracerebral cyclic adenosine 3′, 5’-monophosphate (cAMP) level leads to synaptic plasticity via the de novo synthesis of any protein. Here, the effect of dibutyryl cAMP (dbcAMP), a membrane permeability cAMP analog, on the wnt family was investigated in rat primary-cultured glial cells containing astrocytes and microglia. Among wnt3a, 4, 5a, 7a and 11 mRNA, only wnt4 expression was increased by longer treatment (24 h), compared with short treatment (2 h), with dbcAMP in a concentration-dependent manner, and its effect reached statistical significance at 1 mM. In cultures of isolated astrocytes or microglia, wnt4 expression was not affected by 1 mM dbcAMP for 24 h, and microglial wnt4 protein was undetectable even when cells were treated with the drug. Mixed glial cells treated for 24 h with 1 mM dbcAMP showed significantly increased wnt4 protein, as well as mRNA. Immunofluorescence manifested that cells that expressed wnt4 protein were astrocytes, but not microglia. Intraperitoneal injection of 1.25 mg/kg rolipram, a phosphodiesterase (PDE) IV inhibitor that can pass through the blood brain barrier and inhibits cAMP degradation specifically, showed a tendency to increase wnt4 expression in the adult rat brain after 24 h, and the increases in wnt4 mRNA and protein levels reached statistical significance in the hippocampus and striatum, respectively. This is the first finding to help elucidate the selective biosynthesis of central wnt4 through cAMP-stimulated microglia and astrocytes interaction. - Highlights: • Dibutyryl cAMP increased wnt4, but not wnt3a, 5a, 7a and 11, mRNA in mixed glia. • Wnt4 protein increased in astrocytes co-cultivated with microglia. • It took a long time to robustly increase wnt4 expression. • Rolipram

  20. Selective enhancement of wnt4 expression by cyclic AMP-associated cooperation between rat central astrocytes and microglia

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    Ohnishi, Masatoshi, E-mail: ohnishi@fupharm.fukuyama-u.ac.jp [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Urasaki, Tomoka [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Ochiai, Hiroyuki; Matsuoka, Kohei; Takeo, Shin; Harada, Tomoki; Ohsugi, Yoshihito [Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Inoue, Atsuko [Department of Pharmacotherapeutics, Graduate School of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan); Department of Pharmacotherapeutics, Faculty of Pharmacy and Pharmaceutical Sciences, Fukuyama University, 985-1 Sanzo, Higashimura-cho, Fukuyama, Hiroshima, 729-0292 (Japan)

    2015-11-13

    The wnt protein family has important members involved in cell differentiation, proliferation and plasticity expression; however, little is known about its biosynthesis processes. On the other hand, an increase in the intracerebral cyclic adenosine 3′, 5’-monophosphate (cAMP) level leads to synaptic plasticity via the de novo synthesis of any protein. Here, the effect of dibutyryl cAMP (dbcAMP), a membrane permeability cAMP analog, on the wnt family was investigated in rat primary-cultured glial cells containing astrocytes and microglia. Among wnt3a, 4, 5a, 7a and 11 mRNA, only wnt4 expression was increased by longer treatment (24 h), compared with short treatment (2 h), with dbcAMP in a concentration-dependent manner, and its effect reached statistical significance at 1 mM. In cultures of isolated astrocytes or microglia, wnt4 expression was not affected by 1 mM dbcAMP for 24 h, and microglial wnt4 protein was undetectable even when cells were treated with the drug. Mixed glial cells treated for 24 h with 1 mM dbcAMP showed significantly increased wnt4 protein, as well as mRNA. Immunofluorescence manifested that cells that expressed wnt4 protein were astrocytes, but not microglia. Intraperitoneal injection of 1.25 mg/kg rolipram, a phosphodiesterase (PDE) IV inhibitor that can pass through the blood brain barrier and inhibits cAMP degradation specifically, showed a tendency to increase wnt4 expression in the adult rat brain after 24 h, and the increases in wnt4 mRNA and protein levels reached statistical significance in the hippocampus and striatum, respectively. This is the first finding to help elucidate the selective biosynthesis of central wnt4 through cAMP-stimulated microglia and astrocytes interaction. - Highlights: • Dibutyryl cAMP increased wnt4, but not wnt3a, 5a, 7a and 11, mRNA in mixed glia. • Wnt4 protein increased in astrocytes co-cultivated with microglia. • It took a long time to robustly increase wnt4 expression. • Rolipram

  1. Neural Differentiation of Human Adipose Tissue-Derived Stem Cells Involves Activation of the Wnt5a/JNK Signalling

    Directory of Open Access Journals (Sweden)

    Sujeong Jang

    2015-01-01

    Full Text Available Stem cells are a powerful resource for cell-based transplantation therapies, but understanding of stem cell differentiation at the molecular level is not clear yet. We hypothesized that the Wnt pathway controls stem cell maintenance and neural differentiation. We have characterized the transcriptional expression of Wnt during the neural differentiation of hADSCs. After neural induction, the expressions of Wnt2, Wnt4, and Wnt11 were decreased, but the expression of Wnt5a was increased compared with primary hADSCs in RT-PCR analysis. In addition, the expression levels of most Fzds and LRP5/6 ligand were decreased, but not Fzd3 and Fzd5. Furthermore, Dvl1 and RYK expression levels were downregulated in NI-hADSCs. There were no changes in the expression of ß-catenin and GSK3ß. Interestingly, Wnt5a expression was highly increased in NI-hADSCs by real time RT-PCR analysis and western blot. Wnt5a level was upregulated after neural differentiation and Wnt3, Dvl2, and Naked1 levels were downregulated. Finally, we found that the JNK expression was increased after neural induction and ERK level was decreased. Thus, this study shows for the first time how a single Wnt5a ligand can activate the neural differentiation pathway through the activation of Wnt5a/JNK pathway by binding Fzd3 and Fzd5 and directing Axin/GSK-3ß in hADSCs.

  2. Wnt3a regulates proliferation and migration of HUVEC via canonical and non-canonical Wnt signaling pathways

    International Nuclear Information System (INIS)

    Samarzija, Ivana; Sini, Patrizia; Schlange, Thomas; MacDonald, Gwen; Hynes, Nancy E.

    2009-01-01

    Untangling the signaling pathways involved in endothelial cell biology is of central interest for the development of antiangiogenesis based therapies. Here we report that Wnt3a induces the proliferation and migration of HUVECs, but does not affect their survival. Wnt3a-induced proliferation was VEGFR signaling independent, but reduced upon CamKII inhibition. In a search for the downstream mediators of Wnt3a's effects on HUVEC biology, we found that Wnt3a treatment leads to phosphorylation of DVL3 and stabilization of β-catenin. Moreover, under the same conditions we observed an upregulation in c-MYC, TIE-2 and GJA1 mRNA transcripts. Although treatment of HUVECs with Wnt5a induced DVL3 phosphorylation, we did not observe any of the other effects seen upon Wnt3a stimulation. Taken together, our data indicate that Wnt3a induces canonical and non-canonical Wnt signaling in HUVECs, and stimulates their proliferation and migration.

  3. Wnt5a regulates midbrain dopaminergic axon growth and guidance.

    Directory of Open Access Journals (Sweden)

    Brette D Blakely

    2011-03-01

    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.

  4. WNT5A inhibits human dental papilla cell proliferation and migration

    International Nuclear Information System (INIS)

    Peng, L.; Ye, L.; Dong, G.; Ren, L.B.; Wang, C.L.; Xu, P.; Zhou, X.D.

    2009-01-01

    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.

  5. p38 MAP kinase is required for Wnt3a-mediated osterix expression independently of Wnt-LRP5/6-GSK3β signaling axis in dental follicle cells

    International Nuclear Information System (INIS)

    Sakisaka, Yukihiko; Kanaya, Sousuke; Nakamura, Takashi; Tamura, Masato; Shimauchi, Hidetoshi; Nemoto, Eiji

    2016-01-01

    Wnt3a is a secreted glycoprotein that activates the glycogen synthase kinase-3β (GSK3β)/β-catenin signaling pathway through low-density-lipoprotein receptor-related protein (LRP)5/6 co-receptors. Wnt3a has been implicated in periodontal development and homeostasis, as well as in cementum formation. Recently, we have reported that Wnt3a increases alkaline phosphatase expression through the induction of osterix (Osx) expression in dental follicle cells, a precursor of cementoblasts. However, the molecular mechanism by which Wnt3a induces Osx expression is still unknown. In this study, we show that Wnt3a-induced Osx expression was inhibited in the presence of p38 mitogen-activated protein kinase (MAPK) inhibitors (SB203580 and SB202190) at gene and protein levels, as assessed by real-time PCR and immunocytohistochemistry, respectively. Pretreatment of cells with Dickkopf-1, a potent canonical Wnt antagonist binding to LRP5/6 co-receptors, did not influence Wnt3a-mediated p38 MAPK phosphorylation, suggesting that Wnt3a activates p38 MAPK through LRP5/6-independent signaling. On the other hand, pretreatment with p38 MAPK inhibitors had no effects on the phosphorylated status of GSK3β and β-catenin as well as β-catenin nuclear translocation, but inhibited Wnt3a-mediated β-catenin transcriptional activity. These findings suggest that p38 MAPK modulates canonical Wnt signaling at the β-catenin transcriptional level without any crosstalk with the Wnt3a-mediated LRP5/6-GSK3β signaling axis and subsequent β-catenin nuclear translocation. These findings expand our knowledge of the mechanisms controlling periodontal development and regeneration. - Highlights: • Wnt3a induces Osx expression via p38 MAPK signaling in dental follicle cells. • p38 MAPK has no crosstalk with Wnt3a-mediated LRP5/6 and GSK3β signaling. • p38 MAPK is required for Wnt signaling at the β-catenin transcriptional level.

  6. Noncanonical WNT-5A signaling impairs endogenous lung repair in COPD

    Science.gov (United States)

    Baarsma, Hoeke A.; John-Schuster, Gerrit; Heinzelmann, Katharina; Dagouassat, Maylis; Boczkowski, Jorge; Brusselle, Guy G.; Smits, Ron; Yildirim, Ali Ö.

    2017-01-01

    Chronic obstructive pulmonary disease (COPD) is a leading cause of death worldwide. One main pathological feature of COPD is the loss of functional alveolar tissue without adequate repair (emphysema), yet the underlying mechanisms are poorly defined. Reduced WNT–β-catenin signaling is linked to impaired lung repair in COPD; however, the factors responsible for attenuating this pathway remain to be elucidated. Here, we identify a canonical to noncanonical WNT signaling shift contributing to COPD pathogenesis. We demonstrate enhanced expression of noncanonical WNT-5A in two experimental models of COPD and increased posttranslationally modified WNT-5A in human COPD tissue specimens. WNT-5A was increased in primary lung fibroblasts from COPD patients and induced by COPD-related stimuli, such as TGF-β, cigarette smoke (CS), and cellular senescence. Functionally, mature WNT-5A attenuated canonical WNT-driven alveolar epithelial cell wound healing and transdifferentiation in vitro. Lung-specific WNT-5A overexpression exacerbated airspace enlargement in elastase-induced emphysema in vivo. Accordingly, inhibition of WNT-5A in vivo attenuated lung tissue destruction, improved lung function, and restored expression of β-catenin–driven target genes and alveolar epithelial cell markers in the elastase, as well as in CS-induced models of COPD. We thus identify a novel essential mechanism involved in impaired mesenchymal–epithelial cross talk in COPD pathogenesis, which is amenable to therapy. PMID:27979969

  7. Wnt5 is required for notochord cell intercalation in the ascidian Halocynthia roretzi.

    Science.gov (United States)

    Niwano, Tomoko; Takatori, Naohito; Kumano, Gaku; Nishida, Hiroki

    2009-08-25

    In the embryos of various animals, the body elongates after gastrulation by morphogenetic movements involving convergent extension. The Wnt/PCP (planar cell polarity) pathway plays roles in this process, particularly mediolateral polarization and intercalation of the embryonic cells. In ascidians, several factors in this pathway, including Wnt5, have been identified and found to be involved in the intercalation process of notochord cells. In the present study, the role of the Wnt5 genes, Hr-Wnt5alpha (Halocynthia roretzi Wnt5alpha) and Hr-Wnt5beta, in convergent extension was investigated in the ascidian H. roretzi by injecting antisense oligonucleotides and mRNAs into single precursor blastomeres of various tissues, including notochord, at the 64-cell stage. Hr-Wnt5alpha is expressed in developing notochord and was essential for notochord morphogenesis. Precise quantitative control of its expression level was crucial for proper cell intercalation. Overexpression of Wnt5 proteins in notochord and other tissues that surround the notochord indicated that Wnt5alpha plays a role within the notochord, and is unlikely to be the source of polarizing cues arising outside the notochord. Detailed mosaic analysis of the behaviour of individual notochord cells overexpressing Wnt5alpha indicated that a Wnt5alpha-manipulated cell does not affect the behaviour of neighbouring notochord cells, suggesting that Wnt5alpha works in a cell-autonomous manner. This is further supported by comparison of the results of Wnt5alpha and Dsh (Dishevelled) knockdown experiments. In addition, our results suggest that the Wnt/PCP pathway is also involved in mediolateral intercalation of cells of the ventral row of the nerve cord (floor plate) and the endodermal strand. The present study highlights the role of the Wnt5alpha signal in notochord convergent extension movements in ascidian embryos. Our results raise the novel possibility that Wnt5alpha functions in a cell-autonomous manner in

  8. Genetic Screening of WNT4 and WNT5B in Two Populations with Deviating Bone Mineral Densities

    DEFF Research Database (Denmark)

    Hendrickx, Gretl; Boudin, Eveline; Steenackers, Ellen

    2017-01-01

    A role for WNT4 and WNT5B in bone metabolism was indicated by genome-wide association studies (GWAS) and a Wnt4 knockout mouse model. The aim of this study was therefore to replicate and further investigate the causality between genetic variation in WNT4 and WNT5B and deviating bone mineral density...... (BMD) values. A WNT4 and WNT5B mutation screening was performed in patients with craniotubular hyperostosis using Sanger sequencing. Here, no putative causal mutations were detected. Moreover, a high and low BMD cohort was selected from the Odense Androgen Study population for re-sequencing. In WNT4 we...

  9. Wnt5b-associated exosomes promote cancer cell migration and proliferation.

    Science.gov (United States)

    Harada, Takeshi; Yamamoto, Hideki; Kishida, Shosei; Kishida, Michiko; Awada, Chihiro; Takao, Toshifumi; Kikuchi, Akira

    2017-01-01

    Wnt5b is a member of the same family of proteins as Wnt5a, the overexpression of which is associated with cancer aggressiveness. Wnt5b is also suggested to be involved in cancer progression, however, details remain unclarified. We analyzed the biochemical properties of purified Wnt5b and the mode of secretion of Wnt5b by cancer cells. Wnt5b was glycosylated at three asparagine residues and lipidated at one serine residue, and these post-translational modifications of Wnt5b were essential for secretion. Purified Wnt5b showed Dvl2 phosphorylation and Rac activation abilities to a similar extent as Wnt5a. In cultured-cell conditioned medium, Wnt5b was detected in supernatant or precipitation fractions that were separated by centrifugation at 100 000 g. In PANC-1 pancreatic cancer cells, 55% of secreted endogenous Wnt5b was associated with exosomes. Exosomes from wild-type PANC-1 cells, but not those from Wnt5b-knockout PANC-1 cells, activated Wnt5b signaling in CHO cells and stimulated migration and proliferation of A549 lung adenocarcinoma cells, suggesting that endogenous, Wnt5b-associated exosomes are active. The exosomes were taken up by CHO cells and immunoelectron microscopy revealed that Wnt5b is indeed associated with exosomes. In Caco-2 colon cancer cells, most Wnt5b was recovered in precipitation fractions when Wnt5b was ectopically expressed (Caco-2/Wnt5b cells). Knockdown of TSG101, an exosome marker, decreased the secretion of Wnt5b-associated exosomes from Caco-2/Wnt5b cells and inhibited Wnt5b-dependent cell proliferation. Exosomes secreted from Caco-2/Wnt5b cells stimulated migration and proliferation of A549 cells. These results suggest that Wnt5b-associated exosomes promote cancer cell migration and proliferation in a paracrine manner. © 2016 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.

  10. Wnt-5a/Frizzled9 Receptor Signaling through the Gαo-Gβγ Complex Regulates Dendritic Spine Formation*

    Science.gov (United States)

    Ramírez, Valerie T.; Ramos-Fernández, Eva; Henríquez, Juan Pablo; Lorenzo, Alfredo; Inestrosa, Nibaldo C.

    2016-01-01

    Wnt ligands play crucial roles in the development and regulation of synapse structure and function. Specifically, Wnt-5a acts as a secreted growth factor that regulates dendritic spine formation in rodent hippocampal neurons, resulting in postsynaptic development that promotes the clustering of the PSD-95 (postsynaptic density protein 95). Here, we focused on the early events occurring after the interaction between Wnt-5a and its Frizzled receptor at the neuronal cell surface. Additionally, we studied the role of heterotrimeric G proteins in Wnt-5a-dependent synaptic development. We report that FZD9 (Frizzled9), a Wnt receptor related to Williams syndrome, is localized in the postsynaptic region, where it interacts with Wnt-5a. Functionally, FZD9 is required for the Wnt-5a-mediated increase in dendritic spine density. FZD9 forms a precoupled complex with Gαo under basal conditions that dissociates after Wnt-5a stimulation. Accordingly, we found that G protein inhibition abrogates the Wnt-5a-dependent pathway in hippocampal neurons. In particular, the activation of Gαo appears to be a key factor controlling the Wnt-5a-induced dendritic spine density. In addition, we found that Gβγ is required for the Wnt-5a-mediated increase in cytosolic calcium levels and spinogenesis. Our findings reveal that FZD9 and heterotrimeric G proteins regulate Wnt-5a signaling and dendritic spines in cultured hippocampal neurons. PMID:27402827

  11. Analysis of the expression and function of Wnt-5a and Wnt-5b in developing and regenerating axolotl (Ambystoma mexicanum) limbs.

    Science.gov (United States)

    Ghosh, Sukla; Roy, Stéphane; Séguin, Carl; Bryant, Susan V; Gardiner, David M

    2008-05-01

    Urodele amphibians are unique adult vertebrates because they are able to regenerate body parts after amputation. Studies of urodele limb regeneration, the key model system for vertebrate regeneration, have led to an understanding of the origin of blastema cells and the importance of positional interactions between blastema cells in the control of growth and pattern formation. Progress is now being made in the identification of the signaling pathways that regulate dedifferentiation, blastema morphogenesis, growth and pattern formation. Members of the Wnt family of secreted proteins are expressed in developing and regenerating limbs, and have the potential to control growth, pattern formation and differentiation. We have studied the expression of two non-canonical Wnt genes, Wnt-5a and Wnt-5b. We report that they are expressed in equivalent patterns during limb development and limb regeneration in the axolotl (Ambystoma mexicanum), and during limb development in other tetrapods, implying conservation of function. Our analysis of the effects of ectopic Wnt-5a expression is consistent with the hypothesis that canonical Wnt signaling functions during the early stages of regeneration to control the dedifferentiation of stump cells giving rise to the regeneration-competent cells of the blastema.

  12. Pro-inflammatory wnt5a and anti-inflammatory sFRP5 are differentially regulated by nutritional factors in obese human subjects.

    Directory of Open Access Journals (Sweden)

    Dominik M Schulte

    Full Text Available Obesity is associated with macrophage infiltration of adipose tissue. These inflammatory cells affect adipocytes not only by classical cytokines but also by the secreted glycopeptide wnt5a. Healthy adipocytes are able to release the wnt5a inhibitor sFRP5. This protective effect, however, was found to be diminished in obesity. The aim of the present study was to examine (1 whether obese human subjects exhibit increased serum concentrations of wnt5a and (2 whether wnt5a and/or sFRP5 serum concentrations in obese subjects can be influenced by caloric restriction.23 obese human subjects (BMI 44.1 ± 1.1 kg/m(2 and 12 age- and sex-matched lean controls (BMI 22.3 ± 0.4 kg/m(2 were included in the study. Obese subjects were treated with a very low-calorie diet (approximately 800 kcal/d for 12 weeks. Body composition was assessed by impedance analysis, insulin sensitivity was estimated by HOMA-IR and the leptin-to-adiponectin ratio and wnt5a and sFRP5 serum concentrations were measured by ELISA. sFRP5 expression in human adipose tissue biopsies was further determined on protein level by immunohistology.Pro-inflammatory wnt5a was not measurable in any serum sample of lean control subjects. In patients with obesity, however, wnt5a became significantly detectable consistent with low grade inflammation in such subjects. Caloric restriction resulted in a weight loss from 131.9 ± 4.0 to 112.3 ± 3.2 kg in the obese patients group. This was accompanied by a significant decrease of HOMA-IR and leptin-to-adiponectin ratio, indicating improved insulin sensitivity. Interestingly, these metabolic improvements were associated with a significant increase in serum concentrations of the anti-inflammatory factor and wnt5a-inhibitor sFRP5.Obesity is associated with elevated serum levels of pro-inflammatory wnt5a in humans. Furthermore, caloric restriction beneficially affects serum concentrations of anti-inflammatory sFRP5 in such subjects. These findings suggest a

  13. Wnt-5a and Wnt-4 Regulates Cell Growth in C57MG Mammary Epithelial Cells

    National Research Council Canada - National Science Library

    Olson, Daniel

    1998-01-01

    .... That is, it is important ultimately to understand whether the inappropriate down regulation of certain wnt-genes that are spatially-temporally expressed in developing mammary glands, such as wnt-5a...

  14. 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.

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

    Science.gov (United States)

    Najafov, Ayaz; Seker, Tuncay; Even, Ipek; Hoxhaj, Gerta; Selvi, Osman; Ozel, Duygu Esen; Koman, Ahmet; Birgül-İyison, Necla

    2012-01-01

    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.

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

    International Nuclear Information System (INIS)

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

    2012-01-01

    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.

  17. Mesd Is a Universal Inhibitor of Wnt Co-receptor LRP5/6 and Blocks Wnt/β-catenin Signaling in Cancer Cells†

    Science.gov (United States)

    Lu, Wenyan; Liu, Chia-Chen; Thottassery, Jaideep V.; Bu, Guojun; Li, Yonghe

    2010-01-01

    Mesd is a specialized chaperone for the low-density lipoprotein receptor-related protein-5 (LRP5) and LRP6. In our previous studies, we found that Mesd binds to mature LRP6 on the cell surface and blocks the binding of Wnt antagonist Dickkopf-1(Dkk1) to LRP6. Herein, we demonstrated that Mesd also binds to LRP5 with a high affinity, and is a universal inhibitor of LRP5/6 ligands. Mesd not only blocks Wnt antagonists Dkk1 and Sclerostin binding to LRP5/6, but also inhibits Wnt3A and Rspondin1-induced Wnt/β-catenin signaling in LRP5/6 expressing cells. We also found that Mesd, Dkk1 and Sclerostin compete with one another for binding to LRP5 and LRP6 at the cell surface. More importantly, we demonstrated that Mesd is able to suppress LRP6 phosphorylation and Wnt/β-catenin signaling in prostate cancer PC-3 cells, and inhibits PC-3 cell proliferation. Our results indicate that recombinant Mesd protein is a useful tool for studying Wnt/β-catenin signaling on the cell surface, and has a potential therapeutic role in Wnt-dependent cancers. PMID:20446724

  18. Wnt5a regulates hematopoietic stem cell proliferation and repopulation through the Ryk receptor.

    Science.gov (United States)

    Povinelli, Benjamin J; Nemeth, Michael J

    2014-01-01

    Proper regulation of the balance between hematopoietic stem cell (HSC) proliferation, self-renewal, and differentiation is necessary to maintain hematopoiesis throughout life. The Wnt family of ligands has been implicated as critical regulators of these processes through a network of signaling pathways. Previously, we have demonstrated that the Wnt5a ligand can induce HSC quiescence through a noncanonical Wnt pathway, resulting in an increased ability to reconstitute hematopoiesis. In this study, we tested the hypothesis that the Ryk protein, a Wnt ligand receptor that can bind the Wnt5a ligand, regulated the response of HSCs to Wnt5a. We observed that inhibiting Ryk blocked the ability of Wnt5a to induce HSC quiescence and enhance short-term and long-term hematopoietic repopulation. We found that Wnt5a suppressed production of reactive oxygen species, a known inducer of HSC proliferation. The ability of Wnt5a to inhibit ROS production was also regulated by Ryk. From these data, we propose that Wnt5a regulates HSC quiescence and hematopoietic repopulation through the Ryk receptor and that this process is mediated by suppression of reactive oxygen species. © 2013 AlphaMed Press.

  19. Expression of WNT5A in Idiopathic Pulmonary Fibrosis and Its Control by TGF-β and WNT7B in Human Lung Fibroblasts.

    Science.gov (United States)

    Newman, Donna R; Sills, W Shane; Hanrahan, Katherine; Ziegler, Amanda; Tidd, Kathleen McGinnis; Cook, Elizabeth; Sannes, Philip L

    2016-02-01

    The wingless (Wnt) family of signaling ligands contributes significantly to lung development and is highly expressed in patients with usual interstitial pneumonia (UIP). We sought to define the cellular distribution of Wnt5A in the lung tissue of patients with idiopathic pulmonary fibrosis (IPF) and the signaling ligands that control its expression in human lung fibroblasts and IPF myofibroblasts. Tissue sections from 40 patients diagnosed with IPF or UIP were probed for the immunolocalization of Wnt5A. Further, isolated lung fibroblasts from normal or IPF human lungs, adenovirally transduced for the overexpression or silencing of Wnt7B or treated with TGF-β1 or its inhibitor, were analyzed for Wnt5A protein expression. Wnt5A was expressed in IPF lungs by airway and alveolar epithelium, smooth muscle cells, endothelium, and myofibroblasts of fibroblastic foci and throughout the interstitium. Forced overexpression of Wnt7B with or without TGF-β1 treatment significantly increased Wnt5A protein expression in normal human smooth muscle cells and fibroblasts but not in IPF myofibroblasts where Wnt5A was already highly expressed. The results demonstrate a wide distribution of Wnt5A expression in cells of the IPF lung and reveal that it is significantly increased by Wnt7B and TGF-β1, which, in combination, could represent key signaling pathways that modulate the pathogenesis of IPF. © 2016 The Histochemical Society.

  20. 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

  1. Wnt5a Regulates the Assembly of Human Adipose Derived Stromal Vascular Fraction-Derived Microvasculatures.

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    Venkat M Ramakrishnan

    Full Text Available Human adipose-derived stromal vascular fraction (hSVF cells are an easily accessible, heterogeneous cell system that can spontaneously self-assemble into functional microvasculatures in vivo. However, the mechanisms underlying vascular self-assembly and maturation are poorly understood, therefore we utilized an in vitro model to identify potential in vivo regulatory mechanisms. We utilized passage one (P1 hSVF because of the rapid UEA1+ endothelium (EC loss at even P2 culture. We exposed hSVF cells to a battery of angiogenesis inhibitors and found that the pan-Wnt inhibitor IWP2 produced the most significant hSVF-EC networking decrease (~25%. To determine which Wnt isoform(s and receptor(s may be involved, hSVF was screened by PCR for isoforms associated with angiogenesis, with only WNT5A and its receptor, FZD4, being expressed for all time points observed. Immunocytochemistry confirmed Wnt5a protein expression by hSVF. To see if Wnt5a alone could restore IWP2-induced EC network inhibition, recombinant human Wnt5a (0-150 ng/ml was added to IWP2-treated cultures. The addition of rhWnt5a significantly increased EC network area and significantly decreased the ratio of total EC network length to EC network area compared to untreated controls. To determine if Wnt5a mediates in vivo microvascular self-assembly, 3D hSVF constructs containing an IgG isotype control, anti-Wnt5a neutralizing antibody or rhWnt5a were implanted subcutaneously for 2w in immune compromised mice. Compared to IgG controls, anti-Wnt5a treatment significantly reduced vessel length density by ~41%, while rhWnt5a significantly increased vessel length density by ~62%. However, anti-Wnt5a or rhWnt5a did not significantly affect the density of segments and nodes, both of which measure vascular complexity. Taken together, this data demonstrates that endogenous Wnt5a produced by hSVF plays a regulatory role in microvascular self-assembly in vivo. These findings also suggest that

  2. Effect of Wnt3a on Keratinocytes Utilizing in Vitro and Bioinformatics Analysis

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    Ju-Suk Nam

    2014-03-01

    Full Text Available Wingless-type (Wnt signaling proteins participate in various cell developmental processes. A suppressive role of Wnt5a on keratinocyte growth has already been observed. However, the role of other Wnt proteins in proliferation and differentiation of keratinocytes remains unknown. Here, we investigated the effects of the Wnt ligand, Wnt3a, on proliferation and differentiation of keratinocytes. Keratinocytes from normal human skin were cultured and treated with recombinant Wnt3a alone or in combination with the inflammatory cytokine, tumor necrosis factor α (TNFα. Furthermore, using bioinformatics, we analyzed the biochemical parameters, molecular evolution, and protein–protein interaction network for the Wnt family. Application of recombinant Wnt3a showed an anti-proliferative effect on keratinocytes in a dose-dependent manner. After treatment with TNFα, Wnt3a still demonstrated an anti-proliferative effect on human keratinocytes. Exogenous treatment of Wnt3a was unable to alter mRNA expression of differentiation markers of keratinocytes, whereas an altered expression was observed in TNFα-stimulated keratinocytes. In silico phylogenetic, biochemical, and protein–protein interaction analysis showed several close relationships among the family members of the Wnt family. Moreover, a close phylogenetic and biochemical similarity was observed between Wnt3a and Wnt5a. Finally, we proposed a hypothetical mechanism to illustrate how the Wnt3a protein may inhibit the process of proliferation in keratinocytes, which would be useful for future researchers.

  3. Expression patterns of Wnt genes during development of an anterior part of the chicken eye

    OpenAIRE

    Fokina, Valentina M.; Frolova, Elena I.

    2006-01-01

    To address the roles of Wnts in the development of the anterior eye, we used a chicken model to perform comprehensive expression analysis of all Wnt genes during anterior eye development. In analyzing the available genomic sequences, we found that the chicken genome encodes 18 Wnt proteins that are homologous to corresponding human and mouse proteins. The mRNA sequences for 12 chicken Wnt genes are available in GenBank, and mRNAs for six other Wnt genes (Wnt2, Wnt5b, Wnt7b, Wnt8b, Wnt9b and W...

  4. Caveolin-1 down-regulation is required for Wnt5a-Frizzled 2 signalling in Ha-RasV12 -induced cell transformation.

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    Lin, Hsiu-Kuan; Lin, Hsi-Hui; Chiou, Yu-Wei; Wu, Ching-Lung; Chiu, Wen-Tai; Tang, Ming-Jer

    2018-05-01

    Caveolin-1 (Cav1) is down-regulated during MK4 (MDCK cells harbouring inducible Ha-Ras V12 gene) transformation by Ha-Ras V12 . Cav1 overexpression abrogates the Ha-Ras V12 -driven transformation of MK4 cells; however, the targeted down-regulation of Cav1 is not sufficient to mimic this transformation. Cav1-silenced cells, including MK4/shCav1 cells and MDCK/shCav1 cells, showed an increased cell area and discontinuous junction-related proteins staining. Cellular and mechanical transformations were completed when MDCK/shCav1 cells were treated with medium conditioned by MK4 cells treated with IPTG (MK4+I-CM) but not with medium conditioned by MK4 cells. Nanoparticle tracking analysis showed that Ha-Ras V12 -inducing MK4 cells increased exosome-like microvesicles release compared with their normal counterparts. The cellular and mechanical transformation activities of MK4+I-CM were abolished after heat treatment and exosome depletion and were copied by exosomes derived from MK4+I-CM (MK4+I-EXs). Wnt5a, a downstream product of Ha-Ras V12 , was markedly secreted by MK4+I-CM and MK4+I-EXs. Suppression of Wnt5a expression and secretion using the porcupine inhibitor C59 or Wnt5a siRNA inhibited the Ha-Ras V12 - and MK4+I-CM-induced transformation of MK4 cells and MDCK/shCav1 cells, respectively. Cav1 down-regulation, either by Ha-Ras V12 or targeted shRNA, increased frizzled-2 (Fzd2) protein levels without affecting its mRNA levels, suggesting a novel role of Cav1 in negatively regulating Fzd2 expression. Additionally, silencing Cav1 facilitated the internalization of MK4+I-EXs in MDCK cells. These data suggest that Cav1-dependent repression of Fzd2 and exosome uptake is potentially relevant to its antitransformation activity, which hinders the activation of Ha-Ras V12 -Wnt5a-Stat3 pathway. Altogether, these results suggest that both decreasing Cav1 and increasing exosomal Wnt5a must be implemented during Ha-Ras V12 -driven cell transformation. © 2018 The Authors

  5. 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

  6. Epigenetic mediated transcriptional activation of WNT5A participates in arsenical-associated malignant transformation

    International Nuclear Information System (INIS)

    Jensen, Taylor J.; Wozniak, Ryan J.; Eblin, Kylee E.; Wnek, Sean M.; Gandolfi, A. Jay; Futscher, Bernard W.

    2009-01-01

    Arsenic is a human carcinogen with exposure associated with cancer of the lung, skin, and bladder. Many potential mechanisms have been implicated as playing a role in the process of arsenical-induced malignancy including the perturbation of signaling pathways and aberrant epigenetic regulation. We initiated studies to examine the role of a member of the non-canonical WNT signaling pathway, WNT5A, in UROtsa cells and arsenite [URO-ASSC] and monomethylarsonous acid [URO-MSC] malignantly transformed variants. We present data herein that suggest that WNT5A is transcriptionally activated during arsenical-induced malignant transformation. This WNT5A transcriptional activation is correlated with the enrichment of permissive histone modifications and the reduction of repressive modifications in the WNT5A promoter region. The epigenetic activation of WNT5A expression and acetylation of its promoter remain after the removal of the arsenical, consistent with the maintenance of an anchorage independent growth phenotype in these cells. Additionally, treatment with epigenetic modifying drugs supports a functional role for these epigenetic marks in controlling gene expression. Reduction of WNT5A using lentiviral shRNA greatly attenuated the ability of these cells to grow in an anchorage independent fashion. Extension of our model into human bladder cancer cell lines indicates that each of the cell lines examined also express WNT5A. Taken together, these data suggest that the epigenetic remodeling of the WNT5A promoter is correlated with its transcriptional activation and this upregulation likely participates in arsenical-induced malignant transformation

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

    International Nuclear Information System (INIS)

    Ouji, Yukiteru; Yoshikawa, Masahide; Shiroi, Akira; Ishizaka, Shigeaki

    2006-01-01

    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

  8. CYP3A5 mRNA degradation by nonsense-mediated mRNA decay.

    Science.gov (United States)

    Busi, Florent; Cresteil, Thierry

    2005-09-01

    The total CYP3A5 mRNA level is significantly greater in carriers of the CYP3A5*1 allele than in CYP3A5*3 homozygotes. Most of the CYP3A5*3 mRNA includes an intronic sequence (exon 3B) containing premature termination codons (PTCs) between exons 3 and 4. Two models were used to investigate the degradation of CYP3A5 mRNA: a CYP3A5 minigene consisting of CYP3A5 exons and introns 3 to 6 transfected into MCF7 cells, and the endogenous CYP3A5 gene expressed in HepG2 cells. The 3'-untranslated region g.31611C>T mutation has no effect on CYP3A5 mRNA decay. Splice variants containing exon 3B were more unstable than wild-type (wt) CYP3A5 mRNA. Cycloheximide prevents the recognition of PTCs by ribosomes: in transfected MCF7 and HepG2 cells, cycloheximide slowed down the degradation of exon 3B-containing splice variants, suggesting the participation of nonsense-mediated decay (NMD). When PTCs were removed from pseudoexon 3B or when UPF1 small interfering RNA was used to impair the NMD mechanism, the decay of the splice variant was reduced, confirming the involvement of NMD in the degradation of CYP3A5 splice variants. Induction could represent a source of variability for CYP3A5 expression and could modify the proportion of splice variants. The extent of CYP3A5 induction was investigated after exposure to barbiturates or steroids: CYP3A4 was markedly induced in a pediatric population compared with untreated neonates. However, no effect could be detected in either the total CYP3A5 RNA, the proportion of splice variant RNA, or the protein level. Therefore, in these carriers, induction is unlikely to switch on the phenotypic CYP3A5 expression in carriers of CYP3A5*3/*3.

  9. Hyperuricemia Induces Wnt5a/Ror2 Gene Expression, Epithelial–Mesenchymal Transition, and Kidney Tubular Injury in Mice

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    Wiwit Ananda Wahyu Setyaningsih

    2018-03-01

    Full Text Available Background: Hyperuricemia contributes to kidney injury, characterized by tubular injury with epithelial–mesenchymal transition (EMT. Wnt5a/Ror2 signaling drives EMT in many kidney pathologies. This study sought to evaluate the involvement of Wnt5a/Ror2 in hyperuricemia-induced EMT in kidney tubular injury. Methods: A hyperuricemia model was performed in male Swiss background mice (3 months old, 30–40 g with daily intraperitoneal injections of 125 mg/kg body weight (BW of uric acid. The mice were terminated on day 7 (UA7, n=5 and on day 14 (UA14, n=5. Allopurinol groups (UAl7 and UAl14, each n=5 were added with oral 50 mg/kg BW of allopurinol treatment. The serum uric acid level was quantified, and tubular injury was assessed based on PAS staining. Reverse transcriptase-PCR was done to quantify Wnt5a, Ror2, E-cadherin, and vimentin expressions. IHC staining was done for E-cadherin and collagen I. We used the Shapiro–Wilk for normality testing and one-way ANOVA for variance analysis with a P<0.05 as significance level using SPSS 22 software. Results: The hyperuricemia groups had a higher uric acid level, which was associated with a higher tubular injury score. Meanwhile, the allopurinol groups had a significantly lower uric acid level and tubular injury than the uric acid groups. Reverse transcriptase-PCR revealed downregulation of the E-cadherin expression. While vimentin and collagen I expression are upregulated, which was associated with a higher Wnt5a expression. However, the allopurinol groups had reverse results. Immunostaining revealed a reduction in E-cadherin staining in the epithelial cells and collagen I positive staining in the epithelial cells and the interstitial areas. Conclusion: Hyperuricemia induced tubular injury, which might have been mediated by EMT through the activation of Wnt5a.

  10. 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

  11. Induction of CXC chemokines in human mesenchymal stem cells by stimulation with secreted frizzled-related proteins through non-canonical Wnt signaling.

    Science.gov (United States)

    Bischoff, David S; Zhu, Jian-Hua; Makhijani, Nalini S; Yamaguchi, Dean T

    2015-12-26

    To investigate the effect of secreted frizzled-related proteins (sFRPs) on CXC chemokine expression in human mesenchymal stem cells (hMSCs). CXC chemokines such as CXCL5 and CXCL8 are induced in hMSCs during differentiation with osteogenic differentiation medium (OGM) and may be involved in angiogenic stimulation during bone repair. hMSCs were treated with conditioned medium (CM) from L-cells expressing non-canonical Wnt5a protein, or with control CM from wild type L-cells, or directly with sFRPs for up to 10 d in culture. mRNA expression levels of both CXCL5 and CXCL8 were quantitated by real-time reverse transcriptase-polymerase chain reaction and secreted protein levels of these proteins determined by ELISA. Dose- (0-500 ng/mL) and time-response curves were generated for treatment with sFRP1. Signal transduction pathways were explored by western blot analysis with pan- or phosphorylation-specific antibodies, through use of specific pathway inhibitors, and through use of siRNAs targeting specific frizzled receptors (Fzd)-2 and 5 or the receptor tyrosine kinase-like orphan receptor-2 (RoR2) prior to treatment with sFRPs. CM from L-cells expressing Wnt5a, a non-canonical Wnt, stimulated an increase in CXCL5 mRNA expression and protein secretion in comparison to control L-cell CM. sFRP1, which should inhibit both canonical and non-canonical Wnt signaling, surprisingly enhanced the expression of CXCL5 at 7 and 10 d. Dickkopf1, an inhibitor of canonical Wnt signaling prevented the sFRP-stimulated induction of CXCL5 and actually inhibited basal levels of CXCL5 expression at 7 but not at 10 d post treatment. In addition, all four sFRPs isoforms induced CXCL8 expression in a dose- and time-dependent manner with maximum expression at 7 d with treatment at 150 ng/mL. The largest increases in CXCL5 expression were seen from stimulation with sFRP1 or sFRP2. Analysis of mitogen-activated protein kinase signaling pathways in the presence of OGM showed sFRP1-induced

  12. Sequences within the 5' untranslated region regulate the levels of a kinetoplast DNA topoisomerase mRNA during the cell cycle.

    Science.gov (United States)

    Pasion, S G; Hines, J C; Ou, X; Mahmood, R; Ray, D S

    1996-12-01

    Gene expression in trypanosomatids appears to be regulated largely at the posttranscriptional level and involves maturation of mRNA precursors by trans splicing of a 39-nucleotide miniexon sequence to the 5' end of the mRNA and cleavage and polyadenylation at the 3' end of the mRNA. To initiate the identification of sequences involved in the periodic expression of DNA replication genes in trypanosomatids, we have mapped splice acceptor sites in the 5' flanking region of the TOP2 gene, which encodes the kinetoplast DNA topoisomerase, and have carried out deletion analysis of this region on a plasmid-encoded TOP2 gene. Block deletions within the 5' untranslated region (UTR) identified two regions (-608 to -388 and -387 to -186) responsible for periodic accumulation of the mRNA. Deletion of one or the other of these sequences had no effect on periodic expression of the mRNA, while deletion of both regions resulted in constitutive expression of the mRNA throughout the cell cycle. Subcloning of these sequences into the 5' UTR of a construct lacking both regions of the TOP2 5' UTR has shown that an octamer consensus sequence present in the 5' UTR of the TOP2, RPA1, and DHFR-TS mRNAs is required for normal cycling of the TOP2 mRNA. Mutation of the consensus octamer sequence in the TOP2 5' UTR in a plasmid construct containing only a single consensus octamer and that shows normal cycling of the plasmid-encoded TOP2 mRNA resulted in substantial reduction of the cycling of the mRNA level. These results imply a negative regulation of TOP2 mRNA during the cell cycle by a mechanism involving redundant elements containing one or more copies of a conserved octamer sequence within the 5' UTR of TOP2 mRNA.

  13. FOXQ1, a novel target of the Wnt pathway and a new marker for activation of Wnt signaling in solid tumors.

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    Jon Christensen

    Full Text Available BACKGROUND: The forkhead box transcription factor FOXQ1 has been shown to be upregulated in colorectal cancer (CRC and metastatic breast cancer and involved in tumor development, epithelial-mesenchymal transition and chemoresistance. Yet, its transcriptional regulation is still unknown. METHODS: FOXQ1 mRNA and protein expression were analysed in a panel of CRC cell lines, and laser micro-dissected human biopsy samples by qRT-PCR, microarray GeneChip® U133 Plus 2.0 and western blots. FOXQ1 regulation was assayed by chromatin immunoprecipitation and luciferase reporter assays. RESULTS: FOXQ1 was robustly induced in CRC compared to other tumors, but had no predictive value with regards to grade, metastasis and survival in CRC. Prototype-based gene coexpression and gene set enrichment analysis showed a significant association between FOXQ1 and the Wnt pathway in tumors and cancer cell lines from different tissues. In vitro experiments confirmed, on a molecular level, FOXQ1 as a direct Wnt target. Analysis of known Wnt targets identified FOXQ1 as the most suitable marker for canonical Wnt activation across a wide panel of cell lines derived from different tissues. CONCLUSIONS: Our data show that FOXQ1 is one of the most over-expressed genes in CRC and a direct target of the canonical Wnt pathway. It is a potential new marker for detection of early CRC and Wnt activation in tumors of different origins.

  14. Deregulated WNT signaling in childhood T-cell acute lymphoblastic leukemia

    International Nuclear Information System (INIS)

    Ng, O H; Erbilgin, Y; Firtina, S; Celkan, T; Karakas, Z; Aydogan, G; Turkkan, E; Yildirmak, Y; Timur, C; Zengin, E; Dongen, J J M van; Staal, F J T; Ozbek, U; Sayitoglu, M

    2014-01-01

    WNT signaling has been implicated in the regulation of hematopoietic stem cells and plays an important role during T-cell development in thymus. Here we investigated WNT pathway activation in childhood T-cell acute lymphoblastic leukemia (T-ALL) patients. To evaluate the potential role of WNT signaling in T-cell leukomogenesis, we performed expression analysis of key components of WNT pathway. More than 85% of the childhood T-ALL patients showed upregulated β-catenin expression at the protein level compared with normal human thymocytes. The impact of this upregulation was reflected in high expression of known target genes (AXIN2, c-MYC, TCF1 and LEF). Especially AXIN2, the universal target gene of WNT pathway, was upregulated at both mRNA and protein levels in ∼40% of the patients. When β-CATENIN gene was silenced by small interfering RNA, the cancer cells showed higher rates of apoptosis. These results demonstrate that abnormal WNT signaling activation occurs in a significant fraction of human T-ALL cases independent of known T-ALL risk factors. We conclude that deregulated WNT signaling is a novel oncogenic event in childhood T-ALL

  15. Transcriptome Analysis on Single Small Yellow Follicles Reveals That Wnt4 Is Involved in Chicken Follicle Selection

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    Yiya Wang

    2017-11-01

    Full Text Available Ovarian follicle selection is an important process impacting the laying performance and fecundity of hens, and is regulated by follicle-stimulating hormone (FSH through binding to its receptor [follicle-stimulating hormone receptor (FSHR]. In laying hens, the small yellow follicle (6–8 mm in diameter with the highest expression of FSHR will be recruited into the preovulatory hierarchy during ovarian follicle development. The study of molecular mechanism of chicken follicle selection is helpful for the identification of genes underlying egg-laying traits in chicken and other poultry species. Herein, the transcriptomes of chicken small yellow follicles differing in the mRNA expression of FSHR were compared, and a total of 17,993 genes were identified in 3 pairs of small yellow follicles. The Wnt signaling pathway was significantly enriched in the follicles with the greatest fold change in FSHR expression. In this pathway, the expression level of Wnt4 mRNA was significantly upregulated with a log2(fold change of 2.12. We further investigated the expression, function, and regulation of Wnt4 during chicken follicle selection and found that Wnt4 mRNA reached its peak in small yellow follicles; Wnt4 stimulated the proliferation of follicular granulosa cells (GCs, increased the expression of StAR and CYP11A1 mRNA in prehierarchical and hierarchical follicles, increased the expression of FSHR mRNA, and decreased the expression of anti-Müllerian hormone and OCLN mRNA. Treatment with FSH significantly increased Wnt4 expression in GCs. Moreover, Wnt4 facilitated the effects of FSH on the production of progesterone (P4 and the mRNA expression of steroidogenic enzyme genes in the GCs of hierarchical follicles, but inhibited the effects of FSH in the GCs of prehierarchical follicles. Collectively, these data suggest that Wnt4 plays an important role in chicken follicle selection by stimulating GC proliferation and steroidogenesis. This study provides a

  16. A Wnt5 Activity Asymmetry and Intercellular Signaling via PCP Proteins Polarize Node Cells for Left-Right Symmetry Breaking.

    Science.gov (United States)

    Minegishi, Katsura; Hashimoto, Masakazu; Ajima, Rieko; Takaoka, Katsuyoshi; Shinohara, Kyosuke; Ikawa, Yayoi; Nishimura, Hiromi; McMahon, Andrew P; Willert, Karl; Okada, Yasushi; Sasaki, Hiroshi; Shi, Dongbo; Fujimori, Toshihiko; Ohtsuka, Toshihisa; Igarashi, Yasunobu; Yamaguchi, Terry P; Shimono, Akihiko; Shiratori, Hidetaka; Hamada, Hiroshi

    2017-03-13

    Polarization of node cells along the anterior-posterior axis of mouse embryos is responsible for left-right symmetry breaking. How node cells become polarized has remained unknown, however. Wnt5a and Wnt5b are expressed posteriorly relative to the node, whereas genes for Sfrp inhibitors of Wnt signaling are expressed anteriorly. Here we show that polarization of node cells is impaired in Wnt5a -/- Wnt5b -/- and Sfrp mutant embryos, and also in the presence of a uniform distribution of Wnt5a or Sfrp1, suggesting that Wnt5 and Sfrp proteins act as instructive signals in this process. The absence of planar cell polarity (PCP) core proteins Prickle1 and Prickle2 in individual cells or local forced expression of Wnt5a perturbed polarization of neighboring wild-type cells. Our results suggest that opposing gradients of Wnt5a and Wnt5b and of their Sfrp inhibitors, together with intercellular signaling via PCP proteins, polarize node cells along the anterior-posterior axis for breaking of left-right symmetry. Copyright © 2017 Elsevier Inc. All rights reserved.

  17. Butyrate and bioactive proteolytic form of Wnt-5a regulate colonic epithelial proliferation and spatial development

    Science.gov (United States)

    Uchiyama, Kazuhiko; Sakiyama, Toshio; Hasebe, Takumu; Musch, Mark W.; Miyoshi, Hiroyuki; Nakagawa, Yasushi; He, Tong-Chuan; Lichtenstein, Lev; Naito, Yuji; Itoh, Yoshito; Yoshikawa, Toshikazu; Jabri, Bana; Stappenbeck, Thaddeus; Chang, Eugene B.

    2016-01-01

    Proliferation and spatial development of colonic epithelial cells are highly regulated along the crypt vertical axis, which, when perturbed, can result in aberrant growth and carcinogenesis. In this study, two key factors were identified that have important and counterbalancing roles regulating these processes: pericrypt myofibroblast-derived Wnt-5a and the microbial metabolite butyrate. Cultured YAMC cell proliferation and heat shock protein induction were analzyed after butryate, conditioned medium with Wnt5a activity, and FrzB containing conditioned medium. In vivo studies to modulate Hsp25 employed intra-colonic wall Hsp25 encoding lentivirus. To silence Wnt-5a in vivo, intra-colonic wall Wnt-5a silencing RNA was used. Wnt-5a, secreted by stromal myofibroblasts of the lower crypt, promotes proliferation through canonical β-catenin activation. Essential to this are two key requirements: (1) proteolytic conversion of the highly insoluble ~40 kD Wnt-5a protein to a soluble 36 mer amino acid peptide that activates epithelial β-catenin and cellular proliferation, and (2) the simultaneous inhibition of butyrate-induced Hsp25 by Wnt-5a which is necessary to arrest the proliferative process in the upper colonic crypt. The interplay and spatial gradients of these factors insures that crypt epithelial cell proliferation and development proceed in an orderly fashion, but with sufficient plasticity to adapt to physiological perturbations including inflammation. PMID:27561676

  18. Wnt5a Is Associated with Cigarette Smoke-Related Lung Carcinogenesis via Protein Kinase C

    OpenAIRE

    Whang, Young Mi; Jo, Ukhyun; Sung, Jae Sook; Ju, Hyun Jung; Kim, Hyun Kyung; Park, Kyong Hwa; Lee, Jong Won; Koh, In Song; Kim, Yeul Hong

    2013-01-01

    Wnt5a is overexpressed during the progression of human non-small cell lung cancer. However, the roles of Wnt5a during smoking-related lung carcinogenesis have not been clearly elucidated. We investigated the associations between Wnt5a and the early development of cigarette smoke related lung cancer using human bronchial epithelial (HBE) cells (NHBE, BEAS-2B, 1799, 1198 and 1170I) at different malignant stages established by exposure to cigarette smoke condensate (CSC). Abnormal up-regulation ...

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

    International Nuclear Information System (INIS)

    Adachi, Atsuo; Takahashi, Tomosaburo; Ogata, Takehiro; Imoto-Tsubakimoto, Hiroko; Nakanishi, Naohiko; Ueyama, Tomomi; Matsubara, Hiroaki

    2012-01-01

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

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

    NARCIS (Netherlands)

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

    2005-01-01

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

  1. The role of Wnt/β-catenin signaling in enterocyte turnover during methotrexate-induced intestinal mucositis in a rat.

    Directory of Open Access Journals (Sweden)

    Igor Sukhotnik

    Full Text Available BACKGROUND/AIMS: Intestinal mucositis is a common side-effect in patients who receive aggressive chemotherapy. The Wnt signaling pathway is critical for establishing and maintaining the proliferative compartment of the intestine. In the present study, we tested whether Wnt/β-catenin signaling is involved in methotrexate (MTX-induced intestinal damage in a rat model. METHODS: Non-pretreated and pretreated with MTX Caco-2 cells were evaluated for cell proliferation and apoptosis using FACS analysis. Adult rats were divided into three experimental groups: Control rats; MTX-2 animals were treated with a single dose of MTX given IP and were sacrificed on day 2, and MTX-4 rats were treated with MTX similar to group B and were sacrificed on day 4. Intestinal mucosal damage, mucosal structural changes, enterocyte proliferation, and enterocyte apoptosis were measured at sacrifice. Real Time PCR and Western blot was used to determine the level of Wnt/β-catenin related genes and protein expression. RESULTS: In the vitro experiment, treatment with MTX resulted in marked decrease in early cell proliferation rates following by a 17-fold increase in late cell proliferation rates compared to early proliferation. Treatment with MTX resulted in a significant increase in early and late apoptosis compared to Caco-2 untreated cells. In the vivo experiment, MTX-2 and MTX-4 rats demonstrated intestinal mucosal hypoplasia. MTX-2 rats demonstrated a significant decrease in FRZ-2, Wnt 3A Wnt 5A, β-catenin, c-myc mRNA expression and a significant decrease in β-catenin and Akt protein levels compared to control animals. Four days following MTX administration, rats demonstrated a trend toward a restoration of Wnt/β-catenin signaling especially in ileum. CONCLUSIONS: Wnt/β-catenin signaling is involved in enterocyte turnover during MTX-induced intestinal mucositis in a rat.

  2. WNT5A-JNK regulation of vascular insulin resistance in human obesity.

    Science.gov (United States)

    Farb, Melissa G; Karki, Shakun; Park, Song-Young; Saggese, Samantha M; Carmine, Brian; Hess, Donald T; Apovian, Caroline; Fetterman, Jessica L; Bretón-Romero, Rosa; Hamburg, Naomi M; Fuster, José J; Zuriaga, María A; Walsh, Kenneth; Gokce, Noyan

    2016-12-01

    Obesity is associated with the development of vascular insulin resistance; however, pathophysiological mechanisms are poorly understood. We sought to investigate the role of WNT5A-JNK in the regulation of insulin-mediated vasodilator responses in human adipose tissue arterioles prone to endothelial dysfunction. In 43 severely obese (BMI 44±11 kg/m 2 ) and five metabolically normal non-obese (BMI 26±2 kg/m 2 ) subjects, we isolated arterioles from subcutaneous and visceral fat during planned surgeries. Using videomicroscopy, we examined insulin-mediated, endothelium-dependent vasodilator responses and characterized adipose tissue gene and protein expression using real-time polymerase chain reaction and Western blot analyses. Immunofluorescence was used to quantify endothelial nitric oxide synthase (eNOS) phosphorylation. Insulin-mediated vasodilation was markedly impaired in visceral compared to subcutaneous vessels from obese subjects (p<0.001), but preserved in non-obese individuals. Visceral adiposity was associated with increased JNK activation and elevated expression of WNT5A and its non-canonical receptors, which correlated negatively with insulin signaling. Pharmacological JNK antagonism with SP600125 markedly improved insulin-mediated vasodilation by sixfold (p<0.001), while endothelial cells exposed to recombinant WNT5A developed insulin resistance and impaired eNOS phosphorylation (p<0.05). We observed profound vascular insulin resistance in the visceral adipose tissue arterioles of obese subjects that was associated with up-regulated WNT5A-JNK signaling and impaired endothelial eNOS activation. Pharmacological JNK antagonism markedly improved vascular endothelial function, and may represent a potential therapeutic target in obesity-related vascular disease. © The Author(s) 2016.

  3. Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro.

    Science.gov (United States)

    Zhu, Xuejiao; Wen, Libin; Sheng, Shaoyang; Wang, Wei; Xiao, Qi; Qu, Meng; Hu, Yiyi; Liu, Chuanmin; He, Kongwang

    2018-01-01

    Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro . Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro , elucidated the mechanism of P1's inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS), laying a foundation for elucidating the pathogenesis of P1.

  4. [Expression of ICAT and Wnt signaling-related proteins in the monocytic differentiation of HL-60 cells induced by a new steroidal drug NSC67657].

    Science.gov (United States)

    Wang, J S; Wang, W J; Wang, T; Zhang, Y

    2016-04-01

    To investigate the expression of mRNA and proteins of β-catenin, TCF-4 (ICAT) and Wnt signaling pathway-related genes in the monocytic differentiation of acute myeloid leukemia HL-60 cells induced by a new steroidal drug NSC67657. Wright's staining and α-NBE staining were used to observe the differentiation of HL-60 cells after 5 days of 10 μmol/L NSC67657 treatment. Flow cytometry (FCM) was used to detect the differentiation and cell cycles. The expressions of mRNA and proteins of ICAT and Wnt signaling pathway-related factors, including β-catenin, TCF-4, c-myc, cyclin D1 and TCF-1 before and after differentiation, were detected by RT-PCR and Western blot. Morphological observation showed that NSC67657 induced monocytic differentiation of HL-60 cells. At 5 days after 10 μmol/L NSC67657 treatment, the number of CD14(+) HL-60 cells was (94.37±2.84)%, significantly higher than the (1.31±0.09)% in control group (Pcells were of (18.76±0.98)%, significantly lower than that of (34.38±2.61) % in the control group (Pprotein, and down-regulated the expression of β-catenin mRNA and protin (Pprotein and nuclear protein in the HL-60 cells (P>0.05 for all). The target genes of Wnt signaling pathway, including c-myc, cyclinD1 and TCF-1 mRNA and proteins in the HL-60 cells were significantly down-regulated after NSC67657 treatment (Pcells, and down-regulates the expression of β-catenin and target genes of Wnt signaling pathway. These results indicate that Wnt signaling pathway may be directly or indirectly involved in the monocytic differentiation process of HL-60 cells.

  5. Wnt5a and Wnt11 are essential for second heart field progenitor development

    OpenAIRE

    Cohen, Ethan David; Miller, Mayumi F.; Wang, Zichao; Moon, Randall T.; Morrisey, Edward E.

    2012-01-01

    Wnt/β-catenin has a biphasic effect on cardiogenesis, promoting the induction of cardiac progenitors but later inhibiting their differentiation. Second heart field progenitors and expression of the second heart field transcription factor Islet1 are inhibited by the loss of β-catenin, indicating that Wnt/β-catenin signaling is necessary for second heart field development. However, expressing a constitutively active β-catenin with Islet1-Cre also inhibits endogenous Islet1 expression, reflectin...

  6. Non-equivalence of Wnt and R-spondin ligands during Lgr5+ intestinal stem-cell self-renewal.

    Science.gov (United States)

    Yan, Kelley S; Janda, Claudia Y; Chang, Junlei; Zheng, Grace X Y; Larkin, Kathryn A; Luca, Vincent C; Chia, Luis A; Mah, Amanda T; Han, Arnold; Terry, Jessica M; Ootani, Akifumi; Roelf, Kelly; Lee, Mark; Yuan, Jenny; Li, Xiao; Bolen, Christopher R; Wilhelmy, Julie; Davies, Paige S; Ueno, Hiroo; von Furstenberg, Richard J; Belgrader, Phillip; Ziraldo, Solongo B; Ordonez, Heather; Henning, Susan J; Wong, Melissa H; Snyder, Michael P; Weissman, Irving L; Hsueh, Aaron J; Mikkelsen, Tarjei S; Garcia, K Christopher; Kuo, Calvin J

    2017-05-11

    The canonical Wnt/β-catenin signalling pathway governs diverse developmental, homeostatic and pathological processes. Palmitoylated Wnt ligands engage cell-surface frizzled (FZD) receptors and LRP5 and LRP6 co-receptors, enabling β-catenin nuclear translocation and TCF/LEF-dependent gene transactivation. Mutations in Wnt downstream signalling components have revealed diverse functions thought to be carried out by Wnt ligands themselves. However, redundancy between the 19 mammalian Wnt proteins and 10 FZD receptors and Wnt hydrophobicity have made it difficult to attribute these functions directly to Wnt ligands. For example, individual mutations in Wnt ligands have not revealed homeostatic phenotypes in the intestinal epithelium-an archetypal canonical, Wnt pathway-dependent, rapidly self-renewing tissue, the regeneration of which is fueled by proliferative crypt Lgr5 + intestinal stem cells (ISCs). R-spondin ligands (RSPO1-RSPO4) engage distinct LGR4-LGR6, RNF43 and ZNRF3 receptor classes, markedly potentiate canonical Wnt/β-catenin signalling, and induce intestinal organoid growth in vitro and Lgr5 + ISCs in vivo. However, the interchangeability, functional cooperation and relative contributions of Wnt versus RSPO ligands to in vivo canonical Wnt signalling and ISC biology remain unknown. Here we identify the functional roles of Wnt and RSPO ligands in the intestinal crypt stem-cell niche. We show that the default fate of Lgr5 + ISCs is to differentiate, unless both RSPO and Wnt ligands are present. However, gain-of-function studies using RSPO ligands and a new non-lipidated Wnt analogue reveal that these ligands have qualitatively distinct, non-interchangeable roles in ISCs. Wnt proteins are unable to induce Lgr5 + ISC self-renewal, but instead confer a basal competency by maintaining RSPO receptor expression that enables RSPO ligands to actively drive and specify the extent of stem-cell expansion. This functionally non-equivalent yet cooperative interaction

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

    International Nuclear Information System (INIS)

    Ouji, Yukiteru; Yoshikawa, Masahide; Shiroi, Akira; Ishizaka, Shigeaki

    2006-01-01

    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

  8. [Wnt/β-catenin pathway involved in the regulation of rat mesangial cell proliferation by adipose-derived mesenchymal stem cells].

    Science.gov (United States)

    Li, Zhi; Zhang, Mengying; Li, Xueqin; Lu, Jinming; Xu, Liang

    2016-11-01

    Objective To investigate the effect of adipose-derived mesenchymal stem cells (ADSCs) on glomerular mesangial cell proliferation via Wnt/β-catenin pathway. Methods The rat glomerular mesangial cells (HBZY-1) were incubated in conditioned ADSC medium. Cell cycle was analyzed with flow cytometry; the proliferation rate of HBZY-1 and the expression levels of relative genes and proteins of Wnt signaling pathway were measured using RNA interference, quantitative real-time PCR and Western blotting, respectively. Results HBZY-1 proliferation was significantly inhibited under the action of conditioned ADSC medium, whereas dickkopf WNT signaling pathway inhibitor 1 (DKK1) mRNA level was up-regulated. Fibronectin and TGF-β1 mRNA expression as well as β-catenin and Bcl-2 protein levels of HBZY-1 were significantly down-regulated. DKK1 gene expression level in ADSCs was significantly higher than that of HBZY-1. After RNA interference, DKK1 expression level in ADSCs was markedly inhibited, yet the β-catenin protein level was notably elevated. The β-catenin and Bcl-2 protein levels of HBZY-1 were also significantly raised in HBZY-1 after cultured with conditioned medium containing ADSCs treated with RNA interference. Conclusion Wnt/β-catenin may be a potential signaling pathway involved in the regulative effect of ADSCs on glomerular mesangial cell proliferation.

  9. Bauhinia championi (Benth.) Benth. polysaccharides upregulate Wnt/β-catenin signaling in chondrocytes.

    Science.gov (United States)

    Li, Huiting; Li, Xihai; Liu, Guozhong; Chen, Jiashou; Weng, Xiaping; Liu, Fayuan; Xu, Huifeng; Liu, Xianxiang; Ye, Hongzhi

    2013-12-01

    Bauhinia championi (Benth.) Benth. polysaccharides (BCBPs), extracted from Bauhinia championi (Benth.) Benth., which has been used in traditional Chinese medicine (TCM) for the treatment of osteoarthritis (OA), are the bioactive constituents of Bauhinia championi (Benth.) rattan. However, the molecular mechanisms responsible for their effects on OA are poorly understood. The Wnt/β-catenin signaling pathway plays an important role in the proliferation of chondrocytes. In the present study, the effects of BCBPs on Wnt/β-catenin signaling in chondrocytes were investigated. BCBPs were obtained by hot-water extraction and identified by the modified high performance liquid chromatography (HPLC) method. Chondrocytes were isolated from the knees of Sprague‑Dawley rats and identified by type II collagen immunohistochemistry. The chondrocytes were treated with or without BCBPs for 48 h. Cell viability was evaluated by MTT assay. The mRNA and protein levels of Wnt-4, β-catenin, Frizzled-2, glycogen synthase kinase (GSK)-3β, cyclin D1 and collagen II were detected by western blot analysis and reverse transcription PCR (RT-PCR), respectively. We found that the BCBPs contained at least seven monosaccharides, including D-mannose, rhamnose, D-(+) glucuronic acid, D-(+) galacturonic acid, D-glucose, galactose and arabinose. The cell viability of the chondrocytes treated with 50, 100 and 200 µg/ml BCBPs was significantly higher than that of the chondroctyes in the control group (treated with 0 µg/ml BCBPs). Furthermore, compared with the control group, the mRNA and protein expression of Wnt-4, β-catenin, Frizzled-2 and cyclin D1 in the BCBP-treated groups markedly increased, whereas the mRNA and protein expression of GSK-3β significantly decreased. Of note, the dose of 100 µg/ml BCBPs was more effective than the dose of 50 µg/ml BCBPs and 200 µg/ml BCBPs. In addition, we found that treatment with BCBPs upregulated the protein levels of collagen II in the

  10. Porcine Circovirus-Like Virus P1 Inhibits Wnt Signaling Pathway in Vivo and in Vitro

    Directory of Open Access Journals (Sweden)

    Xuejiao Zhu

    2018-03-01

    Full Text Available Porcine circovirus-like virus P1 is an important pathogen of the current pig industry, the infection mechanism is not entirely clear. Wnt signaling pathway plays an important role in the growth of young animals and infection of some viruses. This study was designed to demonstrate the effects of P1 infection on the Wnt signaling pathway. In vivo experiments, we demonstrated the down-regulatory effects of P1 infection in piglets and mice on the downstream components expression levels of Wnt signaling pathway, and the effects of Wnt signaling pathway activation on the pathogenesis of P1. In vitro studies, we found P1 infection down-regulated protein level of β-catenin and mRNA level of mmp2, prevented the β-catenin from entering into nucleus, abolished the TCF/LEF promoter activity, proved that P1 could inhibit the activation of Wnt signaling pathway in vitro. Finally, we found that VP1 of P1 virus also had the inhibitory effects on Wnt signaling pathway in vitro, elucidated the mechanism of P1’s inhibitory effects on the Wnt signaling pathway and offered the possibility that the suppression of Wnt signaling pathway was involved in the post-weaning multisystemic wasting syndrome (PMWS, laying a foundation for elucidating the pathogenesis of P1.

  11. Boehmenan, a lignan from Hibiscus ficulneus, showed Wnt signal inhibitory activity.

    Science.gov (United States)

    Shono, Takumi; Ishikawa, Naoki; Toume, Kazufumi; Arai, Midori A; Ahmed, Firoj; Sadhu, Samir K; Ishibashi, Masami

    2015-07-15

    The Wnt signal pathway modulates numerous biological processes, and its aberrant activation is related to various diseases. Therefore, inhibition of the Wnt signal may provide an effective (or efficient) strategy for these diseases. Cell-based luciferase assay targeting the Wnt signal (TOP assay) revealed that Hibiscus ficulneus extract inhibited the Wnt signal. The activity-guided isolation of the MeOH extract of H. ficulneus stems yielded four known (1-4) lignans along with myriceric acid (5). Compounds 1-4 potently inhibited the Wnt signal with TOPflash IC50 values of 1.0, 4.5, 6.3, and 1.9 μM, respectively. Compound 1 exhibited cytotoxicity against both Wnt-dependent (HCT116) and Wnt-independent (RKO) cells. Western blot analysis showed that 1 decreased the expression of full, cytosolic and nuclear β-catenin along with c-myc in STF/293 cells. Our results suggested that 1 may have inhibited the Wnt signal by decreasing β-catenin levels. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. M2 macrophages activate WNT signaling pathway in epithelial cells: relevance in ulcerative colitis.

    Directory of Open Access Journals (Sweden)

    Jesús Cosín-Roger

    Full Text Available Macrophages, which exhibit great plasticity, are important components of the inflamed tissue and constitute an essential element of regenerative responses. Epithelial Wnt signalling is involved in mechanisms of proliferation and differentiation and expression of Wnt ligands by macrophages has been reported. We aim to determine whether the macrophage phenotype determines the expression of Wnt ligands, the influence of the macrophage phenotype in epithelial activation of Wnt signalling and the relevance of this pathway in ulcerative colitis. Human monocyte-derived macrophages and U937-derived macrophages were polarized towards M1 or M2 phenotypes and the expression of Wnt1 and Wnt3a was analyzed by qPCR. The effects of macrophages and the role of Wnt1 were analyzed on the expression of β-catenin, Tcf-4, c-Myc and markers of cell differentiation in a co-culture system with Caco-2 cells. Immunohistochemical staining of CD68, CD206, CD86, Wnt1, β-catenin and c-Myc were evaluated in the damaged and non-damaged mucosa of patients with UC. We also determined the mRNA expression of Lgr5 and c-Myc by qPCR and protein levels of β-catenin by western blot. Results show that M2, and no M1, activated the Wnt signaling pathway in co-culture epithelial cells through Wnt1 which impaired enterocyte differentiation. A significant increase in the number of CD206+ macrophages was observed in the damaged mucosa of chronic vs newly diagnosed patients. CD206 immunostaining co-localized with Wnt1 in the mucosa and these cells were associated with activation of canonical Wnt signalling pathway in epithelial cells and diminution of alkaline phosphatase activity. Our results show that M2 macrophages, and not M1, activate Wnt signalling pathways and decrease enterocyte differentiation in co-cultured epithelial cells. In the mucosa of UC patients, M2 macrophages increase with chronicity and are associated with activation of epithelial Wnt signalling and diminution in

  13. MGAT1 is a novel transcriptional target of Wnt/β-catenin signaling pathway.

    Science.gov (United States)

    Akiva, Izzet; Birgül Iyison, Necla

    2018-01-08

    The Wnt/β-catenin signaling pathway is an evolutionary conserved pathway, which has important functions in vertebrate early development, axis formation, cellular proliferation and morphogenesis. Additionally, Wnt/β-catenin signaling pathway is one of the most important intracellular pathways that controls cancer progression. To date most of the identified targets of this pathway are shown to harbor tumorigenic properties. We previously showed that Mannosyl glycoprotein acetylglucosaminyl-transferase (MGAT1) enzyme is among the Wnt/β-catenin signaling putative target genes in hepatocellular carcinoma cell lines (Huh7). MGAT1 protein levels were determined by Western Blotting from Huh7 cell lines in which Wnt/β-catenin pathway was activated by means of different approaches such as LiCl treatment and mutant β-catenin overexpression. Luciferase reporter assay was used to analyze the promoter activity of MGAT1. The mRNA levels of MGAT1 were determined by quantitative real-time PCR from Huh7 cells that were treated with either Wnt agonist or GSK-3β inhibitor. Wound healing and XTT cell proliferation assays were performed in order to determine the proliferation and migration capacities of MGAT1 overexpressing stable Huh7 cells. Finally, xenograft experiments were carried out to measure the tumor formation capacities in vivo. In this study we showed that the activation of Wnt/β-catenin pathway culminates in the upregulation of MGAT1 enzyme both at transcriptional and post-transcriptional levels. We also showed that overexpression of the β-catenin gene (CTNNB1) increased the promoter activity of MGAT1. We applied a set of complementary approaches to elucidate the functional importance of MGAT1 as a vital target of Wnt/β-catenin signaling in Huh7 cells. Our analyses related to cell proliferation and migration assays showed that in comparison to the control cells, MGAT1 expressing Huh7 cells have greater proliferative and invasive capabilities. Furthermore, the

  14. PAI-1 mRNA expression and plasma level in rheumatoid arthritis: relationship with 4G/5G PAI-1 polymorphism.

    Science.gov (United States)

    Muñoz-Valle, José Francisco; Ruiz-Quezada, Sandra Luz; Oregón-Romero, Edith; Navarro-Hernández, Rosa Elena; Castañeda-Saucedo, Eduardo; De la Cruz-Mosso, Ulises; Illades-Aguiar, Berenice; Leyva-Vázquez, Marco Antonio; Castro-Alarcón, Natividad; Parra-Rojas, Isela

    2012-12-01

    Rheumatoid arthritis (RA) is a chronic inflammatory disease affecting the synovial membrane, cartilage and bone. PAI-1 is a key regulator of the fibrinolytic system through which plasminogen is converted to plasmin. The plasmin activates the matrix metalloproteinase system, which is closely related with the joint damage and bone destruction in RA. The aim of this study was to investigate the relationship between 4G/5G PAI-1 polymorphism with mRNA expression and PAI-1 plasma protein levels in RA patients. 113 RA patients and 123 healthy subjects (HS) were included in the study. The 4G/5G PAI-1 polymorphism was determined by polymerase chain reaction-restriction fragment length polymorphism method; the PAI-1 mRNA expression was determined by real-time PCR; and the soluble PAI-1 (sPAI-1) levels were quantified using an ELISA kit. No significant differences in the genotype and allele frequencies of 4G/5G PAI-1 polymorphism were found between RA patients and HS. However, the 5G/5G genotype was the most frequent in both studied groups: RA (42%) and HS (44%). PAI-1 mRNA expression was slightly increased (0.67 fold) in RA patients with respect to HS (P = 0.0001). In addition, in RA patients, the 4G/4G genotype carriers showed increased PAI-1 mRNA expression (3.82 fold) versus 4G/5G and 5G/5G genotypes (P = 0.0001), whereas the sPAI-1 plasma levels did not show significant differences. Our results indicate that the 4G/5G PAI-1 polymorphism is not a marker of susceptibility in the Western Mexico. However, the 4G/4G genotype is associated with high PAI-1 mRNA expression but not with the sPAI-1 levels in RA patients.

  15. Spatio-temporal expression patterns of Wnt signaling pathway during the development of temporomandibular condylar cartilage.

    Science.gov (United States)

    Chen, Kan; Quan, Huixin; Chen, Gang; Xiao, Di

    2017-11-01

    There is a growing body of evidence supporting the involvement of the Wnt signaling pathway in various aspects of skeletal and joint development; however, it is unclear whether it is involved in the process of temporomandibular joint development. In order to clarify this issue, we examined the spatio-temporal distribution of mRNAs and proteins of the Wnt family during the formation of the mandibular condylar cartilage at the prenatal and postnatal stages. An in situ hybridization test revealed no mRNAs of β-catenin and Axin2 during early mesenchymal condensation; the ligands surveyed in this study (including Wnt-4, 5a, and 9a) were clearly detected at various ranges of expression, mainly in the condylar blastema and later distinct cartilaginous layers. Apart from β-catenin and Axin2, the Wnt family members surveyed in this study, including Lef-1, were found to be immunopositive during early chondrogenesis in the condylar cartilage at E14.5. After distinct chondrocyte layers were identified within the cartilage at E16.5, the expression of the Wnt signaling members was different and mainly restricted to proliferating cells and mineralized hypertrophic chondrocytes. In the adult mandibular condylar cartilage, the Wnt-4 mRNA, as well as the Wnt-4 and Wnt-9a proteins, was not observed. Our findings demonstrated that the Wnt signaling pathway was associated with the development of mandibular condylar cartilage. Copyright © 2017 Elsevier B.V. All rights reserved.

  16. Expression profile and function of Wnt signaling mechanisms in malignant mesothelioma cells

    International Nuclear Information System (INIS)

    Fox, Simon A.; Richards, Alex K.; Kusumah, Ivonne; Perumal, Vanathi; Bolitho, Erin M.; Mutsaers, Steven E.; Dharmarajan, Arun M.

    2013-01-01

    Highlights: •Expression profile of Wnt pathway related genes in mesothelioma cells. •Differential expression of key Wnt pathway molecules and regulators. •Wnt3a stimulated mesothelioma growth whereas sFRP4 was inhibitory. •Targeting β-Catenin can sensitise mesothelioma cells to cytotoxic drugs. -- Abstract: Malignant mesothelioma (MM) is an uncommon and particularly aggressive cancer associated with asbestos exposure, which currently presents an intractable clinical challenge. Wnt signaling has been reported to play a role in the neoplastic properties of mesothelioma cells but has not been investigated in detail in this cancer. We surveyed expression of Wnts, their receptors, and other key molecules in this pathway in well established in vitro mesothelioma models in comparison with primary mesothelial cultures. We also tested the biological response of MM cell lines to exogenous Wnt and secreted regulators, as well as targeting β-catenin. We detected frequent expression of Wnt3 and Wnt5a, as well as Fzd 2, 4 and 6. The mRNA of Wnt4, Fzd3, sFRP4, APC and axin2 were downregulated in MM relative to mesothelial cells while LEF1 was overexpressed in MM. Functionally, we observed that Wnt3a stimulated MM proliferation while sFRP4 was inhibitory. Furthermore, directly targeting β-catenin expression could sensitise MM cells to cytotoxic drugs. These results provide evidence for altered expression of a number of Wnt/Fzd signaling molecules in MM. Modulation of Wnt signaling in MM may prove a means of targeting proliferation and drug resistance in this cancer

  17. Expression profile and function of Wnt signaling mechanisms in malignant mesothelioma cells

    Energy Technology Data Exchange (ETDEWEB)

    Fox, Simon A., E-mail: s.fox@curtin.edu.au [Molecular Pharmacology Laboratory, School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA (Australia); Richards, Alex K.; Kusumah, Ivonne; Perumal, Vanathi [Molecular Pharmacology Laboratory, School of Pharmacy, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA (Australia); Bolitho, Erin M. [Western Australian Institute for Medical Research, The University of Western Australia Centre for Medical Research, Perth, WA (Australia); Mutsaers, Steven E. [Lung Institute of Western Australia, Centre for Asthma Allergy and Respiratory Research, University of Western Australia, Nedlands (Australia); Centre for Cell Therapy and Regenerative Medicine, School of Medicine and Pharmacology, University of Western Australia and Western Australian Institute for Medical Research, Nedlands (Australia); Dharmarajan, Arun M. [School of Biomedical Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA (Australia)

    2013-10-11

    Highlights: •Expression profile of Wnt pathway related genes in mesothelioma cells. •Differential expression of key Wnt pathway molecules and regulators. •Wnt3a stimulated mesothelioma growth whereas sFRP4 was inhibitory. •Targeting β-Catenin can sensitise mesothelioma cells to cytotoxic drugs. -- Abstract: Malignant mesothelioma (MM) is an uncommon and particularly aggressive cancer associated with asbestos exposure, which currently presents an intractable clinical challenge. Wnt signaling has been reported to play a role in the neoplastic properties of mesothelioma cells but has not been investigated in detail in this cancer. We surveyed expression of Wnts, their receptors, and other key molecules in this pathway in well established in vitro mesothelioma models in comparison with primary mesothelial cultures. We also tested the biological response of MM cell lines to exogenous Wnt and secreted regulators, as well as targeting β-catenin. We detected frequent expression of Wnt3 and Wnt5a, as well as Fzd 2, 4 and 6. The mRNA of Wnt4, Fzd3, sFRP4, APC and axin2 were downregulated in MM relative to mesothelial cells while LEF1 was overexpressed in MM. Functionally, we observed that Wnt3a stimulated MM proliferation while sFRP4 was inhibitory. Furthermore, directly targeting β-catenin expression could sensitise MM cells to cytotoxic drugs. These results provide evidence for altered expression of a number of Wnt/Fzd signaling molecules in MM. Modulation of Wnt signaling in MM may prove a means of targeting proliferation and drug resistance in this cancer.

  18. Transforming Growth Factor β Activation Primes Canonical Wnt Signaling Through Down-Regulation of Axin-2.

    Science.gov (United States)

    Gillespie, Justin; Ross, Rebecca L; Corinaldesi, Clarissa; Esteves, Filomena; Derrett-Smith, Emma; McDermott, Michael F; Doody, Gina M; Denton, Christopher P; Emery, Paul; Del Galdo, Francesco

    2018-02-06

    Aberrant activation of Wnt signaling has been observed in tissues from patients with systemic sclerosis (SSc). This study aimed to determine the role of transforming growth factor β (TGFβ) in driving the increased Wnt signaling, through modulation of axis inhibition protein 2 (Axin-2), a critical regulator of the Wnt canonical pathway. Canonical Wnt signaling activation was analyzed by TOPflash T cell factor/lymphoid enhancer factor promoter assays. Axin-2 was evaluated in vitro by analysis of Axin-2 primary/mature transcript expression and decay, TGFβ receptor type I (TGFβRI) blockade, small interfering RNA-mediated depletion of tristetraprolin 1, and XAV-939-mediated Axin-2 stabilization. In vivo, Axin-2 messenger RNA (mRNA) and protein expression was determined in skin and lung biopsy samples from mice that express a kinase-deficient TGFβRII specifically on fibroblasts (TβRIIΔk-fib-transgenic mice) and from littermate controls. SSc fibroblasts displayed an increased response to canonical Wnt ligands despite basal levels of Wnt signaling that were comparable to those in healthy control fibroblasts in vitro. Notably, we showed that SSc fibroblasts had reduced basal expression of Axin-2, which was caused by an endogenous TGFβ-dependent increase in Axin-2 mRNA decay. Accordingly, we observed that TGFβ decreased Axin-2 expression both in vitro in healthy control fibroblasts and in vivo in TβRIIΔk-fib-transgenic mice. Additionally, using Axin-2 gain- and loss-of-function experiments, we demonstrated that the TGFβ-induced increased response to Wnt activation characteristic of SSc fibroblasts depended on reduced bioavailability of Axin-2. This study highlights the importance of reduced bioavailability of Axin-2 in mediating the increased canonical Wnt response observed in SSc fibroblasts. This novel mechanism extends our understanding of the processes involved in Wnt/β-catenin-driven pathology and supports the rationale for targeting the TGFβ pathway

  19. Wnt/β-catenin signaling activates nephronectin expression in osteoblasts

    International Nuclear Information System (INIS)

    Ikehata, Mikiko; Yamada, Atsushi; Morimura, Naoko; Itose, Masakatsu; Suzawa, Tetsuo; Shirota, Tatsuo; Chikazu, Daichi; Kamijo, Ryutaro

    2017-01-01

    Nephronectin (Npnt), an extracellular matrix protein, is considered to play critical roles as an adhesion molecule in the development and functions of various organs and tissues, such as the kidneys and bone. In the present study, we found that Wnt3a strongly enhanced Npnt mRNA expression in osteoblast-like MC3T3-E1 cells, while it also induced an increase in Npnt gene expression in both time- and dose-dependent manners via the Wnt/β-catenin signaling pathway. These results suggest novel mechanisms for Wnt3a-induced osteoblast proliferation and cell survival via Npnt gene expression. - Highlights: • Wnt3a enhances nephronectin gene expression. • Nephronectin gene induction by Wnt3a is occurred by time- and dose-dependent manner. • Expression of nephronectin is regulated via β-catenin activation.

  20. The Protective Effects of Curcumin on Obesity-Related Glomerulopathy Are Associated with Inhibition of Wnt/β-Catenin Signaling Activation in Podocytes

    Directory of Open Access Journals (Sweden)

    Bao-li Liu

    2015-01-01

    Full Text Available The present study investigated the effects of curcumin, one of the most important active ingredients of turmeric, on podocyte injury in vitro and obesity-related glomerulopathy (ORG in vivo. Cellular experiments in vitro showed that curcumin significantly antagonized leptin-induced downregulation of the mRNA and protein expression of podocyte-associated molecules including nephrin, podocin, podoplanin, and podocalyxin. Animal experiments in vivo showed that curcumin significantly reduced the body weight, Lee’s index, abdominal fat index, urinary protein excretion, and average glomerular diameter and significantly upregulated the mRNA and protein expressions of the above podocyte-associated molecules in ORG mice. Furthermore, the experiments in vitro and in vivo both displayed that curcumin could downregulate the mRNA and protein expressions of Wnt1, Wnt2b, Wnt6, and β-catenin and upregulate the phosphorylation level of β-catenin protein in podocytes and renal tissue. In conclusion, curcumin is able to alleviate the harmful reaction of leptin on podocytes and reduce the severity of ORG. The above protective effects are associated with the inhibition of Wnt/β-catenin signaling activation in podocytes.

  1. Swimming training alleviated insulin resistance through Wnt3a/β-catenin signaling in type 2 diabetic rats

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    Qiang Yang

    2017-11-01

    Full Text Available Objective(s: Increasing evidence suggests that regular physical exercise improves type 2 diabetes mellitus (T2DM. However, the potential beneficial effects of swimming on insulin resistance and lipid disorder in T2DM, and its underlying mechanisms remain unclear. Materials and Methods: Rats were fed with high fat diet and given a low dosage of Streptozotocin (STZ to induce T2DM model, and subsequently treated with or without swimming exercise. An 8-week swimming program (30, 60 or 120 min per day, 5 days per week decreased body weight, fasting blood glucose and fasting insulin. Results: Swimming ameliorated lipid disorder, improved muscular atrophy and revealed a reduced glycogen deposit in skeletal muscles of diabetic rats. Furthermore, swimming also inhibited the activation of Wnt3a/β-catenin signaling pathway, decreased Wnt3a mRNA and protein level, upregulated GSK3β phosphorylation activity and reduced the expression of β-catenin phosphorylation in diabetic rats. Conclusion: The trend of the result suggests that swimming exercise proved to be a potent ameliorator of insulin resistancein T2DM through the modulation of Wnt3a/β-catenin pathway and therefore, could present a promising therapeutic measure towards the treatment of diabetes and its relatives.

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

    Science.gov (United States)

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

    2017-01-01

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

  3. Activation of the canonical Wnt/β-catenin pathway enhances monocyte adhesion to endothelial cells

    International Nuclear Information System (INIS)

    Lee, Dong Kun; Nathan Grantham, R.; Trachte, Aaron L.; Mannion, John D.; Wilson, Colleen L.

    2006-01-01

    Monocyte adhesion to vascular endothelium has been reported to be one of the early processes in the development of atherosclerosis. In an attempt to develop strategies to prevent or delay atherosclerosis progression, we analyzed effects of the Wnt/β-catenin signaling pathway on monocyte adhesion to various human endothelial cells. Adhesion of fluorescein-labeled monocytes to various human endothelial cells was analyzed under a fluorescent microscope. Unlike sodium chloride, lithium chloride enhanced monocyte adhesion to endothelial cells in a dose-dependent manner. We further demonstrated that inhibitors for glycogen synthase kinase (GSK)-3β or proteosome enhanced monocyte-endothelial cell adhesion. Results of semi-quantitative reverse transcriptase polymerase chain reaction (RT-PCR) indicated that activation of Wnt/β-catenin pathway did not change expression levels of mRNA for adhesion molecules. In conclusion, the canonical Wnt/β-catenin pathway enhanced monocyte-endothelial cell adhesion without changing expression levels of adhesion molecules

  4. Wnt5a-treated midbrain neural stem cells improve dopamine cell replacement therapy in parkinsonian mice

    DEFF Research Database (Denmark)

    Parish, Clare L; Castelo-Branco, Gonçalo; Rawal, Nina

    2008-01-01

    have prevented their clinical application. We present here a method for generating large numbers of DA neurons based on expanding and differentiating ventral midbrain (VM) neural stem cells/progenitors in the presence of key signals necessary for VM DA neuron development. Mouse VM neurospheres (VMNs......Dopamine (DA) cell replacement therapy in Parkinson disease (PD) can be achieved using human fetal mesencephalic tissue; however, limited tissue availability has hindered further developments. Embryonic stem cells provide a promising alternative, but poor survival and risk of teratoma formation......) expanded with FGF2, differentiated with sonic hedgehog and FGF8, and transfected with Wnt5a (VMN-Wnt5a) generated 10-fold more DA neurons than did conventional FGF2-treated VMNs. VMN-Wnt5a cells exhibited the transcriptional and biochemical profiles and intrinsic electrophysiological properties of midbrain...

  5. Regulation and regulatory role of WNT signaling in potentiating FSH action during bovine dominant follicle selection.

    Directory of Open Access Journals (Sweden)

    P S P Gupta

    Full Text Available Follicular development occurs in wave like patterns in monotocous species such as cattle and humans and is regulated by a complex interaction of gonadotropins with local intrafollicular regulatory molecules. To further elucidate potential mechanisms controlling dominant follicle selection, granulosa cell RNA harvested from F1 (largest and F2 (second largest follicles isolated at predeviation (PD and onset of diameter deviation (OD stages of the first follicular wave was subjected to preliminary RNA transcriptome analysis. Expression of numerous WNT system components was observed. Hence experiments were performed to test the hypothesis that WNT signaling modulates FSH action on granulosa cells during follicular waves. Abundance of mRNA for WNT pathway members was evaluated in granulosa cells harvested from follicles at emergence (EM, PD, OD and early dominance (ED stages of the first follicular wave. In F1 follicles, abundance of CTNNB1 and DVL1 mRNAs was higher and AXIN2 mRNA was lower at ED versus EM stages and DVL1 and FZD6 mRNAs were higher and AXIN2 mRNA was lower in F1 versus F2 follicle at the ED stage. Bovine granulosa cells were treated in vitro with increasing doses of the WNT inhibitor IWR-1+/- maximal stimulatory dose of FSH. IWR-1 treatment blocked the FSH-induced increase in granulosa cell numbers and reduced the FSH-induced increase in estradiol. Granulosa cells were also cultured in the presence or absence of FSH +/- IWR-1 and hormonal regulation of mRNA for WNT pathway members and known FSH targets determined. FSH treatment increased CYP19A1, CCND2, CTNNB1, AXIN2 and FZD6 mRNAs and the stimulatory effect on CYP19A1 mRNA was reduced by IWR-1. In contrast, FSH reduced CARTPT mRNA and IWR-1 partially reversed the inhibitory effect of FSH. Results support temporal and hormonal regulation and a potential role for WNT signaling in potentiating FSH action during dominant follicle selection.

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

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    Li Jing

    2010-05-01

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

  7. [Effect of total glucosides of paeony on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats].

    Science.gov (United States)

    Chang, Bao-Chao; Chen, Wei-Dong; Zhang, Yan; Yang, Ping; Liu, Lei; Wang, Jing

    2014-10-01

    The study is to explore the effect of total glucosides of paeony (TGP)on Wnt/β-catenin signal transduction pathway expression in kidney of diabetic rats, and discuss the protection of TGP in diabetic nephropathy and possible mechanism. Ninety male SD rats of 8 weeks age were randomly divided into normal control group (n = 10) and model group (n = 80). Rats of the normal control group were fed with regular diet, while rats of the model group were fed with high-fat high-sugar diet and 4 weeks later were given an intraperitoneal injection of 35 mg x kg(-1) streptozotocin (STZ). The successfully induced type 2 diabetic rat models were then randomly divided into DM group, three TGP (50, 100, 200 mg x kg(-1) x d(-1)) treatment group and tripterygium wilfordii glycosides (8 mg x kg(-1) x d(-1)) control group. Rats of DM group and each treatment group were given high-fat high-sugar diet. At week 14, the levels of blood sugar, 24 hour urine protein, serum creatinine and blood urea nitrogen were tested. The rats were then sacrificed. Renal pathological changes were examined. Renal tissue Wnt-1 and β-catenin expressions were detected by immunohistochemical assay. Wnt-1 mRNA and β-catenin mRNA expression was semi-quantified by RT-PCR. Wnt-1 protein and β-catenin protein expression was semi-quantified by Western blot. The Result show that Wnt-1 and β-catenin expression increased in kidney of high-fat high-sugar induced type 2 diabetic rats. Compared with diabetic group, the level of serum creatinine, blood urea nitrogen, 24 h urine protein, mean glomerular area and mean glomerular volume were decreased, renal histopathology were improved, expression of Wnt-1 and β-catenin mRNA and protein was reduced in TGP group. Tripterygium wilfordii glycosides had the similar effect. In conclusion, these results showed that Wnt/β-catenin abnormal activation in kidney of type 2 diabetic rats, TGP can improve kidney damage in diabetic rats and delay the development of diabetic

  8. Bone Mass and Strength are Significantly Improved in Mice Overexpressing Human WNT16 in Osteocytes.

    Science.gov (United States)

    Alam, Imranul; Reilly, Austin M; Alkhouli, Mohammed; Gerard-O'Riley, Rita L; Kasipathi, Charishma; Oakes, Dana K; Wright, Weston B; Acton, Dena; McQueen, Amie K; Patel, Bhavmik; Lim, Kyung-Eun; Robling, Alexander G; Econs, Michael J

    2017-04-01

    Recently, we demonstrated that osteoblast-specific overexpression of human WNT16 increased both cortical and trabecular bone mass and structure in mice. To further identify the cell-specific role of Wnt16 in bone homeostasis, we created transgenic (TG) mice overexpressing human WNT16 in osteocytes using Dmp1 promoter (Dmp1-hWNT16 TG) on C57BL/6 (B6) background. We analyzed bone phenotypes and serum bone biomarkers, performed gene expression analysis and measured dynamic bone histomorphometry in Dmp1-hWNT16 TG and wild-type (WT) mice. Compared to WT mice, Dmp1-hWNT16 TG mice exhibited significantly higher whole-body, spine and femoral aBMD, BMC and trabecular (BV/TV, Tb.N, and Tb.Th) and cortical (bone area and thickness) parameters in both male and female at 12 weeks of age. Femur stiffness and ultimate force were also significantly improved in the Dmp1-hWNT16 TG female mice, compared to sex-matched WT littermates. In addition, female Dmp1-hWNT16 TG mice displayed significantly higher MS/BS, MAR and BFR/BS compared to the WT mice. Gene expression analysis demonstrated significantly higher mRNA level of Alp in both male and female Dmp1-hWNT16 TG mice and significantly higher levels of Osteocalcin, Opg and Rankl in the male Dmp1-hWNT16 TG mice in bone tissue compared to sex-matched WT mice. These results indicate that WNT16 plays a critical role for acquisition of both cortical and trabecular bone mass and strength. Strategies designed to use WNT16 as a target for therapeutic interventions will be valuable to treat osteoporosis and other low bone mass conditions.

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

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    Jia Guo

    2017-08-01

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

  10. Therapy for BRAFi-Resistant Melanomas: Is WNT5A the Answer?

    International Nuclear Information System (INIS)

    Prasad, Chandra Prakash; Mohapatra, Purusottam; Andersson, Tommy

    2015-01-01

    In recent years, scientists have advocated the use of targeted therapies in the form of drugs that modulate genes and proteins that are directly associated with cancer progression and metastasis. Malignant melanoma is a dreadful cancer type that has been associated with the rapid dissemination of primary tumors to multiple sites, including bone, brain, liver and lungs. The discovery that approximately 40%–50% of malignant melanomas contain a mutation in BRAF at codon 600 gave scientists a new approach to tackle this disease. However, clinical studies on patients have shown that although BRAFi (BRAF inhibitors) trigger early anti-tumor responses, the majority of patients later develop resistance to the therapy. Recent studies have shown that WNT5A plays a key role in enhancing the resistance of melanoma cells to BRAFi. The focus of the current review will be on melanoma development, signaling pathways important to acquired resistance to BRAFi, and why WNT5A inhibitors are attractive candidates to be included in combinatorial therapies for melanoma

  11. TGF-β-activated kinase 1 (TAK1 signaling regulates TGF-β-induced WNT-5A expression in airway smooth muscle cells via Sp1 and β-catenin.

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    Kuldeep Kumawat

    Full Text Available WNT-5A, a key player in embryonic development and post-natal homeostasis, has been associated with a myriad of pathological conditions including malignant, fibroproliferative and inflammatory disorders. Previously, we have identified WNT-5A as a transcriptional target of TGF-β in airway smooth muscle cells and demonstrated its function as a mediator of airway remodeling. Here, we investigated the molecular mechanisms underlying TGF-β-induced WNT-5A expression. We show that TGF-β-activated kinase 1 (TAK1 is a critical mediator of WNT-5A expression as its pharmacological inhibition or siRNA-mediated silencing reduced TGF-β induction of WNT-5A. Furthermore, we show that TAK1 engages p38 and c-Jun N-terminal kinase (JNK signaling which redundantly participates in WNT-5A induction as only simultaneous, but not individual, inhibition of p38 and JNK suppressed TGF-β-induced WNT-5A expression. Remarkably, we demonstrate a central role of β-catenin in TGF-β-induced WNT-5A expression. Regulated by TAK1, β-catenin is required for WNT-5A induction as its silencing repressed WNT-5A expression whereas a constitutively active mutant augmented basal WNT-5A abundance. Furthermore, we identify Sp1 as the transcription factor for WNT-5A and demonstrate its interaction with β-catenin. We discover that Sp1 is recruited to the WNT-5A promoter in a TGF-β-induced and TAK1-regulated manner. Collectively, our findings describe a TAK1-dependent, β-catenin- and Sp1-mediated signaling cascade activated downstream of TGF-β which regulates WNT-5A induction.

  12. Genetic interaction between Lrp6 and Wnt5a during mouse development

    Czech Academy of Sciences Publication Activity Database

    Andersson, E.; Bryjová, Lenka; Biris, K.; Yamaguchi, T.P.; Arenas, E.; Bryja, Vítězslav

    2010-01-01

    Roč. 239, č. 1 (2010), s. 237-245 ISSN 1058-8388 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Wnt 5a * Lrp6 * somitogenesis Subject RIV: BO - Biophysics Impact factor: 2.864, year: 2010

  13. Hydronephrosis in the Wnt5a-ablated kidney is caused by an abnormal ureter-bladder connection.

    Science.gov (United States)

    Yun, Kangsun; Perantoni, Alan O

    The Wnt5a null mouse is a complex developmental model which, among its several posterior-localized axis defects, exhibits multiple kidney phenotypes, including duplex kidney and loss of the medullary zone. We previously reported that ablation of Wnt5a in nascent mesoderm causes duplex kidney formation as a result of aberrant development of the nephric duct and abnormal extension of intermediate mesoderm. However, these mice also display a loss of the medullary region late in gestation. We have now genetically isolated duplex kidney formation from the medullary defect by specifically targeting the progenitors for both the ureteric bud and metanephric mesenchyme. The conditional mutants fail to form a normal renal medulla but no longer exhibit duplex kidney formation. Approximately 1/3 of the mutants develop hydronephrosis in the kidneys either uni- or bilaterally when using Dll1Cre. The abnormal kidney phenotype becomes prominent at E16.5, which approximates the time when urine production begins in the mouse embryonic kidney, and is associated with a dramatic increase in apoptosis only in mutant kidneys with hydronephrosis. Methylene blue dye injection and histologic examination reveal that aberrant cell death likely results from urine toxicity due to an abnormal ureter-bladder connection. This study shows that Wnt5a is not required for development of the renal medulla and that loss of the renal medullary region in the Wnt5a-deleted kidney is caused by an abnormal ureter-bladder connection. Published by Elsevier B.V.

  14. Effects of active acromegaly on bone mRNA and microRNA expression patterns.

    Science.gov (United States)

    Belaya, Zhanna; Grebennikova, Tatiana; Melnichenko, Galina; Nikitin, Alexey; Solodovnikov, Alexander; Brovkina, Olga; Grigoriev, Andrey; Rozhinskaya, Liudmila; Lutsenko, Alexander; Dedov, Ivan

    2018-04-01

    To evaluate the response of bone to chronic long-term growth hormone (GH) and insulin-like growth factor-1 (IGF1) excess by measuring the expression of selected mRNA and microRNA (miR) in bone tissue samples of patients with active acromegaly. Case-control study. Bone tissue samples were obtained during transsphenoidal adenomectomy from the sphenoid bone (sella turcica) from 14 patients with clinically and biochemically confirmed acromegaly and 10 patients with clinically non-functioning pituitary adenoma (NFPA) matched by sex and age. Expression of genes involved in the regulation of bone remodeling was studied using quantitative polymerase chain reaction (qPCR). Of the genes involved in osteoblast and osteoclast activity, only alkaline phosphatase (ALP) mRNA was 50% downregulated in patients with acromegaly. GH excess caused increased expression of the Wnt signaling antagonists ( DKK1) and agonists ( WNT10B) and changes in the levels of miR involved in mesenchymal stem cell commitment to chondrocytes (miR-199a-5p) or adipocytes (miR-27-5p, miR-125b-5p, miR-34a-5p, miR-188-3p) P  Acromegaly had minimal effects on tested mRNAs specific to osteoblast or osteoclast function except for downregulated ALP expression. The expressions of miR known to be involved in mesenchymal stem cell commitment and downregulated TWIST1 expression suggest acromegaly has a negative effect on osteoblastogenesis. © 2018 European Society of Endocrinology.

  15. Wnt/β-catenin signaling is required for distraction osteogenesis in rats.

    Science.gov (United States)

    Wang, Xuemei; Luo, En; Bi, Ruiye; Ye, Bin; Hu, Jing; Zou, Shujuan

    2018-01-01

    The Wnt signaling pathway plays crucial roles in embryonic skeletal development and postnatal bone regeneration. However, mechanisms of Wnt signaling functioning in distraction osteogenesis (DO) haven't been well characterized. We established a DO model using Sprague-Dawley rat tibia. And a Wnt signaling blocking agent, recombinant rat Dickkopf-related protein 1 (rrDkk1), was locally applied in the distracted gap to study the role of Wnt signaling during DO process. Animals in the experimental group received rrDkk1 injections (dose = 25 μg/kg) once daily during distraction period and every third day during consolidation stage (n = 48). Animals in the control group received saline under the same injection strategy (n = 48). Animals at different time points during DO process (1, 3, 6, 12 days after distraction, 10 days and 6 weeks after consolidation) were killed and tissues in the distraction region were harvested for radiography, dual energy X-ray absorptiometry, micro-computed tomography (micro-CT), and histological analyses. Most Wnt ligands, cofactors, receptors, and antagonists were widely expressed in the distraction callus and were significantly upregulated during DO process. After rrDkk1 administration, the majority of these factors were downregulated at the mRNA level, except sFRP and GSK-3β. At the protein level, both β-catenin and Lef-1 were also suppressed by rrDkk1. In the long term, restricted bone healing was observed in the distracted callus in the rrDkk1 injection group. These findings were confirmed by histological and micro-CT analyses. Our findings suggest that Wnt signaling participates in the process of DO, and clinical therapeutic approaches of DO may do well to avoid Wnt pathway suppression.

  16. TRIB3 mediates the expression of Wnt5a and activation of nuclear factor-κB in Porphyromonas endodontalis lipopolysaccharide-treated osteoblasts.

    Science.gov (United States)

    Yu, Y; Qiu, L; Guo, J; Yang, D; Qu, L; Yu, J; Zhan, F; Xue, M; Zhong, M

    2015-08-01

    Porphyromonas endodontalis lipopolysaccharide (LPS) is considered to be correlated with the progression of bone resorption in periodontal and periapical diseases. Wnt5a has recently been implicated in inflammatory processes, but its role is unclear as a P. endodontalis LPS-induced mediator in osteoblasts. Tribbles homolog 3 (TRIB3) encodes a pseudokinase and has been linked to inflammation in certain situations. Here, we found that P. endodontalis LPS induced Wnt5a expression in a dose- and time-dependent manner and it also upregulated translocation, phosphorylation and transcriptional activity of nuclear factor-κB (NF-κB) in MC3T3-E1 cells. Bay 11-7082 blocked the translocation of NF-κB and Wnt5a expression induced by P. endodontalis LPS. Chromatin immunoprecipitation assay further established that induction of Wnt5a by P. endodontalis LPS was mediated through the NF-κB p65 subunit. Additionally, P. endodontalis LPS increased expression of TRIB3 in osteoblasts after 10 h simulated time. Overexpression of TRIB3 enhanced NF-κB phosphorylation and Wnt5a induction, whereas knockdown of TRIB3 inhibited NF-κB phosphorylation and Wnt5a expression in P. endodontalis LPS-stimulated osteoblasts. These results suggest that P. endodontalis LPS has the ability to promote the expression of Wnt5a in mouse osteoblasts, and this induction is mainly mediated by NF-κB pathway. TRIB3 seems to modulate the sustained expression of Wnt5a in osteoblasts stimulated by P. endodontalis LPS, as well as regulating NF-κB phosphorylation. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  17. 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

  18. Wnt6, Wnt10a and Wnt10b inhibit adipogenesis and stimulate osteoblastogenesis through a β-catenin-dependent mechanism

    OpenAIRE

    Cawthorn, William P.; Bree, Adam J.; Yao, Yao; Du, Baowen; Hemati, Nahid; Martinez-Santibañez, Gabriel; MacDougald, Ormond A.

    2011-01-01

    Wnt10b is an established regulator of mesenchymal stem cell (MSC) fate that inhibits adipogenesis and stimulates osteoblastogenesis, thereby impacting bone mass in vivo. However, downstream mechanisms through which Wnt10b exerts these effects are poorly understood. Moreover, whether other endogenous Wnt ligands also modulate MSC fate remains to be fully addressed. In this study, we identify Wnt6 and Wnt10a as additional Wnt family members that, like Wnt10b, are downregulated during developmen...

  19. Identification of Noncanonical Wnt Receptors Required for Wnt-3a-Induced Early Differentiation of Human Neural Stem Cells.

    Science.gov (United States)

    Bengoa-Vergniory, Nora; Gorroño-Etxebarria, Irantzu; López-Sánchez, Inmaculada; Marra, Michele; Di Chiaro, Pierluigi; Kypta, Robert

    2017-10-01

    Wnt proteins preferentially activate either β-catenin-dependent or β-catenin-independent signals, but the activity of a particular Wnt also depends on cellular context and receptor availability. We previously reported that Wnt-3a induces neural differentiation of human embryonic stem cell-derived neural stem cells (NSCs) in a β-catenin-independent manner by activating a signal involving JNK and the AP-1 family member ATF-2. Here, we report the results of a gene silencing approach to identify the Wnt receptors that mediate this response to Wnt-3a. Silencing of ROR2 increased neuronal differentiation, as measured by expression of the genes DCX, NEUROD1, and NGN1, suggesting ROR2 signals normally prevent differentiation. Silencing of the other Wnt receptors singly did not affect Wnt-3a-induced neuronal differentiation. However, pairwise silencing of ROR1 and FZD4 or FZD5 and of LRP6 and FZD4 or FZD5 inhibited neuronal differentiation, as detected by reductions in the expression of neuronal genes and immunocytochemical detection of DCX, NEUROD1 and DCX. Ectopic expression of these receptors in HEK 293 cells increased ATF2-dependent transcription. In addition, ROR1 coimmunoprecipitated with FZD4 and LRP6 in transfected HEK 293 cells and colocalized with FZD4 and with LRP6 at the cell surface of transfected L cells. Wnt-3a did not appear to affect these interactions but did alter the interactions between LRP6 and FZD4/5. Together, these observations highlight roles for ROR1, LRP6, FZD4, and FZD5 in neural stem cell differentiation and provide support for a model in which dynamic interactions among these receptors mediate Wnt-3a activation of ATF2 signaling.

  20. Wnt16 Is Associated with Age-Related Bone Loss and Estrogen Withdrawal in Murine Bone.

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    Henry Todd

    Full Text Available Genome Wide Association Studies suggest that Wnt16 is an important contributor to the mechanisms controlling bone mineral density, cortical thickness, bone strength and ultimately fracture risk. Wnt16 acts on osteoblasts and osteoclasts and, in cortical bone, is predominantly derived from osteoblasts. This led us to hypothesize that low bone mass would be associated with low levels of Wnt16 expression and that Wnt16 expression would be increased by anabolic factors, including mechanical loading. We therefore investigated Wnt16 expression in the context of ageing, mechanical loading and unloading, estrogen deficiency and replacement, and estrogen receptor α (ERα depletion. Quantitative real time PCR showed that Wnt16 mRNA expression was lower in cortical bone and marrow of aged compared to young female mice. Neither increased nor decreased (by disuse mechanical loading altered Wnt16 expression in young female mice, although Wnt16 expression was decreased following ovariectomy. Both 17β-estradiol and the Selective Estrogen Receptor Modulator Tamoxifen increased Wnt16 expression relative to ovariectomy. Wnt16 and ERβ expression were increased in female ERα-/- mice when compared to Wild Type. We also addressed potential effects of gender on Wnt16 expression and while the expression was lower in the cortical bone of aged males as in females, it was higher in male bone marrow of aged mice compared to young. In the kidney, which we used as a non-bone reference tissue, Wnt16 expression was unaffected by age in either males or females. In summary, age, and its associated bone loss, is associated with low levels of Wnt16 expression whereas bone loss associated with disuse has no effect on Wnt16 expression. In the artificially loaded mouse tibia we observed no loading-related up-regulation of Wnt16 expression but provide evidence that its expression is influenced by estrogen receptor signaling. These findings suggest that while Wnt16 is not an

  1. 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

    Full Text Available The long-term stimulation of hyperglycemia greatly increases the incidence of vascular restenosis (RS after angioplasty. Neointimal hyperplasia after vascular injury is the pathological cause of RS, but its mechanism has not been elucidated. MicroRNA-24 (miR-24 has low expression in the injured carotid arteries of diabetic rats. However, the role of miR-24 in the vascular system is unknown. In this study, we explore whether over-expression of miR-24 could attenuate neointimal formation in streptozotocin (STZ-induced diabetic rats. Adenovirus (Ad-miR-24-GFP was used to deliver the miR-24 gene to injured carotid arteries in diabetic rats. The level of neointimal hyperplasia was examined by hematoxylin-eosin (HE staining. Vascular smooth muscle cell (VSMC proliferation in the neointima was evaluated by immunostaining for proliferating cell nuclear antigen (PCNA. The mRNA levels of miR-24, PCNA, wingless-type MMTV integration site family member 4 (Wnt4, disheveled-1 (Dvl-1, β-catenin and cell cycle-associated molecules (Cyclin D1, p21 were determined by Quantitative Real-Time PCR (qRT-PCR. PCNA, Wnt4, Dvl-1, β-catenin, Cyclin D1 and p21 protein levels were measured by Western blotting analysis. STZ administration decreased plasma insulin and increased fasting blood glucose in Sprague-Dawley (SD rats. The expression of miR-24 was decreased in the carotid artery after a balloon injury in diabetic rats, and adenoviral transfection (Ad-miR-24-GFP increased the expression of miR-24. Over-expression of miR-24 suppressed VSMC proliferation and neointimal hyperplasia in diabetic rats at 14 days. Furthermore, compared with Sham group, the mRNA and protein levels of PCNA, Wnt4, Dvl-1, β-catenin, and Cyclin D1 were strikingly up-regulated in the carotid arteries of diabetic rats after a balloon injury. Interestingly, up-regulation of miR-24 significantly reduced the mRNA and protein levels of these above molecules. In contrast, the change trend in p21 mRNA

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

    Science.gov (United States)

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

    2018-02-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-07-15

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

  4. Wnt-1 Signaling in Mammary Carcinogenesis

    Science.gov (United States)

    2000-04-01

    and the notochord (4), Wnt-5A/LRP6 or LRP6 (higher doses) alone induced trunk axis duplication with muscle and neural tissues but lacking head or the... notochord (Fig. lb). It remains unclear whether this is due to quantitative or qualitative differences between Wnt-5a/LRP6 and Wnt-5a/hFz5 co...2 ng) or Wnt-5a (20 pg) plus LRP6 (100 pg) induced trunk axis duplication lacking head and the notochord . Top: the whole embryo phenotype at stage 40

  5. Expression of WNT genes in cervical cancer-derived cells: Implication of WNT7A in cell proliferation and migration

    International Nuclear Information System (INIS)

    Ramos-Solano, Moisés; Meza-Canales, Ivan D.; Torres-Reyes, Luis A.; Alvarez-Zavala, Monserrat

    2015-01-01

    According to the multifactorial model of cervical cancer (CC) causation, it is now recognized that other modifications, in addition to Human papillomavirus (HPV) infection, are necessary for the development of this neoplasia. Among these, it has been proposed that a dysregulation of the WNT pathway might favor malignant progression of HPV-immortalized keratinocytes. The aim of this study was to identify components of the WNT pathway differentially expressed in CC vs. non-tumorigenic, but immortalized human keratinocytes. Interestingly, WNT7A expression was found strongly downregulated in cell lines and biopsies derived from CC. Restoration of WNT7A in CC-derived cell lines using a lentiviral gene delivery system or after adding a recombinant human protein decreases cell proliferation. Likewise, WNT7A silencing in non-tumorigenic cells markedly accelerates proliferation. Decreased WNT7A expression was due to hypermethylation at particular CpG sites. To our knowledge, this is the first study reporting reduced WNT7A levels in CC-derived cells and that ectopic WNT7A restoration negatively affects cell proliferation and migration. - Highlights: • WNT7A is expressed in normal keratinocytes or cervical cells without lesion. • WNT7A is significantly reduced in cervical cancer-derived cells. • Restoration of WNT7A expression in HeLa decreases proliferation and cell migration. • Silencing of WNT7A in HaCaT induces an increased proliferation and migration rate. • Decreased WNT7A expression in this model is due to hypermethylation

  6. Expression of WNT genes in cervical cancer-derived cells: Implication of WNT7A in cell proliferation and migration

    Energy Technology Data Exchange (ETDEWEB)

    Ramos-Solano, Moisés, E-mail: mrsolano84@gmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Meza-Canales, Ivan D., E-mail: imezacanales@ice.mpg.de [Department of Molecular Ecology, Max Planck Institute for Chemical Ecology, 07745 Jena (Germany); Torres-Reyes, Luis A., E-mail: torres_reyes_88@hotmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); Alvarez-Zavala, Monserrat, E-mail: monse_belan@hotmail.com [División de Inmunología, Centro de Investigación Biomédica de Occidente (CIBO)-Instituto Mexicano del Seguro Social (IMSS), Guadalajara, Jalisco (Mexico); Programa de Doctorado en Ciencias Biomédica, Centro Universitario de Ciencias de la Salud (CUCS), Universidad de Guadalajara, Guadalajara, Jalisco (Mexico); and others

    2015-07-01

    According to the multifactorial model of cervical cancer (CC) causation, it is now recognized that other modifications, in addition to Human papillomavirus (HPV) infection, are necessary for the development of this neoplasia. Among these, it has been proposed that a dysregulation of the WNT pathway might favor malignant progression of HPV-immortalized keratinocytes. The aim of this study was to identify components of the WNT pathway differentially expressed in CC vs. non-tumorigenic, but immortalized human keratinocytes. Interestingly, WNT7A expression was found strongly downregulated in cell lines and biopsies derived from CC. Restoration of WNT7A in CC-derived cell lines using a lentiviral gene delivery system or after adding a recombinant human protein decreases cell proliferation. Likewise, WNT7A silencing in non-tumorigenic cells markedly accelerates proliferation. Decreased WNT7A expression was due to hypermethylation at particular CpG sites. To our knowledge, this is the first study reporting reduced WNT7A levels in CC-derived cells and that ectopic WNT7A restoration negatively affects cell proliferation and migration. - Highlights: • WNT7A is expressed in normal keratinocytes or cervical cells without lesion. • WNT7A is significantly reduced in cervical cancer-derived cells. • Restoration of WNT7A expression in HeLa decreases proliferation and cell migration. • Silencing of WNT7A in HaCaT induces an increased proliferation and migration rate. • Decreased WNT7A expression in this model is due to hypermethylation.

  7. Roles of circulating WNT-signaling proteins and WNT-inhibitors in human adiposity, insulin resistance, insulin secretion, and inflammation.

    Science.gov (United States)

    Almario, R U; Karakas, S E

    2015-02-01

    Wingless-type MMTV integration site family member (WNT) signaling and WNT-inhibitors have been implicated in regulation of adipogenesis, insulin resistance, pancreatic function, and inflammation. Our goal was to determine serum proteins involved in WNT signaling (WNT5 and WISP2) and WNT inhibition (SFRP4 and SFRP5) as they relate to obesity, serum adipokines, insulin resistance, insulin secretion, and inflammation in humans. Study population comprised 57 insulin resistant women with polycystic ovary syndrome (PCOS) and 27 reference women. In a cross-sectional study, blood samples were obtained at fasting, during oral, and frequently sampled intravenous glucose tolerance tests. Serum WNT5, WISP2, and SFRP4 concentrations did not differ between PCOS vs. reference women. Serum WNT5 correlated inversely with weight both in PCOS and reference women, and correlated directly with insulin response during oral glucose tolerance test in PCOS women. Serum WISP2 correlated directly with fatty acid binding protein 4. Serum SFRP5 did not differ between obese (n=32) vs. nonobese (n=25) PCOS women, but reference women had lower SFRP5 (pPCOS groups). Serum SFRP5 correlated inversely with IL-1β, TNF-α, cholesterol, and apoprotein B. These findings demonstrated that WNT5 correlated inversely with adiposity and directly with insulin response, and the WNT-inhibitor SFRP5 may be anti-inflammatory. Better understanding of the role of WNT signaling in obesity, insulin resistance, insulin secretion, lipoprotein metabolism, and inflammation is important for prevention and treatment of metabolic syndrome, diabetes and cardiovascular disease. © Georg Thieme Verlag KG Stuttgart · New York.

  8. TC-1 (c8orf4) enhances aggressive biologic behavior in lung cancer through the Wnt/β-catenin pathway.

    Science.gov (United States)

    Su, Kai; Huang, Lijun; Li, Wenhai; Yan, Xiaolong; Li, Xiaofei; Zhang, Zhipei; Jin, Faguang; Lei, Jie; Ba, Guangzhen; Liu, Boya; Wang, Xiaoping; Wang, Yunjie

    2013-11-01

    The thyroid cancer-1 (TC-1) or c8orf4 gene encodes a 106-residue naturally disordered protein that has been found to be associated with thyroid, gastric, and breast cancer. A recent study has indicated that the protein functions as a positive regulator in the Wnt/β-catenin signaling pathway in human breast cancer. However, no research has been done in the area of lung cancer. Therefore, the goal of the present study was to confirm the relationship among TC-1, lung cancer, and the Wnt/β-catenin signaling pathway. The expression of TC-1 was immunohistochemically examined in 147 patients with non-small-cell lung cancer. TC-1-overexpressed and silenced A549 cells were infected using lentivirus and MTT cell proliferation analysis, and Matrigel invasion assays and scratch-wound assays were performed to confirm the biologic behavioral changes in different A549 cell subsets. The Wnt/β-catenin signaling pathway, key gene β-catenin, target genes of vascular endothelial growth factor, cyclin D1, matrix metalloproteinase-7, c-myc, and survivin were tested at the mRNA and protein level. TC-1 was detected in 97 of the 147 non-small-cell lung cancer primary tumor specimens, and its expression correlated with the TNM stage and regional lymph node metastasis (P cell line. Furthermore, expression of TC-1 protein affected the Wnt/β-catenin signaling pathway's downstream genes, such as vascular endothelial growth factor and matrix metalloproteinase-7, at the mRNA and protein level. TC-1 expression is associated with aggressive biologic behavior in lung cancer and might coordinate with the Wnt/β-catenin pathway as a positive upstream regulator that induces these behaviors. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Wnt3 and Gata4 regulate axon regeneration in adult mouse DRG neurons.

    Science.gov (United States)

    Duan, Run-Shan; Liu, Pei-Pei; Xi, Feng; Wang, Wei-Hua; Tang, Gang-Bin; Wang, Rui-Ying; Saijilafu; Liu, Chang-Mei

    2018-05-05

    Neurons in the adult central nervous system (CNS) have a poor intrinsic axon growth potential after injury, but the underlying mechanisms are largely unknown. Wingless-related mouse mammary tumor virus integration site (WNT) family members regulate neural stem cell proliferation, axon tract and forebrain development in the nervous system. Here we report that Wnt3 is an important modulator of axon regeneration. Downregulation or overexpression of Wnt3 in adult dorsal root ganglion (DRG) neurons enhances or inhibits their axon regeneration ability respectively in vitro and in vivo. Especially, we show that Wnt3 modulates axon regeneration by repressing mRNA translation of the important transcription factor Gata4 via binding to the three prime untranslated region (3'UTR). Downregulation of Gata4 could restore the phenotype exhibited by Wnt3 downregulation in DRG neurons. Taken together, these data indicate that Wnt3 is a key intrinsic regulator of axon growth ability of the nervous system. Copyright © 2018 Elsevier Inc. All rights reserved.

  10. LGR5 is expressed by Ewing sarcoma and potentiates Wnt/β-catenin signaling

    Directory of Open Access Journals (Sweden)

    Christopher A Scannell

    2013-04-01

    Full Text Available Ewing sarcoma (ES is an aggressive bone and soft tissue tumor of putative stem cell origin that predominantly occurs in children and young adults. Although most patients with localized ES can be cured with intensive therapy, the clinical course is variable and up to one third of patients relapse following initial remission. Unfortunately, little is yet known about the biologic features that distinguish low-risk from high-risk disease or the mechanisms of ES disease progression. Recent reports have suggested that putative cancer stem cells exist in ES and may contribute to an aggressive phenotype. The cell surface receptor LGR5 (leucine-rich repeat-containing G-protein coupled receptor 5 is a somatic stem cell marker that functions as an oncogene in several human cancers, most notably colorectal carcinoma. LGR5 is a receptor for the R-spondin (RSPO family of ligands and RSPO-mediated activation of LGR5 potentiates Wnt/β-catenin signaling, contributing to stem cell proliferation and self-renewal. Given its presumed stem cell origin, we investigated whether LGR5 contributes to ES pathogenesis. We found that LGR5 is expressed by ES and that its expression is relatively increased in cells and tumors that display a more aggressive phenotype. In particular, LGR5 expression was increased in putative cancer stem cells. We also found that neural crest-derived stem cells express LGR5, raising the possibility that expression of LGR5 may be a feature of ES cells of origin. LGR5-high ES cells showed nuclear localization of ß-catenin and robust activation of TCF-reporter activity when exposed to Wnt ligand and this was potentiated by RSPO. However, modulation of LGR5 or exposure to RSPO had no impact on proliferation confirming that Wnt/ β-catenin signaling in ES cells does not recapitulate signaling in epithelial cells. Together these studies show that the RSPO-LGR5-WNT- β-catenin axis is present and active in ES and may contribute to tumor pathogenesis.

  11. Localization of Bmp-4, Shh and Wnt-5a transcripts during early mice tooth development by in situ hybridization Localização de transcritos de Bmp-4, Shh e Wnt-5a durante as fases iniciais do desenvolvimento dentário de camundongos por hibridização in situ

    Directory of Open Access Journals (Sweden)

    Fábio Daumas Nunes

    2007-06-01

    Full Text Available A comparative nonisotopic in situ hybridization (ISH analysis was carried out for the detection of Bmp-4, Shh and Wnt-5a transcripts during mice odontogenesis from initiation to cap stage. Bmp-4 was expressed early in the epithelium and then in the underlying mesenchyme. Shh expression was seen in the odontogenic epithelial lining thickening, being stronger in the enamel knot area, during the cap stage. Wnt-5a transcripts were expressed only in the mesenchyme during the initiation, bud and cap stages, with strong expression in the dental mesenchyme during the bud stage. The present results showed that Bmp-4, Shh and Wnt-5a are expressed since the very early stages of tooth development, and they suggest that the Wnt-5a gene is expressed in different cell populations than Bmp-4 and Shh.No presente trabalho, realizou-se uma análise comparativa não isotópica por hibridização in situ a fim de se detectar a presença de transcritos de Bmp-4, Shh e Wnt-5a durante as fases iniciais da odontogênese em camundongos, desde a iniciação até o estágio de capuz. No estágio de iniciação, observou-se expressão precoce de Bmp-4 no epitélio e no mesênquima subjacente, enquanto que a expressão de Shh ocorreu durante o estágio de capuz, na região de espessamento do revestimento epitelial odontogênico, tornando-se mais intensa na área de nó do esmalte. Os transcritos de Wnt-5a foram expressos somente no mesênquima durante os estágios de iniciação, botão e capuz, com intenso sinal na região no mesênquima na fase de botão. Estes resultados mostraram que Bmp-4, Shh e Wnt-5a são expressos desde os estágios mais precoces do desenvolvimento dentário, sugerindo que o gene Wnt-5a seja expresso em populações celulares distintas daquelas que expressam Bmp-4 e Shh.

  12. Cirmtuzumab inhibits Wnt5a-induced Rac1 activation in chronic lymphocytic leukemia treated with ibrutinib.

    Science.gov (United States)

    Yu, J; Chen, L; Cui, B; Wu, Christina; Choi, M Y; Chen, Y; Zhang, L; Rassenti, L Z; Widhopf Ii, G F; Kipps, T J

    2017-06-01

    Signaling via the B cell receptor (BCR) plays an important role in the pathogenesis and progression of chronic lymphocytic leukemia (CLL). This is underscored by the clinical effectiveness of ibrutinib, an inhibitor of Bruton's tyrosine kinase (BTK) that can block BCR-signaling. However, ibrutinib cannot induce complete responses (CR) or durable remissions without continued therapy, suggesting alternative pathways also contribute to CLL growth/survival that are independent of BCR-signaling. ROR1 is a receptor for Wnt5a, which can promote activation of Rac1 to enhance CLL-cell proliferation and survival. In this study, we found that CLL cells of patients treated with ibrutinib had activated Rac1. Moreover, Wnt5a could induce Rac1 activation and enhance proliferation of CLL cells treated with ibrutinib at concentrations that were effective in completely inhibiting BTK and BCR-signaling. Wnt5a-induced Rac1 activation could be blocked by cirmtuzumab (UC-961), an anti-ROR1 mAb. We found that treatment with cirmtuzumab and ibrutinib was significantly more effective than treatment with either agent alone in clearing leukemia cells in vivo. This study indicates that cirmtuzumab may enhance the activity of ibrutinib in the treatment of patients with CLL or other ROR1 + B-cell malignancies.

  13. The Wnt receptor, Lrp5, is expressed by mouse mammary stem cells and is required to maintain the basal lineage.

    Directory of Open Access Journals (Sweden)

    Nisha M Badders

    2009-08-01

    Full Text Available Ectopic Wnt signaling induces increased stem/progenitor cell activity in the mouse mammary gland, followed by tumor development. The Wnt signaling receptors, Lrp5/6, are uniquely required for canonical Wnt activity. Previous data has shown that the absence of Lrp5 confers resistance to Wnt1-induced tumor development.Here, we show that all basal mammary cells express Lrp5, and co-express Lrp6 in a similar fashion. Though Wnt dependent transcription of key target genes is relatively unchanged in mammary epithelial cell cultures, the absence of Lrp5 specifically depletes adult regenerative stem cell activity (to less than 1%. Stem cell activity can be enriched by >200 fold (over 80% of activity, based on high Lrp5 expression alone. Though Lrp5 null glands have apparent normal function, the basal lineage is relatively reduced (from 42% basal/total epithelial cells to 22% and Lrp5-/- mammary epithelial cells show enhanced expression of senescence-associated markers in vitro, as measured by expression of p16(Ink4a and TA-p63.This is the first single biomarker that has been demonstrated to be functionally involved in stem cell maintenance. Together, these results demonstrate that Wnt signaling through Lrp5 is an important component of normal mammary stem cell function.

  14. A Wnt1 regulated Frizzled-1/β-Catenin signaling pathway as a candidate regulatory circuit controlling mesencephalic dopaminergic neuron-astrocyte crosstalk: Therapeutical relevance for neuron survival and neuroprotection

    Directory of Open Access Journals (Sweden)

    Pluchino Stefano

    2011-07-01

    Full Text Available Abstract Background Dopamine-synthesizing (dopaminergic, DA neurons in the ventral midbrain (VM constitute a pivotal neuronal population controlling motor behaviors, cognitive and affective brain functions, which generation critically relies on the activation of Wingless-type MMTV integration site (Wnt/β-catenin pathway in their progenitors. In Parkinson's disease, DA cell bodies within the substantia nigra pars compacta (SNpc progressively degenerate, with causes and mechanisms poorly understood. Emerging evidence suggests that Wnt signaling via Frizzled (Fzd receptors may play a role in different degenerative states, but little is known about Wnt signaling in the adult midbrain. Using in vitro and in vivo model systems of DA degeneration, along with functional studies in both intact and SN lesioned mice, we herein highlight an intrinsic Wnt1/Fzd-1/β-catenin tone critically contributing to the survival and protection of adult midbrain DA neurons. Results In vitro experiments identifie Fzd-1 receptor expression at a mRNA and protein levels in dopamine transporter (DAT expressing neurons, and demonstrate the ability of exogenous Wnt1 to exert robust neuroprotective effects against Caspase-3 activation, the loss of tyrosine hydroxylase-positive (TH+ neurons and [3H] dopamine uptake induced by different DA-specific insults, including serum and growth factor deprivation, 6-hydroxydopamine and MPTP/MPP+. Co-culture of DA neurons with midbrain astrocytes phenocopies Wnt1 neuroprotective effects, whereas RNA interference-mediated knockdown of Wnt1 in midbrain astrocytes markedly reduces astrocyte-induced TH+ neuroprotection. Likewise, silencing β-catenin mRNA or knocking down Fzd-1 receptor expression in mesencephalic neurons counteract astrocyte-induced TH+ neuroprotection. In vivo experiments document Fzd-1 co-localization with TH+ neurons within the intact SNpc and blockade of Fzd/β-catenin signaling by unilateral infusion of a Fzd

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

    International Nuclear Information System (INIS)

    Snow, Grace E; Kasper, Allison C; Busch, Alexander M; Schwarz, Elisabeth; Ewings, Katherine E; Bee, Thomas; Spinella, Michael J; Dmitrovsky, Ethan; Freemantle, Sarah J

    2009-01-01

    Testicular germ cell tumors (TGCTs) are classified as seminonas or non-seminomas of which a major subset is embryonal carcinoma (EC) that can differentiate into diverse tissues. The pluripotent nature of human ECs resembles that of embryonic stem (ES) cells. Many Wnt signalling species are regulated during differentiation of TGCT-derived EC cells. This study comprehensively investigated expression profiles of Wnt signalling components regulated during induced differentiation of EC cells and explored the role of key components in maintaining pluripotency. Human embryonal carcinoma cells were stably infected with a lentiviral construct carrying a canonical Wnt responsive reporter to assess Wnt signalling activity following induced differentiation. Cells were differentiated with all-trans retinoic acid (RA) or by targeted repression of pluripotency factor, POU5F1. A Wnt pathway real-time-PCR array was used to evaluate changes in gene expression as cells differentiated. Highlighted Wnt pathway genes were then specifically repressed using siRNA or stable shRNA and transfected EC cells were assessed for proliferation, differentiation status and levels of core pluripotency genes. Canonical Wnt signalling activity was low basally in undifferentiated EC cells, but substantially increased with induced differentiation. Wnt pathway gene expression levels were compared during induced differentiation and many components were altered including ligands (WNT2B), receptors (FZD5, FZD6, FZD10), secreted inhibitors (SFRP4, SFRP1), and other effectors of Wnt signalling (FRAT2, DAAM1, PITX2, Porcupine). Independent repression of FZD5, FZD7 and WNT5A using transient as well as stable methods of RNA interference (RNAi) inhibited cell growth of pluripotent NT2/D1 human EC cells, but did not appreciably induce differentiation or repress key pluripotency genes. Silencing of FZD7 gave the greatest growth suppression in all human EC cell lines tested including NT2/D1, NT2/D1-R1, Tera-1 and 833

  16. Upregulation of Klotho potentially inhibits pulmonary vascular remodeling by blocking the activation of the Wnt signaling pathway in rats with PM2.5-induced pulmonary arterial hypertension.

    Science.gov (United States)

    Cong, Lu-Hong; Du, Shi-Yu; Wu, Yi-Na; Liu, Ying; Li, Tao; Wang, Hui; Li, Gang; Duan, Jun

    2018-01-30

    We evaluated the effects of Klotho on pulmonary vascular remodeling and cell proliferation and apoptosis in rat models with PM2.5-induced pulmonary arterial hypertension (PAH) via the Wnt signaling pathway. After establishing rat models of PM2.5-induced PAH, these Sprague-Dawley male rats were randomized into control and model groups. Cells extracted from the model rats were sub-categorized into different groups. Activation of Wnt/β-catenin signaling transcription factor was detected by a TOPFlash/FOPFlash assay. A serial of experiment was conducted to identify the mechanism of Klotho on PHA via the Wnt signaling pathway. VEGF levels and PaCO 2 content were higher in the model group, while PaO 2, NO 2 - /NO 3 - content and Klotho level was lower compared to the control group. In comparison to the control group, the model group had decreased Klotho and Bax levels, and elevated Wnt-1, β-catenin, bcl-2, survivin, and PCNA expression, VEGF, IL-6, TNF-α, TNF-β1, and bFGF levels, as well as the percentage of pulmonary artery ring contraction. The Klotho vector, DKK-1 and DKK-1 + Klotho vector groups exhibited reduced cell proliferation, luciferase activity, and the expression of Wnt-1, β-catenin, bcl-2, survivin, and PCNA, as well as shortened S phase compared with the blank and NC groups. Compared with the Klotho vector and DKK-1 groups, the DKK-1 + Klotho vector groups had reduced cell proliferation, luciferase activity, and the expression of Wnt-1, β-catenin, bcl-2, survivin, and PCNA, as well as a shortened S phase. Conclusively, Klotho inhibits pulmonary vascular remodeling by inactivation of Wnt signaling pathway. © 2018 Wiley Periodicals, Inc.

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

    International Nuclear Information System (INIS)

    Inadera, Hidekuni; Shimomura, Akiko; Tachibana, Shinjiro

    2009-01-01

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

  18. MicroRNA-200b Suppresses Arsenic-transformed Cell Migration by Targeting Protein Kinase Cα and Wnt5b-Protein Kinase Cα Positive Feedback Loop and Inhibiting Rac1 Activation*

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-01-01

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3′-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. PMID:24841200

  19. MicroRNA-200b suppresses arsenic-transformed cell migration by targeting protein kinase Cα and Wnt5b-protein kinase Cα positive feedback loop and inhibiting Rac1 activation.

    Science.gov (United States)

    Wang, Zhishan; Humphries, Brock; Xiao, Hua; Jiang, Yiguo; Yang, Chengfeng

    2014-06-27

    MicroRNA-200b (miR-200b) is a member of miR-200 family that has been found to inhibit cell migration and cancer metastasis; however, the underlying mechanism is not well understood. We previously reported that miR-200 expression is depleted in arsenic-transformed human bronchial epithelial cells with highly migratory and invasive characteristics, whereas stably re-expressing miR-200b strongly suppresses arsenic-transformed cell migration. This study was performed to investigate how miR-200b inhibits arsenic-transformed cell migration. We found that protein kinase Cα (PKCα) is significantly up-regulated in arsenic-transformed cells. Combining bioinformatics analysis with PKCα 3'-untranslated region vector luciferase reporter assays, we showed that PKCα is a direct target of miR-200b. Inhibiting PKCα activity or knocking down PKCα expression drastically reduced cell migration, phenocoping the inhibitory effect of overexpressing miR-200b. In contrast, forced expression of PKCα in miR-200b overexpressing cells impaired the inhibitory effect of miR-200b on cell migration. In addition, we also found a positive feedback loop between Wnt5b and PKCα in arsenic-transformed cells. Knocking down Wnt5b expression reduced phospho-PKC levels and cell migration; and knocking down PKCα expression decreased Wnt5b level and cell migration. Moreover, forced expression of PKCα increased Wnt5b and phospho-PKC levels and cell migration. Further mechanistic studies revealed that Rac1 is highly activated in arsenic-transformed cells and stably expressing miR-200b abolishes Rac1 activation changing actin cytoskeleton organization. Manipulating PKCα or Wnt5b expression levels significantly altered the level of active Rac1. Together, these findings indicate that miR-200b suppresses arsenic-transformed cell migration by targeting PKCα and Wnt5b-PKCα positive feedback loop and subsequently inhibiting Rac1 activation. © 2014 by The American Society for Biochemistry and Molecular

  20. Wnt/beta-Catenin Signaling and Small Molecule Inhibitors

    Science.gov (United States)

    Voronkov, Andrey; Krauss, Stefan

    2012-01-01

    Wnt/β-catenin signaling is a branch of a functional network that dates back to the first metazoans and it is involved in a broad range of biological systems including stem cells, embryonic development and adult organs. Deregulation of components involved in Wnt/β-catenin signaling has been implicated in a wide spectrum of diseases including a number of cancers and degenerative diseases. The key mediator of Wnt signaling, β-catenin, serves several cellular functions. It functions in a dynamic mode at multiple cellular locations, including the plasma membrane, where β-catenin contributes to the stabilization of intercellular adhesive complexes, the cytoplasm where β-catenin levels are regulated and the nucleus where β-catenin is involved in transcriptional regulation and chromatin interactions. Central effectors of β-catenin levels are a family of cysteine-rich secreted glycoproteins, known as Wnt morphogens. Through the LRP5/6-Frizzled receptor complex, Wnts regulate the location and activity of the destruction complex and consequently intracellular β- catenin levels. However, β-catenin levels and their effects on transcriptional programs are also influenced by multiple other factors including hypoxia, inflammation, hepatocyte growth factor-mediated signaling, and the cell adhesion molecule E-cadherin. The broad implications of Wnt/β-catenin signaling in development, in the adult body and in disease render the pathway a prime target for pharmacological research and development. The intricate regulation of β-catenin at its various locations provides alternative points for therapeutic interventions. PMID:23016862

  1. Mechanisms of Wnt signaling and control.

    Science.gov (United States)

    Grainger, Stephanie; Willert, Karl

    2018-03-30

    The Wnt signaling pathway is a highly conserved system that regulates complex biological processes across all metazoan species. At the cellular level, secreted Wnt proteins serve to break symmetry and provide cells with positional information that is critical to the patterning of the entire body plan. At the organismal level, Wnt signals are employed to orchestrate fundamental developmental processes, including the specification of the anterior-posterior body axis, induction of the primitive streak and ensuing gastrulation movements, and the generation of cell and tissue diversity. Wnt functions extend into adulthood where they regulate stem cell behavior, tissue homeostasis, and damage repair. Disruption of Wnt signaling activity during embryonic development or in adults results in a spectrum of abnormalities and diseases, including cancer. The molecular mechanisms that underlie the myriad of Wnt-regulated biological effects have been the subject of intense research for over three decades. This review is intended to summarize our current understanding of how Wnt signals are generated and interpreted. This article is categorized under: Biological Mechanisms > Cell Signaling Developmental Biology > Stem Cell Biology and Regeneration. © 2018 Wiley Periodicals, Inc.

  2. Ascorbic acid alters cell fate commitment of human neural progenitors in a WNT/β-catenin/ROS signaling dependent manner.

    Science.gov (United States)

    Rharass, Tareck; Lantow, Margareta; Gbankoto, Adam; Weiss, Dieter G; Panáková, Daniela; Lucas, Stéphanie

    2017-10-16

    increased WNT/β-catenin signaling output i.e. MYC mRNA level, whereas RuR attenuated it. Moreover, AA improved neurogenesis as much as LiCl as both TUBB3-positive cell yield and TUBB3 mRNA level increased, while NAC or RuR attenuated neurogenesis. Markedly, the neurogenesis outputs between the short and the full treatment with either NAC or AA were found unchanged, supporting our model that neuronal yield is altered by events taking place at the early phase of differentiation. Our findings demonstrate that AA treatment elevates ROS metabolism in a non-lethal manner prior to the NPCs commitment to their neuronal fate. Such effect stimulates the redox-sensitive DVL2 activation and WNT/β-catenin signaling response that would enhance the ensuing neuronal cell differentiation.

  3. 5-hydroxytryptamine1C receptor density and mRNA levels in choroid plexus epithelial cells after treatment with mianserin and (-)-1-(4-bromo-2,5-dimethoxyphenyl)-2-aminopropane.

    Science.gov (United States)

    Barker, E L; Sanders-Bush, E

    1993-10-01

    5-Hydroxytryptamine (5HT)1C and 5HT2 receptors display paradoxical down-regulation when exposed to receptor antagonists in vivo, a property that is unique to these two subtypes of serotonin (5HT) receptors. Because of the absence of cell culture model systems, the mechanisms involved in this paradoxical down-regulation have been difficult to explore. The present study focuses on the regulation of 5HT1C receptors in primary cultures of rat choroid plexus epithelial cells. Exposure of the epithelial cell cultures to 100 nM mianserin, a receptor antagonist, or (-)-1-(4-bromo-2,5-dimethoxyphenyl)-2-aminopropane, an agonist, for 72 hr caused a loss of 5HT1C receptor binding sites, as determined by [3H]mesulergine binding to crude membrane preparations. No significant changes in Kd values were observed. Neither the agonist nor antagonist caused a significant change in binding sites after 24 hr. A solution hybridization assay was used to determine whether the down-regulation by mianserin or (-)-1-(4-bromo-2,5-dimethoxyphenyl)-2-aminopropane was accompanied by a decrease in the steady state level of 5HT1C receptor mRNA. These studies showed that neither treatment caused an alteration in the levels of 5HT1C receptor mRNA. Thus, it is possible to reproduce the in vivo regulatory effects of drugs on 5HT1C receptors in choroid plexus epithelial cells in culture, including the atypical down-regulation by receptor antagonists. Using this cell culture model system, indirect transynaptic effects and decreases in receptor mRNA levels have been ruled out as mechanisms accounting for the down-regulation.

  4. Wnt-mediated down-regulation of Sp1 target genes by a transcriptional repressor Sp5

    Czech Academy of Sciences Publication Activity Database

    Fujimura, Naoko; Vacík, Tomáš; Machoň, Ondřej; Vlček, Čestmír; Scalabrin, S.; Speth, M.; Diep, D.; Krauss, S.; Kozmik, Zbyněk

    2007-01-01

    Roč. 282, č. 2 (2007), s. 1225-1237 ISSN 0021-9258 Institutional research plan: CEZ:AV0Z50520514 Keywords : Wnt -mediated signaling * Sp5 transcription factor * Sp1 target genes Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 5.581, year: 2007

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

    Science.gov (United States)

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

    2017-03-01

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

  6. Niclosamide suppresses hepatoma cell proliferation via the Wnt pathway

    Directory of Open Access Journals (Sweden)

    Tomizawa M

    2013-11-01

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

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

    Directory of Open Access Journals (Sweden)

    Ezzatollah Fathi

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

  8. WNT-mediated Modulation of Bone Metabolism: Implications for WNT Targeting to Treat Extraskeletal Disorders.

    Science.gov (United States)

    Bullock, Whitney A; Robling, Alexander G

    2017-10-01

    The WNT-signaling pathway is involved in cellular and tissue functions that control such diverse processes as body axis patterning, cellular proliferation, differentiation, and life span. The long list of molecules that can participate or modify WNT signaling makes this pathway one of the most complex in cell biology. In bone tissues, WNT signaling is required for proper skeletal development, and human mutations in various components of the cascade revealed insights into pharmacologic targeting that can be harnessed to improve skeletal health. In particular, mutations in genes that code for the WNT-signaling inhibitor sclerostin or the WNT coreceptor lipoprotein receptor-related protein 5 have highlighted the potential therapeutic value of recapitulating those effects in patients with low bone mass. A constant challenge in this area is selectively modifying WNT components in the tissue of interest, as WNT has manifold effects in nearly every tissue.

  9. Importance of a 5′ Stem-Loop for Longevity of papA mRNA in Escherichia coli

    OpenAIRE

    Bricker, Angela L.; Belasco, Joel G.

    1999-01-01

    High-level expression of the major pilus subunit (PapA) of uropathogenic strains of Escherichia coli results in part from the unusually long lifetime of the mRNA that encodes this protein. Here we report that the longevity of papA mRNA derives in large measure from the protection afforded by its 5′ untranslated region. This papA RNA segment can prolong the lifetime of an otherwise short-lived mRNA to which it is fused. In vivo alkylation studies indicate that, in its natural milieu, the papA ...

  10. miR-375-3p negatively regulates osteogenesis by targeting and decreasing the expression levels of LRP5 and β-catenin.

    Directory of Open Access Journals (Sweden)

    Tianhao Sun

    Full Text Available Wnt signaling pathways are essential for bone formation. Previous studies showed that Wnt signaling pathways were regulated by miR-375. Thus, we aim to explore whether miR-375 could affect osteogenesis. In the present study, we investigated the roles of miR-375 and its downstream targets. Firstly, we revealed that miR-375-3p negatively modulated osteogenesis by suppressing positive regulators of osteogenesis and promoting negative regulators of osteogenesis. In addition, the results of TUNEL cell apoptosis assay showed that miR-375-3p induced MC3T3-E1 cell apoptosis. Secondly, miR-375-3p targeted low-density lipoprotein receptor-related protein 5 (LRP5, a co-receptor of the Wnt signaling pathways, and β-catenin as determined by luciferase activity assay, and it decreased the expression levels of LRP5 and β-catenin. Thirdly, the decline of protein levels of β-catenin was determined by immunocytochemistry and immunofluorescence. Finally, silence of LRP5 in osteoblast precursor cells resulted in diminished cell viability and cell proliferation as detected by WST-1-based colorimetric assay. Additionally, all the parameters including the relative bone volume from μCT measurement suggested that LRP5 knockout in mice resulted in a looser and worse-connected trabeculae. The mRNA levels of important negative modulators relating to osteogenesis increased after the functions of LRP5 were blocked in mice. Last but not least, the expression levels of LRP5 increased during the osteogenesis of MC3T3-E1, while the levels of β-catenin decreased in bone tissues from osteoporotic patients with vertebral compression fractures. In conclusion, we revealed miR-375-3p negatively regulated osteogenesis by targeting LRP5 and β-catenin. In addition, loss of functions of LRP5 damaged bone formation in vivo. Clinically, miR-375-3p and its targets might be used as diagnostic biomarkers for osteoporosis and might be also as novel therapeutic agents in osteoporosis

  11. Pulsed low-level infrared laser alters mRNA levels from muscle repair genes dependent on power output in Wistar rats

    Science.gov (United States)

    Trajano, L. A. S. N.; Trajano, E. T. L.; Thomé, A. M. C.; Sergio, L. P. S.; Mencalha, A. L.; Stumbo, A. C.; Fonseca, A. S.

    2017-10-01

    Satellite cells are present in skeletal muscle functioning in the repair and regeneration of muscle injury. Activation of these cells depends on the expression of myogenic factor 5 (Myf5), myogenic determination factor 1(MyoD), myogenic regulatory factor 4 (MRF4), myogenin (MyoG), paired box transcription factors 3 (Pax3), and 7 (Pax7). Low-level laser irradiation accelerates the repair of muscle injuries. However, data from the expression of myogenic factors have been controversial. Furthermore, the effects of different laser beam powers on the repair of muscle injuries have been not evaluated. The aim of this study was to evaluate the effects of low-level infrared laser at different powers and in pulsed emission mode on the expression of myogenic regulatory factors and on Pax3 and Pax7 in injured skeletal muscle from Wistar rats. Animals that underwent cryoinjury were divided into three groups: injury, injury laser 25 Mw, and injury laser 75 mW. Low-level infrared laser irradiation (904 nm, 3 J cm-2, 5 kHz) was carried out at 25 and 75 mW. After euthanasia, skeletal muscle samples were withdrawn and the total RNA was extracted for the evaluation of mRNA levels from the MyoD, MyoG, MRF4, Myf5, Pax3, and Pax7 gene. Pax 7 mRNA levels did not alter, but Pax3 mRNA levels increased in the injured and laser-irradiated group at 25 mW. MyoD, MyoG, and MYf5 mRNA levels increased in the injured and laser-irradiated animals at both powers, and MRF4 mRNA levels decreased in the injured and laser-irradiated group at 75 mW. In conclusion, exposure to pulsed low-level infrared laser, by power-dependent effect, could accelerate the muscle repair process altering mRNA levels from paired box transcription factors and myogenic regulatory factors.

  12. High basal Wnt signaling is further induced by PI3K/mTor inhibition but sensitive to cSRC inhibition in mammary carcinoma cell lines with HER2/3 overexpression

    International Nuclear Information System (INIS)

    Timmermans-Sprang, Elpetra P. M.; Gracanin, Ana; Mol, Jan A.

    2015-01-01

    Elevated basal, ligand-independent, Wnt signaling in some canine breast cancer cells is not caused by classical mutations in APC, β-Catenin or GSK3β but, at least partially, by enhanced LEF1 expression. We examined the expression and function of EGFR/HER-regulated pathways on the ligand-independent Wnt signaling. Twelve canine mammary tumor cell lines with previously reported differential basal Wnt activity were used. The expression levels of genes related to EGF-signaling were analyzed by cluster analysis. Cell lines with a combined overexpression of EGF-related genes and enhanced basal Wnt activity were treated with PI3K/mTor or cSRC inhibitors or transfected with a construct expressing wild-type PTEN. Subsequently, effects were measured on Wnt activity, cell proliferation, gene expression and protein level. High basal Wnt/LEF1 activity was associated with overexpression of HER2/3, ID1, ID2, RAC1 and HSP90 together with low to absent cMET and PTEN mRNA expression, suggesting a connection between Wnt- and HER-signaling pathways. Inhibition of the HER-regulated PI3K/mTor pathway using the dual PI3K/mTor inhibitor BEZ235 or the mTor inhibitor Everolimus® resulted in reduced cell proliferation. In the cell line with high basal Wnt activity, however, an unexpected further increased Wnt activity was found that could be greatly reduced after inhibition of the HER-regulated cSRC activity. Inhibition of the PI3K/mTor pathway was associated with enhanced expression of β-Catenin, Axin2, MUC1, cMET, EGFR and HER2 and a somewhat increased β-Catenin protein content, whereas cSRC inhibition was associated with slightly enhanced HER3 and SLUG mRNA expression. A high protein expression of HER3 was found only in a cell line with high basal Wnt activity. High basal Wnt activity in some mammary cancer cell lines is associated with overexpression of HER-receptor related genes and HER3 protein, and the absence of PTEN. Inhibition of the PI3K/mTor pathway further stimulated

  13. R-spondin1/Wnt-enhanced Ascl2 autoregulation controls the self-renewal of colorectal cancer progenitor cells.

    Science.gov (United States)

    Ye, Jun; Liu, Shanxi; Shang, Yangyang; Chen, Haoyuan; Wang, Rongquan

    2018-06-25

    The Wnt signaling pathway controls stem cell identity in the intestinal epithelium and cancer stem cells (CSCs). The transcription factor Ascl2 (Wnt target gene) is fate decider of intestinal cryptic stem cells and colon cancer stem cells. It is unclear how Wnt signaling is translated into Ascl2 expression and keeping the self-renewal of CRC progenitor cells. We showed that the exogenous Ascl2 in colorectal cancer (CRC) cells activated the endogenous Ascl2 expression via a direct autoactivatory loop, including Ascl2 binding to its own promoter and further transcriptional activation. Higher Ascl2 expression in human CRC cancerous tissues led to greater enrichment in Ascl2 immunoprecipitated DNA within the Ascl2 promoter in the CRC cancerous sample than the peri-cancerous mucosa. Ascl2 binding to its own promoter and inducing further transcriptional activation of the Ascl2 gene was predominant in the CD133 + CD44 + CRC population. R-spondin1/Wnt activated Ascl2 expression dose-dependently in the CD133 + CD44 + CRC population, but not in the CD133 - CD44 - CRC population, which was caused by differences in Ascl2 autoregulation under R-spondin1/Wnt activation. R-spondin1/Wnt treatment in the CD133 + CD44 + or CRC CD133 - CD44 - populations exerted a different pattern of stemness maintenance, which was defined by alterations of the mRNA levels of stemness-associated genes, the protein expression levels (Bmi1, C-myc, Oct-4 and Nanog) and tumorsphere formation. The results indicated that Ascl2 autoregulation formed a transcriptional switch that was enhanced by Wnt signaling in the CD133 + CD44 + CRC population, thus conferring their self-renewal.

  14. The classification of mRNA expression levels by the phosphorylation state of RNAPII CTD based on a combined genome-wide approach

    Directory of Open Access Journals (Sweden)

    Tachibana Taro

    2011-10-01

    Full Text Available Abstract Background Cellular function is regulated by the balance of stringently regulated amounts of mRNA. Previous reports revealed that RNA polymerase II (RNAPII, which transcribes mRNA, can be classified into the pausing state and the active transcription state according to the phosphorylation state of RPB1, the catalytic subunit of RNAPII. However, genome-wide association between mRNA expression level and the phosphorylation state of RNAPII is unclear. While the functional importance of pausing genes is clear, such as in mouse Embryonic Stem cells for differentiation, understanding this association is critical for distinguishing pausing genes from active transcribing genes in expression profiling data, such as microarrays and RNAseq. Therefore, we examined the correlation between the phosphorylation of RNAPII and mRNA expression levels using a combined analysis by ChIPseq and RNAseq. Results We first performed a precise quantitative measurement of mRNA by performing an optimized calculation in RNAseq. We then visualized the recruitment of various phosphorylated RNAPIIs, such as Ser2P and Ser5P. A combined analysis using optimized RNAseq and ChIPseq for phosphorylated RNAPII revealed that mRNA levels correlate with the various phosphorylation states of RNAPII. Conclusions We demonstrated that the amount of mRNA is precisely reflected by the phased phosphorylation of Ser2 and Ser5. In particular, even the most "pausing" genes, for which only Ser5 is phosphorylated, were detectable at a certain level of mRNA. Our analysis indicated that the complexity of quantitative regulation of mRNA levels could be classified into three categories according to the phosphorylation state of RNAPII.

  15. Cross-talk between insulin and Wnt signaling in preadipocytes

    DEFF Research Database (Denmark)

    Palsgaard, Jane; Emanuelli, Brice; Winnay, Jonathon N

    2012-01-01

    and appears to be due to an inducible interaction between LRP5 and the insulin receptor as demonstrated by co-immunoprecipitation. These data demonstrate that Wnt and insulin signaling pathways exhibit cross-talk at multiple levels. Wnt induces phosphorylation of Akt, ERK1/2, and GSK3β, and this is dependent...... and LRP6 and with and without knock-out of insulin and IGF-1 receptors. We find that Wnt stimulation leads to phosphorylation of insulin signaling key mediators, including Akt, GSK3β, and ERK1/2, although with a lower fold stimulation and slower time course than observed for insulin. These Wnt effects...... are insulin/IGF-1 receptor-dependent and are lost in insulin/IGF-1 receptor double knock-out cells. Conversely, in LRP5 knockdown preadipocytes, insulin-induced phosphorylation of IRS1, Akt, GSK3β, and ERK1/2 is highly reduced. This effect is specific to insulin, as compared with IGF-1, stimulation...

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

    Science.gov (United States)

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

    2011-10-04

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

  17. Surrogate Wnt agonists that phenocopy canonical Wnt and β-catenin signalling

    NARCIS (Netherlands)

    Janda, Claudia Y.; Dang, Luke T.; You, Changjiang; Chang, Junlei; Lau, Wim De; Zhong, Zhendong A.; Yan, Kelley S.; Marecic, Owen; Siepe, DIrk; Li, Xingnan; Moody, James D.; Williams, Bart O.; Clevers, Hans; Piehler, Jacob; Baker, David; Kuo, Calvin J.; Garcia, K. Christopher

    2017-01-01

    Wnt proteins modulate cell proliferation and differentiation and the self-renewal of stem cells by inducing β-catenin-dependent signalling through the Wnt receptor frizzled (FZD) and the co-receptors LRP5 and LRP6 to regulate cell fate decisions and the growth and repair of several tissues. The 19

  18. Wnt Signaling in Cancer Stem Cell Biology

    NARCIS (Netherlands)

    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

  19. The balance of TCF7L2 variants with differential activities in Wnt-signaling is regulated by lithium in a GSK3β-independent manner

    International Nuclear Information System (INIS)

    Struewing, Ian; Boyechko, Tania; Barnett, Corey; Beildeck, Marcy; Byers, Stephen W.; Mao, Catherine D.

    2010-01-01

    Research highlights: → Identification of a novel effect of lithium on the expression of TCF7L2 RNA isoforms and protein variants. → The extent of lithium-induced TCF7L2 form switch mirrors cell responsiveness to Wnt/β-catenin signaling. → Demonstration that lithium has dual GSK3β-dependent and -independent effects on TCF7L2 expression. → Demonstration that TCF7L2 expression is repressed by the transcriptionally active TCF7L2E form. → Evidence for a lithium-induced de-repression mechanism of TCF7L2 expression via TCF7L2 variant switch. -- Abstract: TCF7L2 transcription factor is a downstream effector of the canonical Wnt/β-catenin signaling, which controls cell fate and homeostasis. However, the complexity of TCF7L2 expression with numerous mRNA isoforms coding for proteins with distinct N- and C-termini allows variability in TCF7L2 functions and regulations. Here, we show that although TCF7L2 mRNA isoforms distinguish fetal, immortalized and adult differentiated endothelial cells (EC), they cannot explain the lack of significant β-catenin/TCF7 activities in ECs. Lithium, a Wnt-signaling activator, increases TCF7L2 mRNA levels and induces an RNA isoform switch favoring the expression of TCF7L2-short forms lacking the C-termini domains. Although the latter occurs in different cell types, its extent depends on the overall increase of TCF7L2 transcription, which correlates with cell responsiveness to Wnt/β-catenin signaling. While GSK3β down-regulation increases TCF7L2 expression, there is no concomitant change in TCF7L2 mRNA isoforms, which demonstrate the dual effects of lithium on TCF7L2 expression via a GSK3β-dependent up-regulation and a GSK3β-independent modulation of RNA splicing. TCF7L2E-long forms display a repressor activity on TCF7L2-promoter reporters and lithium induces a decrease of the endogenous TCF7L2 forms bound to native TCF7L2-promoter chromatin at two novel distal TCF7-binding sites. Altogether our data reveal a lithium

  20. Wnt5a regulates ventral midbrain morphogenesis and the development of A9-A10 dopaminergic cells in vivo

    Czech Academy of Sciences Publication Activity Database

    Andersson, E.R.; Prakash, N.; Čajánek, L.; Minina, E.; Bryja, Vítězslav; Bryjová, Lenka; Yamaguchi, T.P.; Hall, A.C.; Wurst, W.; Arenas, E.

    2008-01-01

    Roč. 3, č. 10 (2008), s. 1-14 E-ISSN 1932-6203 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Wnt 5a deficient mouse * ventral midbrain * planar cell polarity Subject RIV: BO - Biophysics

  1. wnt3a but not wnt11 supports self-renewal of embryonic stem cells

    International Nuclear Information System (INIS)

    Singla, Dinender K.; Schneider, David J.; LeWinter, Martin M.; Sobel, Burton E.

    2006-01-01

    wnt proteins (wnts) promote both differentiation of midbrain dopaminergic cells and self-renewal of haematopoietic stem cells. Mouse embryonic stem (ES) cells can be maintained and self-renew on mouse feeder cell layers or in media containing leukemia inhibitory factor (LIF). However, the effects of wnts on ES cells self-renewal and differentiation are not clearly understood. In the present study, we found that conditioned medium prepared from L cells expressing wnt3a can replace feeder cell layers and medium containing LIF in maintaining ES cells in the proliferation without differentiation (self-renewal) state. By contrast, conditioned medium from NIH3T3 cells expressing wnt11 did not. Alkaline phosphatase staining and compact colony formation were used as criteria of cells being in the undifferentiated state. ES cells maintained in medium conditioned by Wnt3a expressing cells underwent freezing and thawing while maintaining properties seen with LIF maintained ES cells. Purified wnt3a did not maintain self-renewal of ES cells for prolonged intervals. Thus, other factors in the medium conditioned by wnt3a expressing cells may have contributed to maintenance of ES cells in a self-renewal state. Pluripotency of ES cells was determined with the use of embryoid bodies in vitro. PD98059, a MEK specific inhibitor, promoted the growth of undifferentiated ES cells maintained in conditioned medium from wnt3a expressing cells. By contrast, the P38 MAPK inhibitor SB230580 did not, suggesting a role for the MEK pathway in self-renewal and differentiation of ES cells maintained in the wnt3a cell conditioned medium. Thus, our results show that conditioned medium from wnt3a but not wnt11 expressing cells can maintain ES cells in self-renewal and in a pluripotent state

  2. Diphtheria Toxin-Induced Cell Death Triggers Wnt-Dependent Hair Cell Regeneration in Neonatal Mice.

    Science.gov (United States)

    Hu, Lingxiang; Lu, Jingrong; Chiang, Hao; Wu, Hao; Edge, Albert S B; Shi, Fuxin

    2016-09-07

    Cochlear hair cells (HCs), the sensory cells that respond to sound, do not regenerate after damage in adult mammals, and their loss is a major cause of deafness. Here we show that HC regeneration in newborn mouse ears occurred spontaneously when the original cells were ablated by treatment with diphtheria toxin (DT) in ears that had been engineered to overexpress the DT receptor, but was not detectable when HCs were ablated in vivo by the aminoglycoside antibiotic neomycin. A variety of Wnts (Wnt1, Wnt2, Wnt2b, Wnt4, Wnt5a, Wnt7b, Wnt9a, Wnt9b, and Wnt11) and Wnt pathway component Krm2 were upregulated after DT damage. Nuclear β-catenin was upregulated in HCs and supporting cells of the DT-damaged cochlea. Pharmacological inhibition of Wnt decreased spontaneous regeneration, confirming a role of Wnt signaling in HC regeneration. Inhibition of Notch signaling further potentiated supporting cell proliferation and HC differentiation that occurred spontaneously. The absence of new HCs in the neomycin ears was correlated to less robust Wnt pathway activation, but the ears subjected to neomycin treatment nonetheless showed increased cell division and HC differentiation after subsequent forced upregulation of β-catenin. These studies suggest, first, that Wnt signaling plays a key role in regeneration, and, second, that the outcome of a regenerative response to damage in the newborn cochlea is determined by reaching a threshold level of Wnt signaling rather than its complete absence or presence. Sensory HCs of the inner ear do not regenerate in the adult, and their loss is a major cause of deafness. We found that HCs regenerated spontaneously in the newborn mouse after diphtheria toxin (DT)-induced, but not neomycin-induced, HC death. Regeneration depended on activation of Wnt signaling, and regeneration in DT-treated ears correlated to a higher level of Wnt activation than occurred in nonregenerating neomycin-treated ears. This is significant because insufficient

  3. Wnt signaling in ovarian development inhibits Sf1 activation of Sox9 via the Tesco enhancer.

    Science.gov (United States)

    Bernard, Pascal; Ryan, Janelle; Sim, Helena; Czech, Daniel P; Sinclair, Andrew H; Koopman, Peter; Harley, Vincent R

    2012-02-01

    Genome analysis of patients with disorders of sex development, and gain- and loss-of-function studies in mice indicate that gonadal development is regulated by opposing signals. In females, the Wnt/β-catenin canonical pathway blocks testicular differentiation by repressing the expression of the Sertoli cell-specific gene Sox9 by an unknown mechanism. Using cell and embryonic gonad culture models, we show that activation of the Wnt/β-catenin pathway inhibits the expression of Sox9 and Amh, whereas mRNA and protein levels of Sry and steroidogenic factor 1 (Sf1), two key transcriptional regulators of Sox9, are not altered. Ectopic activation of Wnt/β-catenin signaling in male gonads led to a loss of Sf1 binding to the Tesco enhancer and absent Sox9 expression that we also observed in wild-type ovaries. Moreover, ectopic Wnt/β-catenin signaling induced the expression of the female somatic cell markers, Bmp2 and Rspo1, as a likely consequence of Sox9 loss. Wnt/β-catenin signaling in XY gonads did not, however, affect gene expression of the steroidogenic Leydig cell Sf1 target gene, Cyp11a1, or Sf1 binding to the Cyp11a1 promoter. Our data support a model in ovary development whereby activation of β-catenin prevents Sf1 binding to the Sox9 enhancer, thereby inhibiting Sox9 expression and Sertoli cell differentiation.

  4. Wnt and the Wnt signaling pathway in bone development and disease

    Science.gov (United States)

    Wang, Yiping; Li, Yi-Ping; Paulson, Christie; Shao, Jian-Zhong; Zhang, Xiaoling; Wu, Mengrui; Chen, Wei

    2014-01-01

    Wnt signaling affects both bone modeling, which occurs during development, and bone remodeling, which is a lifelong process involving tissue renewal. Wnt signals are especially known to affect the differentiation of osteoblasts. In this review, we summarize recent advances in understanding the mechanisms of Wnt signaling, which is divided into two major branches: the canonical pathway and the noncanonical pathway. The canonical pathway is also called the Wnt/β-catenin pathway. There are two major noncanonical pathways: the Wnt-planar cell polarity pathway (Wnt-PCP pathway) and the Wnt-calcium pathway (Wnt-Ca2+ pathway). This review also discusses how Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists affect both the bone modeling and bone remodeling processes. We also review the role of Wnt ligands, receptors, intracellular effectors, transcription factors, and antagonists in bone as demonstrated in mouse models. Disrupted Wnt signaling is linked to several bone diseases, including osteoporosis, van Buchem disease, and sclerosteosis. Studying the mechanism of Wnt signaling and its interactions with other signaling pathways in bone will provide potential therapeutic targets to treat these bone diseases. PMID:24389191

  5. CXXC5 is a novel BMP4-regulated modulator of Wnt signaling in neural stem cells

    Czech Academy of Sciences Publication Activity Database

    Andersson, T.; Södersten, E.; Duckworth, J.K.; Cascante, A.; Fritz, N.; Sacchetti, P.; Červenka, I.; Bryja, Vítězslav; Hermanson, O.

    2008-01-01

    Roč. 284, č. 6 (2008), s. 3672-3681 ISSN 0021-9258 Grant - others:GA AV ČR(CZ) KJB501630801 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : Wnt signaling * CXXC5 * neural stem cells Subject RIV: BO - Biophysics Impact factor: 5.520, year: 2008

  6. Yi Qi Qing Re Gao-containing serum inhibits lipopolysaccharide-induced rat mesangial cell proliferation by suppressing the Wnt pathway and TGF-β1 expression.

    Science.gov (United States)

    Yang, Liping; Sun, Xueyan; Zhan, Yongli; Liu, Huijie; Wen, Yumin; Mao, Huimin; Dong, X I; Li, Ping

    2016-04-01

    The aim of the present study was to investigate the effect of Yi Qi Qing Re Gao-containing serum (YQ-S) on rat mesangial cell (MC) proliferation and to investigate the underlying mechanism. MCs were divided into the control, lipopolysaccharide (LPS)-stimulated, YQ-S and fosinopril-containing serum (For-S) groups, and cultured for 48 h. An MTT assay was used to evaluate the proliferation of MCs. In addition, reverse transcription-quantitative polymerase chain reaction and western blot analysis were conducted to detect the expression levels of Wnt4, β-catenin and transforming growth factor (TGF)-β1 in MCs. The results indicated that YQ-S inhibited LPS-induced MC proliferation. The Wnt4 and TGF-β1 mRNA expression levels were reduced in the YQ-S group (P<0.01 or P<0.05). Furthermore, the Wnt4, β-catenin and TGF-β1 protein expression levels were suppressed in the YQ-S group (P<0.01 or P<0.05). Therefore, YQ-S appears to inhibit MC proliferation, and its mechanism may involve the inhibition of the Wnt signaling pathway and downregulation of TGF-β1 expression.

  7. The extracellular domain of Lrp5/6 inhibits noncanonical Wnt signaling in vivo

    Czech Academy of Sciences Publication Activity Database

    Bryja, Vítězslav; Andersson, E.R.; Schambony, A.; Esner, M.; Bryjová, Lenka; Biris, K.K.; Hall, A.C.; Kraft, B.; Čajánek, L.; Yamaguchi, T.P.; Buckingham, M.; Arenas, E.

    2009-01-01

    Roč. 20, č. 3 (2009), s. 924-936 ISSN 1059-1524 Institutional research plan: CEZ:AV0Z50040507; CEZ:AV0Z50040702 Keywords : non-canonical Wnt signaling * Lrp5/6 * mouse Subject RIV: BO - Biophysics Impact factor: 5.979, year: 2009

  8. 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.

  9. Concurrent Transient Activation of Wnt/β-Catenin Pathway Prevents Radiation Damage to Salivary Glands

    International Nuclear Information System (INIS)

    Hai Bo; Yang Zhenhua; Shangguan Lei; Zhao Yanqiu; Boyer, Arthur; Liu, Fei

    2012-01-01

    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/β-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/β-catenin pathway as physical damage did. Transient expression of Wnt1 in basal epithelia significantly activated the Wnt/β-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/β-catenin pathway could prevent radiation-induced salivary gland dysfunction.

  10. The Wnt-target gene Dlk-1 is regulated by the Prmt5-associated factor Copr5 during adipogenic conversion

    Directory of Open Access Journals (Sweden)

    Conception Paul

    2015-02-01

    Full Text Available Protein arginine methyl transferase 5 (Prmt5 regulates various differentiation processes, including adipogenesis. Here, we investigated adipogenic conversion in cells and mice in which Copr5, a Prmt5- and histone-binding protein, was genetically invalidated. Compared to control littermates, the retroperitoneal white adipose tissue (WAT of Copr5 KO mice was slightly but significantly reduced between 8 and 16 week/old and contained fewer and larger adipocytes. Moreover, the adipogenic conversion of Copr5 KO embryoid bodies (EB and of primary embryo fibroblasts (Mefs was markedly delayed. Differential transcriptomic analysis identified Copr5 as a negative regulator of the Dlk-1 gene, a Wnt target gene involved in the control of adipocyte progenitors cell fate. Dlk-1 expression was upregulated in Copr5 KO Mefs and the Vascular Stromal Fraction (VSF of Copr5 KO WAT. Chromatin immunoprecipitation (ChIP show that the ablation of Copr5 has impaired both the recruitment of Prmt5 and β-catenin at the Dlk-1 promoter. Overall, our data suggest that Copr5 is involved in the transcriptional control exerted by the Wnt pathway on early steps of adipogenesis.

  11. Distinctive Roles of Canonical and Noncanonical Wnt Signaling in Human Embryonic Cardiomyocyte Development

    Directory of Open Access Journals (Sweden)

    Silvia Mazzotta

    2016-10-01

    Full Text Available Wnt signaling is a key regulator of vertebrate heart development; however, specific roles for human cardiomyocyte development remain uncertain. Here we use human embryonic stem cells (hESCs to analyze systematically in human cardiomyocyte development the expression of endogenous Wnt signaling components, monitor pathway activity, and dissect stage-specific requirements for canonical and noncanonical Wnt signaling mechanisms using small-molecule inhibitors. Our analysis suggests that WNT3 and WNT8A, via FZD7 and canonical signaling, regulate BRACHYURY expression and mesoderm induction; that WNT5A/5B, via ROR2 and noncanonical signaling, regulate MESP1 expression and cardiovascular development; and that later in development WNT2, WNT5A/5B, and WNT11, via FZD4 and FZD6, regulate functional cardiomyocyte differentiation via noncanonical Wnt signaling. Our findings confirm in human development previously proposed roles for canonical Wnt signaling in sequential stages of vertebrate cardiomyogenesis, and identify more precise roles for noncanonical signaling and for individual Wnt signal and Wnt receptor genes in human cardiomyocyte development.

  12. Wnt inhibition promotes vascular specification of embryonic cardiac progenitors.

    Science.gov (United States)

    Reichman, David E; Park, Laura; Man, Limor; Redmond, David; Chao, Kenny; Harvey, Richard P; Taketo, Makoto M; Rosenwaks, Zev; James, Daylon

    2018-01-08

    Several studies have demonstrated a multiphasic role for Wnt signaling during embryonic cardiogenesis and developed protocols that enrich for cardiac derivatives during in vitro differentiation of human pluripotent stem cells (hPSCs). However, few studies have investigated the role of Wnt signaling in the specification of cardiac progenitor cells (CPCs) toward downstream fates. Using transgenic mice and hPSCs, we tracked endothelial cells (ECs) that originated from CPCs expressing NKX2.5. Analysis of EC-fated CPCs at discrete phenotypic milestones during hPSC differentiation identified reduced Wnt activity as a hallmark of EC specification, and the enforced activation or inhibition of Wnt reduced or increased, respectively, the degree of vascular commitment within the CPC population during both hPSC differentiation and mouse embryogenesis. Wnt5a, which has been shown to exert an inhibitory influence on Wnt signaling during cardiac development, was dynamically expressed during vascular commitment of hPSC-derived CPCs, and ectopic Wnt5a promoted vascular specification of hPSC-derived and mouse embryonic CPCs. © 2018. Published by The Company of Biologists Ltd.

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

    Directory of Open Access Journals (Sweden)

    Sara Cheleschi

    2017-01-01

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

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

    Science.gov (United States)

    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

  15. Salidroside Protection Against Oxidative Stress Injury Through the Wnt/β-Catenin Signaling Pathway in Rats with Parkinson’s Disease

    Directory of Open Access Journals (Sweden)

    Dong-Mei Wu

    2018-04-01

    Full Text Available Background/Aims: Parkinson’s disease (PD is the second most common neurodegenerative disease after Alzheimer’s disease, and recent studies suggested that oxidative stress (OS contributes to the cascade that leads to dopamine cell degeneration in PD. In this study, we hypothesized that salidroside (SDS offers protection against OS injury in 6-hydroxydopamine (6-OHDA unilaterally lesioned rats as well as the underlying mechanism. Methods: SDS and LiCl (activators of the Wnt/β-catenin signaling pathway administration alone and in combination with 6-OHDA injection in rats was performed 3 days before modeling for 17 consecutive days to verify the regulatory mechanism by which SDS affects the Wnt/β-catenin signaling pathway as well as to evaluate the protective effect of SDS on PD in relation to OS in vivo. In addition, pheochromocytoma 12 (PC12 cells were incubated with 10 µmol/L SDS or LiCl alone or with both in combination for 1 h followed by a 24-h incubation with 100 µmol/L 6-OHDA to obtain in vitro data. Results: In vivo the administration of LiCl was found to ameliorate behavioral deficits and dopaminergic neuron loss; increase superoxide dismutase (SOA activity, glutathione peroxidase (GSH-Px levels, and glycogen synthase kinase 3β phosphorylation (GSK-3β-Ser9; reduce malondialdehyde (MDA accumulation in the striatum and the GSK-3β mRNA level; as well as elevate β-catenin and cyclinD1 mRNA and protein levels in 6-OHDA-injected rats. This SDS treatment regimen was found to strengthen the beneficial effect of LiCl on 6-OHDA-injected rats. In vitro LiCl treatment decreased the toxicity of 6-OHDA on PC12 cells and prevented apoptosis. Additionally, LiCl treatment increased SOA activity, GSH-Px levels, and GSK-3β-Ser9 phosphorylation; decreased MDA accumulation in the striatum and GSK-3β mRNA levels; as well as increased β-catenin and cyclinD1 mRNA and protein levels in 6-OHDA-treated PC12 cells. Additionally, SDS treatment increased

  16. CCL5 promotes proliferation of MCF-7 cells through mTOR-dependent mRNA translation

    International Nuclear Information System (INIS)

    Murooka, Thomas T.; Rahbar, Ramtin; Fish, Eleanor N.

    2009-01-01

    The proliferative capacity of cancer cells is regulated by factors intrinsic to cancer cells and by secreted factors in the microenvironment. Here, we investigated the proto-oncogenic potential of the chemokine receptor, CCR5, in MCF-7 breast cancer cell lines. At physiological levels, CCL5, a ligand for CCR5, enhanced MCF-7.CCR5 proliferation. Treatment with the mTOR inhibitor, rapamycin, inhibited this CCL5-inducible proliferation. Because mTOR directly modulates mRNA translation, we investigated whether CCL5 activation of CCR5 leads to increased translation. CCL5 induced the formation of the eIF4F translation initiation complex through an mTOR-dependent process. Indeed, CCL5 initiated mRNA translation, shown by an increase in high-molecular-weight polysomes. Specifically, we show that CCL5 mediated a rapid up-regulation of protein expression for cyclin D1, c-Myc and Dad-1, without affecting their mRNA levels. Taken together, we describe a mechanism by which CCL5 influences translation of rapamycin-sensitive mRNAs, thereby providing CCR5-positive breast cancer cells with a proliferative advantage.

  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. Pharmacologic Activation of Wnt Signaling by Lithium Normalizes Retinal Vasculature in a Murine Model of Familial Exudative Vitreoretinopathy.

    Science.gov (United States)

    Wang, Zhongxiao; Liu, Chi-Hsiu; Sun, Ye; Gong, Yan; Favazza, Tara L; Morss, Peyton C; Saba, Nicholas J; Fredrick, Thomas W; He, Xi; Akula, James D; Chen, Jing

    2016-10-01

    Familial exudative vitreoretinopathy (FEVR) is characterized by delayed retinal vascular development, which promotes hypoxia-induced pathologic vessels. In severe cases FEVR may lead to retinal detachment and visual impairment. Genetic studies linked FEVR with mutations in Wnt signaling ligand or receptors, including low-density lipoprotein receptor-related protein 5 (LRP5) gene. Here, we investigated ocular pathologies in a Lrp5 knockout (Lrp5(-/-)) mouse model of FEVR and explored whether treatment with a pharmacologic Wnt activator lithium could bypass the genetic defects, thereby protecting against eye pathologies. Lrp5(-/-) mice displayed significantly delayed retinal vascular development, absence of deep layer retinal vessels, leading to increased levels of vascular endothelial growth factor and subsequent pathologic glomeruloid vessels, as well as decreased inner retinal visual function. Lithium treatment in Lrp5(-/-) mice significantly restored the delayed development of retinal vasculature and the intralaminar capillary networks, suppressed formation of pathologic glomeruloid structures, and promoted hyaloid vessel regression. Moreover, lithium treatment partially rescued inner-retinal visual function and increased retinal thickness. These protective effects of lithium were largely mediated through restoration of canonical Wnt signaling in Lrp5(-/-) retina. Lithium treatment also substantially increased vascular tubular formation in LRP5-deficient endothelial cells. These findings suggest that pharmacologic activation of Wnt signaling may help treat ocular pathologies in FEVR and potentially other defective Wnt signaling-related diseases. Copyright © 2016 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  19. WNT Signaling Is Required for Peritoneal Membrane Angiogenesis.

    Science.gov (United States)

    Padwal, Manreet Kaur; Cheng, Genyang; Liu, Limin; Boivin, Felix J; Gangji, Azim; Brimble, Kenneth Scott; Bridgewater, Darren; Margetts, Peter J

    2018-01-24

    The WNT signaling pathway is involved in wound healing and fibrosis. We evaluated the WNT signaling pathway in peritoneal membrane injury. We assessed WNT1 protein expression in the peritoneal effluents of 54 stable peritoneal dialysis (PD) patients and WNT-related gene expression in ex vivo mesothelial cell cultures from 21 PD patients. In a transforming growth factor beta (TGFB) mediated animal model of peritoneal fibrosis, we evaluated regulation of the WNT pathway and the effect of WNT inhibition on peritoneal fibrosis and angiogenesis. WNT1 and WNT2 gene expression were positively correlated with peritoneal membrane solute transport in PD patients. In the mouse peritoneum, TGFΒ-induced peritoneal fibrosis was associated with increased expression of WNT2 and WNT4. Peritoneal b-catenin protein was significantly upregulated after infection with AdTGFB along with elements of the WNT signaling pathway. Treatment with a b-catenin inhibitor (ICG-001) in mice with AdTGFB-induced peritoneal fibrosis resulted in attenuation of peritoneal angiogenesis and reduced vascular endothelial growth factor. Similar results were also observed with the WNT antagonist Dickkopf related protein (DKK) 1. In addition to this, DKK-1 blocked epithelial to mesenchymal transition and increased levels of the cell adhesion protein E-cadherin. We provide evidence that WNT signaling is active in the setting of experimental peritoneal fibrosis and WNT1 correlates with patient peritoneal membrane solute transport in PD patients. Intervention in this pathway is a possible therapy for peritoneal membrane injury.

  20. Serotonin 2A receptor mRNA levels in the neonatal dopamine-depleted rat striatum remain upregulated following suppression of serotonin hyperinnervation.

    Science.gov (United States)

    Basura, G J; Walker, P D

    1999-08-05

    Sixty days after bilateral dopamine (DA) depletion (>98%) with 6-hydroxydopamine (6-OHDA) in neonatal rats, serotonin (5-HT) content doubled and 5-HT(2A) receptor mRNA expression rose 54% within the rostral striatum. To determine if striatal 5-HT(2A) receptor mRNA upregulation is dependent on increased 5-HT levels following DA depletion, neonatal rats received dual injections of 6-OHDA and 5,7-dihydroxytryptamine (5,7-DHT) which suppressed 5-HT content by approximately 90%. In these 6-OHDA/5,7-DHT-treated rats, striatal 5-HT(2A) receptor mRNA expression was still elevated (87% above vehicle controls). Comparative analysis of 5-HT(2C) receptor mRNA expression yielded no significant changes in any experimental group. These results demonstrate that upregulated 5-HT(2A) receptor biosynthesis in the DA-depleted rat is not dependent on subsequent 5-HT hyperinnervation. Copyright 1999 Elsevier Science B.V.

  1. Tyrosine phosphorylation of LRP6 by Src and Fer inhibits Wnt/β-catenin signalling

    Science.gov (United States)

    Chen, Qing; Su, Yi; Wesslowski, Janine; Hagemann, Anja I; Ramialison, Mirana; Wittbrodt, Joachim; Scholpp, Steffen; Davidson, Gary

    2014-01-01

    Low-density lipoprotein receptor-related proteins 5 and 6 (LRP5/6) function as transmembrane receptors to transduce Wnt signals. A key mechanism for signalling is Wnt-induced serine/threonine phosphorylation at conserved PPPSPxS motifs in the LRP6 cytoplasmic domain, which promotes pathway activation. Conserved tyrosine residues are positioned close to all PPPSPxS motifs, which suggests they have a functional significance. Using a cell culture-based cDNA expression screen, we identified the non-receptor tyrosine kinases Src and Fer as novel LRP6 modifiers. Both Src and Fer associate with LRP6 and phosphorylate LRP6 directly. In contrast to the known PPPSPxS Ser/Thr kinases, tyrosine phosphorylation by Src and Fer negatively regulates LRP6-Wnt signalling. Epistatically, they function upstream of β-catenin to inhibit signalling and in agreement with a negative role in regulating LRP6, MEF cells lacking these kinases show enhanced Wnt signalling. Wnt3a treatment of cells enhances tyrosine phosphorylation of endogenous LRP6 and, mechanistically, Src reduces cell surface LRP6 levels and disrupts LRP6 signalosome formation. Interestingly, CK1γ inhibits Fer-induced LRP6 phosphorylation, suggesting a mechanism whereby CK1γ acts to de-represses inhibitory LRP6 tyrosine phosphorylation. We propose that LRP6 tyrosine phosphorylation by Src and Fer serves a negative regulatory function to prevent over-activation of Wnt signalling at the level of the Wnt receptor, LRP6. Subject Categories Membrane & Intracellular Transport; Post-translational Modifications, Proteolysis & Proteomics PMID:25391905

  2. Both canonical and non-canonical Wnt signaling independently promote stem cell growth in mammospheres.

    Directory of Open Access Journals (Sweden)

    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.

  3. Promoter methylation of Wnt-antagonists in polypoid and nonpolypoid colorectal adenomas

    International Nuclear Information System (INIS)

    Voorham, Quirinus JM; Mulder, Chris JJ; Engeland, Manon van; Meijer, Gerrit A; Steenbergen, Renske DM; Carvalho, Beatriz; Janssen, Jerry; Tijssen, Marianne; Snellenberg, Suzanne; Mongera, Sandra; Grieken, Nicole CT van; Grabsch, Heike; Kliment, Martin; Rembacken, Bjorn J

    2013-01-01

    Nonpolypoid adenomas are a subgroup of colorectal adenomas that have been associated with a more aggressive clinical behaviour compared to their polypoid counterparts. A substantial proportion of nonpolypoid and polypoid adenomas lack APC mutations, APC methylation or chromosomal loss of the APC locus on chromosome 5q, suggesting the involvement of other Wnt-pathway genes. The present study investigated promoter methylation of several Wnt-pathway antagonists in both nonpolypoid and polypoid adenomas. Quantitative methylation-specific PCR (qMSP) was used to evaluate methylation of four Wnt-antagonists, SFRP2, WIF-1, DKK3 and SOX17 in 18 normal colorectal mucosa samples, 9 colorectal cancer cell lines, 18 carcinomas, 44 nonpolypoid and 44 polypoid adenomas. Results were integrated with previously obtained data on APC mutation, methylation and chromosome 5q status from the same samples. Increased methylation of all genes was found in the majority of cell lines, adenomas and carcinomas compared to normal controls. WIF-1 and DKK3 showed a significantly lower level of methylation in nonpolypoid compared to polypoid adenomas (p < 0.01). Combining both adenoma types, a positive trend between APC mutation and both WIF-1 and DKK3 methylation was observed (p < 0.05). Methylation of Wnt-pathway antagonists represents an additional mechanism of constitutive Wnt-pathway activation in colorectal adenomas. Current results further substantiate the existence of partially alternative Wnt-pathway disruption mechanisms in nonpolypoid compared to polypoid adenomas, in line with previous observations

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

    Directory of Open Access Journals (Sweden)

    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.

  5. Wnt3a Promotes the Vasculogenic Mimicry Formation of Colon Cancer via Wnt/β-Catenin Signaling.

    Science.gov (United States)

    Qi, Lisha; Song, Wangzhao; Liu, Zhiyong; Zhao, Xiulan; Cao, Wenfeng; Sun, Baocun

    2015-08-10

    Our previous study provided evidence that non-canonical Wnt signaling is involved in regulating vasculogenic mimicry (VM) formation. However, the functions of canonical Wnt signaling in VM formation have not yet been explored. In this study, we found the presence of VM was related to colon cancer histological differentiation (p colon cancer samples showed increased Wnt3a expression (p colon cancer cells promoted the capacity to form tube-like structures in the three-dimensional (3-D) culture together with increased expression of endothelial phenotype-associated proteins such as VEGFR2 and VE-cadherin. The mouse xenograft model showed that Wnt3a-overexpressing cells grew into larger tumor masses and formed more VM than the control cells. In addition, the Wnt/β-catenin signaling antagonist Dickkopf-1(Dkk1) can reverse the capacity to form tube-like structures and can decrease the expressions of VEGFR2 and VE-cadherin in Wnt3a-overexpressing cells. Taken together, our results suggest that Wnt/β-catenin signaling is involved in VM formation in colon cancer and might contribute to the development of more accurate treatment modalities aimed at VM.

  6. Down-regulation of Wnt10a affects odontogenesis and proliferation in mesenchymal cells

    International Nuclear Information System (INIS)

    Liu, Yang; Han, Dong; Wang, Lei; Feng, Hailan

    2013-01-01

    Highlights: •Down-regulation of Wnt10a in dental mesenchymal cells impairs odontogenesis of reassociated tooth germs. •Dspp is down- and up-regulated after Wnt10a-knockdown and overexpression in dental mesenchymal cells. •Down-regulation of Wnt10a inhibits proliferation of dental mesenchymal cells. -- Abstract: The WNT10a mutation has been found in patients with abnormal odontogenesis. In mice, Wnt10a expression is found in the tooth germ, but its role has not yet been elucidated. We aimed to investigate the role of Wnt10a in odontogenesis. Mesenchymal cells of the first mandibular molar germ at the bell stage were isolated, transfected with Wnt10a SiRNA or plasmid, and reassociated with epithelial part of the molar germ. Scrambled SiRNA or empty vector was used in the control group. The reassociated tooth germs were transplanted into mice subrenal capsules. After gene modification, dental mesenchymal cells cultured in vitro were checked for cell proliferation and the expression of Dspp was examined. All 12 reassociated tooth germs in the control group resumed odontogenesis, while only 5 of 12 in the Wnt10a knockdown group developed into teeth. After Wnt10a knockdown, the mesenchymal cells cultured in vitro presented repressed proliferation. Wnt10a knockdown and overexpression led to both down- and up-regulation of Dspp. We conclude that the down-regulation of Wnt10a impairs odontogensis and cell proliferation, and that Wnt10a regulates Dspp expression in mesenchymal cells. These findings help to elucidate the mechanism of abnormal tooth development in patients with the WNT10A mutation

  7. Inhibition of WNT signaling reduces differentiation and induces sensitivity to doxorubicin in human malignant neuroblastoma SH-SY5Y cells.

    Science.gov (United States)

    Suebsoonthron, Junjira; Jaroonwitchawan, Thiranut; Yamabhai, Montarop; Noisa, Parinya

    2017-06-01

    Neuroblastoma is one of the most common cancers in infancy, arising from the neuroblasts during embryonic development. This cancer is difficult to treat and resistance to chemotherapy is often found; therefore, clinical trials of novel therapeutic approaches, such as targeted-cancer signaling, could be an alternative for a better treatment. WNT signaling plays significant roles in the survival, proliferation, and differentiation of human neuroblastoma. In this report, WNT signaling of a malignant human neuroblastoma cell line, SH-SY5Y cells, was inhibited by XAV939, a specific inhibitor of the Tankyrase enzyme. XAV939 treatment led to the reduction of β-catenin within the cells, confirming its inhibitory effect of WNT. The inhibition of WNT signaling by XAV939 did not affect cell morphology, survival, and proliferation; however, the differentiation and sensitivity to anticancer drugs of human neuroblastoma cells were altered. The treatment of XAV939 resulted in the downregulation of mature neuronal markers, including β-tubulin III, PHOX2A, and PHOX2B, whereas neural progenitor markers (PAX6, TFAP2α, and SLUG) were upregulated. In addition, the combination of XAV939 significantly enhanced the sensitivity of SH-SY5Y and IMR-32 cells to doxorubicin in both 2D and 3D culture systems. Microarray gene expression profiling suggested numbers of candidate target genes of WNT inhibition by XAV939, in particular, p21, p53, ubiquitin C, ZBED8, MDM2, CASP3, and FZD1, and this explained the enhanced sensitivity of SH-SY5Y cells to doxorubicin. Altogether, these results proposed that the altered differentiation of human malignant neuroblastoma cells by inhibiting WNT signaling sensitized the cells to anticancer drugs. This approach could thus serve as an effective treatment option for aggressive brain malignancy.

  8. Wnt/β-catenin and LIF-Stat3 signaling pathways converge on Sp5 to promote mouse embryonic stem cell self-renewal.

    Science.gov (United States)

    Ye, Shoudong; Zhang, Dongming; Cheng, Fei; Wilson, Daniel; Mackay, Jeffrey; He, Kan; Ban, Qian; Lv, Feng; Huang, Saifei; Liu, Dahai; Ying, Qi-Long

    2016-01-15

    Activation of leukemia inhibitor factor (LIF)-Stat3 or Wnt/β-catenin signaling promotes mouse embryonic stem cell (mESC) self-renewal. A myriad of downstream targets have been identified in the individual signal pathways, but their common targets remain largely elusive. In this study, we found that the LIF-Stat3 and Wnt/β-catenin signaling pathways converge on Sp5 to promote mESC self-renewal. Forced Sp5 expression can reproduce partial effects of Wnt/β-catenin signaling but mimics most features of LIF-Stat3 signaling to maintain undifferentiated mESCs. Moreover, Sp5 is able to convert mouse epiblast stem cells into a naïve pluripotent state. Thus, Sp5 is an important component of the regulatory network governing mESC naïve pluripotency. © 2016. Published by The Company of Biologists Ltd.

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

    Science.gov (United States)

    Baarsma, H A

    2017-01-01

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

  10. Mesenchymal Wnt/β-catenin signaling limits tooth number.

    Science.gov (United States)

    Järvinen, Elina; Shimomura-Kuroki, Junko; Balic, Anamaria; Jussila, Maria; Thesleff, Irma

    2018-02-21

    Tooth agenesis is one of the predominant developmental anomalies in humans, usually affecting the permanent dentition generated by sequential tooth formation and, in most cases, caused by mutations perturbing epithelial Wnt/β-catenin signaling. In addition, loss-of-function mutations in the Wnt feedback inhibitor AXIN2 lead to human tooth agenesis. We have investigated the functions of Wnt/β-catenin signaling during sequential formation of molar teeth using mouse models. Continuous initiation of new teeth, which is observed after genetic activation of Wnt/β-catenin signaling in the oral epithelium, was accompanied by enhanced expression of Wnt antagonists and a downregulation of Wnt/β-catenin signaling in the dental mesenchyme. Genetic and pharmacological activation of mesenchymal Wnt/β-catenin signaling negatively regulated sequential tooth formation, an effect partly mediated by Bmp4. Runx2 , a gene whose loss-of-function mutations result in sequential formation of supernumerary teeth in the human cleidocranial dysplasia syndrome, suppressed the expression of Wnt inhibitors Axin2 and Drapc1 in dental mesenchyme. Our data indicate that increased mesenchymal Wnt signaling inhibits the sequential formation of teeth, and suggest that Axin2 / Runx2 antagonistic interactions modulate the level of mesenchymal Wnt/β-catenin signaling, underlying the contrasting dental phenotypes caused by human AXIN2 and RUNX2 mutations. © 2018. Published by The Company of Biologists Ltd.

  11. Noncanonical Wnt signaling promotes osteoclast differentiation and is facilitated by the human immunodeficiency virus protease inhibitor ritonavir

    International Nuclear Information System (INIS)

    Santiago, Francisco; Oguma, Junya; Brown, Anthony M.C.; Laurence, Jeffrey

    2012-01-01

    Highlights: ► First demonstration of direct role for noncanonical Wnt in osteoclast differentiation. ► Demonstration of Ryk as a Wnt5a/b receptor in inhibition of canonical Wnt signaling. ► Modulation of noncanonical Wnt signaling by a clinically important drug, ritonavir. ► Establishes a mechanism for an important clinical problem: HIV-associated bone loss. -- Abstract: Wnt proteins that signal via the canonical Wnt/β-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 β-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, β-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 regulation of osteoclast differentiation, and its modulation by a clinically important drug, ritonavir. These studies

  12. Wnt-10b, uniquely among Wnts, promotes epithelial differentiation and shaft growth

    International Nuclear Information System (INIS)

    Ouji, Yukiteru; Yoshikawa, Masahide; Moriya, Kei; Nishiofuku, Mariko; Matsuda, Ryosuke; Ishizaka, Shigeaki

    2008-01-01

    Although Wnts are expressed in hair follicles throughout life from embryo to adult, and considered to be critical for their development and maturation, their roles remain largely unknown. In the present study, we investigated the effects of Wnts (Wnt-3a, Wnt-5a, Wnt-10b, and Wnt-11) on epithelial cell differentiation using adult mouse-derived primary skin epithelial cell (MPSEC) cultures and hair growth using hair follicle organ cultures. Only Wnt-10b showed evident promotion of epithelial cell differentiation and hair shaft growth, in contrast to Wnt-3a, 5a, and 11. Our results suggest that Wnt-10b is unique and plays an important role in differentiation of epithelial cells in the hair follicle

  13. ErbB3 mRNA leukocyte levels as a biomarker for major depressive disorder

    Directory of Open Access Journals (Sweden)

    Milanesi Elena

    2012-09-01

    Full Text Available Abstract Background In recent years, the identification of peripheral biomarkers that are associated with psychiatric diseases, such as Major Depressive Disorder (MDD, has become relevant because these biomarkers may improve the efficiency of the differential diagnosis process and indicate targets for new antidepressant drugs. Two recent candidate genes, ErbB3 and Fgfr1, are growth factors whose mRNA levels have been found to be altered in the leukocytes of patients that are affected by bipolar disorder in a depressive state. On this basis, the aim of the study was to determine if ErbB3 and Fgfr1 mRNA levels could be a biomarkers of MDD. Methods We measured by Real Time PCR ErbB3 and Fgfr1 mRNA expression levels in leukocytes of MDD patients compared with controls. Successively, to assess whether ErbB3 mRNA levels were influenced by previous antidepressant treatment we stratified our patients sample in two cohorts, comparing drug-naive versus drug-free patients. Moreover, we evaluated the levels of the transcript in MDD patients after 12 weeks of antidepressant treatment, and in prefrontal cortex of rats stressed and treated with an antidepressant drug of the same class. Results These results showed that ErbB3 but not Fgfr1 mRNA levels were reduced in leukocytes of MDD patients compared to healthy subjects. Furthermore, ErbB3 levels were not affected by antidepressant treatment in either human or animal models Conclusions Our data suggest that ErbB3 might be considered as a biomarker for MDD and that its deficit may underlie the pathopsysiology of the disease and is not a consequence of treatment. Moreover the study supports the usefulness of leukocytes as a peripheral system for identifying biomarkers in psychiatric diseases.

  14. 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)

    Kawamoto, E.M.; Gleichmann, M.; Yshii, L.M.; Sá Lima, L. de; Mattson, M.P.; Scavone, C.

    2011-01-01

    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 25-35 ; 50 µM). Cells (1 × 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

  15. Involvement of the 5'-leader sequence in coupling the stability of a human H3 histone mRNA with DNA replication

    International Nuclear Information System (INIS)

    Morris, T.; Marashi, F.; Weber, L.; Hickey, E.; Greenspan, D.; Bonner, J.; Stein, J.; Stein, G.

    1986-01-01

    Two lines of evidence derived from fusion gene constructs indicate that sequences residing in the 5'-nontranslated region of a cell cycle-dependent human H3 histone mRNA are involved in the selective destabilization that occurs when DNA synthesis is terminated. The experimental approach was to construct chimeric genes in which fragments of the mRNA coding regions of the H3 histone gene were fused with fragments of genes not expressed in a cell cycle-dependent manner. After transfection in HeLa S3 cells with the recombinant plasmids, levels of fusion mRNAs were determined by S1 nuclease analysis prior to and following DNA synthesis inhibition. When the first 20 nucleotides of an H3 histone mRNA leader were replaced with 89 nucleotides of the leader from a Drosophila heat-shock (hsp70) mRNA, the fusion transcript remained stable during inhibition of DNA synthesis, in contrast to the rapid destabilization of the endogenous histone mRNA in these cells. In a reciprocal experiment, a histone-globin fusion gene was constructed that produced a transcript with the initial 20 nucleotides of the H3 histone mRNA substituted for the human β-globin mRNA leader. In HeLa cells treated with inhibitors of DNA synthesis and/or protein synthesis, cellular levels of this histone-globin fusion mRNA appeared to be regulated in a manner similar to endogenous histone mRNA levels. These results suggest that the first 20 nucleotides of the leader are sufficient to couple histone mRNA stability with DNA replication

  16. Macrophage Migration Inhibitory Factor Promoter Polymorphisms (−794 CATT5–8 and −173 G>C: Relationship with mRNA Expression and Soluble MIF Levels in Young Obese Subjects

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    Inés Matia-García

    2015-01-01

    Full Text Available We analyzed the relationship of −794 CATT5–8 and −173 G>C MIF polymorphisms with mRNA and soluble MIF in young obese subjects. A total of 250 young subjects, 150 normal-weight and 100 obese subjects, were recruited in the study. Genotyping of −794 CATT5–8 and −173 G>C MIF polymorphisms was performed by PCR and PCR-RFLP, respectively. MIF mRNA expression was determined by real-time PCR and serum MIF levels were measured using an ELISA kit. For both MIF promoter polymorphisms, no significant differences in the genotype and allele frequencies between groups were observed. MIF mRNA expression was slightly higher in obese subjects than in normal-weight subjects (1.38-fold, while soluble MIF levels did not show differences between groups. In addition, we found an increase in MIF mRNA expression in carriers of the 6,6 and C/C genotypes and the 6G haplotype of the −794 CATT5–8 and −173 G>C MIF polymorphisms, although it was not significant. In conclusion, this study found no relationship between obesity and MIF gene promoter polymorphisms with MIF mRNA expression in young obese subjects.

  17. Mucin gene mRNA levels in broilers challenged with eimeria and/or Clostridium perfringens.

    Science.gov (United States)

    Kitessa, Soressa M; Nattrass, Gregory S; Forder, Rebecca E A; McGrice, Hayley A; Wu, Shu-Biao; Hughes, Robert J

    2014-09-01

    The effects of Eimeria (EM) and Clostridium perfringens (CP) challenges on the mRNA levels of genes involved in mucin (Muc) synthesis (Muc2, Muc5ac, Muc13, and trefoil family factor-2 [TFF2]), inflammation (tumor necrosis factor alpha [TNF-alpha] and interleukin-18 [IL-18]), and metabolic processes (cluster of differentiation [CD]36) in the jejunum of broilers were investigated. Two parallel experiments involving 1) EM challenge and 2) EM and CP challenges were conducted. The first experiment was a 2 X 2 study with 12 birds per treatment (N = 48) involving fishmeal substitution (25%) in the diet (FM) and EM challenge. The treatments were: Control (FM-, EM-), Fishmeal (FM+, EM-), EM challenge (FM-, EM+), and fishmeal substitution and EM challenge (FM+, EM+). The second experiment was a 2 X 2 X 2 experiment with six birds per treatment (N = 48) involving fishmeal (FM-, FM+), Eimeria (EM-, EM+), and C perfringens (CP-, CP+). In both arms of the study, male broilers were given a starter diet for the whole period of 16 days, except those assigned to FM+, where 25% of the starter ration was replaced with fishmeal from days 8 to 14. EM inoculation was performed on day 9 and CP inoculation on days 14 and 15. The EM challenge birds were euthanatized for sampling on day 13; postmortem examination and sampling for the Eimeria plus C perfringens challenge arm of the study were on day 16. In the Eimeria challenge arm of the study, fishmeal supplementation significantly suppressed the mRNA levels of TNF-alpha, TFF2, and IL-18 pre-CP inoculation but simultaneously increased the levels of Muc13 and CD36 mRNAs. Birds challenged with Eimeria exhibited increased mRNA levels of Muc13, Muc5ac, TNF-alpha, and IL-18. In the Eimeria and C. perfringens challenge arm, birds exposed to EM challenge exhibited significantly lower mRNA levels of Muc2 and CD36. The mRNA levels of CD36 were also significantly suppressed by CP challenge. Our results showed that the transcription of mucin synthesis

  18. 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.

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

    International Nuclear Information System (INIS)

    Marschall, Zofia von; Fisher, Larry W.

    2010-01-01

    Research highlights: → sFRP2 enhances the Wnt3a-induced β-catenin stabilization and its nuclear translocation. → sFRP2 enhances LRP6 phosphorylation and Wnt3a/β-catenin transcriptional reporter activity. → Dickkopf-1 (DKK1) fully antagonizes both Wnt3a/sFRP2-induced LRP6 phosphorylation and transcriptional activity. → 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 β-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/β-catenin signaling, a result with biological impact for both normal development and diverse pathologies such as tumorigenesis.

  20. Wnt9a signaling is required for joint integrity and regulation of Ihh during chondrogenesis.

    Science.gov (United States)

    Später, Daniela; Hill, Theo P; O'sullivan, Roderick J; Gruber, Michaela; Conner, David A; Hartmann, Christine

    2006-08-01

    Joints, which separate skeleton elements, serve as important signaling centers that regulate the growth of adjacent cartilage elements by controlling proliferation and maturation of chondrocytes. Accurate chondrocyte maturation is crucial for endochondral ossification and for the ultimate size of skeletal elements, as premature or delayed maturation results predominantly in shortened elements. Wnt9a has previously been implicated as being a player in joint induction, based on gain-of function experiments in chicken and mouse. We show that loss of Wnt9a does not affect joint induction, but results to synovial chondroid metaplasia in some joints. This phenotype can be enhanced by removal of an additional Wnt gene, Wnt4, suggesting that Wnts are playing a crucial role in directing bi-potential chondro-synovioprogenitors to become synovial connective tissue, by actively suppressing their chondrogenic potential. Furthermore, we show that Wnt9a is a temporal and spatial regulator of Indian hedgehog (Ihh), a central player of skeletogenesis. Loss of Wnt9a activity results in transient downregulation of Ihh and reduced Ihh-signaling activity at E12.5-E13.5. The canonical Wnt/beta-catenin pathway probably mediates regulation of Ihh expression in prehypertrophic chondrocytes by Wnt9a, because embryos double-heterozygous for Wnt9a and beta-catenin show reduced Ihh expression, and in vivo chromatin immunoprecipitation demonstrates a direct interaction between the beta-catenin/Lef1 complex and the Ihh promoter.

  1. High-frequency deregulated expression of Wnt signaling pathway members in breast carcinomas.

    Science.gov (United States)

    Khan, Zahid; Arafah, Maha; Shaik, Jilani Purusottapatnam; Mahale, Alka; Alanazi, Mohammad Saud

    2018-01-01

    Breast carcinoma is the most common malignancy and leading cause of cancer-related deaths in women worldwide including Saudi Arabia. Breast cancer in Saudi women develops at a much early age with median age of onset of 49 years compared to 62 years observed in patients from USA. Aberrations in wingless and integration site growth factor (Wnt) signaling pathway have been pathologically implicated in development of breast cancers and hence its role was examined in Saudi patients. We immunohistochemically examined various components of Wnt signaling pathway including β-catenin, tumor suppressor proteins, adenomatous polyposis coli (APC), and Axin, expression of naturally occurring pathway antagonists such as Dickkopf Wnt signaling pathway inhibitor 3 (DKK3), FRP2, and WIF1, as well as Wnt target cyclin D1 and c-Myc to establish if the pathway is constitutively activated in breast cancers arising in Saudi women. Cytoplasmic β-catenin, indicative of activation of the pathway, was observed in 24% of cases. Expression of APC and Axin, which are components of β-catenin destruction complex, was lost in 5% and 10% of tumors, respectively. Additionally, Wnt signaling inhibitors DKK3, FRP2, and Wnt inhibitory factor 1 (WIF1) were not expressed in 8%, 14%, and 5% breast tumors, respectively. Overall, accumulation of cytoplasmic β-catenin and downregulation of other Wnt pathway proteins (APC/Axin/DKK3/FRP2/WIF1) were found in approximately half of the breast cancers (47%) in our cohort. Consistent with this, analysis of Wnt target genes demonstrated moderate-to-strong expression of c-Myc in 58% and cyclin D1 in 50% of breast cancers. Deregulation of Wnt pathway was not associated with age of onset of the disease, tumor grade, and triple-negative status of breast cancers. High level of deregulated expression of Wnt pathway proteins suggests its important role in pathogenesis of breast cancers arising in Saudi women who may benefit from development of therapeutic drugs

  2. (Pro)renin Receptor Is an Amplifier of Wnt/β-Catenin Signaling in Kidney Injury and Fibrosis.

    Science.gov (United States)

    Li, Zhen; Zhou, Lili; Wang, Yongping; Miao, Jinhua; Hong, Xue; Hou, Fan Fan; Liu, Youhua

    2017-08-01

    The (pro)renin receptor (PRR) is a transmembrane protein with multiple functions. However, its regulation and role in the pathogenesis of CKD remain poorly defined. Here, we report that PRR is a downstream target and an essential component of Wnt/ β -catenin signaling. In mouse models, induction of CKD by ischemia-reperfusion injury (IRI), adriamycin, or angiotensin II infusion upregulated PRR expression in kidney tubular epithelium. Immunohistochemical staining of kidney biopsy specimens also revealed induction of renal PRR in human CKD. Overexpression of either Wnt1 or β -catenin induced PRR mRNA and protein expression in vitro Notably, forced expression of PRR potentiated Wnt1-mediated β -catenin activation and augmented the expression of downstream targets such as fibronectin, plasminogen activator inhibitor 1, and α -smooth muscle actin ( α -SMA). Conversely, knockdown of PRR by siRNA abolished β -catenin activation. PRR potentiation of Wnt/ β -catenin signaling did not require renin, but required vacuolar H + ATPase activity. In the mouse model of IRI, transfection with PRR or Wnt1 expression vectors promoted β -catenin activation, aggravated kidney dysfunction, and worsened renal inflammation and fibrotic lesions. Coexpression of PRR and Wnt1 had a synergistic effect. In contrast, knockdown of PRR expression ameliorated kidney injury and fibrosis after IRI. These results indicate that PRR is both a downstream target and a crucial element in Wnt signal transmission. We conclude that PRR can promote kidney injury and fibrosis by amplifying Wnt/ β -catenin signaling. Copyright © 2017 by the American Society of Nephrology.

  3. Fibrin-Enhanced Canonical Wnt Signaling Directs Plasminogen Expression in Cementoblasts

    Directory of Open Access Journals (Sweden)

    Saeed Ur Rahman

    2017-11-01

    Full Text Available Cementum is a mineralized layer on the tooth’s root surface and facilitates the biomechanical anchoring of fibrous connective tissues as a part of tooth-supportive complexes. Previously, we observed that OCCM30 cementoblasts cultured on fibrin matrices underwent apoptosis due to fibrin degradation through the expression of proteases. Here, we demonstrated that OCCM30 on fibrin matrices (OCCM30-fibrin enhanced canonical Wnt signaling, which directed to plasminogen expression. The OCCM30-fibrin showed higher levels of Wnt3a expression, nuclear translocation of β-catenin, and T-cell factor (TCF optimal motif (TOP reporter activity than the cells on tissue culture dishes (OCCM30-TCD, indicating that the OCCM30-fibrin enhanced canonical Wnt/β-catenin signaling. Also, OCCM30-fibrin expressed biomineralization-associated markers at higher levels than OCCM30-TCD, of which levels were further increased with LiCl, a Wnt signaling activator. The OCCM30 cementoblasts simultaneously showed that high levels of plasminogen, a critical component of fibrinolysis, were expressed in the OCCM30-fibrin. Activation of canonical Wnt signaling with LiCl treatment or with forced lymphoid enhancer factor 1 (LEF1-expression increased the expression of plasminogen. On the contrary, the inhibition of canonical Wnt signaling with siRNAs against Wnt3a or β-catenin abrogated fibrin-enhanced plasminogen expression. Furthermore, there are three conserved putative response elements for the LEF1/β-catenin complex in the plasminogen proximal promoter regions (−900 to +54. Site-directed mutations and chromatin immunoprecipitation indicated that canonical Wnt signaling directed plasminogen expression. Taken together, this study suggests that fibrin-based materials can modulate functional periodontal formations in controlling cementoblast differentiation and fibrin degradation.

  4. CACN-1/Cactin plays a role in Wnt signaling in C. elegans.

    Directory of Open Access Journals (Sweden)

    Melissa LaBonty

    Full Text Available Wnt signaling is tightly regulated during animal development and controls cell proliferation and differentiation. In C. elegans, activation of Wnt signaling alters the activity of the TCF/LEF transcription factor, POP-1, through activation of the Wnt/β-catenin or Wnt/β-catenin asymmetry pathways. In this study, we have identified CACN-1 as a potential regulator of POP-1 in C. elegans larval development. CACN-1/Cactin is a well-conserved protein of unknown molecular function previously implicated in the regulation of several developmental signaling pathways. Here we have used activation of POPTOP, a POP-1-responsive reporter construct, as a proxy for Wnt signaling. POPTOP requires POP-1 and SYS-1/β-catenin for activation in L4 uterine cells. RNAi depletion experiments show that CACN-1 is needed to prevent excessive activation of POPTOP and for proper levels and/or localization of POP-1. Surprisingly, high POPTOP expression correlates with increased levels of POP-1 in uterine nuclei, suggesting POPTOP may not mirror endogenous gene expression in all respects. Genetic interaction studies suggest that CACN-1 may act partially through LIT-1/NLK to alter POP-1 localization and POPTOP activation. Additionally, CACN-1 is required for proper proliferation of larval seam cells. Depletion of CACN-1 results in a loss of POP-1 asymmetry and reduction of terminal seam cell number, suggesting an adoption of the anterior, differentiated fate by the posterior daughter cells. These findings suggest CACN-1/Cactin modulates Wnt signaling during larval development.

  5. Efficacy of Wnt-1 monoclonal antibody in sarcoma cells

    International Nuclear Information System (INIS)

    Mikami, Iwao; Koizumi, Kiyoshi; Jablons, David M; You, Liang; He, Biao; Xu, Zhidong; Batra, Sonny; Lee, Amie Y; Mazieres, Julien; Reguart, Noemi; Uematsu, Kazutsugu

    2005-01-01

    Sarcomas are one of the most refractory diseases among malignant tumors. More effective therapies based on an increased understanding of the molecular biology of sarcomas are needed as current forms of therapy remain inadequate. Recently, it has been reported that Wnt-1/β-catenin signaling inhibits apoptosis in several cancers. In this study, we investigated the efficacy of a monoclonal anti-Wnt-1 antibody in sarcoma cells. We treated cell lines A-204, SJSA-1, and fresh primary cultures of lung metastasis of sarcoma with a monoclonal anti-Wnt-1 antibody. Wnt-1 siRNA treatment was carried out in A-204. We assessed cell death using Crystal Violet staining. Apoptosis induction was estimated by flow cytometry analysis (Annexin V and PI staining). Cell signaling changes were determined by western blotting analysis. We detected Wnt-1 expression in all tissue samples and cell lines. Significant apoptosis induction was found in monoclonal anti-Wnt-1 antibody treated cells compared to control monoclonal antibody treated cells (p < 0.02). Similarly, we observed increased apoptosis in Wnt-1 siRNA treated cells. Blockade of Wnt-1 signaling in both experiments was confirmed by analyzing intracellular levels of Dishevelled-3 and of cytosolic β-catenin. Furthermore, the monoclonal anti-Wnt-1 antibody also induced cell death in fresh primary cultures of metastatic sarcoma in which Wnt-1 signaling was active. Our results indicate that Wnt-1 blockade by either monoclonal antibody or siRNA induces cell death in sarcoma cells. These data suggest that Wnt-1 may be a novel therapeutic target for the treatment of a subset of sarcoma cells in which Wnt-1/β-catenin signaling is active

  6. The key role of proinflammatory cytokines, matrix proteins, RANKL/OPG and Wnt/β-catenin in bone healing of hip arthroplasty patients.

    Science.gov (United States)

    Cassuto, Jean; Folestad, Agnetha; Göthlin, Jan; Malchau, Henrik; Kärrholm, Johan

    2018-02-01

    We still lack understanding of why some implants fail while most remain stable after decades of use. Proinflammatory cytokines, matrix proteins and bone regulating cytokines of the RANKL/OPG (receptor activator of nuclear factor kappa B ligand/osteoprotegerin) and Wnt/β-catenin pathways are mandatory for normal bone repair but their spatial and temporal role in the healing of primary total hip arthroplasties (THA) has not been previously shown. Twenty-four osteoarthritis patients with one-sided well-fixed primary THA were prospectively monitored during 18years (18Y) with repeated blood samples, clinical variables and radiographs. Eighty-one healthy donors divided in three age- and gender-matched groups and twenty osteoarthritis patients awaiting THA and serving as control of the validity of stored plasma in THA patients, were included. Plasma was analyzed for C-reactive protein (CRP), interleukin (IL)-6, IL-8, IL-1β, tumor necrosis factor (TNF)-α, osteopontin (OPN), secreted protein acidic and rich in cysteine (SPARC/osteonectin), osteocalcin (OC), bone specific alkaline phosphatase (BALP), N-terminal propeptide of collagen type I (P1NP), RANKL, OPG, the Wnt agonistic ligands (Wnt)-1 and Wnt-3a, and the Wnt antagonists sclerostin, Dickkopf (Dkk)-1, Dkk-3, Dkk-4, secreted frizzled related protein (sFRP)-1, sFRP-3 and Wnt inhibitory factor-1 (Wif-1). Inflammatory mediators in arthroplasty patients (CRP, IL-6, OPN) increased significantly on day one after surgery vs preoperative value (PR) and healthy subjects and returned to baseline at 6W. TNF-α did not change relative preoperative level or healthy subjects. SPARC and OC increased in a biphasic fashion with the primary phase beginning shortly after surgery and lasting 3M (SPARC) and 2Y (OC) while the secondary phase peaked at 1Y (SPARC) and 13Y (OC), with both returning to basal level at 15Y. BALP peaked at 3M after surgery with a return to basal level at 2Y followed by a continuous increase from 5Y until 18Y. P

  7. Olfactory memory is enhanced in mice exposed to extremely low-frequency electromagnetic fields via Wnt/β-catenin dependent modulation of subventricular zone neurogenesis.

    Science.gov (United States)

    Mastrodonato, Alessia; Barbati, Saviana Antonella; Leone, Lucia; Colussi, Claudia; Gironi, Katia; Rinaudo, Marco; Piacentini, Roberto; Denny, Christine A; Grassi, Claudio

    2018-01-10

    Exposure to extremely low-frequency electromagnetic fields (ELFEF) influences the expression of key target genes controlling adult neurogenesis and modulates hippocampus-dependent memory. Here, we assayed whether ELFEF stimulation affects olfactory memory by modulating neurogenesis in the subventricular zone (SVZ) of the lateral ventricle, and investigated the underlying molecular mechanisms. We found that 30 days after the completion of an ELFEF stimulation protocol (1 mT; 50 Hz; 3.5 h/day for 12 days), mice showed enhanced olfactory memory and increased SVZ neurogenesis. These effects were associated with upregulated expression of mRNAs encoding for key regulators of adult neurogenesis and were mainly dependent on the activation of the Wnt pathway. Indeed, ELFEF stimulation increased Wnt3 mRNA expression and nuclear localization of its downstream target β-catenin. Conversely, inhibition of Wnt3 by Dkk-1 prevented ELFEF-induced upregulation of neurogenic genes and abolished ELFEF's effects on olfactory memory. Collectively, our findings suggest that ELFEF stimulation increases olfactory memory via enhanced Wnt/β-catenin signaling in the SVZ and point to ELFEF as a promising tool for enhancing SVZ neurogenesis and olfactory function.

  8. ERAD-dependent control of the Wnt secretory factor Evi.

    Science.gov (United States)

    Glaeser, Kathrin; Urban, Manuela; Fenech, Emma; Voloshanenko, Oksana; Kranz, Dominique; Lari, Federica; Christianson, John C; Boutros, Michael

    2018-02-15

    Active regulation of protein abundance is an essential strategy to modulate cellular signaling pathways. Within the Wnt signaling cascade, regulated degradation of β-catenin by the ubiquitin-proteasome system (UPS) affects the outcome of canonical Wnt signaling. Here, we found that abundance of the Wnt cargo receptor Evi (Wls/GPR177), which is required for Wnt protein secretion, is also regulated by the UPS through endoplasmic reticulum (ER)-associated degradation (ERAD). In the absence of Wnt ligands, Evi is ubiquitinated and targeted for ERAD in a VCP-dependent manner. Ubiquitination of Evi involves the E2-conjugating enzyme UBE2J2 and the E3-ligase CGRRF1. Furthermore, we show that a triaging complex of Porcn and VCP determines whether Evi enters the secretory or the ERAD pathway. In this way, ERAD-dependent control of Evi availability impacts the scale of Wnt protein secretion by adjusting the amount of Evi to meet the requirement of Wnt protein export. As Wnt and Evi protein levels are often dysregulated in cancer, targeting regulatory ERAD components might be a useful approach for therapeutic interventions. © 2018 The Authors. Published under the terms of the CC BY 4.0 license.

  9. Wnt ligands signal in a cooperative manner to promote foregut organogenesis

    OpenAIRE

    Miller, Mayumi F.; Cohen, Ethan David; Baggs, Julie E.; Lu, Min Min; Hogenesch, John B.; Morrisey, Edward E.

    2012-01-01

    Endoderm-mesenchyme cross-talk is a central process in the development of foregut-derived organs. How signaling pathways integrate the activity of multiple ligands to guide organ development is poorly understood. We show that two Wnt ligands, Wnt2 and Wnt7b, cooperatively induce Wnt signaling without affecting the stabilization of the Wnt canonical effector β-catenin despite it being necessary for Wnt2–Wnt7b cooperativity. Wnt2–Wnt7b cooperation is specific for mesenchymal cell lineages and t...

  10. Wnt signaling in cancer

    Science.gov (United States)

    Zhan, T; Rindtorff, N; Boutros, M

    2017-01-01

    Wnt signaling is one of the key cascades regulating development and stemness, and has also been tightly associated with cancer. The role of Wnt signaling in carcinogenesis has most prominently been described for colorectal cancer, but aberrant Wnt signaling is observed in many more cancer entities. Here, we review current insights into novel components of Wnt pathways and describe their impact on cancer development. Furthermore, we highlight expanding functions of Wnt signaling for both solid and liquid tumors. We also describe current findings how Wnt signaling affects maintenance of cancer stem cells, metastasis and immune control. Finally, we provide an overview of current strategies to antagonize Wnt signaling in cancer and challenges that are associated with such approaches. PMID:27617575

  11. Wise, a context-dependent activator and inhibitor of Wnt signalling.

    Science.gov (United States)

    Itasaki, Nobue; Jones, C Michael; Mercurio, Sara; Rowe, Alison; Domingos, Pedro M; Smith, James C; Krumlauf, Robb

    2003-09-01

    We have isolated a novel secreted molecule, Wise, by a functional screen for activities that alter the anteroposterior character of neuralised Xenopus animal caps. Wise encodes a secreted protein capable of inducing posterior neural markers at a distance. Phenotypes arising from ectopic expression or depletion of Wise resemble those obtained when Wnt signalling is altered. In animal cap assays, posterior neural markers can be induced by Wnt family members, and induction of these markers by Wise requires components of the canonical Wnt pathway. This indicates that in this context Wise activates the Wnt signalling cascade by mimicking some of the effects of Wnt ligands. Activation of the pathway was further confirmed by nuclear accumulation of beta-catenin driven by Wise. By contrast, in an assay for secondary axis induction, extracellularly Wise antagonises the axis-inducing ability of Wnt8. Thus, Wise can activate or inhibit Wnt signalling in a context-dependent manner. The Wise protein physically interacts with the Wnt co-receptor, lipoprotein receptor-related protein 6 (LRP6), and is able to compete with Wnt8 for binding to LRP6. These activities of Wise provide a new mechanism for integrating inputs through the Wnt coreceptor complex to modulate the balance of Wnt signalling.

  12. Wnt modulates MCL1 to control cell survival in triple negative breast cancer

    International Nuclear Information System (INIS)

    Yang, Lixin; Zhang, Hang; Zheng, Shu; Liu, Zheng; Ann, David; Yen, Yun; Perez, Aldwin Apollo; Fujie, Sayuri; Warden, Charles; Li, Jie; Wang, Yafan; Yung, Bryan; Chen, Yun-Ru; Liu, Xiyong

    2014-01-01

    Triple negative breast cancer (TNBC) has higher rates of recurrence and distant metastasis, and poorer outcome as compared to non-TNBC. Aberrant activation of WNT signaling has been detected in TNBC, which might be important for triggering oncogenic conversion of breast epithelial cell. Therefore, we directed our focus on identifying the WNT ligand and its underlying mechanism in TNBC cells. We performed large-scale analysis of public microarray data to screen the WNT ligands and the clinical significance of the responsible ligand in TNBC. WNT5B was identified and its overexpression in TNBC was confirmed by immunohistochemistry staining, Western blot and ELISA. ShRNA was used to knockdown WNT5B expression (shWNT5B). Cellular functional alteration with shWNT5B treatment was determined by using wound healing assay, mammosphere assay; while cell cycle and apoptosis were examined by flowcytometry. Mitochondrial morphology was photographed by electron microscope. Biological change of mitochondria was detected by RT-PCR and oxygen consumption assay. Activation of WNT pathway and its downstream targets were evaluated by liciferase assay, immunohistochemistry staining and immunoblot analysis. Statistical methods used in the experiments besides microarray analysis was two-tailed t-test. WNT5B was elevated both in the tumor and the patients’ serum. Suppression of WNT5B remarkably impaired cell growth, migration and mammosphere formation. Additionally, G0/G1 cell cycle arrest and caspase-independent apoptosis was observed. Study of the possible mechanism indicated that these effects occurred through suppression of mitochondrial biogenesis, as evidenced by reduced mitochondrial DNA (MtDNA) and compromised oxidative phosphorylation (OXPHOS). In Vivo and in vitro data uncovered that WNT5B modulated mitochondrial physiology was mediated by MCL1, which was regulated by WNT/β-catenin responsive gene, Myc. Clinic data analysis revealed that both WNT5B and MCL1 are associated with

  13. Enhanced chondrogenesis and Wnt signaling in PTH-treated fractures.

    Science.gov (United States)

    Kakar, Sanjeev; Einhorn, Thomas A; Vora, Siddharth; Miara, Lincoln J; Hon, Gregory; Wigner, Nathan A; Toben, Daniel; Jacobsen, Kimberly A; Al-Sebaei, Maisa O; Song, Michael; Trackman, Philip C; Morgan, Elise F; Gerstenfeld, Louis C; Barnes, George L

    2007-12-01

    Studies have shown that systemic PTH treatment enhanced the rate of bone repair in rodent models. However, the mechanisms through which PTH affects bone repair have not been elucidated. In these studies we show that PTH primarily enhanced the earliest stages of endochondral bone repair by increasing chondrocyte recruitment and rate of differentiation. In coordination with these cellular events, we observed an increased level of canonical Wnt-signaling in PTH-treated bones at multiple time-points across the time-course of fracture repair, supporting the conclusion that PTH responses are at least in part mediated through Wnt signaling. Since FDA approval of PTH [PTH(1-34); Forteo] as a treatment for osteoporosis, there has been interest in its use in other musculoskeletal conditions. Fracture repair is one area in which PTH may have a significant clinical impact. Multiple animal studies have shown that systemic PTH treatment of healing fractures increased both callus volume and return of mechanical competence in models of fracture healing. Whereas the potential for PTH has been established, the mechanism(s) by which PTH produces these effects remain elusive. Closed femoral fractures were generated in 8-wk-old male C57Bl/6 mice followed by daily systemic injections of either saline (control) or 30 microg/kg PTH(1-34) for 14 days after fracture. Bones were harvested at days 2, 3, 5, 7, 10, 14, 21, and 28 after fracture and analyzed at the tissue level by radiography and histomorphometry and at the molecular and biochemical levels level by RNase protection assay (RPA), real-time PCR, and Western blot analysis. Quantitative muCT analysis showed that PTH treatment induced a larger callus cross-sectional area, length, and total volume compared with controls. Molecular analysis of the expression of extracellular matrix genes associated with chondrogenesis and osteogenesis showed that PTH treated fractures displayed a 3-fold greater increase in chondrogenesis relative to

  14. Lentiviral Modulation of Wnt/β-Catenin Signaling Affects In Vivo LTP.

    Science.gov (United States)

    Ivanova, Olga Ya; Dobryakova, Yulia V; Salozhin, Sergey V; Aniol, Viktor A; Onufriev, Mikhail V; Gulyaeva, Natalia V; Markevich, Vladimir A

    2017-10-01

    Wnt signaling is involved in hippocampal development and synaptogenesis. Numerous recent studies have been focused on the role of Wnt ligands in the regulation of synaptic plasticity. Inhibitors and activators of canonical Wnt signaling were demonstrated to decrease or increase, respectively, in vitro long-term potentiation (LTP) maintenance in hippocampal slices (Chen et al. in J Biol Chem 281:11910-11916, 2006; Vargas et al. in J Neurosci 34:2191-2202, 2014, Vargas et al. in Exp Neurol 264:14-25, 2015). Using lentiviral approach to down- and up-regulate the canonical Wnt signaling, we explored whether Wnt/β-catenin signaling is critical for the in vivo LTP. Chronic suppression of Wnt signaling induced an impairment of in vivo LTP expression 14 days after lentiviral suspension injection, while overexpression of Wnt3 was associated with a transient enhancement of in vivo LTP magnitude. Both effects were related to the early phase LTP and did not affect LTP maintenance. A loss-of-function study demonstrated decreased initial paired pulse facilitation ratio, β-catenin, and phGSK-3β levels. A gain-of-function study revealed not only an increase in PSD-95, β-catenin, and Cyclin D1 protein levels, but also a reduced phGSK-3β level and enhanced GSK-3β kinase activity. These results suggest a presynaptic dysfunction predominantly underlying LTP impairment while postsynaptic modifications are primarily involved in transient LTP amplification. This study is the first demonstration of the involvement of Wnt/β-catenin signaling in synaptic plasticity regulation in an in vivo LTP model.

  15. Effect of in vitro estrogenic pesticides on human oestrogen receptor α and β mRNA levels

    DEFF Research Database (Denmark)

    Theander Grünfeld, Heidi; Bonefeld-Jørgensen, Eva Cecilie

    2004-01-01

    of the ERα mRNA level, but only significantly for prochloraz, dieldrin, and tolchlofos-methyl. Alone no pesticides affected the ERβ mRNA level significantly, but chlorpyrifos increased the mRNA level weakly. Co-exposure with E2 elicited a significant increased ERβ mRNA level by prochloraz, fenarimol...

  16. Wnt3a upregulates brain-derived insulin by increasing NeuroD1 via Wnt/β-catenin signaling in the hypothalamus.

    Science.gov (United States)

    Lee, Jaemeun; Kim, Kyungchan; Yu, Seong-Woon; Kim, Eun-Kyoung

    2016-03-08

    Insulin plays diverse roles in the brain. Although insulin produced by pancreatic β-cells that crosses the blood-brain barrier is a major source of brain insulin, recent studies suggest that insulin is also produced locally within the brain. However, the mechanisms underlying the production of brain-derived insulin (BDI) are not yet known. Here, we examined the effect of Wnt3a on BDI production in a hypothalamic cell line and hypothalamic tissue. In N39 hypothalamic cells, Wnt3a treatment significantly increased the expression of the Ins2 gene, which encodes the insulin isoform predominant in the mouse brain, by activating Wnt/β-catenin signaling. The concentration of insulin was higher in culture medium of Wnt3a-treated cells than in that of untreated cells. Interestingly, neurogenic differentiation 1 (NeuroD1), a target of Wnt/β-catenin signaling and one of transcription factors for insulin, was also induced by Wnt3a treatment in a time- and dose-dependent manner. In addition, the treatment of BIO, a GSK3 inhibitor, also increased the expression of Ins2 and NeuroD1. Knockdown of NeuroD1 by lentiviral shRNAs reduced the basal expression of Ins2 and suppressed Wnt3a-induced Ins2 expression. To confirm the Wnt3a-induced increase in Ins2 expression in vivo, Wnt3a was injected into the hypothalamus of mice. Wnt3a increased the expression of NeuroD1 and Ins2 in the hypothalamus in a manner similar to that observed in vitro. Taken together, these results suggest that BDI production is regulated by the Wnt/β-catenin/NeuroD1 pathway in the hypothalamus. Our findings will help to unravel the regulation of BDI production in the hypothalamus.

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

    Science.gov (United States)

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

    2015-12-01

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

  18. [Intervention effects of Zuoguiwan containing serum on osteoblast through ERK1/2 and Wnt/β-catenin signaling pathway in models with kidney-Yang-deficiency, kidney-Yin-deficiency osteoporosis syndromes].

    Science.gov (United States)

    Zhang, Jian-Hua; Xin, Jing; Fan, Lian-Xia; Yin, Hua

    2017-10-01

    To clarify the effects of Zuoguiwan containing serum on osteoblast proliferation and alkaline phosphatase(ALP) expression and its effects on the expression of β-catenin, ERK1, ERK2 mRNA and protein of osteoblast through ERK1/2, Wnt/β-catenin signaling pathway in models with osteoporosis(OP) kidney-Yang-deficiency, osteoporosis(OP) kidney-Yin-deficiency syndrome. Rat osteoporosis models were established by ovariectomy surgery, and 10 weeks after surgery, hydrocortisone was injected and thyroxine was administered by intragastric administration to establish OP kidney-Yang-deficiency rat model, and OP kidney-Yin-deficiency rat model. Osteoblasts were obtained from 24 h newborn rat skull and were identified by alkaline phosphatase and alizarin red staining. Zuoguiwan containing serum of OP, OP kidney-Yang-deficiency, and OP kidney-Yin-deficiency, as well as the blank serum were used to intervene the osteoblast, and the cells proliferation was detected by MTS. ELISA assay was used to detect ALP expression. RT-PCR assay was used to detect the mRNA expression of ERK1, ERK2, β-catenin and protein expression levels were detected by Western blot. The results showed that Zuoguiwan containing serum in OP kidney-Yin-deficiency model had stronger effect than OP kidney-Yang-deficiency in promoting osteoblast proliferation, ALP expression, osteoblast ERK1/2, Wnt/β-catenin signaling pathway related factors β-catenin, ERK1, ERK2 mRNA and protein expression levels. This was consistent with the TCM theory of "Zuoguiwan nourishes kidney Yin", providing a scientific basis for the clinical and dialectical treatment of osteoporosis. Zuoguiwan could regulate the proliferation and differentiation of bone cells by ERK1/2 and Wnt/β-catenin signaling pathway, which may be one of the mechanisms of Zuoguiwan for the prevention of osteoporosis. Copyright© by the Chinese Pharmaceutical Association.

  19. A SNX3-dependent retromer pathway mediates retrograde transport of the Wnt sorting receptor Wntless and is required for Wnt secretion

    NARCIS (Netherlands)

    Harterink, M.; Port, F.; Lorenowicz, M.J.; McGough, I.J.; Silhankova, M.; Betist, M.C.; van Weering, J.R.; van Heesbeen, R.G.; Middelkoop, T.C.; Basler, K.; Cullen, P.J.; Korswagen, H.C.

    2011-01-01

    Wnt proteins are lipid-modified glycoproteins that play a central role in development, adult tissue homeostasis and disease. Secretion of Wnt proteins is mediated by the Wnt-binding protein Wntless (Wls), which transports Wnt from the Golgi network to the cell surface for release. It has recently

  20. Apcdd1 is a novel Wnt inhibitor Mutated in Hereditary Hypotrichosis Simplex

    Science.gov (United States)

    Shimomura, Yutaka; Agalliu, Dritan; Vonica, Alin; Luria, Victor; Wajid, Muhammad; Baumer, Alessandra; Belli, Serena; Petukhova, Lynn; Schinzel, Albert; Brivanlou, Ali H.; Barres, Ben A.; Christiano, Angela M.

    2011-01-01

    Hereditary hypotrichosis simplex (HHS) is a rare autosomal dominant form of hair loss characterized by hair follicle (HF) miniaturization1, 2. Using genetic linkage analysis, we mapped a novel locus for HHS to chromosome 18p11.22, and identified a mutation (L9R) in the APCDD1 gene in three families. We show that APCDD1 is a membrane-bound glycoprotein that is abundantly expressed in human HFs, and can interact in vitro with WNT3A and LRP5, two essential components of Wnt signaling. Functional studies revealed that APCDD1 inhibits Wnt signaling in a cell-autonomous manner and functions upstream of β-catenin. Moreover, APCDD1 represses activation of Wnt reporters and target genes, and inhibits the biological effects of Wnt signaling during both the generation of neurons from progenitors in the developing chick nervous system, and axis specification in Xenopus embryos. The mutation L9R is located in the signal peptide of APCDD1, and perturbs its translational processing from ER to the plasma membrane. L9R-APCDD1 likely functions in a dominant-negative manner to inhibit the stability and membrane localization of the wild-type protein. These findings describe a novel inhibitor of the Wnt signaling pathway with an essential role in human hair growth. Since APCDD1 is expressed in a broad repertoire of cell types3, our findings suggest that APCDD1 may regulate a diversity of biological processes controlled by Wnt signaling. PMID:20393562

  1. Use of a molecular genetic platform technology to produce human Wnt proteins reveals distinct local and distal signaling abilities.

    Directory of Open Access Journals (Sweden)

    Jennifer L Green

    Full Text Available Functional and mechanistic studies of Wnt signaling have been severely hindered by the inaccessibility of bioactive proteins. To overcome this long-standing barrier, we engineered and characterized a panel of Chinese hamster ovary (CHO cell lines with inducible transgenes encoding tagged and un-tagged human WNT1, WNT3A, WNT5A, WNT7A, WNT11, WNT16 or the soluble Wnt antagonist Fzd8CRD, all integrated into an identical genomic locus. Using a quantitative real-time bioluminescence assay, we show that cells expressing WNT1, 3A and 7A stimulate Wnt/beta-catenin reporter activity, while the other WNT expressing cell lines interfere with this activation. Additionally, in contrast to WNT3A, WNT1 only exhibits activity when cell-associated, and thus only signals to neighboring cells. The reporter assay also revealed a rapid decline of Wnt activity at 37°C, indicating that Wnt activity is highly labile. These engineered cell lines will reduce the cost of making and purifying Wnt proteins and serve as a continuous, reliable and regulatable source of Wnts to research laboratories around the world.

  2. High levels of pigment epithelium-derived factor in diabetes impair wound healing through suppression of Wnt signaling.

    Science.gov (United States)

    Qi, Weiwei; Yang, Chuan; Dai, Zhiyu; Che, Di; Feng, Juan; Mao, Yuling; Cheng, Rui; Wang, Zhongxiao; He, Xuemin; Zhou, Ti; Gu, Xiaoqiong; Yan, Li; Yang, Xia; Ma, Jian-Xing; Gao, Guoquan

    2015-04-01

    Diabetic foot ulcer (DFU) caused by impaired wound healing is a common vascular complication of diabetes. The current study revealed that plasma levels of pigment epithelium-derived factor (PEDF) were elevated in type 2 diabetic patients with DFU and in db/db mice. To test whether elevated PEDF levels contribute to skin wound-healing delay in diabetes, endogenous PEDF was neutralized with an anti-PEDF antibody in db/db mice. Our results showed that neutralization of PEDF accelerated wound healing, increased angiogenesis in the wound skin, and improved the functions and numbers of endothelial progenitor cells (EPCs) in the diabetic mice. Further, PEDF-deficient mice showed higher baseline blood flow in the skin, higher density of cutaneous microvessels, increased skin thickness, improved numbers and functions of circulating EPCs, and accelerated wound healing compared with wild-type mice. Overexpression of PEDF suppressed the Wnt signaling pathway in the wound skin. Lithium chloride-induced Wnt signaling activation downstream of the PEDF interaction site attenuated the inhibitory effect of PEDF on EPCs and rescued the wound-healing deficiency in diabetic mice. Taken together, these results suggest that elevated circulating PEDF levels contribute to impaired wound healing in the process of angiogenesis and vasculogenesis through the inhibition of Wnt/β-catenin signaling. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  3. Multi-level interactions between the nuclear receptor TRα1 and the WNT effectors β-catenin/Tcf4 in the intestinal epithelium.

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    Maria Sirakov

    Full Text Available Intestinal homeostasis results from complex cross-regulation of signaling pathways; their alteration induces intestinal tumorigenesis. Previously, we found that the thyroid hormone nuclear receptor TRα1 activates and synergizes with the WNT pathway, inducing crypt cell proliferation and promoting tumorigenesis. Here, we investigated the mechanisms and implications of the cross-regulation between these two pathways in gut tumorigenesis in vivo and in vitro. We analyzed TRα1 and WNT target gene expression in healthy mucosae and tumors from mice overexpressing TRα1 in the intestinal epithelium in a WNT-activated genetic background (vil-TRα1/Apc mice. Interestingly, increased levels of β-catenin/Tcf4 complex in tumors from vil-TRα1/Apc mice blocked TRα1 transcriptional activity. This observation was confirmed in Caco2 cells, in which TRα1 functionality on a luciferase reporter-assay was reduced by the overexpression of β-catenin/Tcf4. Moreover, TRα1 physically interacted with β-catenin/Tcf4 in the nuclei of these cells. Using molecular approaches, we demonstrated that the binding of TRα1 to its DNA target sequences within the tumors was impaired, while it was newly recruited to WNT target genes. In conclusion, our observations strongly suggest that increased β-catenin/Tcf4 levels i correlated with reduced TRα1 transcriptional activity on its target genes and, ii were likely responsible for the shift of TRα1 binding on WNT targets. Together, these data suggest a novel mechanism for the tumor-promoting activity of the TRα1 nuclear receptor.

  4. Low-level lasers alter mRNA levels from traditional reference genes used in breast cancer cells

    Science.gov (United States)

    Teixeira, A. F.; Canuto, K. S.; Rodrigues, J. A.; Fonseca, A. S.; Mencalha, A. L.

    2017-07-01

    Cancer is among the leading causes of mortality worldwide, increasing the importance of treatment development. Low-level lasers are used in several diseases, but some concerns remains on cancers. Reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) is a technique used to understand cellular behavior through quantification of mRNA levels. Output data from target genes are commonly relative to a reference that cannot vary according to treatment. This study evaluated reference genes levels from MDA-MB-231 cells exposed to red or infrared lasers at different fluences. Cultures were exposed to red and infrared lasers, incubated (4 h, 37 °C), total RNA was extracted and cDNA synthesis was performed to evaluate mRNA levels from ACTB, GUSB and TRFC genes by RT-qPCR. Specific amplification was verified by melting curves and agarose gel electrophoresis. RefFinder enabled data analysis by geNorm, NormFinder and BestKeeper. Specific amplifications were obtained and, although mRNA levels from ACTB, GUSB or TRFC genes presented no significant variation through traditional statistical analysis, Excel-based tools revealed that the use of these reference genes are dependent of laser characteristics. Our data showed that exposure to low-level red and infrared lasers at different fluences alter the mRNA levels from ACTB, GUSB and TRFC in MDA-MB-231 cells.

  5. Casein kinase 1-epsilon or 1-delta required for Wnt-mediated intestinal stem cell maintenance.

    Science.gov (United States)

    Morgenstern, Yael; Das Adhikari, Upasana; Ayyash, Muneef; Elyada, Ela; Tóth, Beáta; Moor, Andreas; Itzkovitz, Shalev; Ben-Neriah, Yinon

    2017-10-16

    The intestinal epithelium holds an immense regenerative capacity mobilized by intestinal stem cells (ISCs), much of it supported by Wnt pathway activation. Several unique regulatory mechanisms ensuring optimal levels of Wnt signaling have been recognized in ISCs. Here, we identify another Wnt signaling amplifier, CKIε, which is specifically upregulated in ISCs and is essential for ISC maintenance, especially in the absence of its close isoform CKIδ. Co-ablation of CKIδ/ε in the mouse gut epithelium results in rapid ISC elimination, with subsequent growth arrest, crypt-villous shrinking, and rapid mouse death. Unexpectedly, Wnt activation is preserved in all CKIδ/ε-deficient enterocyte populations, with the exception of Lgr5 + ISCs, which exhibit Dvl2-dependent Wnt signaling attenuation. CKIδ/ε-depleted gut organoids cease proliferating and die rapidly, yet survive and resume self-renewal upon reconstitution of Dvl2 expression. Our study underscores a unique regulation mode of the Wnt pathway in ISCs, possibly providing new means of stem cell enrichment for regenerative medicine. © 2017 The Authors.

  6. Identification and expression characterization of WntA during intestinal regeneration in the sea cucumber Apostichopus japonicus.

    Science.gov (United States)

    Li, Xiaoni; Sun, Lina; Yang, Hongsheng; Zhang, Libin; Miao, Ting; Xing, Lili; Huo, Da

    2017-08-01

    Wnt genes encode secreted glycoproteins that act as signaling molecules; these molecules direct cell proliferation, migration, differentiation and survival during animal development, maintenance of homeostasis and regeneration. At present, although the regeneration mechanism in Apostichopus japonicus has been studied, there is a little research on the Wnt signaling pathway in A. japonicus. To understand the potential role of the Wnt signaling pathway in A. japonicus, we cloned and sequenced the WntA gene in A. japonicus. Protein localization analysis showed that WntA protein was ubiquitously expressed in epidermal cells, the muscle and submucosa of the intestinal tissue. After stimulation and evisceration, the dynamic changes in expression of the WntA gene and protein showed that WntA was constitutively expressed during different stages of intestine regeneration in A. japonicus, with higher levels during the early wound healing stage and late lumen formation in the residual and nascent intestinal tissues, indicating its response to intestinal regeneration. Simultaneously, cell proliferation and apoptosis analysis showed that the patterns of cell proliferation were similar to the patterns of WntA protein expression during different intestinal regeneration stages in this organism. Taken together, these results suggested that WntA might participate in intestinal regeneration and may be connected with cell proliferation, apoptosis in different intestinal layers. This research could establish a basis for further examination of WntA functions in A. japonicus and Wnt genes in other echinoderms. Copyright © 2017 Elsevier Inc. All rights reserved.

  7. 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.

  8. Noncanonical Wnt signaling promotes obesity-induced adipose tissue inflammation and metabolic dysfunction independent of adipose tissue expansion.

    Science.gov (United States)

    Fuster, José J; Zuriaga, María A; Ngo, Doan Thi-Minh; Farb, Melissa G; Aprahamian, Tamar; Yamaguchi, Terry P; Gokce, Noyan; Walsh, Kenneth

    2015-04-01

    Adipose tissue dysfunction plays a pivotal role in the development of insulin resistance in obese individuals. Cell culture studies and gain-of-function mouse models suggest that canonical Wnt proteins modulate adipose tissue expansion. However, no genetic evidence supports a role for endogenous Wnt proteins in adipose tissue dysfunction, and the role of noncanonical Wnt signaling remains largely unexplored. Here we provide evidence from human, mouse, and cell culture studies showing that Wnt5a-mediated, noncanonical Wnt signaling contributes to obesity-associated metabolic dysfunction by increasing adipose tissue inflammation. Wnt5a expression is significantly upregulated in human visceral fat compared with subcutaneous fat in obese individuals. In obese mice, Wnt5a ablation ameliorates insulin resistance, in parallel with reductions in adipose tissue inflammation. Conversely, Wnt5a overexpression in myeloid cells augments adipose tissue inflammation and leads to greater impairments in glucose homeostasis. Wnt5a ablation or overexpression did not affect fat mass or adipocyte size. Mechanistically, Wnt5a promotes the expression of proinflammatory cytokines by macrophages in a Jun NH2-terminal kinase-dependent manner, leading to defective insulin signaling in adipocytes. Exogenous interleukin-6 administration restores insulin resistance in obese Wnt5a-deficient mice, suggesting a central role for this cytokine in Wnt5a-mediated metabolic dysfunction. Taken together, these results demonstrate that noncanonical Wnt signaling contributes to obesity-induced insulin resistance independent of adipose tissue expansion. © 2015 by the American Diabetes Association. Readers may use this article as long as the work is properly cited, the use is educational and not for profit, and the work is not altered.

  9. Abnormal Wnt and PI3Kinase signaling in the malformed intestine of lama5 deficient mice.

    Directory of Open Access Journals (Sweden)

    Léa Ritié

    Full Text Available Laminins are major constituents of basement membranes and are essential for tissue homeostasis. Laminin-511 is highly expressed in the intestine and its absence causes severe malformation of the intestine and embryonic lethality. To understand the mechanistic role of laminin-511 in tissue homeostasis, we used RNA profiling of embryonic intestinal tissue of lama5 knockout mice and identified a lama5 specific gene expression signature. By combining cell culture experiments with mediated knockdown approaches, we provide a mechanistic link between laminin α5 gene deficiency and the physiological phenotype. We show that laminin α5 plays a crucial role in both epithelial and mesenchymal cell behavior by inhibiting Wnt and activating PI3K signaling. We conclude that conflicting signals are elicited in the absence of lama5, which alter cell adhesion, migration as well as epithelial and muscle differentiation. Conversely, adhesion to laminin-511 may serve as a potent regulator of known interconnected PI3K/Akt and Wnt signaling pathways. Thus deregulated adhesion to laminin-511 may be instrumental in diseases such as human pathologies of the gut where laminin-511 is abnormally expressed as it is shown here.

  10. Canonical Wnt signaling in differentiated osteoblasts controls osteoclast differentiation.

    NARCIS (Netherlands)

    Glass, D.A.; Bialek, P.; Ahn, J.D.; Starbuck, M.; Patel, M.S.; Clevers, J.C.; Taketo, M.M.; Long, F.; McMahon, A.P.; Lang, R.A.; Karsenty, G.

    2005-01-01

    Inactivation of beta-catenin in mesenchymal progenitors prevents osteoblast differentiation; inactivation of Lrp5, a gene encoding a likely Wnt coreceptor, results in low bone mass (osteopenia) by decreasing bone formation. These observations indicate that Wnt signaling controls osteoblast

  11. Discovery and characterization of a potent Wnt and hedgehog signaling pathways dual inhibitor.

    Science.gov (United States)

    Ma, Haikuo; Chen, Qin; Zhu, Fang; Zheng, Jiyue; Li, Jiajun; Zhang, Hongjian; Chen, Shuaishuai; Xing, Haimei; Luo, Lusong; Zheng, Long Tai; He, Sudan; Zhang, Xiaohu

    2018-04-10

    Embryonic stem cell pathways such as hedgehog and Wnt pathways are central to the tumorigenic properties of cancer stem cells (CSC). Since CSCs are characterized by their ability to self-renew, form differentiated progeny, and develop resistance to anticancer therapies, targeting the Wnt and hedgehog signaling pathways has been an important strategy for cancer treatment. Although molecules targeting either Wnt or hedgehog are common, to the best of our knowledge, those targeting both pathways have not been documented. Here we report a small molecule (compound 1) that inhibits both Wnt (IC 50  = 0.5 nM) and hedgehog (IC 50  = 71 nM) pathways based on reporter gene assays. We further identified that the molecular target of 1 for Wnt pathway inhibition was porcupine (a member of the membrane-bound O-acyltransferase family of proteins), a post-translational modification node in Wnt signaling; while the target of 1 mitigating hedgehog pathway was Smoothened, a key G protein coupled receptor (GPCR) mediating hedgehog signal transduction. Preliminary analysis of structure-activity-relationship identified key functional elements for hedgehog/Wnt inhibition. In in vivo studies, compound 1 demonstrated good oral exposure and bioavailability while eliciting no overt toxicity in mice. An important consideration in cancer treatment is the potential therapeutic escape through compensatory activation of an interconnected pathway when only one signaling pathway is inhibited. Toward this end, compound 1 may not only lead to the development of new therapeutics for Wnt and hedgehog related cancers, but may also help to develop potential cancer treatment which needs to target Wnt and hedgehog signaling simultaneously. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  12. Canonical Wnts, specifically Wnt-10b, show ability to maintain dermal papilla cells

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    Ouji, Yukiteru, E-mail: oujix@naramed-u.ac.jp; Nakamura-Uchiyama, Fukumi; Yoshikawa, Masahide, E-mail: myoshika@naramed-u.ac.jp

    2013-08-30

    Highlights: •First report on effects of various Wnts on DP cells. •Wnt-10b promoted trichogenesis, while Wnt-3a showed to a limited extent. •Canonical Wnts, specifically Wnt-10b, is important for DP cells maintenance. -- Abstract: Although Wnts are expressed in hair follicles (HFs) and considered to be crucial for maintaining dermal papilla (DP) cells, the functional differences among them remain largely unknown. In the present study, we investigated the effects of Wnts (Wnt-3a, 5a, 10b, 11) on the proliferation of mouse-derived primary DP cells in vitro as well as their trichogenesis-promoting ability using an in vivo skin reconstitution protocol. Wnt-10b promoted cell proliferation and trichogenesis, while Wnt-3a showed those abilities to a limited extent, and Wnt-5a and 11 had no effects. Furthermore, we investigated the effects of these Wnts on cultured DP cells obtained from versican-GFP transgenic mice and found that Wnt-10b had a potent ability to sustain their GFP-positivity. These results suggest that canonical Wnts, specifically Wnt-10b, play important roles in the maintenance of DP cells and trichogenesis.

  13. Effect of oxygen on cardiac differentiation in mouse iPS cells: role of hypoxia inducible factor-1 and Wnt/beta-catenin signaling.

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    Tanya L Medley

    Full Text Available BACKGROUND: Disturbances in oxygen levels have been found to impair cardiac organogenesis. It is known that stem cells and differentiating cells may respond variably to hypoxic conditions, whereby hypoxia may enhance stem cell pluripotency, while differentiation of multiple cell types can be restricted or enhanced under hypoxia. Here we examined whether HIF-1alpha modulated Wnt signaling affected differentiation of iPS cells into beating cardiomyocytes. OBJECTIVE: We investigated whether transient and sustained hypoxia affects differentiation of cardiomyocytes derived from murine induced pluripotent stem (iPS cells, assessed the involvement of HIF-1alpha (hypoxia-inducible factor-1alpha and the canonical Wnt pathway in this process. METHODS: Embryoid bodies (EBs derived from iPS cells were differentiated into cardiomyocytes and were exposed either to 24 h normoxia or transient hypoxia followed by a further 13 days of normoxic culture. RESULTS: At 14 days of differentiation, 59 ± 2% of normoxic EBs were beating, whilst transient hypoxia abolished beating at 14 days and EBs appeared immature. Hypoxia induced a significant increase in Brachyury and islet-1 mRNA expression, together with reduced troponin C expression. Collectively, these data suggest that transient and sustained hypoxia inhibits maturation of differentiating cardiomyocytes. Compared to normoxia, hypoxia increased HIF-1alpha, Wnt target and ligand genes in EBs, as well as accumulation of HIF-1alpha and beta-catenin in nuclear protein extracts, suggesting involvement of the Wnt/beta-catenin pathway. CONCLUSION: Hypoxia impairs cardiomyocyte differentiation and activates Wnt signaling in undifferentiated iPS cells. Taken together the study suggests that oxygenation levels play a critical role in cardiomyocyte differentiation and suggest that hypoxia may play a role in early cardiogenesis.

  14. Regulation of Wnt signaling by nociceptive input in animal models

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    Shi Yuqiang

    2012-06-01

    Full Text Available Abstract Background Central sensitization-associated synaptic plasticity in the spinal cord dorsal horn (SCDH critically contributes to the development of chronic pain, but understanding of the underlying molecular pathways is still incomplete. Emerging evidence suggests that Wnt signaling plays a crucial role in regulation of synaptic plasticity. Little is known about the potential function of the Wnt signaling cascades in chronic pain development. Results Fluorescent immunostaining results indicate that β-catenin, an essential protein in the canonical Wnt signaling pathway, is expressed in the superficial layers of the mouse SCDH with enrichment at synapses in lamina II. In addition, Wnt3a, a prototypic Wnt ligand that activates the canonical pathway, is also enriched in the superficial layers. Immunoblotting analysis indicates that both Wnt3a a β-catenin are up-regulated in the SCDH of various mouse pain models created by hind-paw injection of capsaicin, intrathecal (i.t. injection of HIV-gp120 protein or spinal nerve ligation (SNL. Furthermore, Wnt5a, a prototypic Wnt ligand for non-canonical pathways, and its receptor Ror2 are also up-regulated in the SCDH of these models. Conclusion Our results suggest that Wnt signaling pathways are regulated by nociceptive input. The activation of Wnt signaling may regulate the expression of spinal central sensitization during the development of acute and chronic pain.

  15. Secreted and Transmembrane Wnt Inhibitors and Activators

    Science.gov (United States)

    Cruciat, Cristina-Maria; Niehrs, Christof

    2013-01-01

    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

  16. Transcriptomic analysis of Portunus trituberculatus reveals a critical role for WNT4 and WNT signalling in limb regeneration.

    Science.gov (United States)

    Liu, Lei; Fu, Yuanyuan; Zhu, Fang; Mu, Changkao; Li, Ronghua; Song, Weiwei; Shi, Ce; Ye, Yangfang; Wang, Chunlin

    2018-06-05

    The swimming crab (Portunus trituberculatus) is among the most economically important seawater crustacean species in Asia. Despite its commercial importance and being well-studied status, genomic and transcriptomic data are scarce for this crab species. In the present study, limb bud tissue was collected at different developmental stages post amputation for transcriptomic analysis. Illumina RNA-sequencing was applied to characterise the limb regeneration transcriptome and identify the most characteristic genes. A total of 289,018 transcripts were obtained by clustering and assembly of clean reads, producing 150,869 unigenes with an average length of 956 bp. Subsequent analysis revealed WNT signalling as the key pathway involved in limb regeneration, with WNT4 a key mediator. Overall, limb regeneration appears to be regulated by multiple signalling pathways, with numerous cell differentiation, muscle growth, moult, metabolism, and immune-related genes upregulated, including WNT4, LAMA, FIP2, FSTL5, TNC, HUS1, SWI5, NCGL, SLC22, PLA2, Tdc2, SMOX, GDH, and SMPD4. This is the first experimental study done on regenerating claws of P. trituberculatus. These findings expand existing sequence resources for crab species, and will likely accelerate research into regeneration and development in crustaceans, particularly functional studies on genes involved in limb regeneration. Copyright © 2018 Elsevier B.V. All rights reserved.

  17. Ilexonin A Promotes Neuronal Proliferation and Regeneration via Activation of the Canonical Wnt Signaling Pathway after Cerebral Ischemia Reperfusion in Rats

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    Bi-Qin Zhang

    2016-01-01

    Full Text Available Aims. Ilexonin A (IA, a component of the Chinese medicine Ilex pubescens, has been shown to be neuroprotective during ischemic injury. However, the specific mechanism underlying this neuroprotective effect remains unclear. Methods. In this study, we employed a combination of immunofluorescence staining, western blotting, RT-PCR, and behavioral tests, to investigate the molecular mechanisms involved in IA regulation of neuronal proliferation and regeneration after cerebral ischemia and reperfusion in rodents. Results. Increases in β-catenin protein and LEF1 mRNA and decreases in GSK3β protein and Axin mRNA observed in IA-treated compared to control rodents implicated the canonical Wnt pathway as a key signaling mechanism activated by IA treatment. Furthermore, rodents in the IA treatment group showed less neurologic impairment and a corresponding increase in the number of Brdu/nestin and Brdu/NeuN double positive neurons in the parenchymal ischemia tissue following middle cerebral artery occlusion compared to matched controls. Conclusion. Altogether, our data indicate that IA can significantly diminish neurological deficits associated with cerebral ischemia reperfusion in rats as a result of increased neuronal survival via modulation of the canonical Wnt pathway.

  18. Updating the Wnt pathways

    Science.gov (United States)

    Yu, Jia; Virshup, David M.

    2014-01-01

    In the three decades since the discovery of the Wnt1 proto-oncogene in virus-induced mouse mammary tumours, our understanding of the signalling pathways that are regulated by the Wnt proteins has progressively expanded. Wnts are involved in an complex signalling network that governs multiple biological processes and cross-talk with multiple additional signalling cascades, including the Notch, FGF (fibroblast growth factor), SHH (Sonic hedgehog), EGF (epidermal growth factor) and Hippo pathways. The Wnt signalling pathway also illustrates the link between abnormal regulation of the developmental processes and disease manifestation. Here we provide an overview of Wnt-regulated signalling cascades and highlight recent advances. We focus on new findings regarding the dedicated Wnt production and secretion pathway with potential therapeutic targets that might be beneficial for patients with Wnt-related diseases. PMID:25208913

  19. Interleukin-1β-induced autophagy-related gene 5 regulates proliferation of embryonic stem cell-derived odontoblastic cells.

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    Nobuaki Ozeki

    Full Text Available We previously established a method for the differentiation of induced pluripotent stem cells and embryonic stem cells into α2 integrin-positive odontoblast-like cells. We also reported that Wnt5 in response to interleukin (IL-1β induces matrix metalloproteinase (MMP-3-regulated cell proliferation in these cells. Our findings suggest that MMP-3 plays a potentially unique physiological role in the generation of odontoblast-like cells under an inflammatory state. Here, we examined whether up-regulation of autophagy-related gene (Atg 5 by IL-1β was mediated by Wnt5 signaling, thus leading to increased proliferation of odontoblast-like cells. IL-1β increased the mRNA and protein levels of Atg5, microtubule-associated protein 1 light chain (LC3, a mammalian homolog of yeast Atg8 and Atg12. Treatment with siRNAs against Atg5, but not LC3 and Atg12, suppressed the IL-1β-induced increase in MMP-3 expression and cell proliferation. Our siRNA analyses combined with western blot analysis revealed a unique sequential cascade involving Atg5, Wnt5a and MMP-3, which resulted in the potent increase in odontoblastic cell proliferation. These results demonstrate the unique involvement of Atg5 in IL-1β-induced proliferation of embryonic stem cell-derived odontoblast-like cells.

  20. APC Inhibits Ligand-Independent Wnt Signaling by the Clathrin Endocytic Pathway.

    Science.gov (United States)

    Saito-Diaz, Kenyi; Benchabane, Hassina; Tiwari, Ajit; Tian, Ai; Li, Bin; Thompson, Joshua J; Hyde, Annastasia S; Sawyer, Leah M; Jodoin, Jeanne N; Santos, Eduardo; Lee, Laura A; Coffey, Robert J; Beauchamp, R Daniel; Williams, Christopher S; Kenworthy, Anne K; Robbins, David J; Ahmed, Yashi; Lee, Ethan

    2018-03-12

    Adenomatous polyposis coli (APC) mutations cause Wnt pathway activation in human cancers. Current models for APC action emphasize its role in promoting β-catenin degradation downstream of Wnt receptors. Unexpectedly, we find that blocking Wnt receptor activity in APC-deficient cells inhibits Wnt signaling independently of Wnt ligand. We also show that inducible loss of APC is rapidly followed by Wnt receptor activation and increased β-catenin levels. In contrast, APC2 loss does not promote receptor activation. We show that APC exists in a complex with clathrin and that Wnt pathway activation in APC-deficient cells requires clathrin-mediated endocytosis. Finally, we demonstrate conservation of this mechanism in Drosophila intestinal stem cells. We propose a model in which APC and APC2 function to promote β-catenin degradation, and APC also acts as a molecular "gatekeeper" to block receptor activation via the clathrin pathway. Copyright © 2018 Elsevier Inc. All rights reserved.

  1. Functional Wnt signaling is increased in idiopathic pulmonary fibrosis.

    Directory of Open Access Journals (Sweden)

    Melanie Königshoff

    Full Text Available BACKGROUND: Idiopathic pulmonary fibrosis (IPF is a fatal lung disease, characterized by distorted lung architecture and loss of respiratory function. Alveolar epithelial cell injury and hyperplasia, enhanced extracellular matrix deposition, and (myofibroblast activation are features of IPF. Wnt/beta-catenin signaling has been shown to determine epithelial cell fate during development. As aberrant reactivation of developmental signaling pathways has been suggested to contribute to IPF pathogenesis, we hypothesized that Wnt/beta-catenin signaling is activated in epithelial cells in IPF. Thus, we quantified and localized the expression and activity of the Wnt/beta-catenin pathway in IPF. METHODOLOGY/PRINCIPAL FINDINGS: The expression of Wnt1, 3a, 7b, and 10b, the Wnt receptors Fzd1-4, Lrp5-6, as well as the intracellular signal transducers Gsk-3beta, beta-catenin, Tcf1, 3, 4, and Lef1 was analyzed in IPF and transplant donor lungs by quantitative real-time (qRT-PCR. Wnt1, 7b and 10b, Fzd2 and 3, beta-catenin, and Lef1 expression was significantly increased in IPF. Immunohistochemical analysis localized Wnt1, Wnt3a, beta-catenin, and Gsk-3beta expression largely to alveolar and bronchial epithelium. This was confirmed by qRT-PCR of primary alveolar epithelial type II (ATII cells, demonstrating a significant increase of Wnt signaling in ATII cells derived from IPF patients. In addition, Western blot analysis of phospho-Gsk-3beta, phospho-Lrp6, and beta-catenin, and qRT-PCR of the Wnt target genes cyclin D1, Mmp 7, or Fibronectin 1 demonstrated increased functional Wnt/beta-catenin signaling in IPF compared with controls. Functional in vitro studies further revealed that Wnt ligands induced lung epithelial cell proliferation and (myofibroblast activation and collagen synthesis. CONCLUSIONS/SIGNIFICANCE: Our study demonstrates that the Wnt/beta-catenin pathway is expressed and operative in adult lung epithelium. Increased Wnt/beta-catenin signaling

  2. Low-level lasers on microRNA and uncoupling protein 2 mRNA levels in human breast cancer cells

    Science.gov (United States)

    Canuto, K. S.; Teixeira, A. F.; Rodrigues, J. A.; Paoli, F.; Nogueira, E. M.; Mencalha, A. L.; Fonseca, A. S.

    2017-06-01

    MicroRNA is short non-coding RNA and is a mediator of post-transcriptional regulation of gene expression. In addition, uncoupling proteins (UCPs) regulate thermogenesis, metabolic and energy balance, and decrease reactive oxygen species production. Both microRNA and UCP2 expression can be altered in cancer cells. At low power, laser wavelength, frequency, fluence and emission mode deternube photobiological responses, which are the basis of low-level laser therapy. There are few studies on miRNA and UCP mRNA levels after low-level laser exposure on cancer cells. In this work, we evaluate the micrRNA (mir-106b and mir-15a) and UCP2 mRNA levels in human breast cancer cells exposed to low-level lasers. MDA-MB-231 human breast cancer cells were exposed to low-level red and infrared lasers, total RNA was extracted for cDNA synthesis and mRNA levels by real time quantitative polymerase chain reaction were evaluated. Data show that mir-106b and mir-15a relative levels are not altered, but UCP2 mRNA relative levels are increased in MDA-MB-231 human breast cancer cells exposed to low-level red and infrared lasers at fluences used in therapeutic protocols.

  3. Amphioxus Sp5 is a member of a conserved Specificity Protein complement and is modulated by Wnt/beta-catenin signalling

    Czech Academy of Sciences Publication Activity Database

    Dailey, S.C.; Kozmiková, Iryna; Somorjai, I.M.L.

    2017-01-01

    Roč. 61, č. 10-12 (2017), s. 723-732 ISSN 0214-6282 R&D Projects: GA ČR GC15-21285J Institutional support: RVO:68378050 Keywords : Specificity protein * Brachyury * Branchiostoma * Wnt * Sp5 Subject RIV: EB - Gene tics ; Molecular Biology OBOR OECD: Biology (theoretical, mathematical, thermal, cryobiology, biological rhythm), Evolutionary biology Impact factor: 1.981, year: 2016

  4. Downregulation of adenomatous polyposis coli by microRNA-663 promotes odontogenic differentiation through activation of Wnt/beta-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae-Sung; Park, Min-Gyeong; Lee, Seul Ah; Park, Sun-Young; Kim, Heung-Joong; Yu, Sun-Kyoung; Kim, Chun Sung; Kim, Su-Gwan; Oh, Ji-Su; You, Jae-Seek; Kim, Jin-Soo; Seo, Yo-Seob [Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 501-759 (Korea, Republic of); Chun, Hong Sung [Department of Biomedical Science, Chosun University, Gwangju 501-759 (Korea, Republic of); Park, Joo-Cheol [Department of Oral Histology-Developmental Biology, School of Dentistry and Dental Research Institute, BK 21, Seoul National University, Seoul 110-749 (Korea, Republic of); Kim, Do Kyung, E-mail: kdk@chosun.ac.kr [Oral Biology Research Institute, School of Dentistry, Chosun University, Gwangju 501-759 (Korea, Republic of)

    2014-04-18

    Highlights: • miR-663 is significantly up-regulated during MDPC-23 odontoblastic cell differentiation. • miR-663 accelerates mineralization in MDPC-23 odontoblastic cells without cell proliferation. • miR-663 promotes odontoblastic cell differentiation by targeting APC and activating Wnt/β-catenin signaling in MDPC-23 cells. - Abstract: MicroRNAs (miRNAs) regulate cell differentiation by inhibiting mRNA translation or by inducing its degradation. However, the role of miRNAs in odontogenic differentiation is largely unknown. In this present study, we observed that the expression of miR-663 increased significantly during differentiation of MDPC-23 cells to odontoblasts. Furthermore, up-regulation of miR-663 expression promoted odontogenic differentiation and accelerated mineralization without proliferation in MDPC-23 cells. In addition, target gene prediction for miR-663 revealed that the mRNA of the adenomatous polyposis coli (APC) gene, which is associated with the Wnt/β-catenin signaling pathway, has a miR-663 binding site in its 3′-untranslated region (3′UTR). Furthermore, APC expressional was suppressed significantly by miR-663, and this down-regulation of APC expression triggered activation of Wnt/β-catenin signaling through accumulation of β-catenin in the nucleus. Taken together, these findings suggest that miR-663 promotes differentiation of MDPC-23 cells to odontoblasts by targeting APC-mediated activation of Wnt/β-catenin signaling. Therefore, miR-663 can be considered a critical regulator of odontoblast differentiation and can be utilized for developing miRNA-based therapeutic agents.

  5. Collagen mRNA levels changes during colorectal cancer carcinogenesis

    DEFF Research Database (Denmark)

    Skovbjerg, Hanne; Anthonsen, Dorit; Lothe, Inger M B

    2009-01-01

    BACKGROUND: Invasive growth of epithelial cancers is a complex multi-step process which involves dissolution of the basement membrane. Type IV collagen is a major component in most basement membranes. Type VII collagen is related to anchoring fibrils and is found primarily in the basement membrane...... zone of stratified epithelia. Immunohistochemical studies have previously reported changes in steady-state levels of different alpha(IV) chains in several epithelial cancer types. In the present study we aimed to quantitatively determine the mRNA levels of type IV collagen (alpha1/alpha 4/alpha 6......) and type VII collagen (alpha1) during colorectal cancer carcinogenesis. METHODS: Using quantitative RT-PCR, we have determined the mRNA levels for alpha1(IV), alpha 4(IV), alpha 6(IV), and alpha1(VII) in colorectal cancer tissue (n = 33), adenomas (n = 29) and in normal tissue from the same individuals...

  6. Inhibition of Wnt/β-catenin signaling by a soluble collagen-derived frizzled domain interacting with Wnt3a and the receptors frizzled 1 and 8.

    Directory of Open Access Journals (Sweden)

    Ismaïl Hendaoui

    Full Text Available The Wnt/β-catenin pathway controls cell proliferation, death and differentiation. Several families of extracellular proteins can antagonize Wnt/β-catenin signaling, including the decoy receptors known as secreted frizzled related proteins (SFRPs, which have a cysteine-rich domain (CRD structurally similar to the extracellular Wnt-binding domain of the frizzled receptors. SFRPs inhibit Wnt signaling by sequestering Wnts through the CRD or by forming inactive complexes with the frizzled receptors. Other endogenous molecules carrying frizzled CRDs inhibit Wnt signaling, such as V3Nter, which is proteolytically derived from the cell surface component collagen XVIII and contains a biologically active frizzled domain (FZC18 inhibiting in vivo cell proliferation and tumor growth in mice. We recently showed that FZC18 expressing cells deliver short-range signals to neighboring cells, decreasing their proliferation in vitro and in vivo through the Wnt/β-catenin signaling pathway. Here, using low concentrations of soluble FZC18 and Wnt3a, we show that they physically interact in a cell-free system. In addition, soluble FZC18 binds the frizzled 1 and 8 receptors' CRDs, reducing cell sensitivity to Wnt3a. Conversely, inhibition of Wnt/β-catenin signaling was partially rescued by the expression of full-length frizzled 1 and 8 receptors, but enhanced by the expression of a chimeric cell-membrane-tethered frizzled 8 CRD. Moreover, soluble, partially purified recombinant FZC18_CRD inhibited Wnt3a-induced β-catenin activation. Taken together, the data indicate that collagen XVIII-derived frizzled CRD shifts Wnt sensitivity of normal cells to a lower pitch and controls their growth.

  7. Role of WNT signaling in epididymal sperm maturation.

    Science.gov (United States)

    Cheng, Jin-Mei; Tang, Ji-Xin; Li, Jian; Wang, Yu-Qian; Wang, Xiu-Xia; Zhang, Yan; Chen, Su-Ren; Liu, Yi-Xun

    2018-02-01

    Spermatozoa maturation, a process required for spermatozoa to acquire progressive motility and the ability to fertilize ova, primarily occurs in the caput and corpus of the epididymis. Despite considerable efforts, the factor(s) promoting epididymal sperm maturation remains unclear. Recently, WNT signaling has been implicated in epididymal sperm maturation. To further investigate WNT signaling function in epididymal sperm maturation, we generated Wntless conditional knockout mice (Wls cKO), Wls flox/flox ; Lcn5-Cre. In these mice, WNTLESS (WLS), a conserved membrane protein required for all WNT protein secretion, was specifically disrupted in the principal cells of the caput epididymidis. Immunoblot analysis showed that WLS was significantly reduced in the caput epididymidis of Wls cKO mice. In the caput epididymidis of Wls cKO mice, WNT 10A and WNT 2b, which are typically secreted by the principal cells of the caput epididymis, were not secreted. Interestingly, sperm motility analysis showed that the WLS deficiency in the caput epididymidis had no effect on sperm motility. Moreover, fertility tests showed that Wls cKO male mice had normal fertility. These results indicate that the disruption of WLS in principal cells of the caput epididymidis inhibits WNT protein secretion but has no effect on sperm motility and male fertility, suggesting that WNT signaling in the caput epididymidis may be dispensable for epididymal sperm maturation in mice.

  8. Wnt signaling requires retromer-dependent recycling of MIG-14/Wntless in Wnt-producing cells.

    NARCIS (Netherlands)

    Yang, P.T.; Lorenowicz, M.J.; Silhankova, M.; Coudreuse, D.Y.M.; Betist, M.C.; Korswagen, H.C.

    2008-01-01

    Wnt proteins are secreted signaling molecules that play a central role in development and adult tissue homeostasis. We have previously shown that Wnt signaling requires retromer function in Wnt-producing cells. The retromer is a multiprotein complex that mediates endosome-to-Golgi transport of

  9. A Monoclonal Antibody against Wnt-1 Induces Apoptosis in Human Cancer Cells

    Directory of Open Access Journals (Sweden)

    Biao He

    2004-01-01

    Full Text Available Aberrant activation of the Wingless-type (Wnt/β-catenin signaling pathway is associated with a variety of human cancers. Little is known regarding the role that Wnt ligands play in human carcinogenesis. To test whether a Wnt-1 signal is a survival factor in human cancer cells and thus may serve as a potential cancer therapeutic target, we investigated the effect of inhibition of Wnt-1 signaling in a variety of human cancer cell lines, including non small cell lung cancer, breast cancer, mesothelioma, and sarcoma. Both monoclonal antibody and RNA interference (RNAi were used to inhibit Wnt-1 signaling. We found that incubation of a monoclonal anti-Wnt-1 antibody induced apoptosis and caused downstream protein changes in cancer cells overexpressing Wnt-1. In contrast, apoptosis was not detected in cells lacking or having minimal Wnt-1 expression after the antibody incubation. RNAi targeting of Wnt-1 in cancer cells overexpressing Wnt-1 demonstrated similar downstream protein changes and induction of apoptosis. The antibody also suppressed tumor growth in vivo. Our results indicate that both monoclonal anti-Wnt-1 antibody and Wnt-1 siRNA inhibit Wnt-1 signaling and can induce apoptosis in human cancer cells. These findings hold promise as a novel therapeutic strategy for cancer.

  10. Inhibition of adipocytogenesis by canonical WNT signaling in human mesenchymal stem cells

    International Nuclear Information System (INIS)

    Shen, Longxiang; Glowacki, Julie; Zhou, Shuanhu

    2011-01-01

    The WNT signaling pathway plays important roles in the self-renewal and differentiation of mesenchymal stem cells (MSCs). Little is known about WNT signaling in adipocyte differentiation of human MSCs. In this study, we tested the hypothesis that canonical and non-canonical WNTs differentially regulate in vitro adipocytogenesis in human MSCs. The expression of adipocyte gene PPARγ2, lipoprotein lipase, and adipsin increased during adipocytogenesis of hMSCs. Simultaneously, the expression of canonical WNT2, 10B, 13, and 14 decreased, whereas non-canonical WNT4 and 11 increased, and WNT5A was unchanged. A small molecule WNT mimetic, SB-216763, increased accumulation of β-catenin protein, inhibited induction of WNT4 and 11 and inhibited adipocytogenesis. In contrast, knockdown of β-catenin with siRNA resulted in spontaneous adipocytogenesis. These findings support the view that canonical WNT signaling inhibits and non-canonical WNT signaling promotes adipocytogenesis in adult human marrow-derived mesenchymal stem cells.

  11. IER5 gene's mRNA expression after irradiation

    International Nuclear Information System (INIS)

    Ding Kuke; Shen Jingjing; Xu Lili; Li Yanling; Zhou Ping; Ma Binrong; Zhao Zengqiang; Sui Jianli; Zhou Pingkun

    2008-01-01

    Objective: To explore the effect of irradiation on IER5 gene expression. Methods: Two kinds of cells (AHH-1 and HeLa) and the BALB/c-nu mice inoculated with tumor cells were exposed to 60 Co γ- rays and analyzed by real-time PCR. The above-mentioned irradiated objects were firstly divided into groups by different doses and post-radiation time, then mRNA were extracted and reverse-transcripted to DNA before real-time PCR test. Results: Under the same condition, AHH-1 was more sensitive to radiation than HeLa. The dose level corresponding to the expression peak of AHH-1 was less than that of HeLa. For AHH-1 cells, the response to 2 Gy irradiation was earlier than that to 10 Gy. But there was not remarkable difference for HeLa response between 2 and 10 Gy, and the top transcriptional levels for both cells nearly simultaneously appeared at 2 h after irradiation. In addition, the IER5 gene of human liver tumor was more sensitive than that of lung cancer and brain tumor. Conclusions: IER5 might be a candidate biomarker of radiation injury, and had the potential value in radiation-therapy for liver tumor. (authors)

  12. Activation of Wnt Planar Cell Polarity (PCP) signaling promotes growth plate column formation in vitro.

    Science.gov (United States)

    Randall, Rachel M; Shao, Yvonne Y; Wang, Lai; Ballock, R Tracy

    2012-12-01

    Disrupting the Wnt Planar Cell Polarity (PCP) signaling pathway in vivo results in loss of columnar growth plate architecture, but it is unknown whether activation of this pathway in vitro is sufficient to promote column formation. We hypothesized that activation of the Wnt PCP pathway in growth plate chondrocyte cell pellets would promote columnar organization in these cells that are normally oriented randomly in culture. Rat growth plate chondrocytes were transfected with plasmids encoding the Fzd7 cell-surface Wnt receptor, a Fzd7 deletion mutant lacking the Wnt-binding domain, or Wnt receptor-associated proteins Ror2 or Vangl2, and then cultured as three-dimensional cell pellets in the presence of recombinant Wnt5a or Wnt5b for 21 days. Cellular morphology was evaluated using histomorphometric measurements. Activation of Wnt PCP signaling components promoted the initiation of columnar morphogenesis in the chondrocyte pellet culture model, as measured by histomorphometric analysis of the column index (ANOVA p = 0.01). Activation of noncanonical Wnt signaling through overexpression of both the cell-surface Wnt receptor Fzd7 and receptor-associated protein Ror2 with addition of recombinant Wnt5a promotes the initiation of columnar architecture of growth plate chondrocytes in vitro, representing an important step toward growth plate regeneration. Copyright © 2012 Orthopaedic Research Society.

  13. Wnt signaling in limb organogenesis

    OpenAIRE

    Geetha-Loganathan, Poongodi; Nimmagadda, Suresh; Scaal, Martin

    2008-01-01

    Secreted signaling molecules of the Wnt family have been found to play a central role in controlling embryonic development of a wide range of taxa from Hydra to humans. The most extensively studied Wnt signaling pathway is the canonical Wnt pathway, which controls gene expression by stabilizing β-catenin, and regulates a multitude of developmental processes. More recently, noncanonical Wnt pathways, which are β-catenin-independent, have been found to be important developmental regulators. Und...

  14. Modulating Wnt Signaling Rescues Palate Morphogenesis in Pax9 Mutant Mice.

    Science.gov (United States)

    Li, C; Lan, Y; Krumlauf, R; Jiang, R

    2017-10-01

    Cleft palate is a common birth defect caused by disruption of palatogenesis during embryonic development. Although mutations disrupting components of the Wnt signaling pathway have been associated with cleft lip and palate in humans and mice, the mechanisms involving canonical Wnt signaling and its regulation in secondary palate development are not well understood. Here, we report that canonical Wnt signaling plays an important role in Pax9-mediated regulation of secondary palate development. We found that cleft palate pathogenesis in Pax9-deficient embryos is accompanied by significantly reduced expression of Axin2, an endogenous target of canonical Wnt signaling, in the developing palatal mesenchyme, particularly in the posterior regions of the palatal shelves. We found that expression of Dkk2, encoding a secreted Wnt antagonist, is significantly increased whereas the levels of active β-catenin protein, the essential transcriptional coactivator of canonical Wnt signaling, is significantly decreased in the posterior regions of the palatal shelves in embryonic day 13.5 Pax9-deficent embryos in comparison with control littermates. We show that small molecule-mediated inhibition of Dickkopf (DKK) activity in utero during palatal shelf morphogenesis partly rescued secondary palate development in Pax9-deficient embryos. Moreover, we found that genetic inactivation of Wise, which is expressed in the developing palatal shelves and encodes another secreted antagonist of canonical Wnt signaling, also rescued palate morphogenesis in Pax9-deficient mice. Furthermore, whereas Pax9 del/del embryos exhibit defects in palatal shelf elevation/reorientation and significant reduction in accumulation of hyaluronic acid-a high molecular extracellular matrix glycosaminoglycan implicated in playing an important role in palatal shelf elevation-80% of Pax9 del/del ;Wise -/- double-mutant mouse embryos exhibit rescued palatal shelf elevation/reorientation, accompanied by restored

  15. Overexpression of miR‑21 promotes neural stem cell proliferation and neural differentiation via the Wnt/β‑catenin signaling pathway in vitro.

    Science.gov (United States)

    Zhang, Wei-Min; Zhang, Zhi-Ren; Yang, Xi-Tao; Zhang, Yong-Gang; Gao, Yan-Sheng

    2018-01-01

    The primary aim of the present study was to examine the effects of microRNA‑21 (miR‑21) on the proliferation and differentiation of rat primary neural stem cells (NSCs) in vitro. miR‑21 was overexpressed in NSCs by transfection with a miR‑21 mimic. The effects of miR‑21 overexpression on NSC proliferation were revealed by Cell Counting kit 8 and 5‑ethynyl‑2'‑deoxyuridine incorporation assay, and miR‑21 overexpression was revealed to increase NSC proliferation. miR‑21 overexpression was confirmed using reverse transcription‑quantitative polymerase chain reaction (RT‑qPCR). mRNA and protein expression levels of key molecules (β‑catenin, cyclin D1, p21 and miR‑21) in the Wnt/β‑catenin signaling pathway were studied by RT‑qPCR and western blot analysis. RT‑qPCR and western blot analyses revealed that miR‑21 overexpression increased β‑catenin and cyclin D1 expression, and decreased p21 expression. These results suggested that miR‑21‑induced increase in proliferation was mediated by activation of the Wnt/β‑catenin signaling pathway, since overexpression of miR‑21 increased β‑catenin and cyclin D1 expression and reduced p21 expression. Furthermore, inhibition of the Wnt/β‑catenin pathway with FH535 attenuated the influence of miR‑21 overexpression on NSC proliferation, indicating that the factors activated by miR‑21 overexpression were inhibited by FH535 treatment. Furthermore, overexpression of miR‑21 enhanced the differentiation of NSCs into neurons and inhibited their differentiation into astrocytes. The present study indicated that in primary rat NSCs, overexpression of miR‑21 may promote proliferation and differentiation into neurons via the Wnt/β‑catenin signaling pathway in vitro.

  16. Dual Function of Wnt Signaling during Neuronal Differentiation of Mouse Embryonic Stem Cells

    Directory of Open Access Journals (Sweden)

    Hanjun Kim

    2015-01-01

    Full Text Available Activation of Wnt signaling enhances self-renewal of mouse embryonic and neural stem/progenitor cells. In contrast, undifferentiated ES cells show a very low level of endogenous Wnt signaling, and ectopic activation of Wnt signaling has been shown to block neuronal differentiation. Therefore, it remains unclear whether or not endogenous Wnt/β-catenin signaling is necessary for self-renewal or neuronal differentiation of ES cells. To investigate this, we examined the expression profiles of Wnt signaling components. Expression levels of Wnts known to induce β-catenin were very low in undifferentiated ES cells. Stable ES cell lines which can monitor endogenous activity of Wnt/β-catenin signaling suggest that Wnt signaling was very low in undifferentiated ES cells, whereas it increased during embryonic body formation or neuronal differentiation. Interestingly, application of small molecules which can positively (BIO, GSK3β inhibitor or negatively (IWR-1-endo, Axin stabilizer control Wnt/β-catenin signaling suggests that activation of that signaling at different time periods had differential effects on neuronal differentiation of 46C ES cells. Further, ChIP analysis suggested that β-catenin/TCF1 complex directly regulated the expression of Sox1 during neuronal differentiation. Overall, our data suggest that Wnt/β-catenin signaling plays differential roles at different time points of neuronal differentiation.

  17. Targeting Wnt Pathways in Disease

    Science.gov (United States)

    Zimmerman, Zachary F.; Moon, Randall T.

    2012-01-01

    Wnt-mediated signal transduction pathways have long been recognized for their roles in regulating embryonic development, and have more recently been linked to cancer, neurologic diseases, inflammatory diseases, and disorders of endocrine function and bone metabolism in adults. Although therapies targeting Wnt signaling are attractive in theory, in practice it has been difficult to obtain specific therapeutics because many components of Wnt signaling pathways are also involved in other cellular processes, thereby reducing the specificity of candidate therapeutics. New technologies, and advances in understanding the mechanisms of Wnt signaling, have improved our understanding of the nuances of Wnt signaling and are leading to promising new strategies to target Wnt signaling pathways. PMID:23001988

  18. Secreted Wnt antagonists in leukemia: A road yet to be paved.

    Science.gov (United States)

    Pehlivan, Melek; Çalışkan, Ceyda; Yüce, Zeynep; Sercan, Hakki Ogun

    2018-03-28

    Wnt signaling has been a topic of research for many years for its diverse and fundamental functions in physiological (such as embryogenesis, organogenesis, proliferation, tissue repair and cellular differentiation) and pathological (carcinogenesis, congenital/genetic diseases, and tissue degeneration) processes. Wnt signaling pathway aberrations are associated with both solid tumors and hematological malignancies. Unregulated Wnt signaling observed in malignancies may be due to a wide spectrum of abnormalities, from mutations in the genes of key players to epigenetic modifications of Wnt antagonists. Of these, Wnt antagonists are gaining significant attention for their potential of being targets for treatment and inhibition of Wnt signaling. In this review, we discuss and summarize the significance of Wnt signaling antagonists in the pathogenesis and treatment of hematological malignancies. Copyright © 2018 Elsevier Ltd. All rights reserved.

  19. Significance of the BRAF mRNA Expression Level in Papillary Thyroid Carcinoma: An Analysis of The Cancer Genome Atlas Data.

    Directory of Open Access Journals (Sweden)

    Young Jun Chai

    Full Text Available BRAFV600E is the most common mutation in papillary thyroid carcinoma (PTC, and it is associated with high-risk prognostic factors. However, the significance of the BRAF mRNA level in PTC remains unknown. We evaluated the significance of BRAF mRNA expression level by analyzing PTC data from The Cancer Genome Atlas (TCGA database.Data from 499 patients were downloaded from the TCGA database. After excluding other PTC variants, we selected 353 cases of classic PTC, including 193 cases with BRAFV600E and 160 cases with the wild-type BRAF. mRNA abundances were measured using RNA-Seq with the Expectation Maximization algorithm.The mean BRAF mRNA level was significantly higher in BRAFV600E patients than in patients with wild-type BRAF (197.6 vs. 179.3, p = 0.031. In wild-type BRAF patients, the mean BRAF mRNA level was higher in cases with a tumor > 2 cm than those with a tumor ≤ 2.0 cm (189.4 vs. 163.8, p = 0.046, and was also higher in cases with lymph node metastasis than in those without lymph node metastasis (188.5 vs. 157.9, p = 0.040. Within BRAFV600E patients, higher BRAF mRNA expression was associated with extrathyroidal extension (186.4 vs. 216.4, p = 0.001 and higher T stage (188.1 vs. 210.2, p = 0.016.A higher BRAF mRNA expression level was associated with tumor aggressiveness in classic PTC regardless of BRAF mutational status. Evaluation of BRAF mRNA level may be helpful in prognostic risk stratification of PTC.

  20. A new synthetic drug 5-(2-aminopropyl)indole (5-IT) induces rewarding effects and increases dopamine D1 receptor and dopamine transporter mRNA levels.

    Science.gov (United States)

    Botanas, Chrislean Jun; Yoon, Seong Shoon; de la Peña, June Bryan; Dela Peña, Irene Joy; Kim, Mikyung; Custodio, Raly James; Woo, Taeseon; Seo, Joung-Wook; Jang, Choon-Gon; Yang, Ji Seul; Yoon, Yoon Mi; Lee, Yong Sup; Kim, Hee Jin; Cheong, Jae Hoon

    2018-04-02

    In recent years, there has been a marked increase in the use of recreational synthetic psychoactive substances, which is a cause of concern among healthcare providers and legal authorities. In particular, there have been reports on the misuse of 5-(2-aminopropyl)indole (5-API; 5-IT), a new synthetic drug, and of fatal and non-fatal intoxication. Despite these reports, little is known about its psychopharmacological effects and abuse potential. Here, we investigated the abuse potential of 5-IT by evaluating its rewarding and reinforcing effects through conditioned place preference (CPP) (1, 10, and 30 mg/kg, i.p.) in mice and self-administration test (0.1, 0.3, 1, and 3 mg/kg/inf., i.v.) in rats. We also examined whether 5-IT (1, 3, and 10 mg/kg, i.p.) induces locomotor sensitization in mice following a 7-day treatment and drug challenge. Then, we explored the effects of 5-IT (10 mg/kg, i.p.) on dopamine-related genes in the striatum, prefrontal cortex (PFC), and substantia nigra pars compacta (SNc)/ventral tegmental (VTA) of mice by quantitative real-time polymerase chain reaction. 5-IT produced CPP in mice but was not reliably self-administered by rats. 5-IT also induced locomotor sensitization following repeated administration and drug challenge. Moreover, 5-IT increased mRNA levels of dopamine D1 receptor in the striatum and PFC and dopamine transporter in the SNc/VTA of mice. These results indicate that 5-IT has psychostimulant and rewarding properties, which may be attributed to its ability to affect the dopaminergic system in the brain. These findings suggest that 5-IT poses a substantial risk for abuse and addiction in humans. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. Crosstalk between Wnt Signaling and RNA Processing in Colorectal Cancer

    Directory of Open Access Journals (Sweden)

    Michael Bordonaro

    2013-01-01

    Full Text Available RNA processing involves a variety of processes affecting gene expression, including the removal of introns through RNA splicing, as well as 3' end processing (cleavage and polyadenylation. Alternative RNA processing is fundamentally important for gene regulation, and aberrant processing is associated with the initiation and progression of cancer. Deregulated Wnt signaling, which is the initiating event in the development of most cases of human colorectal cancer (CRC, has been linked to modified RNA processing, which may contribute to Wnt-mediated colonic carcinogenesis. Crosstalk between Wnt signaling and alternative RNA splicing with relevance to CRC includes effects on the expression of Rac1b, an alternatively spliced gene associated with tumorigenesis, which exhibits alternative RNA splicing that is influenced by Wnt activity. In addition, Tcf4, a crucial component of Wnt signaling, also exhibits alternative splicing, which is likely involved in colonic tumorigenesis. Modulation of 3' end formation, including of the Wnt target gene COX-2, also can influence the neoplastic process, with implications for CRC. While many human genes are dependent on introns and splicing for normal levels of gene expression, naturally intronless genes exist with a unique metabolism that allows for intron-independent gene expression. Effects of Wnt activity on the RNA metabolism of the intronless Wnt-target gene c-jun is a likely contributor to cancer development. Further, butyrate, a breakdown product of dietary fiber and a histone deacetylase inhibitor, upregulates Wnt activity in CRC cells, and also modulates RNA processing; therefore, the interplay between Wnt activity, the modulation of this activity by butyrate, and differential RNA metabolism in colonic cells can significantly influence tumorigenesis. Determining the role played by altered RNA processing in Wnt-mediated neoplasia may lead to novel interventions aimed at restoring normal RNA metabolism for

  2. Crosstalk between Wnt Signaling and RNA Processing in Colorectal Cancer.

    Science.gov (United States)

    Bordonaro, Michael

    2013-01-01

    RNA processing involves a variety of processes affecting gene expression, including the removal of introns through RNA splicing, as well as 3' end processing (cleavage and polyadenylation). Alternative RNA processing is fundamentally important for gene regulation, and aberrant processing is associated with the initiation and progression of cancer. Deregulated Wnt signaling, which is the initiating event in the development of most cases of human colorectal cancer (CRC), has been linked to modified RNA processing, which may contribute to Wnt-mediated colonic carcinogenesis. Crosstalk between Wnt signaling and alternative RNA splicing with relevance to CRC includes effects on the expression of Rac1b, an alternatively spliced gene associated with tumorigenesis, which exhibits alternative RNA splicing that is influenced by Wnt activity. In addition, Tcf4, a crucial component of Wnt signaling, also exhibits alternative splicing, which is likely involved in colonic tumorigenesis. Modulation of 3' end formation, including of the Wnt target gene COX-2, also can influence the neoplastic process, with implications for CRC. While many human genes are dependent on introns and splicing for normal levels of gene expression, naturally intronless genes exist with a unique metabolism that allows for intron-independent gene expression. Effects of Wnt activity on the RNA metabolism of the intronless Wnt-target gene c-jun is a likely contributor to cancer development. Further, butyrate, a breakdown product of dietary fiber and a histone deacetylase inhibitor, upregulates Wnt activity in CRC cells, and also modulates RNA processing; therefore, the interplay between Wnt activity, the modulation of this activity by butyrate, and differential RNA metabolism in colonic cells can significantly influence tumorigenesis. Determining the role played by altered RNA processing in Wnt-mediated neoplasia may lead to novel interventions aimed at restoring normal RNA metabolism for therapeutic benefit

  3. Peripheral T-lymphocytes express WNT7A and its restoration in leukemia-derived lymphoblasts inhibits cell proliferation

    International Nuclear Information System (INIS)

    Ochoa-Hernández, Alejandra B; Bravo-Cuellar, Alejandro; Jave-Suarez, Luis F; Barros-Núñez, Patricio; Aguilar-Lemarroy, Adriana; Ramos-Solano, Moisés; Meza-Canales, Ivan D; García-Castro, Beatriz; Rosales-Reynoso, Mónica A; Rosales-Aviña, Judith A; Barrera-Chairez, Esperanza; Ortíz-Lazareno, Pablo C; Hernández-Flores, Georgina

    2012-01-01

    WNT7a, a member of the Wnt ligand family implicated in several developmental processes, has also been reported to be dysregulated in some types of tumors; however, its function and implication in oncogenesis is poorly understood. Moreover, the expression of this gene and the role that it plays in the biology of blood cells remains unclear. In addition to determining the expression of the WNT7A gene in blood cells, in leukemia-derived cell lines, and in samples of patients with leukemia, the aim of this study was to seek the effect of this gene in proliferation. We analyzed peripheral blood mononuclear cells, sorted CD3 and CD19 cells, four leukemia-derived cell lines, and blood samples from 14 patients with Acute lymphoblastic leukemia (ALL), and 19 clinically healthy subjects. Reverse transcription followed by quantitative Real-time Polymerase chain reaction (qRT-PCR) analysis were performed to determine relative WNT7A expression. Restoration of WNT7a was done employing a lentiviral system and by using a recombinant human protein. Cell proliferation was measured by addition of WST-1 to cell cultures. WNT7a is mainly produced by CD3 T-lymphocytes, its expression decreases upon activation, and it is severely reduced in leukemia-derived cell lines, as well as in the blood samples of patients with ALL when compared with healthy controls (p ≤0.001). By restoring WNT7A expression in leukemia-derived cells, we were able to demonstrate that WNT7a inhibits cell growth. A similar effect was observed when a recombinant human WNT7a protein was used. Interestingly, restoration of WNT7A expression in Jurkat cells did not activate the canonical Wnt/β-catenin pathway. To our knowledge, this is the first report evidencing quantitatively decreased WNT7A levels in leukemia-derived cells and that WNT7A restoration in T-lymphocytes inhibits cell proliferation. In addition, our results also support the possible function of WNT7A as a tumor suppressor gene as well as a therapeutic

  4. Fatty acid modification of Wnt1 and Wnt3a at serine is prerequisite for lipidation at cysteine and is essential for Wnt signalling

    Czech Academy of Sciences Publication Activity Database

    Doubravská, Lenka; Krausová, Michaela; Gradl, D.; Vojtěchová, Martina; Tůmová, Lucie; Lukáš, Jan; Valenta, Tomáš; Pospíchalová, Vendula; Fafílek, Bohumil; Plachý, Jiří; Sebesta, O.; Kořínek, Vladimír

    2011-01-01

    Roč. 23, č. 5 (2011), s. 837-848 ISSN 0898-6568 R&D Projects: GA ČR(CZ) GA204/07/1567; GA MŠk 1M0506 Institutional research plan: CEZ:AV0Z50520514 Keywords : Wnt signaling * post-translational modification * acylation Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 4.058, year: 2011

  5. Multinuclear giant cell formation is enhanced by down-regulation of Wnt signaling in gastric cancer cell line, AGS

    International Nuclear Information System (INIS)

    Kim, Shi-Mun; Kim, Rockki; Ryu, Jae-Hyun; Jho, Eek-Hoon; Song, Ki-Joon; Jang, Shyh-Ing; Kee, Sun-Ho

    2005-01-01

    AGS cells, which were derived from malignant gastric adenocarcinoma tissue, lack E-cadherin-mediated cell adhesion but have a high level of nuclear β-catenin, which suggests altered Wnt signal. In addition, approximately 5% of AGS cells form multinuclear giant cells in the routine culture conditions, while taxol treatment causes most AGS cells to become giant cells. The observation of reduced nuclear β-catenin levels in giant cells induced by taxol treatment prompted us to investigate the relationship between Wnt signaling and giant cell formation. After overnight serum starvation, the shape of AGS cells became flattened, and this morphological change was accompanied by decrease in Myc expression and an increase in the giant cell population. Lithium chloride treatment, which inhibits GSK3β activity, reversed these serum starvation effects, which suggests an inverse relationship between Wnt signaling and giant cell formation. Furthermore, the down-regulation of Wnt signaling caused by the over-expression of ICAT, E-cadherin, and Axin enhanced giant cell formation. Therefore, down-regulation of Wnt signaling may be related to giant cell formation, which is considered to be a survival mechanism against induced cell death

  6. The Effects of the WNT-Signaling Modulators BIO and PKF118-310 on the Chondrogenic Differentiation of Human Mesenchymal Stem Cells.

    Science.gov (United States)

    Huang, Xiaobin; Zhong, Leilei; Hendriks, Jan; Post, Janine N; Karperien, Marcel

    2018-02-13

    Mesenchymal stem cells (MSCs) are multipotent cells, mainly from bone marrow, and an ideal source of cells in bone and cartilage tissue engineering. A study of the chondrogenic differentiation of MSCs is of particular interest for MSCs-based cartilage regeneration. In this study, we aimed to optimize the conditions for the chrondogenic differentiation of MSCs by regulating WNT signaling using the small molecule WNT inhibitor PKF118-310 and activator BIO. Human mesenchymal stem cells (hMSCs) were isolated from bone marrow aspirates and cultured in hMSCs proliferation medium. Pellet culture was subsequently established for three-dimensional chondrogenic differentiation of 5 weeks. WNT signaling was increased by the small molecule glycogen synthase kinase-3 inhibitor 6-bromoindirubin-3-oxim (BIO) and decreased by the WNT inhibitor PKF118-310 (PKF). The effects of BIO and PKF on the chondrogenesis of hMSCs was examined by real-time PCR, histological methods, and ELISA. We found that activation of canonical WNT-signaling by BIO significantly downregulated the expression of cartilage-specific genes SOX9 , COL2A1, and ACAN , and matrix metalloproteinase genes MMP1/3/9/13, but increased ADAMTS 4/5 . Inhibition of WNT signaling by PKF increased the expression of SOX9 , COL2A1 , ACAN , and MMP9, but decreased MMP13 and ADAMTS4/5 . In addition, a high level of WNT signaling induced the expression of hypertrophic markers COL10A1, ALPL , and RUNX2, the dedifferentiation marker COL1A1 , and glycolysis genes GULT1 and PGK1 . Deposition of glycosaminoglycan (GAG) and collagen type II in the pellet matrix was significantly lost in the BIO-treated group and increased in the PKF-treated group. The protein level of COL10A1 was also highly induced in the BIO group. Interestingly, BIO decreased the number of apoptotic cells while PKF significantly induced apoptosis during chondrogenesis. The natural WNT antagonist DKK1 and the protein level of MMP1 in the pellet culture medium were

  7. The Effects of the WNT-Signaling Modulators BIO and PKF118-310 on the Chondrogenic Differentiation of Human Mesenchymal Stem Cells

    Directory of Open Access Journals (Sweden)

    Xiaobin Huang

    2018-02-01

    Full Text Available Mesenchymal stem cells (MSCs are multipotent cells, mainly from bone marrow, and an ideal source of cells in bone and cartilage tissue engineering. A study of the chondrogenic differentiation of MSCs is of particular interest for MSCs-based cartilage regeneration. In this study, we aimed to optimize the conditions for the chrondogenic differentiation of MSCs by regulating WNT signaling using the small molecule WNT inhibitor PKF118-310 and activator BIO. Human mesenchymal stem cells (hMSCs were isolated from bone marrow aspirates and cultured in hMSCs proliferation medium. Pellet culture was subsequently established for three-dimensional chondrogenic differentiation of 5 weeks. WNT signaling was increased by the small molecule glycogen synthase kinase-3 inhibitor 6-bromoindirubin-3-oxim (BIO and decreased by the WNT inhibitor PKF118-310 (PKF. The effects of BIO and PKF on the chondrogenesis of hMSCs was examined by real-time PCR, histological methods, and ELISA. We found that activation of canonical WNT-signaling by BIO significantly downregulated the expression of cartilage-specific genes SOX9, COL2A1, and ACAN, and matrix metalloproteinase genes MMP1/3/9/13, but increased ADAMTS 4/5. Inhibition of WNT signaling by PKF increased the expression of SOX9, COL2A1, ACAN, and MMP9, but decreased MMP13 and ADAMTS4/5. In addition, a high level of WNT signaling induced the expression of hypertrophic markers COL10A1, ALPL, and RUNX2, the dedifferentiation marker COL1A1, and glycolysis genes GULT1 and PGK1. Deposition of glycosaminoglycan (GAG and collagen type II in the pellet matrix was significantly lost in the BIO-treated group and increased in the PKF-treated group. The protein level of COL10A1 was also highly induced in the BIO group. Interestingly, BIO decreased the number of apoptotic cells while PKF significantly induced apoptosis during chondrogenesis. The natural WNT antagonist DKK1 and the protein level of MMP1 in the pellet culture medium were

  8. Sailing with the Wnt: charting the Wnt processing and secretion route

    NARCIS (Netherlands)

    Lorenowicz, M.J.; Korswagen, H.C.

    2009-01-01

    Wnt proteins are members of a highly conserved family of signalling molecules that play a central role in development and disease. During the past years, the different signalling pathways that are triggered by Wnt proteins have been studied in detail, but it is still largely unknown how a functional

  9. Transcriptome analysis of Wnt3a-treated triple-negative breast cancer cells.

    Directory of Open Access Journals (Sweden)

    Sylvie Maubant

    Full Text Available The canonical Wnt/β-catenin pathway is activated in triple-negative breast cancer (TNBC. The activation of this pathway leads to the expression of specific target genes depending on the cell/tissue context. Here, we analyzed the transcriptome of two different TNBC cell lines to define a comprehensive list of Wnt target genes. The treatment of cells with Wnt3a for 6h up-regulated the expression (fold change > 1.3 of 59 genes in MDA-MB-468 cells and 241 genes in HCC38 cells. Thirty genes were common to both cell lines. Beta-catenin may also be a transcriptional repressor and we found that 18 and 166 genes were down-regulated in response to Wnt3a treatment for 6h in MDA-MB-468 and HCC38 cells, respectively, of which six were common to both cell lines. Only half of the activated and the repressed transcripts have been previously described as Wnt target genes. Therefore, our study reveals 137 novel genes that may be positively regulated by Wnt3a and 104 novel genes that may be negatively regulated by Wnt3a. These genes are involved in the Wnt pathway itself, and also in TGFβ, p53 and Hedgehog pathways. Thorough characterization of these novel potential Wnt target genes may reveal new regulators of the canonical Wnt pathway. The comparison of our list of Wnt target genes with those published in other cellular contexts confirms the notion that Wnt target genes are tissue-, cell line- and treatment-specific. Genes up-regulated in Wnt3a-stimulated cell lines were more strongly expressed in TNBC than in luminal A breast cancer samples. These genes were also overexpressed, but to a much lesser extent, in HER2+ and luminal B tumors. We identified 72 Wnt target genes higher expressed in TNBCs (17 with a fold change >1.3 which may reflect the chronic activation of the canonical Wnt pathway that occurs in TNBC tumors.

  10. Hamp1 mRNA and plasma hepcidin levels are influenced by sex and strain but do not predict tissue iron levels in inbred mice.

    Science.gov (United States)

    McLachlan, Stela; Page, Kathryn E; Lee, Seung-Min; Loguinov, Alex; Valore, Erika; Hui, Simon T; Jung, Grace; Zhou, Jie; Lusis, Aldons J; Fuqua, Brie; Ganz, Tomas; Nemeth, Elizabeta; Vulpe, Chris D

    2017-11-01

    Iron homeostasis is tightly regulated, and the peptide hormone hepcidin is considered to be a principal regulator of iron metabolism. Previous studies in a limited number of mouse strains found equivocal sex- and strain-dependent differences in mRNA and serum levels of hepcidin and reported conflicting data on the relationship between hepcidin ( Hamp1 ) mRNA levels and iron status. Our aim was to clarify the relationships between strain, sex, and hepcidin expression by examining multiple tissues and the effects of different dietary conditions in multiple inbred strains. Two studies were done: first, Hamp1 mRNA, liver iron, and plasma diferric transferrin levels were measured in 14 inbred strains on a control diet; and second, Hamp1 mRNA and plasma hepcidin levels in both sexes and iron levels in the heart, kidneys, liver, pancreas, and spleen in males were measured in nine inbred/recombinant inbred strains raised on an iron-sufficient or high-iron diet. Both sex and strain have a significant effect on both hepcidin mRNA (primarily a sex effect) and plasma hepcidin levels (primarily a strain effect). However, liver iron and diferric transferrin levels are not predictors of Hamp1 mRNA levels in mice fed iron-sufficient or high-iron diets, nor are the Hamp1 mRNA and plasma hepcidin levels good predictors of tissue iron levels, at least in males. We also measured plasma erythroferrone, performed RNA-sequencing analysis of liver samples from six inbred strains fed the iron-sufficient, low-iron, or high-iron diets, and explored differences in gene expression between the strains with the highest and lowest hepcidin levels. NEW & NOTEWORTHY Both sex and strain have a significant effect on both hepcidin mRNA (primarily a sex effect) and plasma hepcidin levels (primarily a strain effect). Liver iron and diferric transferrin levels are not predictors of Hamp1 mRNA levels in mice, nor are the Hamp1 mRNA and plasma hepcidin levels good predictors of tissue iron levels, at least

  11. Canonical Wnt signaling in diabetic retinopathy.

    Science.gov (United States)

    Chen, Qian; Ma, Jian-Xing

    2017-10-01

    Diabetic retinopathy (DR) is a common eye complication of diabetes, and the pathogenic mechanism of DR is still under investigation. The canonical Wnt signaling pathway is an evolutionarily conserved pathway that plays fundamental roles in embryogenesis and adult tissue homeostasis. Wnt signaling regulates expression of multiple genes that control retinal development and eye organogenesis, and dysregulated Wnt signaling plays pathophysiological roles in many ocular diseases, including DR. This review highlights recent progress in studies of Wnt signaling in DR. We discuss Wnt signaling regulation in the retina and dysregulation of Wnt signaling associated with ocular diseases with an emphasis on DR. We also discuss the therapeutic potential of modulating Wnt signaling in DR. Continued studies in this field will advance our current understanding on DR and contribute to the development of new treatments. Copyright © 2017 Elsevier Ltd. All rights reserved.

  12. Regulation of mesenchymal stromal cells through fine tuning of canonical Wnt signaling

    Directory of Open Access Journals (Sweden)

    Jin-A Kim

    2015-05-01

    Full Text Available Mesenchymal stromal cells (MSCs have been extensively utilized for various cell therapeutic trials, but the signals regulating their stromal function remain largely unclear. Here, we show that canonical Wnt signals distinctively regulate MSCs in a biphasic manner depending on signal intensity, i.e., MSCs exhibit proliferation and progenitor self-renewal under low Wnt/β-catenin signaling, whereas they exhibit enhanced osteogenic differentiation with priming to osteoblast-like lineages under high Wnt/β-catenin signaling. Moreover, low or high levels of β-catenin in MSCs distinctly regulated the hematopoietic support of MSCs to promote proliferation or the undifferentiated state of hematopoietic progenitors, respectively. A gene expression study demonstrated that different intracellular levels of β-catenin in MSCs induce distinct transcriptomic changes in subsets of genes belonging to different gene function categories. Different β-catenin levels also induced differences in intracellular levels of the β-catenin co-factors, Tcf-1 and Lef-1. Moreover, nano-scale mass spectrometry of proteins that co-precipitated with β-catenin revealed distinctive spectra of proteins selectively interacting with β-catenin at specific expression levels. Together, these results show that Wnt/β-catenin signals can coax distinct transcription milieu to induce different transcription profiles in MSCs depending on the signal intensity and that fine-tuning of the canonical Wnt signaling intensity can regulate the phase-specific functionality of MSCs.

  13. The 0.3-kb fragment containing the R-U5-5'leader sequence of Friend murine leukemia virus influences the level of protein expression from spliced mRNA.

    Science.gov (United States)

    Choo, Yeng Cheng; Seki, Yohei; Machinaga, Akihito; Ogita, Nobuo; Takase-Yoden, Sayaka

    2013-04-19

    A neuropathogenic variant of Friend murine leukemia virus (Fr-MLV) clone A8 induces spongiform neurodegeneration when infected into neonatal rats. Studies with chimeras constructed from the A8 virus and the non-neuropathogenic Fr-MLV clone 57 identified a 0.3-kb KpnI-AatII fragment containing a R-U5-5'leader sequence as an important determinant for inducing spongiosis, in addition to the env gene of A8 as the primary determinant. This 0.3-kb fragment contains a 17-nucleotide difference between the A8 and 57 sequences. We previously showed that the 0.3-kb fragment influences expression levels of Env protein in both cultured cells and rat brain, but the corresponding molecular mechanisms are not well understood. Studies with expression vectors constructed from the full-length proviral genome of Fr-MLV that incorporated the luciferase (luc) gene instead of the env gene found that the vector containing the A8-0.3-kb fragment yielded a larger amount of spliced luc-mRNA and showed higher expression of luciferase when compared to the vector containing the 57-0.3-kb fragment. The amount of total transcripts from the vectors, the poly (A) tail length of their mRNAs, and the nuclear-cytoplasm distribution of luc-mRNA in transfected cells were also evaluated. The 0.3-kb fragment did not influence transcription efficiency, mRNA polyadenylation or nuclear export of luc-mRNA. Mutational analyses were carried out to determine the importance of nucleotides that differ between the A8 and 57 sequences within the 0.3-kb fragment. In particular, seven nucleotides upstream of the 5'splice site (5'ss) were found to be important in regulating the level of protein expression from spliced messages. Interestingly, these nucleotides reside within the stem-loop structure that has been speculated to limit the recognition of 5'ss. The 0.3-kb fragment containing the R-U5-5'leader sequence of Fr-MLV influences the level of protein expression from the spliced-mRNA by regulating the splicing

  14. A hairpin within YAP mRNA 3′UTR functions in regulation at post-transcription level

    Energy Technology Data Exchange (ETDEWEB)

    Gao, Yuen; Wang, Yuan; Feng, Jinyan; Feng, Guoxing; Zheng, Minying; Yang, Zhe; Xiao, Zelin; Lu, Zhanping [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China); Ye, Lihong [State Key Laboratory of Medicinal Chemical Biology, Department of Biochemistry, College of Life Sciences, Nankai University, Tianjin 300071 (China); Zhang, Xiaodong, E-mail: zhangxd@nankai.edu.cn [State Key Laboratory of Medicinal Chemical Biology, Department of Cancer Research, College of Life Sciences, Nankai University, Tianjin 300071 (China)

    2015-04-03

    The central dogma of gene expression is that DNA is transcribed into messenger RNAs, which in turn serve as the template for protein synthesis. Recently, it has been reported that mRNAs display regulatory roles that rely on their ability to compete for microRNA binding, independent of their protein-coding function. However, the regulatory mechanism of mRNAs remains poorly understood. Here, we report that a hairpin within YAP mRNA 3′untranslated region (3′UTR) functions in regulation at post-transcription level through generating endogenous siRNAs (esiRNAs). Bioinformatics analysis for secondary structure showed that YAP mRNA displayed a hairpin structure (termed standard hairpin, S-hairpin) within its 3′UTR. Surprisingly, we observed that the overexpression of S-hairpin derived from YAP 3′UTR (YAP-sh) increased the luciferase reporter activities of transcriptional factor NF-κB and AP-1 in 293T cells. Moreover, we identified that a fragment from YAP-sh, an esiRNA, was able to target mRNA 3′UTR of NF2 (a member of Hippo-signaling pathway) and YAP mRNA 3′UTR itself in hepatoma cells. Thus, we conclude that the YAP-sh within YAP mRNA 3′UTR may serve as a novel regulatory element, which functions in regulation at post-transcription level. Our finding provides new insights into the mechanism of mRNAs in regulatory function. - Highlights: • An S-hairpin within YAP mRNA 3′UTR possesses regulatory function. • YAP-sh acts as a regulatory element for YAP at post-transcription level. • YAP-sh-3p20, an esiRNA derived from YAP-sh, targets mRNAs of YAP and NF2. • YAP-sh-3p20 depresses the proliferation of HepG2 cells in vitro.

  15. A hairpin within YAP mRNA 3′UTR functions in regulation at post-transcription level

    International Nuclear Information System (INIS)

    Gao, Yuen; Wang, Yuan; Feng, Jinyan; Feng, Guoxing; Zheng, Minying; Yang, Zhe; Xiao, Zelin; Lu, Zhanping; Ye, Lihong; Zhang, Xiaodong

    2015-01-01

    The central dogma of gene expression is that DNA is transcribed into messenger RNAs, which in turn serve as the template for protein synthesis. Recently, it has been reported that mRNAs display regulatory roles that rely on their ability to compete for microRNA binding, independent of their protein-coding function. However, the regulatory mechanism of mRNAs remains poorly understood. Here, we report that a hairpin within YAP mRNA 3′untranslated region (3′UTR) functions in regulation at post-transcription level through generating endogenous siRNAs (esiRNAs). Bioinformatics analysis for secondary structure showed that YAP mRNA displayed a hairpin structure (termed standard hairpin, S-hairpin) within its 3′UTR. Surprisingly, we observed that the overexpression of S-hairpin derived from YAP 3′UTR (YAP-sh) increased the luciferase reporter activities of transcriptional factor NF-κB and AP-1 in 293T cells. Moreover, we identified that a fragment from YAP-sh, an esiRNA, was able to target mRNA 3′UTR of NF2 (a member of Hippo-signaling pathway) and YAP mRNA 3′UTR itself in hepatoma cells. Thus, we conclude that the YAP-sh within YAP mRNA 3′UTR may serve as a novel regulatory element, which functions in regulation at post-transcription level. Our finding provides new insights into the mechanism of mRNAs in regulatory function. - Highlights: • An S-hairpin within YAP mRNA 3′UTR possesses regulatory function. • YAP-sh acts as a regulatory element for YAP at post-transcription level. • YAP-sh-3p20, an esiRNA derived from YAP-sh, targets mRNAs of YAP and NF2. • YAP-sh-3p20 depresses the proliferation of HepG2 cells in vitro

  16. Characterization of the ptr5+ gene involved in nuclear mRNA export in fission yeast

    International Nuclear Information System (INIS)

    Watanabe, Nobuyoshi; Ikeda, Terumasa; Mizuki, Fumitaka; Tani, Tokio

    2012-01-01

    Highlights: ► We cloned the ptr5 + gene involved in nuclear mRNA export in fission yeast. ► The ptr5 + gene was found to encode nucleoporin 85 (Nup85). ► Seh1p and Mlo3p are multi-copy suppressors for the ptr5 mutation. ► Ptr5p/Nup85p functions in nuclear mRNA export through the mRNA export factor Rae1p. ► Ptr5p/Nup85p interacts genetically with pre-mRNA splicing factors. -- Abstract: To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A) + RNA transport] 1 to 11, which accumulate poly(A) + RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5–1 mutant shows dots- or a ring-like accumulation of poly(A) + RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5 + gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5–1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5–1 mutation. In addition, we found that the ptr5–1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5–1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.

  17. Role of TRIM33 in Wnt signaling during mesendoderm differentiation.

    Science.gov (United States)

    Xia, Xiaojie; Zuo, Feifei; Luo, Maoguo; Sun, Ye; Bai, Jianbo; Xi, Qiaoran

    2017-10-01

    Tripartite motif 33 (TRIM33), a member of the transcription intermediate factor 1 (TIF1) family of transcription cofactors, mediates transforming growth factor-beta (TGF-β) signaling through its PHD-Bromo cassette in mesendoderm differentiation during early mouse embryonic development. However, the role of the TRIM33 RING domain in embryonic differentiation is less clear. Here, we report that TRIM33 mediates Wnt signaling by directly regulating the expression of a specific subset of Wnt target genes, and this action is independent of its RING domain. We show that TRIM33 interacts with β-catenin, a central player in Wnt signaling in mouse embryonic stem cells (mESCs). In contrast to previous reports in cancer cell lines, the RING domain does not appear to function as the E3 ligase for β-catenin, since neither knockout nor overexpression of TRIM33 had an effect on β-catenin protein levels in mESCs. Furthermore, we show that although TRIM33 seems to be dispensable for Wnt signaling through a reporter assay, loss of TRIM33 significantly impairs the expression of a subset of Wnt target genes, including Mixl1, in a Wnt signaling-dependent manner. Together, our results indicate that TRIM33 regulates Wnt signaling independent of the E3 ligase activity of its RING domain for β-catenin in mESCs.

  18. Anteroposterior axis patterning by early canonical Wnt signaling during hemichordate development

    Science.gov (United States)

    Darras, Sébastien; Fritzenwanker, Jens H.; Uhlinger, Kevin R.; Farrelly, Ellyn; Pani, Ariel M.; Hurley, Imogen A.; Norris, Rachael P.; Osovitz, Michelle; Terasaki, Mark; Wu, Mike; Aronowicz, Jochanan; Kirschner, Marc; Gerhart, John C.

    2018-01-01

    The Wnt family of secreted proteins has been proposed to play a conserved role in early specification of the bilaterian anteroposterior (A/P) axis. This hypothesis is based predominantly on data from vertebrate embryogenesis as well as planarian regeneration and homeostasis, indicating that canonical Wnt (cWnt) signaling endows cells with positional information along the A/P axis. Outside of these phyla, there is strong support for a conserved role of cWnt signaling in the repression of anterior fates, but little comparative support for a conserved role in promotion of posterior fates. We further test the hypothesis by investigating the role of cWnt signaling during early patterning along the A/P axis of the hemichordate Saccoglossus kowalevskii. We have cloned and investigated the expression of the complete Wnt ligand and Frizzled receptor complement of S. kowalevskii during early development along with many secreted Wnt modifiers. Eleven of the 13 Wnt ligands are ectodermally expressed in overlapping domains, predominantly in the posterior, and Wnt antagonists are localized predominantly to the anterior ectoderm in a pattern reminiscent of their distribution in vertebrate embryos. Overexpression and knockdown experiments, in combination with embryological manipulations, establish the importance of cWnt signaling for repression of anterior fates and activation of mid-axial ectodermal fates during the early development of S. kowalevskii. However, surprisingly, terminal posterior fates, defined by posterior Hox genes, are unresponsive to manipulation of cWnt levels during the early establishment of the A/P axis at late blastula and early gastrula. We establish experimental support for a conserved role of Wnt signaling in the early specification of the A/P axis during deuterostome body plan diversification, and further build support for an ancestral role of this pathway in early evolution of the bilaterian A/P axis. We find strong support for a role of cWnt in

  19. Mutation in WNT10A is associated with an autosomal recessive ectodermal dysplasia: the odonto-onycho-dermal dysplasia.

    Science.gov (United States)

    Adaimy, Lynn; Chouery, Eliane; Megarbane, Hala; Mroueh, Salman; Delague, Valerie; Nicolas, Elsa; Belguith, Hanen; de Mazancourt, Philippe; Megarbane, Andre

    2007-10-01

    Odonto-onycho-dermal dysplasia is a rare autosomal recessive syndrome in which the presenting phenotype is dry hair, severe hypodontia, smooth tongue with marked reduction of fungiform and filiform papillae, onychodysplasia, keratoderma and hyperhidrosis of palms and soles, and hyperkeratosis of the skin. We studied three consanguineous Lebanese Muslim Shiite families that included six individuals affected with odonto-onycho-dermal dysplasia. Using a homozygosity-mapping strategy, we assigned the disease locus to an ~9-cM region at chromosome 2q35-q36.2, located between markers rs16853834 and D2S353, with a maximum multipoint LOD score of 5.7. Screening of candidate genes in this region led us to identify the same c.697G-->T (p.Glu233X) homozygous nonsense mutation in exon 3 of the WNT10A gene in all patients. At the protein level, the mutation is predicted to result in a premature truncated protein of 232 aa instead of 417 aa. This is the first report to our knowledge of a human phenotype resulting from a mutation in WNT10A, and it is the first demonstration of an ectodermal dysplasia caused by an altered WNT signaling pathway, expanding the list of WNT-related diseases.

  20. 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

    alterations of the intracellular Wnt pathway signaling components β-catenin, Gsk3β and Tcf7l1/Tcf3 and the phosphorylation state of β-catenin and Gsk3β in the hippocampus suggestive of a link between AD and aberrant canonical activity. Alterations in Gsk3β co-appeared with hippocampal kinase...... on isolated Wnt pathway components. Here, we provide the first comprehensive pathway-focused evaluation of the Wnt pathway in the entorhinal cortex and hippocampus of AD brains. Our data demonstrate altered Wnt pathway gene expression at all levels of the pathway in both medial temporal lobe regions...

  1. HPV16 E6 and E6AP differentially cooperate to stimulate or augment Wnt signaling

    International Nuclear Information System (INIS)

    Sominsky, Sophia; Kuslansky, Yael; Shapiro, Beny; Jackman, Anna; Haupt, Ygal; Rosin-Arbesfeld, Rina; Sherman, Levana

    2014-01-01

    The present study investigated the roles of E6 and E6AP in the Wnt pathway. We showed that E6 levels are markedly reduced in cells in which Wnt signaling is activated. Coexpression of wild-type or mutant E6AP (C820A) in Wnt-activated cells stabilized E6 and enhanced Wnt/β-catenin/TCF transcription. Expression of E6AP alone in nonstimulated cells elevated β-catenin level, promoted its nuclear accumulation, and activated β-catenin/TCF transcription. A knockdown of E6AP lowered β-catenin levels. Coexpression with E6 intensified the activities of E6AP. Further experiments proved that E6AP/E6 stabilize β-catenin by protecting it from proteasomal degradation. This function was dependent on the catalytic activity of E6AP, the kinase activity of GSK3β and the susceptibility of β-catenin to GSK3β phosphorylation. Thus, this study identified E6AP as a novel regulator of the Wnt signaling pathway, capable of cooperating with E6 in stimulating or augmenting Wnt/β-catenin signaling, thereby possibly contributing to HPV carcinogenesis. - Highlights: • The roles of E6 and E6AP in the Wnt pathway were investigated. • E6AP stabilizes E6 and enhances E6 activity in augmentation of Wnt signaling. • E6AP cooperates with E6 to stabilize β-catenin and stimulate Wnt/β-catenin signaling. • E6AP and E6 act through different mechanisms to augment or stimulate Wnt signaling

  2. HPV16 E6 and E6AP differentially cooperate to stimulate or augment Wnt signaling

    Energy Technology Data Exchange (ETDEWEB)

    Sominsky, Sophia, E-mail: sophia.tab@gmail.com [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Kuslansky, Yael, E-mail: ykuslansky@gmail.com [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Shapiro, Beny, E-mail: benyshap@gmail.com [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Jackman, Anna, E-mail: jackman@post.tau.ac.il [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Haupt, Ygal, E-mail: ygal.haupt@petermac.org [Research Division, The Peter MacCallum Cancer Centre, East Melbourne (Australia); Rosin-Arbesfeld, Rina, E-mail: arina@post.tau.ac.il [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel); Sherman, Levana, E-mail: lsherman@post.tau.ac.il [Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978 (Israel)

    2014-11-15

    The present study investigated the roles of E6 and E6AP in the Wnt pathway. We showed that E6 levels are markedly reduced in cells in which Wnt signaling is activated. Coexpression of wild-type or mutant E6AP (C820A) in Wnt-activated cells stabilized E6 and enhanced Wnt/β-catenin/TCF transcription. Expression of E6AP alone in nonstimulated cells elevated β-catenin level, promoted its nuclear accumulation, and activated β-catenin/TCF transcription. A knockdown of E6AP lowered β-catenin levels. Coexpression with E6 intensified the activities of E6AP. Further experiments proved that E6AP/E6 stabilize β-catenin by protecting it from proteasomal degradation. This function was dependent on the catalytic activity of E6AP, the kinase activity of GSK3β and the susceptibility of β-catenin to GSK3β phosphorylation. Thus, this study identified E6AP as a novel regulator of the Wnt signaling pathway, capable of cooperating with E6 in stimulating or augmenting Wnt/β-catenin signaling, thereby possibly contributing to HPV carcinogenesis. - Highlights: • The roles of E6 and E6AP in the Wnt pathway were investigated. • E6AP stabilizes E6 and enhances E6 activity in augmentation of Wnt signaling. • E6AP cooperates with E6 to stabilize β-catenin and stimulate Wnt/β-catenin signaling. • E6AP and E6 act through different mechanisms to augment or stimulate Wnt signaling.

  3. A growing field: The regulation of axonal regeneration by Wnt signaling.

    Science.gov (United States)

    Garcia, Armando L; Udeh, Adanna; Kalahasty, Karthik; Hackam, Abigail S

    2018-01-01

    The canonical Wnt/β-catenin pathway is a highly conserved signaling cascade that plays critical roles during embryogenesis. Wnt ligands regulate axonal extension, growth cone guidance and synaptogenesis throughout the developing central nervous system (CNS). Recently, studies in mammalian and fish model systems have demonstrated that Wnt/β-catenin signaling also promotes axonal regeneration in the adult optic nerve and spinal cord after injury, raising the possibility that Wnt could be developed as a therapeutic strategy. In this review, we summarize experimental evidence that reveals novel roles for Wnt signaling in the injured CNS, and discuss possible mechanisms by which Wnt ligands could overcome molecular barriers inhibiting axonal growth to promote regeneration. A central challenge in the neuroscience field is developing therapeutic strategies that induce robust axonal regeneration. Although adult axons have the capacity to respond to axonal guidance molecules after injury, there are several major obstacles for axonal growth, including extensive neuronal death, glial scars at the injury site, and lack of axonal guidance signals. Research in rodents demonstrated that activation of Wnt/β-catenin signaling in retinal neurons and radial glia induced neuronal survival and axonal growth, but that activation within reactive glia at the injury site promoted proliferation and glial scar formation. Studies in zebrafish spinal cord injury models confirm an axonal regenerative role for Wnt/β-catenin signaling and identified the cell types responsible. Additionally, in vitro and in vivo studies demonstrated that Wnt induces axonal and neurite growth through transcription-dependent effects of its central mediator β-catenin, potentially by inducing regeneration-promoting genes. Canonical Wnt signaling may also function through transcription-independent interactions of β-catenin with cytoskeletal elements, which could stabilize growing axons and control growth cone

  4. 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.

  5. HCV core protein-induced down-regulation of microRNA-152 promoted aberrant proliferation by regulating Wnt1 in HepG2 cells.

    Directory of Open Access Journals (Sweden)

    Shifeng Huang

    Full Text Available Hepatitis C virus (HCV has been reported to regulate cellular microRNAs (miRNAs. The HCV core protein is considered to be a potential oncoprotein in HCV-related hepatocellular carcinoma (HCV-HCC, but HCV core-regulated miRNAs are largely unknown. Our preliminary experiments revealed significant down-regulation of microRNA-152 (miR-152 by HCV core protein in HepG2 cells. Through target gene prediction softwares, Wnt1 was predicted to be a potential target of miR-152. The present study was initiated to investigate whether miR-152 is aberrantly regulated by the HCV core protein, and involved in the regulation of the aberrant proliferation of HCV-HCC cells.MiR-152 levels were examined by stem-loop real-time RT-PCR (SLqRT-PCR. Cell proliferation was analyzed by MTT and colony formation assay. Cell cycle analysis was performed by flow cytometry. Luciferase reporter assay was conducted to confirm miRNA-target association. Wnt1 expression was determined by real-time qPCR and Western blotting.HCV core protein significantly suppressed miR-152 expression, and led to significant Wnt1 up-regulation with a concomitant aberrantly promoted proliferation. Moreover, we validated that miR-152 inhibition promoted, while miR-152 mimics inhibited cell proliferation. Using, qRT-PCR and western blot, Wnt1 was demonstrated to be regulated by miR-152. Luciferase activity assay showed that while miR-152 mimics significantly reduced the luciferase activity by 83.76% (P<0.0001, miR-152 inhibitor showed no effect on luciferase reporter. Most notably, salvage expression of miR-152 after Ad-HCV core infection for 24 h almost totally reversed the proliferation-promoting effect of the HCV core protein, and meanwhile, reduced the expression of both Wnt1 mRNA and protein to basal levels.These findings provide important evidence that the reduced miR-152 expression by HCV core protein can indirectly lose an inhibitory effect on Wnt1, which might, at least partially lead to cell

  6. Chemical Modulation of WNT Signaling in Cancer.

    Science.gov (United States)

    Zhang, Li-Shu; Lum, Lawrence

    2018-01-01

    Genetically based observations stemming from defects in development and in regeneration form the foundation of our understanding regarding how the secreted WNT proteins control coordinated cell fate decision-making in adult tissues. At the same time, our anticipation of potential benefits and unwanted toxicities associated with candidate anticancer agents targeting WNT signal transduction are also reliant upon this blueprint of WNT-associated physiology. Despite the long established role of WNT signaling in cancer, the emergence of WNT signaling as a suppressor of immunological attack in melanoma reveals an unanticipated anticancer potential in targeting WNT signaling. Here we review the literature associated with WNT signaling in cancer and discuss potential challenges that may be associated with the chemical attack of this important cellular process in achieving therapeutic goals. Although a number of small molecules targeting WNT signaling are introduced here, we center our discussion on antagonists of the WNT acyltransferase porcupine (PORCN) given the recent entry of two candidate molecules in clinical testing. Copyright © 2018 Elsevier Inc. All rights reserved.

  7. Creatine kinase and alpha-actin mRNA levels decrease in diabetic rat hearts

    International Nuclear Information System (INIS)

    Popovich, B.; Barrieux, A.; Dillmann, W.H.

    1987-01-01

    Diabetic cardiomyopathy is associated with cardiac atrophy and isoenzyme redistribution. To determine if tissue specific changes occur in mRNAs coding for α-actin and creatine kinase (CK), they performed RNA blot analysis. Total ventricular RNA from control (C) and 4 wk old diabetic (D) rats were hybridized with 32 P cDNA probes for α-actin and CK. A tissue independent cDNA probe, CHOA was also used. Signal intensity was quantified by photodensitometry. D CK mRNA was 47 +/- 16% lower in D vs C. Insulin increases CK mRNA by 20% at 1.5 hs, and completely reverses the deficit after 4 wks. D α-actin mRNA is 66 +/- 18% lower in D vs C. Insulin normalized α-actin mRNA by 5 hs. CHOA mRNA is unchanged in D vs C, but D + insulin CHOA mRNA is 30 +/- 2% lower than C. In rats with diabetic cardiomyopathy, muscle specific CK and α-actin mRNAs are decreased. Insulin treatment reverses these changes

  8. 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. Copyright © 2015 Gorrepati et al.

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

    Directory of Open Access Journals (Sweden)

    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.

  10. Time-course of 5-HT(6) receptor mRNA expression during memory consolidation and amnesia.

    Science.gov (United States)

    Huerta-Rivas, A; Pérez-García, G; González-Espinosa, C; Meneses, A

    2010-01-01

    Growing evidence indicates that antagonists of the 5-hydroxytryptamine (serotonin) receptor(6) (5-HT(6)) improve memory and reverse amnesia although the mechanisms involved are poorly understood. Hence, in this paper RT-PCR was used to evaluate changes in mRNA expression of 5-HT(6) receptor in trained and untrained rats treated with the 5-HT(6) receptor antagonist SB-399885 and amnesic drugs scopolamine or dizocilpine. Changes in mRNA expression of 5-HT(6) receptor were investigated at different times in prefrontal cortex, hippocampus and striatum. Data indicated that memory in the Pavlovian/instrumental autoshaping task was a progressive process associated to reduced mRNA expression of 5-HT(6) receptor in the three structures examined. SB-399885 improved long-term memory at 48h, while the muscarinic receptor antagonist scopolamine or the non-competitive NMDA receptor antagonist dizocilpine impaired it at 24h. Autoshaping training and treatment with SB-399885 increased 5-HT(6) receptor mRNA expression in (maximum increase) prefrontal cortex and striatum, 24 or 48h. The scopolamine-induced amnesia suppressed 5-HT(6) receptor mRNA expression while the dizocilpine-induced amnesia did not modify 5-HT(6) receptor mRNA expression. SB-399885 and scopolamine or dizocilpine were able to reestablish memory and 5-HT(6) receptor mRNA expression. These data confirmed previous memory evidence and of more interest is the observation that training, SB-399885 and amnesic drugs modulated 5-HT(6) receptor mRNA expression in prefrontal cortex, hippocampus and striatum. Further investigation in different memory tasks, times and amnesia models together with more complex control groups might provide further clues. Copyright 2009 Elsevier Inc. All rights reserved.

  11. The Wnt Transcriptional Switch: TLE Removal or Inactivation?

    Science.gov (United States)

    Ramakrishnan, Aravinda-Bharathi; Sinha, Abhishek; Fan, Vinson B; Cadigan, Ken M

    2018-02-01

    Many targets of the Wnt/β-catenin signaling pathway are regulated by TCF transcription factors, which play important roles in animal development, stem cell biology, and oncogenesis. TCFs can regulate Wnt targets through a "transcriptional switch," repressing gene expression in unstimulated cells and promoting transcription upon Wnt signaling. However, it is not clear whether this switch mechanism is a general feature of Wnt gene regulation or limited to a subset of Wnt targets. Co-repressors of the TLE family are known to contribute to the repression of Wnt targets in the absence of signaling, but how they are inactivated or displaced by Wnt signaling is poorly understood. In this mini-review, we discuss several recent reports that address the prevalence and molecular mechanisms of the Wnt transcription switch, including the finding of Wnt-dependent ubiquitination/inactivation of TLEs. Together, these findings highlight the growing complexity of the regulation of gene expression by the Wnt pathway. © 2017 WILEY Periodicals, Inc.

  12. Wnt, RSPO and Hippo Signalling in the Intestine and Intestinal Stem Cells.

    Science.gov (United States)

    Kriz, Vitezslav; Korinek, Vladimir

    2018-01-08

    In this review, we address aspects of Wnt, R-Spondin (RSPO) and Hippo signalling, in both healthy and transformed intestinal epithelium. In intestinal stem cells (ISCs), the Wnt pathway is essential for intestinal crypt formation and renewal, whereas RSPO-mediated signalling mainly affects ISC numbers. In human colorectal cancer (CRC), aberrant Wnt signalling is the driving mechanism initiating this type of neoplasia. The signalling role of the RSPO-binding transmembrane proteins, the leucine-rich-repeat-containing G-protein-coupled receptors (LGRs), is possibly more pleiotropic and not only limited to the enhancement of Wnt signalling. There is growing evidence for multiple crosstalk between Hippo and Wnt/β-catenin signalling. In the ON state, Hippo signalling results in serine/threonine phosphorylation of Yes-associated protein (YAP1) and tafazzin (TAZ), promoting formation of the β-catenin destruction complex. In contrast, YAP1 or TAZ dephosphorylation (and YAP1 methylation) results in β-catenin destruction complex deactivation and β-catenin nuclear localization. In the Hippo OFF state, YAP1 and TAZ are engaged with the nuclear β-catenin and participate in the β-catenin-dependent transcription program. Interestingly, YAP1/TAZ are dispensable for intestinal homeostasis; however, upon Wnt pathway hyperactivation, the proteins together with TEA domain (TEAD) transcription factors drive the transcriptional program essential for intestinal cell transformation. In addition, in many CRC cells, YAP1 phosphorylation by YES proto-oncogene 1 tyrosine kinase (YES1) leads to the formation of a transcriptional complex that includes YAP1, β-catenin and T-box 5 (TBX5) DNA-binding protein. YAP1/β-catenin/T-box 5-mediated transcription is necessary for CRC cell proliferation and survival. Interestingly, dishevelled (DVL) appears to be an important mediator involved in both Wnt and Hippo (YAP1/TAZ) signalling and some of the DVL functions were assigned to the nuclear DVL

  13. WNT Stimulation Dissociates a Frizzled 4 Inactive-State Complex with Gα12/13.

    Science.gov (United States)

    Arthofer, Elisa; Hot, Belma; Petersen, Julian; Strakova, Katerina; Jäger, Stefan; Grundmann, Manuel; Kostenis, Evi; Gutkind, J Silvio; Schulte, Gunnar

    2016-10-01

    Frizzleds (FZDs) are unconventional G protein-coupled receptors that belong to the class Frizzled. They are bound and activated by the Wingless/Int-1 lipoglycoprotein (WNT) family of secreted lipoglycoproteins. To date, mechanisms of signal initiation and FZD-G protein coupling remain poorly understood. Previously, we showed that FZD6 assembles with Gαi1/Gαq (but not with Gαs, Gαo and Ga12/13), and that these inactive-state complexes are dissociated by WNTs and regulated by the phosphoprotein Dishevelled (DVL). Here, we investigated the inactive-state assembly of heterotrimeric G proteins with FZD4, a receptor important in retinal vascular development and frequently mutated in Norrie disease or familial exudative vitreoretinopathy. Live-cell imaging experiments using fluorescence recovery after photobleaching show that human FZD4 assembles-in a DVL-independent manner-with Gα12/13 but not representatives of other heterotrimeric G protein subfamilies, such as Gαi1, Gαo, Gαs, and Gαq The FZD4-G protein complex dissociates upon stimulation with WNT-3A, WNT-5A, WNT-7A, and WNT-10B. In addition, WNT-induced dynamic mass redistribution changes in untransfected and, even more so, in FZD4 green fluorescent protein-transfected cells depend on Gα12/13 Furthermore, expression of FZD4 and Gα12 or Gα13 in human embryonic kidney 293 cells induces WNT-dependent membrane recruitment of p115-RHOGEF (RHO guanine nucleotide exchange factor, molecular weight 115 kDa), a direct target of Gα12/13 signaling, underlining the functionality of an FZD4-Gα12/13-RHO signaling axis. In summary, Gα12/13-mediated WNT/FZD4 signaling through p115-RHOGEF offers an intriguing and previously unappreciated mechanistic link of FZD4 signaling to cytoskeletal rearrangements and RHO signaling with implications for the regulation of angiogenesis during embryonic and tumor development. Copyright © 2016 by The American Society for Pharmacology and Experimental Therapeutics.

  14. Wnt some lose some: transcriptional governance of stem cells by Wnt/β-catenin signaling

    Science.gov (United States)

    Lien, Wen-Hui; Fuchs, Elaine

    2014-01-01

    In mammals, Wnt/β-catenin signaling features prominently in stem cells and cancers, but how and for what purposes have been matters of much debate. In this review, we summarize our current knowledge of Wnt/β-catenin signaling and its downstream transcriptional regulators in normal and malignant stem cells. We centered this review largely on three types of stem cells—embryonic stem cells, hair follicle stem cells, and intestinal epithelial stem cells—in which the roles of Wnt/β-catenin have been extensively studied. Using these models, we unravel how many controversial issues surrounding Wnt signaling have been resolved by dissecting the diversity of its downstream circuitry and effectors, often leading to opposite outcomes of Wnt/β-catenin-mediated regulation and differences rooted in stage- and context-dependent effects. PMID:25030692

  15. FSTL5 is a marker of poor prognosis in non-WNT/non-SHH medulloblastoma

    NARCIS (Netherlands)

    Remke, Marc; Hielscher, Thomas; Korshunov, Andrey; Northcott, Paul A.; Bender, Sebastian; Kool, Marcel; Westermann, Frank; Benner, Axel; Cin, Huriye; Ryzhova, Marina; Sturm, Dominik; Witt, Hendrik; Haag, Daniel; Toedt, Grischa; Wittmann, Andrea; Schöttler, Anna; von Bueren, André O.; von Deimling, Andreas; Rutkowski, Stefan; Scheurlen, Wolfram; Kulozik, Andreas E.; Taylor, Michael D.; Lichter, Peter; Pfister, Stefan M.

    2011-01-01

    Integrated genomics approaches have revealed at least four distinct biologic variants of medulloblastoma: WNT (wingless), SHH (sonic hedgehog), group C, and group D. Because of the remarkable clinical heterogeneity of group D tumors and the dismal prognosis of group C patients, it is vital to

  16. Regulation of elastin synthesis in developing sheep nuchal ligament by elastin mRNA levels

    International Nuclear Information System (INIS)

    Davidson, J.M.; Smith, K.; Shibahara, S.; Tolstoshev, P.; Crystal, R.G.

    1982-01-01

    Levels of elastin production in explant culture of fetal sheep nuchal ligament and corresponding levels of translatable elastin mRNA were determined in parallel studies during a period of rapid growth of the embryo. The identity of the explant culture and cell-free proucts was confirmed by peptide mapping, immunoprecipitation, and the characteristic lack of histidine and methionine. Elastin production was quantitated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and radioimmune precipitation. The translation products could be labeled with methionine only when NH 2 -terminally donated as f-Met-tRNA/sup Met//sub f/. Explant cultures showed a large rise in elastin production from 70 days after conception to 150 days after conception. Cell free translation of RNA demonstrated a parallel in elastin mRNA levels and in elastin mRNA per cell. It appears, therefore, that the marked emphasis the differentiating muchal ligament places on elastin production is modulated, at least in part, by the quantities of available elastin in mRNA

  17. Presence of HLA-B27 is associated with changes of serum levels of mediators of the Wnt and hedgehog pathway.

    Science.gov (United States)

    Aschermann, Sarah; Englbrecht, Matthias; Bergua, Antonio; Spriewald, Bernd M; Said-Nahal, Rhula; Breban, Maxime; Schett, Georg; Rech, Jürgen

    2016-01-01

    HLA-B27 is present in 5% of the Caucasian population and is strongly associated with the development of spondyloarthritis (SpA), a disease characterized by inflammation and substantial bone changes. We hypothesized that the presence of HLA-B27 in itself is associated with alterations of key regulatory of bone homeostasis. Sera of 241 individuals were assessed for the serum levels of Wnt pathway regulators, sclerostin and dickkopf (Dkk)-1 as well as Indian hedgehog (IHH) and collagen type I cleavage products (CTX1). Of the 151 HLA-B27+ subjects, 31 had SpA, 30 had anterior uveitis, 30 were healthy individuals and 60 healthy siblings of patients with SpA. Sclerostin levels were significantly (P<0.001) lower in HLA-B27+ subjects (314±21pg/mL) compared to HLA-B27 negative controls (mean±SEM: 492±30pg/mL), no matter if subjects were either healthy, or affected by SpA or uveitis. Similar results were found for Dkk-1. No differences between the groups with respect to the bone resorption marker CTX1 were found. In contrast, IHH levels were significantly (P<0.001) higher in the carriers of HLA-B27 than in the negative controls. Changes in key regulators of the Wnt pathway as well as IHH, a molecule regulating endochondral ossification, are found in HLA-B27 carriers, independent if they were healthy or affected by uveitis or SpA. Copyright © 2015 Société française de rhumatologie. Published by Elsevier SAS. All rights reserved.

  18. Regulation of Wnt/β-catenin signaling by posttranslational modifications

    Science.gov (United States)

    2014-01-01

    The canonical Wnt signaling pathway (or Wnt/β-catenin pathway) plays a pivotal role in embryonic development and adult homeostasis; deregulation of the Wnt pathway contributes to the initiation and progression of human diseases including cancer. Despite its importance in human biology and disease, how regulation of the Wnt/β-catenin pathway is achieved remains largely undefined. Increasing evidence suggests that post-translational modifications (PTMs) of Wnt pathway components are essential for the activation of the Wnt/β-catenin pathway. PTMs create a highly dynamic relay system that responds to Wnt stimulation without requiring de novo protein synthesis and offer a platform for non-Wnt pathway components to be involved in the regulation of Wnt signaling, hence providing alternative opportunities for targeting the Wnt pathway. This review highlights the current status of PTM-mediated regulation of the Wnt/β-catenin pathway with a focus on factors involved in Wnt-mediated stabilization of β-catenin. PMID:24594309

  19. Parkin protects dopaminergic neurons from excessive Wnt/β-catenin signaling

    International Nuclear Information System (INIS)

    Rawal, Nina; Corti, Olga; Sacchetti, Paola; Ardilla-Osorio, Hector; Sehat, Bita; Brice, Alexis; Arenas, Ernest

    2009-01-01

    Parkinson's disease (PD) is caused by degeneration of the dopaminergic (DA) neurons of the substantia nigra but the molecular mechanisms underlying the degenerative process remain elusive. Several reports suggest that cell cycle deregulation in post-mitotic neurons could lead to neuronal cell death. We now show that Parkin, an E3 ubiquitin ligase linked to familial PD, regulates β-catenin protein levels in vivo. Stabilization of β-catenin in differentiated primary ventral midbrain neurons results in increased levels of cyclin E and proliferation, followed by increased levels of cleaved PARP and loss of DA neurons. Wnt3a signaling also causes death of post-mitotic DA neurons in parkin null animals, suggesting that both increased stabilization and decreased degradation of β-catenin results in DA cell death. These findings demonstrate a novel regulation of Wnt signaling by Parkin and suggest that Parkin protects DA neurons against excessive Wnt signaling and β-catenin-induced cell death.

  20. Parkin protects dopaminergic neurons from excessive Wnt/{beta}-catenin signaling

    Energy Technology Data Exchange (ETDEWEB)

    Rawal, Nina [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden); Corti, Olga [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Sacchetti, Paola [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden); Ardilla-Osorio, Hector [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Sehat, Bita [Cancer Center Karolinska, Karolinska Institute, S-17177 Stockholm (Sweden); Brice, Alexis [Universite Pierre et Marie Curie-Paris 6, CRICM UMR-S975, Inserm, U975 (France); CNRS, UMR 7225, Paris (France); Department of Genetics and Cytogenetics, AP-HP, Groupe Hospitalier Pitie-Salpetriere, Paris (France); Arenas, Ernest, E-mail: Ernest.Arenas@ki.se [Laboratory of Molecular Neurobiology, MBB, DBRM, Karolinska Institute, S-17177 Stockholm (Sweden)

    2009-10-23

    Parkinson's disease (PD) is caused by degeneration of the dopaminergic (DA) neurons of the substantia nigra but the molecular mechanisms underlying the degenerative process remain elusive. Several reports suggest that cell cycle deregulation in post-mitotic neurons could lead to neuronal cell death. We now show that Parkin, an E3 ubiquitin ligase linked to familial PD, regulates {beta}-catenin protein levels in vivo. Stabilization of {beta}-catenin in differentiated primary ventral midbrain neurons results in increased levels of cyclin E and proliferation, followed by increased levels of cleaved PARP and loss of DA neurons. Wnt3a signaling also causes death of post-mitotic DA neurons in parkin null animals, suggesting that both increased stabilization and decreased degradation of {beta}-catenin results in DA cell death. These findings demonstrate a novel regulation of Wnt signaling by Parkin and suggest that Parkin protects DA neurons against excessive Wnt signaling and {beta}-catenin-induced cell death.

  1. Frequent epigenetic inactivation of Wnt antagonist genes in breast cancer

    Science.gov (United States)

    Suzuki, H; Toyota, M; Caraway, H; Gabrielson, E; Ohmura, T; Fujikane, T; Nishikawa, N; Sogabe, Y; Nojima, M; Sonoda, T; Mori, M; Hirata, K; Imai, K; Shinomura, Y; Baylin, S B; Tokino, T

    2008-01-01

    Although mutation of APC or CTNNB1 (β-catenin) is rare in breast cancer, activation of Wnt signalling is nonetheless thought to play an important role in breast tumorigenesis, and epigenetic silencing of Wnt antagonist genes, including the secreted frizzled-related protein (SFRP) and Dickkopf (DKK) families, has been observed in various tumours. In breast cancer, frequent methylation and silencing of SFRP1 was recently documented; however, altered expression of other Wnt antagonist genes is largely unknown. In the present study, we found frequent methylation of SFRP family genes in breast cancer cell lines (SFRP1, 7 out of 11, 64%; SFRP2, 11 out of 11, 100%; SFRP5, 10 out of 11, 91%) and primary breast tumours (SFRP1, 31 out of 78, 40%; SFRP2, 60 out of 78, 77%; SFRP5, 55 out of 78, 71%). We also observed methylation of DKK1, although less frequently, in cell lines (3 out of 11, 27%) and primary tumours (15 out of 78, 19%). Breast cancer cell lines express various Wnt ligands, and overexpression of SFRPs inhibited cancer cell growth. In addition, overexpression of a β-catenin mutant and depletion of SFRP1 using small interfering RNA synergistically upregulated transcriptional activity of T-cell factor/lymphocyte enhancer factor. Our results confirm the frequent methylation and silencing of Wnt antagonist genes in breast cancer, and suggest that their loss of function contributes to activation of Wnt signalling in breast carcinogenesis. PMID:18283316

  2. The Roles of the Wnt-Antagonists Axin and Lrp4 during Embryogenesis of the Red Flour Beetle Tribolium castaneum.

    Science.gov (United States)

    Prühs, Romy; Beermann, Anke; Schröder, Reinhard

    2017-10-15

    In both vertebrates and invertebrates, the Wnt-signaling pathway is essential for numerous processes in embryogenesis and during adult life. Wnt activity is fine-tuned at various levels by the interplay of a number of Wnt-agonists (Wnt ligands, Frizzled-receptors, Lrp5/6 coreceptors) and Wnt-antagonists (among them Axin, Secreted frizzled and Lrp4) to define anterior-posterior polarity of the early embryo and specify cell fate in organogenesis. So far, the functional analysis of Wnt-pathway components in insects has concentrated on the roles of Wnt-agonists and on the Wnt-antagonist Axin. We depict here additional features of the Wnt-antagonist Axin in the flour beetle Tribolium castaneum . We show that Tc-axin is dynamically expressed throughout embryogenesis and confirm its essential role in head development. In addition, we describe an as yet undetected, more extreme Tc-axin RNAi-phenotype, the ectopic formation of posterior abdominal segments in reverse polarity and a second hindgut at the anterior. For the first time, we describe here that an lrp4 ortholog is involved in axis formation in an insect. The Tribolium Lrp4 ortholog is ubiquitously expressed throughout embryogenesis. Its downregulation via maternal RNAi results in the reduction of head structures but not in axis polarity reversal. Furthermore, segmentation is impaired and larvae develop with a severe gap-phenotype. We conclude that, as in vertebrates, Tc-lrp4 functions as a Wnt-inhibitor in Tribolium during various stages of embryogenesis. We discuss the role of both components as negative modulators of Wnt signaling in respect to axis formation and segmentation in Tribolium .

  3. Inhibition of canonical WNT signaling attenuates human leiomyoma cell growth

    Science.gov (United States)

    Ono, Masanori; Yin, Ping; Navarro, Antonia; Moravek, Molly B.; Coon, John S.; Druschitz, Stacy A.; Gottardi, Cara J.; Bulun, Serdar E.

    2014-01-01

    Objective Dysregulation of WNT signaling plays a central role in tumor cell growth and progression. Our goal was to assess the effect of three WNT/β-catenin pathway inhibitors, Inhibitor of β-Catenin And TCF4 (ICAT), niclosamide, and XAV939 on the proliferation of primary cultures of human uterine leiomyoma cells. Design Prospective study of human leiomyoma cells obtained from myomectomy or hysterectomy. Setting University research laboratory. Patient(s) Women (n=38) aged 27–53 years undergoing surgery. Intervention(s) Adenoviral ICAT overexpression or treatment with varying concentrations of niclosamide or XAV939. Main Outcome Measure(s) Cell proliferation, cell death, WNT/β-catenin target gene expression or reporter gene regulation, β-catenin levels and cellular localization. Result(s) ICAT, niclosamide, or XAV939 inhibit WNT/β-catenin pathway activation and exert anti-proliferative effects in primary cultures of human leiomyoma cells. Conclusion(s) Three WNT/β-catenin pathway inhibitors specifically block human leiomyoma growth and proliferation, suggesting that the canonical WNT pathway may be a potential therapeutic target for the treatment of uterine leiomyoma. Our findings provide rationale for further preclinical and clinical evaluation of ICAT, niclosamide, and XAV939 as candidate anti-tumor agents for uterine leiomyoma. PMID:24534281

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

    Science.gov (United States)

    Liang, Li; Zhou, Wei; Yang, Nan; Yu, Jifeng; Liu, Hongchen

    2016-01-01

    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. PMID:26884650

  5. 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.

  6. Wnt signaling: Ig-norrin the dogma.

    Science.gov (United States)

    Clevers, Hans

    2004-06-08

    Secreted Wnt proteins trigger the intracellular Wnt signaling cascade upon engagement of dedicated Frizzled-Lrp receptor complexes. Unexpectedly, a non-Wnt ligand for this receptor complex has now been discovered. This novel ligand, Norrin, is mutated in the hereditary ocular Norrie syndrome. Copyright 2004 Elsevier Ltd.

  7. Wnt Signaling in Skeletal Muscle Development and Regeneration.

    Science.gov (United States)

    Girardi, Francesco; Le Grand, Fabien

    2018-01-01

    Wnt is a family of signaling molecules involved in embryogenesis, adult tissue repair, and cancer. They activate canonical and noncanonical Wnt signaling cascades in target cells. Several studies, within the last decades, showed that several Wnt ligands are involved in myogenesis and both canonical and noncanonical Wnt pathways regulate muscle formation and the maintenance of adult tissue homeostasis. In this review, we provide a comprehensive overview of the roles of Wnt signaling during muscle development and an updated description of Wnt functions during muscle repair. Lastly, we discuss the crosstalk between Wnt and TGFβ signaling pathways in skeletal muscle. Copyright © 2018 Elsevier Inc. All rights reserved.

  8. Indirect effects of Wnt3a/β-catenin signalling support mouse spermatogonial stem cells in vitro.

    Directory of Open Access Journals (Sweden)

    Jonathan R Yeh

    Full Text Available Proper regulation of spermatogonial stem cells (SSCs is crucial for sustaining steady-state spermatogenesis. Previous work has identified several paracrine factors involved in this regulation, in particular, glial cell line-derived neurotrophic factor and fibroblast growth factor 2, which promote long-term SSC self-renewal. Using a SSC culture system, we have recently reported that Wnt5a promotes SSC self-renewal through a β-catenin-independent Wnt mechanism whereas the β-catenin-dependent Wnt pathway is not active in SSCs. In contrast, another study has reported that Wnt3a promotes SSC self-renewal through the β-catenin-dependent pathway, as it can stimulate the proliferation of a spermatogonia cell line. To reconcile these two contradictory reports, we assessed Wnt3a effects on SSCs and progenitor cells, rather than a cell line, in vitro. We observed that Wnt3a induced β-catenin-dependent signalling in a large subset of germ cells and increased SSC numbers. However, further investigation revealed that cell populations with greater β-catenin-signalling activity contained fewer SSCs. The increased maintenance of SSCs by Wnt3a coincided with more active cell cycling and the formation of germ cell aggregates, or communities, under feeder-free conditions. Therefore, the results of this study suggest that Wnt3a selectively stimulates proliferation of progenitors that are committed to differentiation or are in the process of exiting the SSC state, leading to enhanced formation of germ cell communities, which indirectly support SSCs and act as an in vitro niche.

  9. Changes in rRNA levels during stress invalidates results from mRNA blotting: Fluorescence in situ rRNA hybridization permits renormalization for estimation of cellular mRNA levels

    DEFF Research Database (Denmark)

    Hansen, M.C.; Nielsen, A.K.; Molin, Søren

    2001-01-01

    obtained by these techniques are compared between experiments in which differences in growth rates, strains, or stress treatments occur, the normalization procedure may have a significant impact on the results. In this report we present a solution to the normalization problem in RNA slot blotting...... the relative level of rRNA per cell, and slot blotting to rRNA probes, which estimates the level of rRNA per extracted total RNA, the amount of RNA per cell was calculated in a series of heat shock experiments with the gram-positive bacterium Lactococcus lactis. It was found that the level of rRNA per cell...... decreased to 30% in the course of the heat shock. This lowered ribosome level led to a decrease in the total RNA content, resulting in a gradually increasing overestimation of the mRNA levels throughout the experiment. Using renormalized cellular mRNA levels, the HrcA-mediated regulation of the genes...

  10. Conditional Expression of Wnt4 during Chondrogenesis Leads to Dwarfism in Mice

    Science.gov (United States)

    Lee, Hu-Hui; Behringer, Richard R.

    2007-01-01

    Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26) locus by gene targeting in embryonic stem (ES) cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo) that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF). These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype. PMID:17505543

  11. Conditional expression of Wnt4 during chondrogenesis leads to dwarfism in mice.

    Directory of Open Access Journals (Sweden)

    Hu-Hui Lee

    Full Text Available Wnts are expressed in the forming long bones, suggesting roles in skeletogenesis. To examine the action of Wnts in skeleton formation, we developed a genetic system to conditionally express Wnt4 in chondrogenic tissues of the mouse. A mouse Wnt4 cDNA was introduced into the ubiquitously expressed Rosa26 (R26 locus by gene targeting in embryonic stem (ES cells. The expression of Wnt4 from the R26 locus was blocked by a neomycin selection cassette flanked by loxP sites (floxneo that was positioned between the Rosa26 promoter and the Wnt4 cDNA, creating the allele designated R26(floxneoWnt4. Wnt4 expression was activated during chondrogenesis using Col2a1-Cre transgenic mice that express Cre recombinase in differentiating chondrocytes. R26(floxneoWnt4; Col2a1-Cre double heterozygous mice exhibited a growth deficiency, beginning approximately 7 to 10 days after birth, that resulted in dwarfism. In addition, they also had craniofacial abnormalities, and delayed ossification of the lumbar vertebrae and pelvic bones. Histological analysis revealed a disruption in the organization of the growth plates and a delay in the onset of the primary and secondary ossification centers. Molecular studies showed that Wnt4 overexpression caused decreased proliferation and altered maturation of chondrocytes. In addition, R26(floxneoWnt4; Col2a1-Cre mice had decreased expression of vascular endothelial growth factor (VEGF. These studies demonstrate that Wnt4 overexpression leads to dwarfism in mice. The data indicate that Wnt4 levels must be regulated in chondrocytes for normal growth plate development and skeletogenesis. Decreased VEGF expression suggests that defects in vascularization may contribute to the dwarf phenotype.

  12. Wnt Signaling in Kidney Development and Disease.

    Science.gov (United States)

    Wang, Yongping; Zhou, Chengji J; Liu, Youhua

    2018-01-01

    Wnt signal cascade is an evolutionarily conserved, developmental pathway that regulates embryogenesis, injury repair, and pathogenesis of human diseases. It is well established that Wnt ligands transmit their signal via canonical, β-catenin-dependent and noncanonical, β-catenin-independent mechanisms. Mounting evidence has revealed that Wnt signaling plays a key role in controlling early nephrogenesis and is implicated in the development of various kidney disorders. Dysregulations of Wnt expression cause a variety of developmental abnormalities and human diseases, such as congenital anomalies of the kidney and urinary tract, cystic kidney, and renal carcinoma. Multiple Wnt ligands, their receptors, and transcriptional targets are upregulated during nephron formation, which is crucial for mediating the reciprocal interaction between primordial tissues of ureteric bud and metanephric mesenchyme. Renal cysts are also associated with disrupted Wnt signaling. In addition, Wnt components are important players in renal tumorigenesis. Activation of Wnt/β-catenin is instrumental for tubular repair and regeneration after acute kidney injury. However, sustained activation of this signal cascade is linked to chronic kidney diseases and renal fibrosis in patients and experimental animal models. Mechanistically, Wnt signaling controls a diverse array of biologic processes, such as cell cycle progression, cell polarity and migration, cilia biology, and activation of renin-angiotensin system. In this chapter, we have reviewed recent findings that implicate Wnt signaling in kidney development and diseases. Targeting this signaling may hold promise for future treatment of kidney disorders in patients. Copyright © 2018 Elsevier Inc. All rights reserved.

  13. Interaction between LRP5 and periostin gene polymorphisms on serum periostin levels and cortical bone microstructure.

    Science.gov (United States)

    Pepe, J; Bonnet, N; Herrmann, F R; Biver, E; Rizzoli, R; Chevalley, T; Ferrari, S L

    2018-02-01

    We investigated the interaction between periostin SNPs and the SNPs of the genes assumed to modulate serum periostin levels and bone microstructure in a cohort of postmenopausal women. We identified an interaction between LRP5 SNP rs648438 and periostin SNP rs9547970 on serum periostin levels and on radial cortical porosity. The purpose of this study is to investigate the interaction between periostin gene polymorphisms (SNPs) and other genes potentially responsible for modulating serum periostin levels and bone microstructure in a cohort of postmenopausal women. In 648 postmenopausal women from the Geneva Retirees Cohort, we analyzed 6 periostin SNPs and another 149 SNPs in 14 genes, namely BMP2, CTNNB1, ESR1, ESR2, LRP5, LRP6, PTH, SPTBN1, SOST, TGFb1, TNFRSF11A, TNFSF11, TNFRSF11B and WNT16. Volumetric BMD and bone microstructure were measured by high-resolution peripheral quantitative computed tomography at the distal radius and tibia. Serum periostin levels were associated with radial cortical porosity, including after adjustment for age, BMI, and years since menopause (p = 0.036). Sixteen SNPs in the ESR1, LRP5, TNFRSF11A, SOST, SPTBN1, TNFRSF11B and TNFSF11 genes were associated with serum periostin levels (p range 0.03-0.001) whereas 26 SNPs in 9 genes were associated with cortical porosity at the radius and/or at the tibia. WNT 16 was the gene with the highest number of SNPs associated with both trabecular and cortical microstructure. The periostin SNP rs9547970 was also associated with cortical porosity (p = 0.04). In particular, SNPs in LRP5, ESR1 and near the TNFRSF11A gene were associated with both cortical porosity and serum periostin levels. Eventually, we identified an interaction between LRP5 SNP rs648438 and periostin SNP rs9547970 on serum periostin levels (interaction p = 0.01) and on radial cortical porosity (interaction p = 0.005). These results suggest that periostin expression is genetically modulated, particularly by polymorphisms

  14. Characterization of the ptr5{sup +} gene involved in nuclear mRNA export in fission yeast

    Energy Technology Data Exchange (ETDEWEB)

    Watanabe, Nobuyoshi; Ikeda, Terumasa; Mizuki, Fumitaka [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 (Japan); Tani, Tokio, E-mail: ttani@sci.kumamoto-u.ac.jp [Department of Biological Sciences, Graduate School of Science and Technology, Kumamoto University, Kurokami, Kumamoto 860-8555 (Japan)

    2012-02-03

    Highlights: Black-Right-Pointing-Pointer We cloned the ptr5{sup +} gene involved in nuclear mRNA export in fission yeast. Black-Right-Pointing-Pointer The ptr5{sup +} gene was found to encode nucleoporin 85 (Nup85). Black-Right-Pointing-Pointer Seh1p and Mlo3p are multi-copy suppressors for the ptr5 mutation. Black-Right-Pointing-Pointer Ptr5p/Nup85p functions in nuclear mRNA export through the mRNA export factor Rae1p. Black-Right-Pointing-Pointer Ptr5p/Nup85p interacts genetically with pre-mRNA splicing factors. -- Abstract: To analyze the mechanisms of mRNA export from the nucleus to the cytoplasm, we have isolated eleven mutants, ptr [poly(A){sup +} RNA transport] 1 to 11, which accumulate poly(A){sup +} RNA in the nucleus at a nonpermissive temperature in Schizosaccharomyces pombe. Of those, the ptr5-1 mutant shows dots- or a ring-like accumulation of poly(A){sup +} RNA at the nuclear periphery after shifting to the nonpermissive temperature. We cloned the ptr5{sup +} gene and found that it encodes a component of the nuclear pore complex (NPC), nucleoporin 85 (Nup85). The ptr5-1 mutant shows no defects in protein transport, suggesting the specific involvement of Ptr5p/Nup85p in nuclear mRNA export in S. pombe. We identified Seh1p, a nucleoporin interacting with Nup85p, an mRNA-binding protein Mlo3p, and Sac3p, a component of the TREX-2 complex involved in coupling of nuclear mRNA export with transcription, as multi-copy suppressors for the ptr5-1 mutation. In addition, we found that the ptr5-1 mutation is synthetically lethal with a mutation of the mRNA export factor Rae1p, and that the double mutant exaggerates defective nuclear mRNA export, suggesting that Ptr5p/Nup85p is involved in nuclear mRNA export through Rae1p. Interestingly, the ptr5-1 mutation also showed synthetic effects with several prp pre-mRNA splicing mutations, suggesting a functional linkage between the NPCs and the splicing apparatus in the yeast nucleus.

  15. Metastatic tumor antigen 3 is a direct corepressor of the Wnt4 pathway

    OpenAIRE

    Zhang, Hao; Singh, Rajesh R.; Talukder, Amjad H.; Kumar, Rakesh

    2006-01-01

    Here we show that expression of MTA3 inhibits ductal branching in virgin and pregnant murine transgenic mammary glands. MTA3 also suppresses the Wnt4 pathway and, thus, these findings parallel phenotypic changes in Wnt4-null mice. MTA3 represses Wnt4 transcription and Wnt4 secretion, inhibiting Wnt-target genes in mammary epithelial cells. Accordingly, knockdown of endogenous MTA3 stimulates Wnt4 expression and Wnt cellular targets. The MTA3–NuRD (nucleosome remodeling and deacetylase) comple...

  16. Protein Phosphatase 2A in the Regulation of Wnt Signaling, Stem Cells, and Cancer.

    Science.gov (United States)

    Thompson, Joshua J; Williams, Christopher S

    2018-02-26

    Protein phosphorylation is a ubiquitous cellular process that allows for the nuanced and reversible regulation of protein activity. Protein phosphatase 2A (PP2A) is a heterotrimeric serine-threonine phosphatase-composed of a structural, regulatory, and catalytic subunit-that controls a variety of cellular events via protein dephosphorylation. While much is known about PP2A and its basic biochemistry, the diversity of its components-especially the multitude of regulatory subunits-has impeded the determination of PP2A function. As a consequence of this complexity, PP2A has been shown to both positively and negatively regulate signaling networks such as the Wnt pathway. Wnt signaling modulates major developmental processes, and is a dominant mediator of stem cell self-renewal, cell fate, and cancer stem cells. Because PP2A affects Wnt signaling both positively and negatively and at multiple levels, further understanding of this complex dynamic may ultimately provide insight into stem cell biology and how to better treat cancers that result from alterations in Wnt signaling. This review will summarize literature that implicates PP2A as a tumor suppressor, explore PP2A mutations identified in human malignancy, and focus on PP2A in the regulation of Wnt signaling and stem cells so as to better understand how aberrancy in this pathway can contribute to tumorigenesis.

  17. USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination

    Directory of Open Access Journals (Sweden)

    Laura Novellasdemunt

    2017-10-01

    Full Text Available The tumor suppressor gene adenomatous polyposis coli (APC is mutated in most colorectal cancers (CRCs, resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs.

  18. miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

    Energy Technology Data Exchange (ETDEWEB)

    Li, Zhi [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Li, Youjun, E-mail: liyoujunn@126.com [Department of Human Anatomy and Histoembryology, College of Basic Medical Sciences, Jilin University (China); Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong [Central Hospital Affiliated to Shenyang Medical College (China)

    2016-03-18

    miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

  19. miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis in osteosarcoma cells

    International Nuclear Information System (INIS)

    Li, Zhi; Li, Youjun; Wang, Nan; Yang, Lifeng; Zhao, Wei; Zeng, Xiandong

    2016-01-01

    miR-130b was significantly up-regulated in osteosarcoma (OS) cells. Naked cuticle homolog 2 (NKD2) inhibited tumor growth and metastasis in OS by suppressing Wnt signaling. We used three miRNA target analysis tools to identify potential targets of miR-130b, and found that NKD2 is a potential target of miR-130b. Based on these findings, we hypothesize that miR-130b might target NKD2 and regulate the Wnt signaling to promote OS growth. We detected the expression of miR-130b and NKD2 mRNA and protein by quantitative Real-Time PCR (qRT-PCR) and western blot assays, respectively, and found up-regulation of miR-130b and down-regulation of NKD2 mRNA and protein exist in OS cell lines. MTT and flow cytometry assays showed that miR-130b inhibitors inhibit proliferation and promote apoptosis in OS cells. Furthermore, we showed that NKD2 is a direct target of miR-130b, and miR-130b regulated proliferation and apoptosis of OS cells by targeting NKD2. We further investigated whether miR-130b and NKD2 regulate OS cell proliferation and apoptosis by inhibiting Wnt signaling, and the results confirmed our speculation that miR-130b targets NKD2 and regulates the Wnt signaling to promote proliferation and inhibit apoptosis of OS cells. These findings will offer new clues for OS development and progression, and novel potential therapeutic targets for OS. - Highlights: • miR-130b is up-regulated and NKD2 is down-regulated in osteosarcoma cell lines. • Down-regulation of miR-130b inhibits proliferation of osteosarcoma cells. • Down-regulation of miR-130b promotes apoptosis of osteosarcoma cells. • miR-130b directly targets NKD2. • NKD2 regulates OS cell proliferation and apoptosis by inhibiting the Wnt signaling.

  20. Wnt signaling inhibits CTL memory programming.

    Science.gov (United States)

    Xiao, Zhengguo; Sun, Zhifeng; Smyth, Kendra; Li, Lei

    2013-12-01

    Induction of functional CTLs is one of the major goals for vaccine development and cancer therapy. Inflammatory cytokines are critical for memory CTL generation. Wnt signaling is important for CTL priming and memory formation, but its role in cytokine-driven memory CTL programming is unclear. We found that wnt signaling inhibited IL-12-driven CTL activation and memory programming. This impaired memory CTL programming was attributed to up-regulation of eomes and down-regulation of T-bet. Wnt signaling suppressed the mTOR pathway during CTL activation, which was different to its effects on other cell types. Interestingly, the impaired memory CTL programming by wnt was partially rescued by mTOR inhibitor rapamycin. In conclusion, we found that crosstalk between wnt and the IL-12 signaling inhibits T-bet and mTOR pathways and impairs memory programming which can be recovered in part by rapamycin. In addition, direct inhibition of wnt signaling during CTL activation does not affect CTL memory programming. Therefore, wnt signaling may serve as a new tool for CTL manipulation in autoimmune diseases and immune therapy for certain cancers. Copyright © 2013 Elsevier Ltd. All rights reserved.

  1. Maternal exposure to prostaglandin E2 modifies expression of Wnt genes in mouse brain – An autism connection

    Directory of Open Access Journals (Sweden)

    Ravneet Rai-Bhogal

    2018-07-01

    Full Text Available Prostaglandin E2 (PGE2 is a lipid signaling molecule important for brain development and function. Various genetic and environmental factors can influence the level of PGE2 and increase the risk of developing Autism Spectrum Disorder (ASD. We have previously shown that in neuronal cell lines and mouse brain, PGE2 can interfere with the Wnt canonical pathway, which is essential during early brain development. Higher levels of PGE2 increased Wnt-dependent motility and proliferation of neuroectodermal stem cells, and modified the expression of Wnt genes previously linked to autism disorders. We also recently established a cross-talk between these two pathways in the prenatal mouse brain lacking PGE2 producing enzyme (COX-/-. The current study complements the published data and reveals that PGE2 signaling also converges with the Wnt canonical pathway in the developing mouse brain after maternal exposure to PGE2 at the onset of neurogenesis. We found significant changes in the expression level of Wnt-target genes, Mmp7, Wnt2, and Wnt3a, during prenatal and early postnatal stages. Interestingly, we observed variability in the expression level of these genes between genetically-identical pups within the same pregnancy. Furthermore, we found that all the affected genes have been previously associated with disorders of the central nervous system, including autism. We determined that prenatal exposure to PGE2 affects the Wnt pathway at the level of β-catenin, the major downstream regulator of Wnt-dependent gene transcription. We discuss how these results add new knowledge into the molecular mechanisms by which PGE2 may interfere with neuronal development during critical periods.

  2. Canonical Wnt signaling maintains the quiescent stage of hepatic stellate cells

    International Nuclear Information System (INIS)

    Kordes, Claus; Sawitza, Iris; Haeussinger, Dieter

    2008-01-01

    It is well known that hepatic stellate cells (HSC) develop into cells, which are thought to contribute to liver fibrogenesis. Recent data suggest that HSC are progenitor cells with the capacity to differentiate into cells of endothelial and hepatocyte lineages. The present study shows that β-catenin-dependent canonical Wnt signaling is active in freshly isolated HSC of rats. Mimicking of the canonical Wnt pathway in cultured HSC by TWS119, an inhibitor of the glycogen synthase kinase 3β, led to reduced β-catenin phosphorylation, induced nuclear translocation of β-catenin, elevated glutamine synthetase production, impeded synthesis of α-smooth muscle actin and Wnt5a, but promoted the expression of glial fibrillary acidic protein, Wnt10b, and paired-like homeodomain transcription factor 2c. In addition, canonical Wnt signaling lowered DNA synthesis and hindered HSC from entering the cell cycle. The findings demonstrate that β-catenin-dependent Wnt signaling maintains the quiescent state of HSC and, similar to stem and progenitor cells, influences their developmental fate

  3. Early Transcriptional Changes Induced by Wnt/β-Catenin Signaling in Hippocampal Neurons

    Directory of Open Access Journals (Sweden)

    Eduardo Pérez-Palma

    2016-01-01

    Full Text Available Wnt/β-catenin signaling modulates brain development and function and its deregulation underlies pathological changes occurring in neurodegenerative and neurodevelopmental disorders. Since one of the main effects of Wnt/β-catenin signaling is the modulation of target genes, in the present work we examined global transcriptional changes induced by short-term Wnt3a treatment (4 h in primary cultures of rat hippocampal neurons. RNAseq experiments allowed the identification of 170 differentially expressed genes, including known Wnt/β-catenin target genes such as Notum, Axin2, and Lef1, as well as novel potential candidates Fam84a, Stk32a, and Itga9. Main biological processes enriched with differentially expressed genes included neural precursor (GO:0061364, p-adjusted = 2.5 × 10−7, forebrain development (GO:0030900, p-adjusted = 7.3 × 10−7, and stem cell differentiation (GO:0048863 p-adjusted = 7.3 × 10−7. Likewise, following activation of the signaling cascade, the expression of a significant number of genes with transcription factor activity (GO:0043565, p-adjusted = 4.1 × 10−6 was induced. We also studied molecular networks enriched upon Wnt3a activation and detected three highly significant expression modules involved in glycerolipid metabolic process (GO:0046486, p-adjusted = 4.5 × 10−19, learning or memory (GO:0007611, p-adjusted = 4.0 × 10−5, and neurotransmitter secretion (GO:0007269, p-adjusted = 5.3 × 10−12. Our results indicate that Wnt/β-catenin mediated transcription controls multiple biological processes related to neuronal structure and activity that are affected in synaptic dysfunction disorders.

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2009-10-15

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

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

    International Nuclear Information System (INIS)

    Zhou, Haibin; Shang, Linshan; Li, Xi; Zhang, Xiyu; Gao, Guimin; Guo, Chenhong; Chen, Bingxi; Liu, Qiji; Gong, Yaoqin; Shao, Changshun

    2009-01-01

    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 β-catenin dose-dependently and time-dependently. As a consequence of the increased nuclear accumulation of β-catenin, the ability to activate transcription of β-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 β-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 β-catenin upregulation, this inhibitory effect can be abolished in resveratrol-treated cells. Furthermore, we showed that the level of glycogen synthase kinase 3β (GSK-3β), which phosphorylates and destabilizes β-catenin, was reduced in response to resveratrol treatment. The phosphorylation of GSK-3β requires extracellular signal-regulated kinase (ERK)1/2. Together, our data indicate that resveratrol promotes osteoblastogenesis and bone formation by augmenting Wnt signaling.

  6. Wnt signaling in triple-negative breast cancer

    Science.gov (United States)

    Pohl, SÖ-G; Brook, N; Agostino, M; Arfuso, F; Kumar, A P; Dharmarajan, A

    2017-01-01

    Wnt signaling regulates a variety of cellular processes, including cell fate, differentiation, proliferation and stem cell pluripotency. Aberrant Wnt signaling is a hallmark of many cancers. An aggressive subtype of breast cancer, known as triple-negative breast cancer (TNBC), demonstrates dysregulation in canonical and non-canonical Wnt signaling. In this review, we summarize regulators of canonical and non-canonical Wnt signaling, as well as Wnt signaling dysfunction that mediates the progression of TNBC. We review the complex molecular nature of TNBC and the emerging therapies that are currently under investigation for the treatment of this disease. PMID:28368389

  7. Roles of Wnt/β-catenin signaling in epithelial differentiation of mesenchymal stem cells

    International Nuclear Information System (INIS)

    Wang, Yajing; Sun, Zhaorui; Qiu, Xuefeng; Li, Yan; Qin, Jizheng; Han, Xiaodong

    2009-01-01

    Bone marrow-derived mesenchymal stem cells (MSCs) have been demonstrated to be able to differentiate into epithelial lineage, but the precise mechanisms controlling this process are unclear. Our aim is to explore the roles of Wnt/β-catenin in the epithelial differentiation of MSCs. Using indirect co-culture of rat MSCs with rat airway epithelial cells (RTE), MSCs expressed several airway epithelial markers (cytokeratin 18, tight junction protein occudin, cystic fibrosis transmembrance regulator). The protein levels of some important members in Wnt/β-catenin signaling were determined, suggested down-regulation of Wnt/β-catenin with epithelial differentiation of MSCs. Furthermore, Wnt3α can inhibit the epithelial differentiation of MSCs. A loss of β-catenin induced by Dickkopf-1 can enhance MSCs differentiation into epithelial cells. Lithium chloride transiently activated β-catenin expression and subsequently decreased β-catenin level and at last inhibited MSCs to differentiate into airway epithelium. Taken together, our study indicated that RTE cells can trigger epithelial differentiation of MSCs. Blocking Wnt/β-catenin signaling may promote MSCs to differentiate towards airway epithelial cells.

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

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    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.

  9. Variation in WNT7A is unlikely to be a cause of familial Congenital Talipes Equinovarus

    Directory of Open Access Journals (Sweden)

    Hennekam Raoul

    2008-06-01

    Full Text Available Abstract Background Genetic factors make an important contribution to the aetiology of congenital talipes equinovarus (CTEV, the most common developmental disorder of the lower limb. WNT7A was suggested as a candidate gene for CTEV on the basis of a genome-wide scan for linkage in a large multi-case family. WNT7A is a plausible candidate gene for CTEV as it provides a signal for pattern formation during limb development, and mutation in WNT7A has been reported in a number of limb malformation syndromes. Methods We investigated the role of WNT7A using a family-based linkage approach in our large series of European multi-case CTEV families. Three microsatellite markers were used, of which one (D3S2385 is intragenic, and the other two (D3S2403, D3S1252 are 700 kb 5' to the start and 20 kb from the 3' end of the gene, respectively. Ninety-one CTEV families, comprising 476 individuals of whom 211 were affected, were genotyped. LOD scores using recessive and incomplete-dominant inheritance models, and non-parametric linkage scores, excluded linkage. Results No significant evidence for linkage was observed using either parametric or non-parametric models. LOD scores for the parametric models remained strongly negative in the regions between the markers, and in the 0.5 cM intervals outside the marker map. No significant lod scores were obtained when the data were analysed allowing for heterogeneity. Conclusion Our evidence suggests that the WNT7A gene is unlikely to be a major contributor to the aetiology of familial CTEV.

  10. WNT7A/β-catenin signaling induces FGF1 and influences sensitivity to niclosamide in ovarian cancer.

    Science.gov (United States)

    King, M L; Lindberg, M E; Stodden, G R; Okuda, H; Ebers, S D; Johnson, A; Montag, A; Lengyel, E; MacLean Ii, J A; Hayashi, K

    2015-06-01

    We previously characterized the link between WNT7A and the progression of ovarian cancer. Other groups have identified FGF1 as a relevant risk factor in ovarian cancer. Here, we show a linkage between these two signaling pathways that may be exploited to improve treatment and prognosis of patients with ovarian cancer. High expression of WNT7A and FGF1 are correlated in ovarian carcinomas and poor overall patient survival. A chromatin immunoprecipitation assay demonstrated that WNT7A/β-catenin signaling directly regulates FGF1 expression via TCF binding elements in the FGF1-1C promoter locus. In vitro gene manipulation studies revealed that FGF1 is sufficient to drive the tumor-promoting effects of WNT7A. In vivo xenograft studies confirmed that the stable overexpression of WNT7A or FGF1 induced a significant increase in tumor incidence, whereas FGF1 knockdown in WNT7A overexpressing cells caused a significant reduction in tumor size. Niclosamide most efficiently abrogated WNT7A/β-catenin signaling in our model, inhibited β-catenin transcriptional activity and cell viability, and increased cell death. Furthermore, niclosamide decreased cell migration following an increase in E-cadherin subsequent to decreased levels of SLUG. The effects of niclosamide on cell functions were more potent in WNT7A-overexpressing cells. Oral niclosamide inhibited tumor growth and progression in an intraperitoneal xenograft mouse model representative of human ovarian cancer. Collectively, these results indicate that FGF1 is a direct downstream target of WNT7A/β-catenin signaling and this pathway has potential as a therapeutic target in ovarian cancer. Moreover, niclosamide is a promising inhibitor of this pathway and may have clinical relevance.

  11. Runx expression is mitogenic and mutually linked to Wnt activity in blastula-stage sea urchin embryos.

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    Anthony J Robertson

    Full Text Available The Runt homology domain (Runx defines a metazoan family of sequence-specific transcriptional regulatory proteins that are critical for animal development and causally associated with a variety of mammalian cancers. The sea urchin Runx gene SpRunt-1 is expressed throughout the blastula stage embryo, and is required globally during embryogenesis for cell survival and differentiation.Depletion of SpRunt-1 by morpholino antisense-mediated knockdown causes a blastula stage deficit in cell proliferation, as shown by bromodeoxyuridine (BrdU incorporation and direct cell counts. Reverse transcription coupled polymerase chain reaction (RT-PCR studies show that the cell proliferation deficit is presaged by a deficit in the expression of several zygotic wnt genes, including wnt8, a key regulator of endomesoderm development. In addition, SpRunt-1-depleted blastulae underexpress cyclinD, an effector of mitogenic Wnt signaling. Blastula stage cell proliferation is also impeded by knockdown of either wnt8 or cyclinD. Chromatin immunoprecipitation (ChIP indicates that Runx target sites within 5' sequences flanking cyclinD, wnt6 and wnt8 are directly bound by SpRunt-1 protein at late blastula stage. Furthermore, experiments using a green fluorescent protein (GFP reporter transgene show that the blastula-stage operation of a cis-regulatory module previously shown to be required for wnt8 expression (Minokawa et al., Dev. Biol. 288: 545-558, 2005 is dependent on its direct sequence-specific interaction with SpRunt-1. Finally, inhibitor studies and immunoblot analysis show that SpRunt-1 protein levels are negatively regulated by glycogen synthase kinase (GSK-3.These results suggest that Runx expression and Wnt signaling are mutually linked in a feedback circuit that controls cell proliferation during development.

  12. The function of endocytosis in Wnt signaling.

    Science.gov (United States)

    Brunt, Lucy; Scholpp, Steffen

    2018-03-01

    Wnt growth factors regulate one of the most important signaling networks during development, tissue homeostasis and disease. Despite the biological importance of Wnt signaling, the mechanism of endocytosis during this process is ill described. Wnt molecules can act as paracrine signals, which are secreted from the producing cells and transported through neighboring tissue to activate signaling in target cells. Endocytosis of the ligand is important at several stages of action: One central function of endocytic trafficking in the Wnt pathway occurs in the source cell. Furthermore, the β-catenin-dependent Wnt ligands require endocytosis for signal activation and to regulate gene transcription in the responding cells. Alternatively, Wnt/β-catenin-independent signaling regulates endocytosis of cell adherence plaques to control cell migration. In this comparative review, we elucidate these three fundamental interconnected functions, which together regulate cellular fate and cellular behavior. Based on established hypotheses and recent findings, we develop a revised picture for the complex function of endocytosis in the Wnt signaling network.

  13. Relevance of Wnt10b and activation of β-catenin/GCMa/syncytin-1 pathway in BeWo cell fusion.

    Science.gov (United States)

    Malhotra, Sudha Saryu; Banerjee, Priyanka; Chaudhary, Piyush; Pal, Rahul; Gupta, Satish Kumar

    2017-10-01

    To study the involvement of specific Wnt(s) ligand during trophoblastic BeWo cell differentiation. BeWo cells on treatment with forskolin/human chorionic gonadotropin (hCG) were studied for cell fusion by desmoplakin I+II staining and/or hCG secretion by ELISA. Levels of Wnt10b/β-catenin/glial cell missing a (GCMa)/syncytin-1 were studied by qPCR/Western blotting in forskolin-/hCG-treated control siRNA and Wnt10b silenced BeWo cells. BeWo cells on treatment with hCG (5 IU/mL) led to a 94-fold increase in Wnt10b transcript. Wnt10b silencing showed significant decrease in forskolin-/hCG-mediated BeWo cell fusion and/or hCG secretion. It led to down-regulation of β-catenin (nuclear and cytoplasmic), GCMa and syncytin-1 expression. Treatment of BeWo cells with H89, protein kinase A (PKA) signaling inhibitor, significantly reduced forskolin-/hCG-induced Wnt10b, β-catenin, and syncytin-1 expression, which also resulted in reduced cell fusion. Wnt10b is involved in forskolin/hCG-mediated BeWo cell fusion via β-catenin/GCMa/syncytin pathway, which may also involve activation of PKA. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  14. Canonical Wnt signaling transiently stimulates proliferation and enhances neurogenesis in neonatal neural progenitor cultures

    International Nuclear Information System (INIS)

    Hirsch, Cordula; Campano, Louise M.; Woehrle, Simon; Hecht, Andreas

    2007-01-01

    Canonical Wnt signaling triggers the formation of heterodimeric transcription factor complexes consisting of β-catenin and T cell factors, and thereby controls the execution of specific genetic programs. During the expansion and neurogenic phases of embryonic neural development canonical Wnt signaling initially controls proliferation of neural progenitor cells, and later neuronal differentiation. Whether Wnt growth factors affect neural progenitor cells postnatally is not known. Therefore, we have analyzed the impact of Wnt signaling on neural progenitors isolated from cerebral cortices of newborn mice. Expression profiling of pathway components revealed that these cells are fully equipped to respond to Wnt signals. However, Wnt pathway activation affected only a subset of neonatal progenitors and elicited a limited increase in proliferation and neuronal differentiation in distinct subsets of cells. Moreover, Wnt pathway activation only transiently stimulated S-phase entry but did not support long-term proliferation of progenitor cultures. The dampened nature of the Wnt response correlates with the predominant expression of inhibitory pathway components and the rapid actuation of negative feedback mechanisms. Interestingly, in differentiating cell cultures activation of canonical Wnt signaling reduced Hes1 and Hes5 expression suggesting that during postnatal neural development, Wnt/β-catenin signaling enhances neurogenesis from progenitor cells by interfering with Notch pathway activity

  15. Genetic variation in ATP5O is associated with skeletal muscle ATP50 mRNA expression and glucose uptake in young twins.

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    Tina Rönn

    Full Text Available BACKGROUND: Impaired oxidative capacity of skeletal muscle mitochondria contribute to insulin resistance and type 2 diabetes (T2D. Furthermore, mRNA expression of genes involved in oxidative phosphorylation, including ATP5O, is reduced in skeletal muscle from T2D patients. Our aims were to investigate mechanisms regulating ATP5O expression in skeletal muscle and association with glucose metabolism, and the relationship between ATP5O single nucleotide polymorphisms (SNPs and risk of T2D. METHODOLOGY/PRINCIPAL FINDINGS: ATP5O mRNA expression was analyzed in skeletal muscle from young (n = 86 and elderly (n = 68 non-diabetic twins before and after a hyperinsulinemic euglycemic clamp. 11 SNPs from the ATP5O locus were genotyped in the twins and a T2D case-control cohort (n = 1466. DNA methylation of the ATP5O promoter was analyzed in twins (n = 22 using bisulfite sequencing. The mRNA level of ATP5O in skeletal muscle was reduced in elderly compared with young twins, both during basal and insulin-stimulated conditions (p<0.0005. The degree of DNA methylation around the transcription start of ATP5O was <1% in both young and elderly twins and not associated with mRNA expression (p = 0.32. The mRNA level of ATP5O in skeletal muscle was positively related to insulin-stimulated glucose uptake (regression coefficient = 6.6; p = 0.02. Furthermore, two SNPs were associated with both ATP5O mRNA expression (rs12482697: T/T versus T/G; p = 0.02 and rs11088262: A/A versus A/G; p = 0.004 and glucose uptake (rs11088262: A/A versus A/G; p = 0.002 and rs12482697: T/T versus T/G; p = 0.005 in the young twins. However, we could not detect any genetic association with T2D. CONCLUSIONS/SIGNIFICANCE: Genetic variation and age are associated with skeletal muscle ATP5O mRNA expression and glucose disposal rate, suggesting that combinations of genetic and non-genetic factors may cause the reduced expression of ATP5O in T2D muscle. These findings propose a role for ATP5O, in

  16. TMEM59 potentiates Wnt signaling by promoting signalosome formation.

    Science.gov (United States)

    Gerlach, Jan P; Jordens, Ingrid; Tauriello, Daniele V F; van 't Land-Kuper, Ineke; Bugter, Jeroen M; Noordstra, Ivar; van der Kooij, Johanneke; Low, Teck Y; Pimentel-Muiños, Felipe X; Xanthakis, Despina; Fenderico, Nicola; Rabouille, Catherine; Heck, Albert J R; Egan, David A; Maurice, Madelon M

    2018-04-09

    Wnt/β-catenin signaling controls development and adult tissue homeostasis by regulating cell proliferation and cell fate decisions. Wnt binding to its receptors Frizzled (FZD) and low-density lipoprotein-related 6 (LRP6) at the cell surface initiates a signaling cascade that leads to the transcription of Wnt target genes. Upon Wnt binding, the receptors assemble into large complexes called signalosomes that provide a platform for interactions with downstream effector proteins. The molecular basis of signalosome formation and regulation remains elusive, largely due to the lack of tools to analyze its endogenous components. Here, we use internally tagged Wnt3a proteins to isolate and characterize activated, endogenous Wnt receptor complexes by mass spectrometry-based proteomics. We identify the single-span membrane protein TMEM59 as an interactor of FZD and LRP6 and a positive regulator of Wnt signaling. Mechanistically, TMEM59 promotes the formation of multimeric Wnt-FZD assemblies via intramembrane interactions. Subsequently, these Wnt-FZD-TMEM59 clusters merge with LRP6 to form mature Wnt signalosomes. We conclude that the assembly of multiprotein Wnt signalosomes proceeds along well-ordered steps that involve regulated intramembrane interactions. Copyright © 2018 the Author(s). Published by PNAS.

  17. The mRNA level of MLH1 in peripheral blood is a biomarker for the diagnosis of hereditary nonpolyposis colorectal cancer.

    Science.gov (United States)

    Yu, Hong; Li, Hui; Cui, Yongan; Xiao, Wei; Dai, Guihong; Huang, Junxing; Wang, Chaofu

    2016-01-01

    Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by functional defects in mismatch repair (MMR) genes, including mutL homolog 1 (MLH1) and mutS homolog 2 (MSH2). This study aimed to assess whether the mRNA expression of MLH1 in peripheral blood could be used as a biomarkers for the diagnosis of HNPCC. The mRNA level of MLH1 was determined in 19 HNPCC families (46 members) using real-time quantitative polymerase chain reaction (qPCR). The mRNA levels of MLH1 in HNPCC were significantly lower than controls (P MLH1 for the diagnosis of HNPCC with the area under curve of 0.858. At an optimal cut-off value (0.511), the mRNA level of MLH1 had a sensitivity of 81.3% and a specificity of 86.7% for distinguishing HNPCC from controls. In conclusion, the mRNA expression of MLH1 in peripheral blood may serve as a biomarker for the diagnosis of HNPCC.

  18. Role of MiR-3619-5p in β-Catenin-Mediated Non-Small Cell Lung Cancer Growth and Invasion

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    Xuecai Niu

    2015-10-01

    Full Text Available Background/Aims: The malignancy of non-small cell lung cancer (NSCLC is largely due to its fast growth and invasion. WNT/β-catenin signaling plays a critical role in regulating NSCLC carcinogenesis. Hence, suppression of β-catenin signal transduction in NSCLC cells may improve the therapeutic outcome. Methods: We analyzed the levels of β-catenin and miR-3619-5p in NSCLC specimens, compared to paired non-tumor normal lung tissue (NT. We did Bioinformatics analyses on the binding sites of 3'-UTR of β-catenin mRNA by miR-3619-5p. We modified the levels of miR-3619-5p in NSCLC cells and examined their effects on β-catenin levels, and on the growth and invasion of NSCLC cells in an MTT assay and a transwell cell migration assay, respectively. Results: NSCLC specimens had significant higher levels of β-catenin, and significantly lower levels of miR-3619-5p, compared to NT. The levels of β-catenin and miR-3619-5p were inversely correlated in NSCLC specimens. Bioinformatics analyses showed that miR-3619-5p bound to 3'-UTR of β-catenin mRNA in NSCLC cells to inhibit its translation. Overexpression of miR-3619-5p decreased β-catenin protein, while depletion of miR-3619-5p increased β-catenin protein in NSCLC cells, without altering β-catenin mRNA levels. Overexpression of miR-3619-5p in NSCLC cells inhibited cell growth and invasion, while depletion of miR-3619-5p in NSCLC lines increased cell growth and invasion. Conclusion: Our data demonstrate a previously unappreciated role for miR-3619-5p in suppression of β-catenin-mediated cancer growth and invasion in NSCLC cells, and highlight miR-3619-5p as a novel cancer suppressor in NSCLC.

  19. Alteration of canonical and non-canonical WNT-signaling by crystalline silica in human lung epithelial cells

    International Nuclear Information System (INIS)

    Perkins, Timothy N.; Dentener, Mieke A.; Stassen, Frank R.; Rohde, Gernot G.; Mossman, Brooke T.; Wouters, Emiel F.M.; Reynaert, Niki L.

    2016-01-01

    Growth and development of the mature lung is a complex process orchestrated by a number of intricate developmental signaling pathways. Wingless-type MMTV-integration site (WNT) signaling plays critical roles in controlling branching morphogenesis cell differentiation, and formation of the conducting and respiratory airways. In addition, WNT pathways are often re-activated in mature lungs during repair and regeneration. WNT- signaling has been elucidated as a crucial contributor to the development of idiopathic pulmonary fibrosis as well as other hyper-proliferative lung diseases. Silicosis, a detrimental occupational lung disease caused by excessive inhalation of crystalline silica dust, is hallmarked by repeated cycles of damaging inflammation, epithelial hyperplasia, and formation of dense, hyalinized nodules of whorled collagen. However, mechanisms of epithelial cell hyperplasia and matrix deposition are not well understood, as most research efforts have focused on the pronounced inflammatory response. Microarray data from our previous studies has revealed a number of WNT-signaling and WNT-target genes altered by crystalline silica in human lung epithelial cells. In the present study, we utilize pathway analysis to designate connections between genes altered by silica in WNT-signaling networks. Furthermore, we confirm microarray findings by QRT-PCR and demonstrate both activation of canonical (β-catenin) and down-regulation of non-canonical (WNT5A) signaling in immortalized (BEAS-2B) and primary (PBEC) human bronchial epithelial cells. These findings suggest that WNT-signaling and cross-talk with other pathways (e.g. Notch), may contribute to proliferative, fibrogenic and inflammatory responses to silica in lung epithelial cells. - Highlights: • Pathway analysis reveals silica-induced WNT-signaling in lung epithelial cells. • Silica-induced canonical WNT-signaling is mediated by autocrine/paracrine signals. • Crystalline silica decreases non-canonical WNT

  20. Alteration of canonical and non-canonical WNT-signaling by crystalline silica in human lung epithelial cells

    Energy Technology Data Exchange (ETDEWEB)

    Perkins, Timothy N.; Dentener, Mieke A. [Department of Respiratory Medicine, Maastricht University Medical Centre +, Maastricht University Maastricht (Netherlands); Stassen, Frank R. [Department of Medical Microbiology, Maastricht University Medical Centre +, Maastricht University Maastricht (Netherlands); Rohde, Gernot G. [Department of Respiratory Medicine, Maastricht University Medical Centre +, Maastricht University Maastricht (Netherlands); Mossman, Brooke T. [Department of Pathology, University of Vermont College of Medicine, Burlington, VT (United States); Wouters, Emiel F.M. [Department of Respiratory Medicine, Maastricht University Medical Centre +, Maastricht University Maastricht (Netherlands); Reynaert, Niki L., E-mail: n.reynaert@maastrichtuniversity.nl [Department of Respiratory Medicine, Maastricht University Medical Centre +, Maastricht University Maastricht (Netherlands)

    2016-06-15

    Growth and development of the mature lung is a complex process orchestrated by a number of intricate developmental signaling pathways. Wingless-type MMTV-integration site (WNT) signaling plays critical roles in controlling branching morphogenesis cell differentiation, and formation of the conducting and respiratory airways. In addition, WNT pathways are often re-activated in mature lungs during repair and regeneration. WNT- signaling has been elucidated as a crucial contributor to the development of idiopathic pulmonary fibrosis as well as other hyper-proliferative lung diseases. Silicosis, a detrimental occupational lung disease caused by excessive inhalation of crystalline silica dust, is hallmarked by repeated cycles of damaging inflammation, epithelial hyperplasia, and formation of dense, hyalinized nodules of whorled collagen. However, mechanisms of epithelial cell hyperplasia and matrix deposition are not well understood, as most research efforts have focused on the pronounced inflammatory response. Microarray data from our previous studies has revealed a number of WNT-signaling and WNT-target genes altered by crystalline silica in human lung epithelial cells. In the present study, we utilize pathway analysis to designate connections between genes altered by silica in WNT-signaling networks. Furthermore, we confirm microarray findings by QRT-PCR and demonstrate both activation of canonical (β-catenin) and down-regulation of non-canonical (WNT5A) signaling in immortalized (BEAS-2B) and primary (PBEC) human bronchial epithelial cells. These findings suggest that WNT-signaling and cross-talk with other pathways (e.g. Notch), may contribute to proliferative, fibrogenic and inflammatory responses to silica in lung epithelial cells. - Highlights: • Pathway analysis reveals silica-induced WNT-signaling in lung epithelial cells. • Silica-induced canonical WNT-signaling is mediated by autocrine/paracrine signals. • Crystalline silica decreases non-canonical WNT

  1. The human HECA interacts with cyclins and CDKs to antagonize Wnt-mediated proliferation and chemoresistance of head and neck cancer cells

    Energy Technology Data Exchange (ETDEWEB)

    Dowejko, Albert, E-mail: Albert.Dowejko@klinik.uni-regensburg.de [Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg (Germany); Bauer, Richard; Bauer, Karin [Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg (Germany); Mueller-Richter, Urs D.A. [Department of Oral and Maxillofacial Plastic Surgery, University of Wuerzburg, Pleicherwall 2, 97070 Wuerzburg (Germany); Reichert, Torsten E. [Department of Oral and Maxillofacial Surgery, University Hospital Regensburg, Franz-Josef-Strauss-Allee 11, 93053 Regensburg (Germany)

    2012-03-10

    There is a growing evidence that the human homologue of the Drosophila headcase (HECA) plays an important role in human carcinogenesis. So far specific protein interaction partners and affected signaling pathways of HECA are still elusive. In a recent study we showed that HECA overexpression in oral squamous-cell carcinoma (OSCC) keratinocytes has tumor suppressive effects resulting in a recuperation of cell cycle control concerning the entry and progression of S-phase, G2- and M-phase. Currently, quantitative RT-PCR and immunohistochemical analysis of primary tumor tissue from OSCC patients demonstrate that HECA expression is markedly decreased compared to normal control patients with abundant HECA expression. Additionally, there is nearly no HECA expression in OSCC metastases. Here, we show that HECA expression is negatively controlled by the Wnt-pathway and TCF4, a Wnt related transcription factor, binds to the HECA promoter. Furthermore, immunocytochemistry reveals colocalization of HECA with the cyclin dependent kinase CDK9. Immunoprecipitation experiments and proximity ligation assays further reveal an interaction of HECA with CDK2, CDK9, Cyclin A and Cyclin K, a direct transcriptional target of the p53 tumor suppressor. Silencing HECA in OSCC cell lines leads to a significant increase of cell division and a markedly increased resistance against the chemotherapeutic cisplatin. On the contrary, HECA overexpressing OSCC cell lines show decreased resistance of OSCC cells against cisplatin. Therefore, HECA could be considered as future therapeutic agent against Wnt-dependent tumor progression. -- Highlights: Black-Right-Pointing-Pointer HECA is a new cell cycle regulator with anti-tumor features in head and neck cancer. Black-Right-Pointing-Pointer During tumor progression HECA mRNA and protein expression decrease. Black-Right-Pointing-Pointer The HECA promotor is a direct target of the Wnt/beta-catenin/TCF-pathway. Black-Right-Pointing-Pointer The HECA protein

  2. PAX5α and PAX5β mRNA expression in breast Cancer: Relation to ...

    African Journals Online (AJOL)

    Background: Many studies evaluated the role of paired box gene 5 (PAX5) in breast cancer. However, few investigated PAX5α and PAX5β isoforms individually. Objective: The aim of the present study is to evaluate mRNA expression of PAX5α and PAX5β in breast cancer and assessing their underlying pathological roles ...

  3. Non-conventional Frizzled ligands and Wnt receptors.

    Science.gov (United States)

    Hendrickx, Marijke; Leyns, Luc

    2008-05-01

    The Wnt family of secreted signaling factors plays numerous roles in embryonic development and in stem cell biology. In the adult, Wnt signaling is involved in tissue homeostasis and mutations that lead to the overexpression of Wnt can be linked to cancer. Wnt signaling is transduced intracellularly by the Frizzled (Fzd) family of receptors. In the canonical pathway, accumulation of beta-catenin and the subsequent formation of a complex with T cell factors (TCF) or lymphoid enhancing factors (Lef) lead to target gene activation. The identification of Ryk as an alternative Wnt receptor and the discovery of the novel Fzd ligands Norrie disease protein (NDP) and R-Spondin, changed the traditional view of Wnts binding to Fzd receptors. Mouse R-Spondin cooperates with Wnt signaling and Low density lipoprotein (LDL) receptor related protein (LRP) to activate beta-catenin dependent gene expression and is involved in processes such as limb and placental development in the mouse. NDP is the product of the Norrie disease gene and controls vascular development in the retina, inner ear and in the female reproductive system during pregnancy. In this review a functional overview of the interactions of the different Wnt and non-Wnt ligands with the Fzd receptors is given as well as a survey of Wnts binding to Ryk and we discuss the biological significance of these interactions.

  4. Wnt signaling and polarity in freshwater sponges.

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    Windsor Reid, Pamela J; Matveev, Eugueni; McClymont, Alexandra; Posfai, Dora; Hill, April L; Leys, Sally P

    2018-02-02

    The Wnt signaling pathway is uniquely metazoan and used in many processes during development, including the formation of polarity and body axes. In sponges, one of the earliest diverging animal groups, Wnt pathway genes have diverse expression patterns in different groups including along the anterior-posterior axis of two sponge larvae, and in the osculum and ostia of others. We studied the function of Wnt signaling and body polarity formation through expression, knockdown, and larval manipulation in several freshwater sponge species. Sponge Wnts fall into sponge-specific and sponge-class specific subfamilies of Wnt proteins. Notably Wnt genes were not found in transcriptomes of the glass sponge Aphrocallistes vastus. Wnt and its signaling genes were expressed in archaeocytes of the mesohyl throughout developing freshwater sponges. Osculum formation was enhanced by GSK3 knockdown, and Wnt antagonists inhibited both osculum development and regeneration. Using dye tracking we found that the posterior poles of freshwater sponge larvae give rise to tissue that will form the osculum following metamorphosis. Together the data indicate that while components of canonical Wnt signaling may be used in development and maintenance of osculum tissue, it is likely that Wnt signaling itself occurs between individual cells rather than whole tissues or structures in freshwater sponges.

  5. TP53 and ATM mRNA expression in skin and skeletal muscle after low-level laser exposure.

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    Guedes de Almeida, Luciana; Sergio, Luiz Philippe da Silva; de Paoli, Flavia; Mencalha, Andre Luiz; da Fonseca, Adenilson de Souza

    2017-08-01

    Low-level lasers are widespread in regenerative medicine, but the molecular mechanisms involved in their biological effects are not fully understood, particularly those on DNA stability. Therefore, this study aimed to investigate mRNA expression of genes related to DNA genomic stability in skin and skeletal muscle tissue from Wistar rats exposed to low-level red and infrared lasers. For this, TP53 (Tumor Protein 53) and ATM (Ataxia Telangiectasia Mutated gene) mRNA expressions were evaluated by real-time quantitative PCR (RT-qPCR) technique 24 hours after low-level red and infrared laser exposure. Our data showed that relative TP53 mRNA expression was not significantly altered in both tissues exposed to lasers. For ATM, relative mRNA expression in skin tissue was not significantly altered, but in muscle tissue, laser exposure increased relative ATM mRNA expression. Low-level red and infrared laser radiations alter ATM mRNA expression related to DNA stability in skeletal muscle tissue.

  6. USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination.

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    Novellasdemunt, Laura; Foglizzo, Valentina; Cuadrado, Laura; Antas, Pedro; Kucharska, Anna; Encheva, Vesela; Snijders, Ambrosius P; Li, Vivian S W

    2017-10-17

    The tumor suppressor gene adenomatous polyposis coli (APC) is mutated in most colorectal cancers (CRCs), resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID) in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs. Copyright © 2017 The Francis Crick Institute. Published by Elsevier Inc. All rights reserved.

  7. Canonical Wnt signaling induces a primitive endoderm metastable state in mouse embryonic stem cells.

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    Price, Feodor D; Yin, Hang; Jones, Andrew; van Ijcken, Wilfred; Grosveld, Frank; Rudnicki, Michael A

    2013-04-01

    Activation of the canonical Wnt signaling pathway synergizes with leukemia inhibitory factor (LIF) to maintain pluripotency of mouse embryonic stem cells (mESCs). However, in the absence of LIF, Wnt signaling is unable to maintain ESCs in the undifferentiated state. To investigate the role of canonical Wnt signaling in pluripotency and lineage specification, we expressed Wnt3a in mESCs and characterized them in growth and differentiation. We found that activated canonical Wnt signaling induced the formation of a reversible metastable primitive endoderm state in mESC. Upon subsequent differentiation, Wnt3a-stimulated mESCs gave rise to large quantities of visceral endoderm. Furthermore, we determined that the ability of canonical Wnt signaling to induce a metastable primitive endoderm state was mediated by Tbx3. Our data demonstrates a specific role for canonical Wnt signaling in promoting pluripotency while at the same time priming cells for subsequent differentiation into the primitive endoderm lineage. Copyright © 2013 AlphaMed Press.

  8. Cytotoxic activities of Telectadium dongnaiense and its constituents by inhibition of the Wnt/β-catenin signaling pathway.

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    Kim, Won Kyung; Bach, Duc-Hiep; Ryu, Hyung Won; Oh, Jedo; Park, Hyen Joo; Hong, Ji-Young; Song, Hyuk-Hwan; Eum, Sangmi; Bach, Tran The; Lee, Sang Kook

    2017-10-15

    Wnt/β-catenin signaling pathway is a potential target for the treatment of human colon cancer. Thus, the inhibitory effects of various plant extracts on cell proliferation and Wnt signal transduction were evaluated to discover a Wnt signaling inhibitor. The present study aimed to investigate the cytotoxicity involved in Wnt pathway of the MeOH extract from Telectadium dongnaiense bark (TDB) and to identify its bioactive constituents by bioassay-guided fractionation. The sulforhodamine B-based proliferation assay and the β-catenin/TCF-responsive reporter gene assay were employed as screening systems. The isolation and identification of compounds were elucidated on the basis of spectroscopic methods. Inhibitory effects on the expression levels of Wnt target genes were determined by real-time PCR and western blotting. The extract of TDB most strongly inhibited cell proliferation and TOPflash activity (IC 50 = 1.5 and 2.0 µg/ml), which was correlated with its inhibitory effects on the expression of Wnt target genes. Three major compounds were isolated from bioactive fractions and were identified as 1,4-dicaffeoylquinic acid (1), quercetin 3-rutinoside (2), and periplocin (3). Only compound 3 showed anti-proliferative activity (IC 50 = 0.06 µM) and exhibited Wnt signaling inhibitory effects in HCT116 colon cancer cells. This study contributes to understanding the cytotoxic properties of TDB extract and its constituents and provides a potent strategy for its further application. Copyright © 2017 The Authors. Published by Elsevier GmbH.. All rights reserved.

  9. Efficient Purification and Optimization of Wnt3a, a Novel Therapeutic for Tissue Regeneration

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    Madhav, D.; Helms, J.; Dhamdhere, G.

    2012-12-01

    Wnt is a secreted protein that is present naturally in the body. When an organism is injured the amount of Wnt in the affected area increases. This protein acts as an activator of adult stem cells and signals them to begin differentiating and proliferating. This stem cell response augments the ongoing efforts of injured cells to heal faster by becoming the cells that were damaged by the injury. Adult stem cells play a great role in the healing of wounds, but as organisms age the amount of stem cells in their body decreases. This decrease, in effect, slows the healing of injuries because no stem cells are present to help the regenerative efforts of the body. The Wnt protein induces these stem cells not only to differentiate and proliferate, but also to self-replicate. The ability of Wnt to induce adult stem cells to self -replicate gives us an option to use the protein as a potential tissue regenerative drug. Post-translational Wnt has a lipid modification that makes the protein insoluble in water. To overcome this we fuse the protein with a liposome. A liposome is a lipid sphere with an aqueous center and a phospholipid membrane. The Wnt protein does not lose its function when joined with a liposome. Using this knowledge we can develop a viable means to inject the Wnt protein directly into organisms. The big problem now is to make enough purified Wnt to manufacture on a large scale.

  10. The way Wnt works: Components and mechanism

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    SAITO-DIAZ, KENYI; CHEN, TONY W.; WANG, XIAOXI; THORNE, CURTIS A.; WALLACE, HEATHER A.; PAGE-MCCAW, ANDREA; LEE, ETHAN

    2013-01-01

    The canonical Wnt/β-catenin pathway is an ancient and evolutionarily conserved signaling pathway that is required for the proper development of all metazoans, from the basal demosponge Amphimedon queenslandica to humans. Misregulation of Wnt signaling is implicated in many human diseases, making this pathway an intense area of research in industry as well as academia. In this review, we explore our current understanding of the molecular steps involved in the transduction of a Wnt signal. We will focus on how the critical Wnt pathway component, β-catenin, is in a “futile cycle” of constant synthesis and degradation and how this cycle is disrupted upon pathway activation. We describe the role of the Wnt pathway in major human cancers and in the control of stem cell self-renewal in the developing organism and in adults. Finally, we describe well-accepted criteria that have been proposed as evidence for the involvement of a molecule in regulating the canonical Wnt pathway. PMID:23256519

  11. Renal Tubule Repair: Is Wnt/β-Catenin a Friend or Foe?

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    Gewin, Leslie S

    2018-01-24

    Wnt/β-catenin signaling is extremely important for proper kidney development. This pathway is also upregulated in injured renal tubular epithelia, both in acute kidney injury and chronic kidney disease. The renal tubular epithelium is an important target of kidney injury, and its response (repair versus persistent injury) is critical for determining whether tubulointerstitial fibrosis, the hallmark of chronic kidney disease, develops. This review discusses how Wnt/β-catenin signaling in the injured tubular epithelia promotes either repair or fibrosis after kidney injury. There is data suggesting that epithelial Wnt/β-catenin signaling is beneficial in acute kidney injury and important in tubular progenitors responsible for epithelial repair. The role of Wnt/β-catenin signaling in chronically injured epithelia is less clear. There is convincing data that Wnt/β-catenin signaling in interstitial fibroblasts and pericytes contributes to the extracellular matrix accumulation that defines fibrosis. However, some recent studies question whether Wnt/β-catenin signaling in chronically injured epithelia actually promotes fibrosis or repair.

  12. The function and evolution of Wnt genes in arthropods.

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    Murat, Sophie; Hopfen, Corinna; McGregor, Alistair P

    2010-11-01

    Wnt signalling is required for a wide range of developmental processes, from cleavage to patterning and cell migration. There are 13 subfamilies of Wnt ligand genes and this diverse repertoire appeared very early in metazoan evolution. In this review, we first summarise the known Wnt gene repertoire in various arthropods. Insects appear to have lost several Wnt subfamilies, either generally, such as Wnt3, or in lineage specific patterns, for example, the loss of Wnt7 in Anopheles. In Drosophila and Acyrthosiphon, only seven and six Wnt subfamilies are represented, respectively; however, the finding of nine Wnt genes in Tribolium suggests that arthropods had a larger repertoire ancestrally. We then discuss what is currently known about the expression and developmental function of Wnt ligands in Drosophila and other insects in comparison to other arthropods, such as the spiders Achaearanea and Cupiennius. We conclude that studies of Wnt genes have given us much insight into the developmental roles of some of these ligands. However, given the frequent loss of Wnt genes in insects and the derived development of Drosophila, further studies of these important genes are required in a broader range of arthropods to fully understand their developmental function and evolution. Copyright © 2010 Elsevier Ltd. All rights reserved.

  13. Human placental trophoblast invasion and differentiation: a particular focus on Wnt signalling

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    Martin eKnöfler

    2013-09-01

    Full Text Available Wingless ligands, a family of secreted proteins, are critically involved in organ development and tissue homeostasis by ensuring balanced rates of stem cell proliferation, cell death and differentiation. Wnt signalling components also play crucial roles in murine placental development controlling trophoblast lineage determination, chorioallantoic fusion and placental branching morphogenesis. However, the role of the pathway in human placentation, trophoblast development and differentiation is only partly understood. Here, we summarize our present knowledge about Wnt signalling in the human placenta and discuss its potential role in physiological and aberrant trophoblast invasion, gestational diseases and choriocarcinoma formation. Differentiation of proliferative first trimester cytotrophoblasts into invasive extravillous trophoblasts is associated with nuclear recruitment of β-catenin and induction of Wnt-dependent T-cell factor 4 suggesting that canonical Wnt signalling could be important for the formation and function of extravillous trophoblasts. Indeed, activation of the pathway was shown to promote trophoblast invasion in different in vitro trophoblast model systems as well as trophoblast cell fusion. Methylation-mediated silencing of inhibitors of Wnt signalling provided evidence for epigenetic activation of the pathway in placental tissues and choriocarcinoma cells. Similarly, abundant nuclear expression of β-catenin in invasive trophoblasts of complete hydatidiform moles suggested a role for hyper-activated Wnt signalling. In contrast, upregulation of Wnt inhibitors was noticed in placentae of women with preeclampsia, a disease characterized by shallow trophoblast invasion and incomplete spiral artery remodelling. Moreover, changes in Wnt signalling have been observed upon cytomegalovirus infection and in recurrent abortions. In summary, the current literature suggests a critical role of Wnt signalling in physiological and abnormal

  14. Al-Awadi-Raas-Rothschild syndrome with dental anomalies and a novel WNT7A mutation.

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    Kantaputra, Piranit Nik; Kapoor, Seema; Verma, Prashant; Kaewgahya, Massupa; Kawasaki, Katsushige; Ohazama, Atsushi; Ketudat Cairns, James R

    2017-12-01

    Al-Awadi-Raas-Rothschild syndrome (AARRS; OMIM 276820) is a very rare autosomal recessive limb malformation syndrome caused by WNT7A mutations. AARRS is characterized by various degrees of limb aplasia and hypoplasia. Normal intelligence and malformations of urogenital system are frequent findings. Complete loss of WNT7A function has been shown to cause AARRS, however, its partial loss leads to the milder malformation, Fuhrmann syndrome. An Indian boy affected with AARRS is reported. A novel homozygous base substitution mutation c.550A > C (p.Asn184Asp) is identified in the patient. Parents were heterozygous for the mutation. In addition to the typical features of AARRS, the patient had agenesis of the mandibular left deciduous lateral incisor. The heterozygous parents had microdontia of the maxillary left permanent third molar and taurodontism (enlarged dental pulp chamber at the expense of root) in a number of their permanent molars. Whole exome sequencing of the patient and his parents ruled out mutations in 11 known hypodontia-associated genes including WNT10A, MSX1, EDA, EDAR, EDARADD, PAX9, AXIN2, GREM2, NEMO, KRT17, and TFAP2B. In situ hybridization during tooth development showed Wnt7a expression in wild-type tooth epithelium at E14.5. All lines of evidence suggest that WNT7A has important role in tooth development and its mutation may lead to tooth agenesis, microdontia, and taurodontism. Oral examination of patients with AARRS and Fuhrmann syndromes is highly recommended. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  15. Eosinophils enhance WNT-5a and TGF-β1 genes expression in airway smooth muscle cells and promote their proliferation by increased extracellular matrix proteins production in asthma.

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    Januskevicius, Andrius; Vaitkiene, Simona; Gosens, Reinoud; Janulaityte, Ieva; Hoppenot, Deimante; Sakalauskas, Raimundas; Malakauskas, Kestutis

    2016-06-13

    Recent studies have suggested that eosinophils may have a direct effect on airway smooth muscle cells (ASMC), causing their proliferation in patients with asthma, but the precise mechanism of the interaction between these cells remains unknown. We propose that changes in Wnt signaling activity and extracellular matrix (ECM) production may help explain these findings. Therefore, the aim of this study was to investigate the effect of eosinophils from asthmatic and non-asthmatic subjects on Wnt-5a, transforming growth factor β1 (TGF-β1), and ECM protein (fibronectin and collagen) gene expression and ASMC proliferation. A total of 18 subjects were involved in the study: 8 steroid-free asthma patients and 10 healthy subjects. Peripheral blood eosinophils were isolated using centrifugation and magnetic separation. An individual co-culture of eosinophils with human ASMC was prepared for each study subject. Adhesion of eosinophils to ASMC (evaluated by assaying eosinophil peroxidase activity) was determined following various incubation periods (30, 45, 60, 120, and 240 min). The expression of Wnt-5a, TGF-β1, and ECM protein genes in ASMC was measured using quantitative real-time polymerase chain reaction (PCR) after 24 h of co-culture. Proliferation of ASMC was measured using the Alamar blue method after 48 h and 72 h of co-culture with eosinophils. Eosinophils from asthmatic subjects demonstrated increased adhesion to ASMC compared with eosinophils from healthy subjects (p eosinophils from asthmatic subjects, while co-culture of ASMC with eosinophils from healthy subjects increased only TGF-β1 and fibronectin gene expression. ASMC proliferation was augmented after co-culture with eosinophils from asthma patients compared with co-culture with eosinophils from healthy subjects (p Eosinophils enhance Wnt-5a, TGF-β1, fibronectin, and collagen gene expression in ASMC and promote proliferation of these cells in asthma. ClinicalTrials.gov Identifier: NCT02648074 .

  16. Systematic and quantitative mRNA expression analysis of TRP channel genes at the single trigeminal and dorsal root ganglion level in mouse

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    Vandewauw Ine

    2013-02-01

    Full Text Available Abstract Background Somatosensory nerve fibres arising from cell bodies within the trigeminal ganglia (TG in the head and from a string of dorsal root ganglia (DRG located lateral to the spinal cord convey endogenous and environmental stimuli to the central nervous system. Although several members of the transient receptor potential (TRP superfamily of cation channels have been implicated in somatosensation, the expression levels of TRP channel genes in the individual sensory ganglia have never been systematically studied. Results Here, we used quantitative real-time PCR to analyse and compare mRNA expression of all TRP channels in TG and individual DRGs from 27 anatomically defined segments of the spinal cord of the mouse. At the mRNA level, 17 of the 28 TRP channel genes, TRPA1, TRPC1, TRPC3, TRPC4, TRPC5, TRPM2, TRPM3, TRPM4, TRPM5, TRPM6, TRPM7, TRPM8, TRPV1, TRPV2, TRPV4, TRPML1 and TRPP2, were detectable in every tested ganglion. Notably, four TRP channels, TRPC4, TRPM4, TRPM8 and TRPV1, showed statistically significant variation in mRNA levels between DRGs from different segments, suggesting ganglion-specific regulation of TRP channel gene expression. These ganglion-to-ganglion differences in TRP channel transcript levels may contribute to the variability in sensory responses in functional studies. Conclusions We developed, compared and refined techniques to quantitatively analyse the relative mRNA expression of all TRP channel genes at the single ganglion level. This study also provides for the first time a comparative mRNA distribution profile in TG and DRG along the entire vertebral column for the mammalian TRP channel family.

  17. WNT10A missense mutation associated with a complete odonto-onycho-dermal dysplasia syndrome.

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    Nawaz, Sadia; Klar, Joakim; Wajid, Muhammad; Aslam, Muhammad; Tariq, Muhammad; Schuster, Jens; Baig, Shahid Mahmood; Dahl, Niklas

    2009-12-01

    Wnt signalling is one of a few pathways that are crucial for controlling genetic programs during embryonic development as well as in adult tissues. WNT10A is expressed in the skin and epidermis and it has shown to be critical for the development of ectodermal appendages. A nonsense mutation in WNT10A was recently identified in odonto-onycho-dermal dysplasia (OODD; MIM 257980), a rare syndrome characterised by severe hypodontia, nail dystrophy, smooth tongue, dry skin, keratoderma and hyperhydrosis of palms and soles. We identified a large consanguineous Pakistani pedigree comprising six individuals affected by a complete OODD syndrome. Autozygosity mapping using SNP array analysis showed that the affected individuals are homozygous for the WNT10A gene region. Subsequent mutation screening showed a homozygous c.392C>T transition in exon 3 of WNT10A, which predicts a p.A131V substitution in a conserved alpha-helix domain. We report here on the first inherited missense mutation in WNT10A with associated ectodermal features.

  18. The Wnt Co-Receptor Lrp5 Is Required for Cranial Neural Crest Cell Migration in Zebrafish.

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    Bernd Willems

    Full Text Available During vertebrate neurulation, cranial neural crest cells (CNCCs undergo epithelial to mesenchymal transition (EMT, delaminate from the neural plate border, and migrate as separate streams into different cranial regions. There, they differentiate into distinct parts of the craniofacial skeleton. Canonical Wnt signaling has been shown to be essential for this process at different levels but the involved receptors remained unclear. Here we show that the frizzled co-receptor low-density-lipoprotein (LDL receptor-related protein 5 (Lrp5 plays a crucial role in CNCC migration and morphogenesis of the cranial skeleton. Early during induction and migration of CNCCs, lrp5 is expressed ubiquitously but later gets restricted to CNCC derivatives in the ventral head region besides different regions in the CNS. A knock-down of lrp5 does not interfere with induction of CNCCs but leads to reduced proliferation of premigratory CNCCs. In addition, cell migration is disrupted as CNCCs are found in clusters at ectopic positions in the dorsomedial neuroepithelium after lrp5 knock-down and transient CRISPR/Cas9 gene editing. These migratory defects consequently result in malformations of the craniofacial skeleton. To date, Lrp5 has mainly been associated with bone homeostasis in mammals. Here we show that in zebrafish, lrp5 also controls cell migration during early morphogenetic processes and contributes to shaping the craniofacial skeleton.

  19. Aberrant Wnt Signaling in Leukemia

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    Frank J. T. Staal

    2016-08-01

    Full Text Available 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.

  20. Tiam1 Regulates the Wnt/Dvl/Rac1 Signaling Pathway and the Differentiation of Midbrain Dopaminergic Neurons

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    Čajánek, Lukáš; Ganji, Ranjani Sri; Henriques-Oliveira, Catarina; Theofilopoulos, Spyridon; Koník, Peter

    2013-01-01

    Understanding the mechanisms that drive the differentiation of dopaminergic (DA) neurons is crucial for successful development of novel therapies for Parkinson's disease, in which DA neurons progressively degenerate. However, the mechanisms underlying the differentiation-promoting effects of Wnt5a on DA precursors are poorly understood. Here, we present the molecular and functional characterization of a signaling pathway downstream of Wnt5a, the Wnt/Dvl/Rac1 pathway. First, we characterize the interaction between Rac1 and Dvl and identify the N-terminal part of Dvl3 as necessary for Rac1 binding. Next, we show that Tiam1, a Rac1 guanosine exchange factor (GEF), is expressed in the ventral midbrain, interacts with Dvl, facilitates Dvl-Rac1 interaction, and is required for Dvl- or Wnt5a-induced activation of Rac1. Moreover, we show that Wnt5a promotes whereas casein kinase 1 (CK1), a negative regulator of the Wnt/Dvl/Rac1 pathway, abolishes the interactions between Dvl and Tiam1. Finally, using ventral midbrain neurosphere cultures, we demonstrate that the generation of DA neurons in culture is impaired after Tiam1 knockdown, indicating that Tiam1 is required for midbrain DA differentiation. In summary, our data identify Tiam1 as a novel regulator of DA neuron development and as a Dvl-associated and Rac1-specific GEF acting in the Wnt/Dvl/Rac1 pathway. PMID:23109420

  1. LncRNA, TUG1 regulates the oral squamous cell carcinoma progression possibly via interacting with Wnt/β-catenin signaling.

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    Liang, Shuang; Zhang, Songzi; Wang, Peng; Yang, Chao; Shang, Chen; Yang, Jianjun; Wang, Jun

    2017-04-15

    Oral squamous cell carcinoma (OSCC) is one the most common cancer affecting the head and neck region, and the molecular mechanisms underlying OSCC development is largely unknown. Long non-coding RNAs (lncRNAs) are emerging as key regulators in tumor development. The present study aimed to investigate the role of lncRNA, taurine upregulated gene 1 (TUG1) in OSCC development. The mRNA and protein expression levels were determined by qRT-PCR and western blotting; flow cytometry and ELISA experiments were employed to examine the cell apoptosis; CCK-8 assay, MTT assay, colony formation assay, and cell invasion assay was used to determine cell growth, cell proliferation and cell invasion, respectively. qRT-PCR results showed that TUG1 was up-regulated in both OSCC tissues and cell lines. The high expression level of TUG1 was significantly correlated with TNM stage, lymph node metastasis and tumor grade in OSCC patients. CCK-8 assay, MTT assay, colony formation assay, and cell invasion assay results showed that knock-down of TUG1 by siRNA transfection suppressed cell growth, cell proliferation, and cell invasion in OSCC cell lines (Tca8113 and TSCCA). The cell apoptosis was induced in Tca8113 and TSCCA cells transfected with TUG1 siRNA. In addition, knock-down of TUG1 in Tca8113 and TSCCA cells significantly suppressed the mRNA and protein expression levels of β-catenin, cyclin D1, and c-myc. Wnt/β-catenin pathway activator (LiCl) reversed the TUG1 knock-down effect on cell proliferation, cell invasion and cell apoptosis in Tca8113 and TSCCA cells. In summary, knock-down of TUG1 suppressed cell growth, proliferation and invasion, and also induced apoptosis of OSCC possibly via targeting Wnt/β-catenin signaling. Our data suggest that knock-down of TUG1 may represent a novel therapeutic target for the management of OSCC. Copyright © 2017. Published by Elsevier B.V.

  2. Wnt and lithium: a common destiny in the therapy of nervous system pathologies?

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    Meffre, Delphine; Grenier, Julien; Bernard, Sophie; Courtin, Françoise; Dudev, Todor; Shackleford, Ghjuvan'Ghjacumu; Jafarian-Tehrani, Mehrnaz; Massaad, Charbel

    2014-04-01

    Wnt signaling is required for neurogenesis, the fate of neural progenitors, the formation of neuronal circuits during development, neuron positioning and polarization, axon and dendrite development and finally for synaptogenesis. This signaling pathway is also implicated in the generation and differentiation of glial cells. In this review, we describe the mechanisms of action of Wnt signaling pathways and their implication in the development and correct functioning of the nervous system. We also illustrate how a dysregulated Wnt pathway could lead to psychiatric, neurodegenerative and demyelinating pathologies. Lithium, used for the treatment of bipolar disease, inhibits GSK3β, a central enzyme of the Wnt/β-catenin pathway. Thus, lithium could, to some extent, mimic Wnt pathway. We highlight the possible dialogue between lithium therapy and modulation of Wnt pathway in the treatment of the diseases of the nervous system.

  3. Photobiomodulation effects on mRNA levels from genomic and chromosome stabilization genes in injured muscle.

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    da Silva Neto Trajano, Larissa Alexsandra; Trajano, Eduardo Tavares Lima; da Silva Sergio, Luiz Philippe; Teixeira, Adilson Fonseca; Mencalha, Andre Luiz; Stumbo, Ana Carolina; de Souza da Fonseca, Adenilson

    2018-04-26

    Muscle injuries are the most prevalent type of injury in sports. A great number of athletes have relapsed in muscle injuries not being treated properly. Photobiomodulation therapy is an inexpensive and safe technique with many benefits in muscle injury treatment. However, little has been explored about the infrared laser effects on DNA and telomeres in muscle injuries. Thus, the aim of this study was to evaluate photobiomodulation effects on mRNA relative levels from genes related to telomere and genomic stabilization in injured muscle. Wistar male rats were randomly divided into six groups: control, laser 25 mW, laser 75 mW, injury, injury laser 25 mW, and injury laser 75 mW. Photobiomodulation was performed with 904 nm, 3 J/cm 2 at 25 or 75 mW. Cryoinjury was induced by two applications of a metal probe cooled in liquid nitrogen directly on the tibialis anterior muscle. After euthanasia, skeletal muscle samples were withdrawn and total RNA extracted for evaluation of mRNA levels from genomic (ATM and p53) and chromosome stabilization (TRF1 and TRF2) genes by real-time quantitative polymerization chain reaction. Data show that photobiomodulation reduces the mRNA levels from ATM and p53, as well reduces mRNA levels from TRF1 and TRF2 at 25 and 75 mW in injured skeletal muscle. In conclusion, photobiomodulation alters mRNA relative levels from genes related to genomic and telomere stabilization in injured skeletal muscle.

  4. Liposomal packaging generates Wnt protein with in vivo biological activity.

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    Nathan T Morrell

    2008-08-01

    Full Text Available Wnt signals exercise strong cell-biological and regenerative effects of considerable therapeutic value. There are, however, no specific Wnt agonists and no method for in vivo delivery of purified Wnt proteins. Wnts contain lipid adducts that are required for activity and we exploited this lipophilicity by packaging purified Wnt3a protein into lipid vesicles. Rather than being encapsulated, Wnts are tethered to the liposomal surface, where they enhance and sustain Wnt signaling in vitro. Molecules that effectively antagonize soluble Wnt3a protein but are ineffective against the Wnt3a signal presented by a cell in a paracrine or autocrine manner are also unable to block liposomal Wnt3a activity, suggesting that liposomal packaging mimics the biological state of active Wnts. When delivered subcutaneously, Wnt3a liposomes induce hair follicle neogenesis, demonstrating their robust biological activity in a regenerative context.

  5. 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.

  6. Inhibition of human melanoma cell growth by dietary flavonoid fisetin is associated with disruption of Wnt/β-catenin signaling and decreased Mitf levels

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    Syed, Deeba N.; Afaq, Farrukh; Maddodi, Nityanand; Johnson, Jeremy J.; Sarfaraz, Sami; Ahmad, Adeel; Setaluri, Vijayasaradhi; Mukhtar, Hasan

    2011-01-01

    The prognosis of advanced melanoma remains poor in spite of treatment advances, emphasizing the importance of additional preventive measures. Flavonoids, natural components of our diet are being investigated for their chemopreventive/therapeutic properties. Microphthalmia-associated transcription factor (Mitf), downstream of Wnt/β-catenin pathway has become an important prognostic marker of melanoma. Here, we show that treatment of 451Lu melanoma cells with the dietary flavonoid fisetin resulted in decreased cell viability with G1-phase arrest and disruption of Wnt/β-catenin signaling. This was accompanied with a decrease in expression of Wnt protein and its co-receptors and a parallel increase in the expression of endogenous Wnt inhibitors. Fisetin-treated cells showed increased cytosolic levels of Axin and β-TrCP and decreased phosphorylation of GSK3-β assocaited with decreased β-catenin stabilization. Fisetin-mediated interference with the functional cooperation between β-catenin and LEF/TCF-2 resulted in downregulation of positively regulated TCF targets such as c-myc, Brn-2 and Mitf. Flowcytometric analysis of Mitf overexpressing cells showed that fisetin repressed Mitf-induced cell proliferation. Finally, administration of fisetin to 451Lu xenografted nude mice resulted in inhibition of tumor development and decreased Mitf expression. Our data suggest that fisetin can be developed as an effective agent against melanoma due to its potential inhibitory effect on β-catenin/Mitf signaling. PMID:21346776

  7. Role of the Wnt receptor Frizzled-1 in presynaptic differentiation and function

    Directory of Open Access Journals (Sweden)

    Alvarez Alejandra R

    2009-11-01

    Full Text Available Abstract Background The Wnt signaling pathway regulates several fundamental developmental processes and recently has been shown to be involved in different aspects of synaptic differentiation and plasticity. Some Wnt signaling components are localized at central synapses, and it is thus possible that this pathway could be activated at the synapse. Results We examined the distribution of the Wnt receptor Frizzled-1 in cultured hippocampal neurons and determined that this receptor is located at synaptic contacts co-localizing with presynaptic proteins. Frizzled-1 was found in functional synapses detected with FM1-43 staining and in synaptic terminals from adult rat brain. Interestingly, overexpression of Frizzled-1 increased the number of clusters of Bassoon, a component of the active zone, while treatment with the extracellular cysteine-rich domain (CRD of Frizzled-1 decreased Bassoon clustering, suggesting a role for this receptor in presynaptic differentiation. Consistent with this, treatment with the Frizzled-1 ligand Wnt-3a induced presynaptic protein clustering and increased functional presynaptic recycling sites, and these effects were prevented by co-treatment with the CRD of Frizzled-1. Moreover, in synaptically mature neurons Wnt-3a was able to modulate the kinetics of neurotransmitter release. Conclusion Our results indicate that the activation of the Wnt pathway through Frizzled-1 occurs at the presynaptic level, and suggest that the synaptic effects of the Wnt signaling pathway could be modulated by local activation through synaptic Frizzled receptors.

  8. Activation of the Wnt/β-catenin signaling pathway is associated with glial proliferation in the adult spinal cord of ALS transgenic mice

    International Nuclear Information System (INIS)

    Chen, Yanchun; Guan, Yingjun; Liu, Huancai; Wu, Xin; Yu, Li; Wang, Shanshan; Zhao, Chunyan; Du, Hongmei; Wang, Xin

    2012-01-01

    Highlights: ► Wnt3a and Cyclin D1 were upregulated in the spinal cord of the ALS mice. ► β-catenin translocated from the cell membrane to the nucleus in the ALS mice. ► Wnt3a, β-catenin and Cyclin D1 co-localized for astrocytes were all increased. ► BrdU/Cyclin D1 double-positive cells were increased in the spinal cord of ALS mice. ► 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, β-catenin, and Cyclin D1 are three key signaling molecules of the Wnt/β-catenin signaling pathway. We determined the expression of Wnt3a, β-catenin, and Cyclin D1 in the adult spinal cord of SOD1 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, β-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, β-catenin, and Cyclin D1 were also expressed in both neurons and astrocytes. The expression of Wnt3a, β-catenin or Cyclin D1 in mature GFAP + astrocytes increased. Moreover, BrdU/Cyclin D1/GFAP triple-positive cells were detected in the ALS mice. Our findings suggest that neurodegeneration activates the Wnt/β-catenin signaling pathway, which is associated with glial proliferation in the adult spinal cord of ALS transgenic mice. This

  9. The Wnt Signaling Pathway Is Differentially Expressed during the Bovine Herpesvirus 1 Latency-Reactivation Cycle: Evidence That Two Protein Kinases Associated with Neuronal Survival, Akt3 and BMPR2, Are Expressed at Higher Levels during Latency.

    Science.gov (United States)

    Workman, Aspen; Zhu, Liqian; Keel, Brittney N; Smith, Timothy P L; Jones, Clinton

    2018-04-01

    Sensory neurons in trigeminal ganglia (TG) of calves latently infected with bovine herpesvirus 1 (BoHV-1) abundantly express latency-related (LR) gene products, including a protein (ORF2) and two micro-RNAs. Recent studies in mouse neuroblastoma cells (Neuro-2A) demonstrated ORF2 interacts with β-catenin and a β-catenin coactivator, high-mobility group AT-hook 1 (HMGA1) protein, which correlates with increased β-catenin-dependent transcription and cell survival. β-Catenin and HMGA1 are readily detected in a subset of latently infected TG neurons but not TG neurons from uninfected calves or reactivation from latency. Consequently, we hypothesized that the Wnt/β-catenin signaling pathway is differentially expressed during the latency and reactivation cycle and an active Wnt pathway promotes latency. RNA-sequencing studies revealed that 102 genes associated with the Wnt/β-catenin signaling pathway were differentially expressed in TG during the latency-reactivation cycle in calves. Wnt agonists were generally expressed at higher levels during latency, but these levels decreased during dexamethasone-induced reactivation. The Wnt agonist bone morphogenetic protein receptor 2 (BMPR2) was intriguing because it encodes a serine/threonine receptor kinase that promotes neuronal differentiation and inhibits cell death. Another differentially expressed gene encodes a protein kinase (Akt3), which is significant because Akt activity enhances cell survival and is linked to herpes simplex virus 1 latency and neuronal survival. Additional studies demonstrated ORF2 increased Akt3 steady-state protein levels and interacted with Akt3 in transfected Neuro-2A cells, which correlated with Akt3 activation. Conversely, expression of Wnt antagonists increased during reactivation from latency. Collectively, these studies suggest Wnt signaling cooperates with LR gene products, in particular ORF2, to promote latency. IMPORTANCE Lifelong BoHV-1 latency primarily occurs in sensory neurons

  10. 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.

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

    KAUST Repository

    Wong, Yue Him; Wang, Hao; Ravasi, Timothy; Qian, Pei-Yuan

    2012-01-01

    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. The Meckel-Gruber syndrome protein TMEM67 controls basal body positioning and epithelial branching morphogenesis in mice via the non-canonical Wnt pathway

    Directory of Open Access Journals (Sweden)

    Zakia A. Abdelhamed

    2015-06-01

    Full Text Available Ciliopathies are a group of developmental disorders that manifest with multi-organ anomalies. Mutations in TMEM67 (MKS3 cause a range of human ciliopathies, including Meckel-Gruber and Joubert syndromes. In this study we describe multi-organ developmental abnormalities in the Tmem67tm1Dgen/H1 knockout mouse that closely resemble those seen in Wnt5a and Ror2 knockout mice. These include pulmonary hypoplasia, ventricular septal defects, shortening of the body longitudinal axis, limb abnormalities, and cochlear hair cell stereociliary bundle orientation and basal body/kinocilium positioning defects. The basal body/kinocilium complex was often uncoupled from the hair bundle, suggesting aberrant basal body migration, although planar cell polarity and apical planar asymmetry in the organ of Corti were normal. TMEM67 (meckelin is essential for phosphorylation of the non-canonical Wnt receptor ROR2 (receptor-tyrosine-kinase-like orphan receptor 2 upon stimulation with Wnt5a-conditioned medium. ROR2 also colocalises and interacts with TMEM67 at the ciliary transition zone. Additionally, the extracellular N-terminal domain of TMEM67 preferentially binds to Wnt5a in an in vitro binding assay. Cultured lungs of Tmem67 mutant mice failed to respond to stimulation of epithelial branching morphogenesis by Wnt5a. Wnt5a also inhibited both the Shh and canonical Wnt/β-catenin signalling pathways in wild-type embryonic lung. Pulmonary hypoplasia phenotypes, including loss of correct epithelial branching morphogenesis and cell polarity, were rescued by stimulating the non-canonical Wnt pathway downstream of the Wnt5a-TMEM67-ROR2 axis by activating RhoA. We propose that TMEM67 is a receptor that has a main role in non-canonical Wnt signalling, mediated by Wnt5a and ROR2, and normally represses Shh signalling. Downstream therapeutic targeting of the Wnt5a-TMEM67-ROR2 axis might, therefore, reduce or prevent pulmonary hypoplasia in ciliopathies and other congenital

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

    Directory of Open Access Journals (Sweden)

    Kalkman Hans

    2012-10-01

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

  14. β-TrCP1 Is a Vacillatory Regulator of Wnt Signaling.

    Science.gov (United States)

    Long, Marcus John; Lin, Hong-Yu; Parvez, Saba; Zhao, Yi; Poganik, Jesse Richard; Huang, Paul; Aye, Yimon

    2017-08-17

    Simultaneous hyperactivation of Wnt and antioxidant response (AR) are often observed during oncogenesis. However, it remains unclear how the β-catenin-driven Wnt and the Nrf2-driven AR mutually regulate each other. The situation is compounded because many players in these two pathways are redox sensors, rendering bolus redox signal-dosing methods uninformative. Herein we examine the ramifications of single-protein target-specific AR upregulation in various knockdown lines. Our data document that Nrf2/AR strongly inhibits β-catenin/Wnt. The magnitude and mechanism of this negative regulation are dependent on the direct interaction between β-catenin N terminus and β-TrCP1 (an antagonist of both Nrf2 and β-catenin), and independent of binding between Nrf2 and β-TrCP1. Intriguingly, β-catenin positively regulates AR. Because AR is a negative regulator of Wnt regardless of β-catenin N terminus, this switch of function is likely sufficient to establish a new Wnt/AR equilibrium during tumorigenesis. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. PAX5О± and PAX5ОІ mRNA expression in breast Cancer: Relation ...

    African Journals Online (AJOL)

    Manal Basyouni Ahmed

    mRNA expression of PAX5a and PAX5b in breast cancer and assessing their underlying pathological roles through ... the molecular alterations that contribute to disease initiation and ... ring growth and survival of cancer cells [3]. PAX5 is ..... and CA15-3 are prognostic parameters for different molecular subtypes of · breast ...

  16. Electro-acupuncture exerts beneficial effects against cerebral ischemia and promotes the proliferation of neural progenitor cells in the cortical peri-infarct area through the Wnt/β-catenin signaling pathway

    Science.gov (United States)

    CHEN, BIN; TAO, JING; LIN, YUKUN; LIN, RUHUI; LIU, WEILIN; CHEN, LIDIAN

    2015-01-01

    Electro-acupuncture (EA) is a novel therapy based on combining traditional acupuncture with modern electrotherapy, and it is currently being investigated as a treatment for ischemic stroke. In the present study, we aimed to investigate the mechanisms through which EA regulates the proliferation of neural progenitor cells (NPCs) in the cortical peri-infarct area after stroke. The neuroprotective effects of EA on ischemic rats were evaluated by determining the neurological deficit scores and cerebral infarct volumes. The proliferation of the NPCs and the activation of the Wnt/β-catenin signaling pathway in the cortical peri-infarct area were examined. Our results revealed that EA significantly alleviated neurological deficits, reduced the infarct volume and enhanced NPC proliferation [nestin/glial fibrillary acidic protein (GFAP)-double positive] in the cortex of rats subjected to middle cerebral artery occlusion (MCAO). Moreover, the Wnt1 and β-catenin mRNA and protein levels were increased, while glycogen synthase kinase-3 (GSK3) transcription was suppressed by EA. These results suggest that the upregulatory effects of EA on the Wnt/β-catenin signaling pathway may promote NPC proliferation in the cortical peri-infarct area after stroke, consequently providing a therapeutic effect against cerebral ischemia. PMID:26329606

  17. Lactate/pyruvate transporter MCT-1 is a direct Wnt target that confers sensitivity to 3-bromopyruvate in colon cancer.

    Science.gov (United States)

    Sprowl-Tanio, Stephanie; Habowski, Amber N; Pate, Kira T; McQuade, Miriam M; Wang, Kehui; Edwards, Robert A; Grun, Felix; Lyou, Yung; Waterman, Marian L

    2016-01-01

    There is increasing evidence that oncogenic Wnt signaling directs metabolic reprogramming of cancer cells to favor aerobic glycolysis or Warburg metabolism. In colon cancer, this reprogramming is due to direct regulation of pyruvate dehydrogenase kinase 1 ( PDK1 ) gene transcription. Additional metabolism genes are sensitive to Wnt signaling and exhibit correlative expression with PDK1. Whether these genes are also regulated at the transcriptional level, and therefore a part of a core metabolic gene program targeted by oncogenic WNT signaling, is not known. Here, we identify monocarboxylate transporter 1 (MCT-1; encoded by SLC16A1 ) as a direct target gene supporting Wnt-driven Warburg metabolism. We identify and validate Wnt response elements (WREs) in the proximal SLC16A1 promoter and show that they mediate sensitivity to Wnt inhibition via dominant-negative LEF-1 (dnLEF-1) expression and the small molecule Wnt inhibitor XAV939. We also show that WREs function in an independent and additive manner with c-Myc, the only other known oncogenic regulator of SLC16A1 transcription. MCT-1 can export lactate, the byproduct of Warburg metabolism, and it is the essential transporter of pyruvate as well as a glycolysis-targeting cancer drug, 3-bromopyruvate (3-BP). Using sulforhodamine B (SRB) assays to follow cell proliferation, we tested a panel of colon cancer cell lines for sensitivity to 3-BP. We observe that all cell lines are highly sensitive and that reduction of Wnt signaling by XAV939 treatment does not synergize with 3-BP, but instead is protective and promotes rapid recovery. We conclude that MCT-1 is part of a core Wnt signaling gene program for glycolysis in colon cancer and that modulation of this program could play an important role in shaping sensitivity to drugs that target cancer metabolism.

  18. Wnt/β-catenin signaling mediates the suppressive effects of diallyl trisulfide on colorectal cancer stem cells.

    Science.gov (United States)

    Zhang, Qi; Li, Xiao-Ting; Chen, Yue; Chen, Jia-Qi; Zhu, Jian-Yun; Meng, Yu; Wang, Xiao-Qian; Li, Yuan; Geng, Shan-Shan; Xie, Chun-Feng; Wu, Jie-Shu; Zhong, Cai-Yun; Han, Hong-Yu

    2018-06-01

    Cancer stem cells (CSCs) are responsible for colorectal cancer (CRC) initiation, growth, and metastasis. Garlic-derived organosulfur compound diallyl trisulfide (DATS) possesses cancer suppressive properties. Wnt/β-catenin signaling is a key target for CSCs inhibition. However, the interventional effect of DATS on colorectal CSCs has not been clarified. We aimed to illustrate the regulation of Wnt/β-catenin in DATS-induced colorectal CSCs inhibition. Serum-free medium culture was used to enrich colorectal CSCs. SW480 and DLD-1 sphere-forming cells were treated with different concentrations of DATS for 5 days; LiCl and β-catenin plasmids were used to stimulate the activity of Wnt/β-catenin pathway. The size and number of colonspheres were detected by tumorsphere formation assay; the expression of colorectal CSCs-related genes was detected by Western blotting and qRT-PCR; the capacities of colorectal CSCs proliferation and apoptosis were detected by Cell Counting Kit-8, Hoechst 33258 cell staining and flow cytometry, respectively. The levels of colorectal CSCs markers were elevated in the tumorspheres cells. DATS efficiently suppressed the activity of colorectal CSCs, as evidenced by reducing the size and number of colonspheres, decreasing the expression of colorectal CSCs markers, promoting apoptosis and inhibiting the proliferation of colorectal CSCs. Moreover, DATS suppressed the activity of Wnt/β-catenin pathway, while upregulation of Wnt/β-catenin diminished the inhibitory effect of DATS on colorectal CSCs. Wnt/β-catenin pathway mediates DATS-induced colorectal CSCs suppression. These findings support the use of DATS for targeting colorectal CSCs.

  19. Inhibition of the WNT/β-catenin pathway by fine particulate matter in haze: Roles of metals and polycyclic aromatic hydrocarbons

    Science.gov (United States)

    Lee, Kang-Yun; Cao, Jun-Ji; Lee, Chii-Hong; Hsiao, Ta-Chih; Yeh, Chi-Tai; Huynh, Thanh-Tuan; Han, Yong-Ming; Li, Xiang-Dong; Chuang, Kai-Jen; Tian, Linwei; Ho, Kin-Fai; Chuang, Hsiao-Chi

    2015-05-01

    Air pollution might have a great impact on pulmonary health, but biological evidence in response to particulate matter less than 2.5 μm in size (PM2.5) has been lacking. Physicochemical characterization of haze PM2.5 collected from Beijing, Xian and Hong Kong was performed. Biological pathways were identified by proteomic profiling in mouse lungs, suggesting that WNT/β-catenin is important in the response to haze PM2.5. Suppression of β-catenin levels, activation of caspase-3 and alveolar destruction, as well as IL-6, TNF-α and IFN-γ production, were observed in the lungs. The inhibition of β-catenin, TCF4 and cyclin D1 was observed in vitro in response to haze PM2.5. The inhibition of WNT/β-catenin signaling, apoptosis-related results (caspase-3 and alveolar destruction), and inflammation, particularly including caspase-3 and alveolar destruction, were more highly associated with polycyclic aromatic hydrocarbons in haze PM2.5. In conclusion, decreased WNT/β-catenin expression modulated by haze PM2.5 could be involved in alveolar destruction and inflammation during haze episodes.

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

    Directory of Open Access Journals (Sweden)

    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

  1. Genomic response to Wnt signalling is highly context-dependent - Evidence from DNA microarray and chromatin immunoprecipitation screens of Wnt/TCF targets

    International Nuclear Information System (INIS)

    Railo, Antti; Pajunen, Antti; Itaeranta, Petri; Naillat, Florence; Vuoristo, Jussi; Kilpelaeinen, Pekka; Vainio, Seppo

    2009-01-01

    Wnt proteins are important regulators of embryonic development, and dysregulated Wnt signalling is involved in the oncogenesis of several human cancers. Our knowledge of the downstream target genes is limited, however. We used a chromatin immunoprecipitation-based assay to isolate and characterize the actual gene segments through which Wnt-activatable transcription factors, TCFs, regulate transcription and an Affymetrix microarray analysis to study the global transcriptional response to the Wnt3a ligand. The anti-β-catenin immunoprecipitation of DNA-protein complexes from mouse NIH3T3 fibroblasts expressing a fusion protein of β-catenin and TCF7 resulted in the identification of 92 genes as putative TCF targets. GeneChip assays of gene expression performed on NIH3T3 cells and the rat pheochromocytoma cell line PC12 revealed 355 genes in NIH3T3 and 129 genes in the PC12 cells with marked changes in expression after Wnt3a stimulus. Only 2 Wnt-regulated genes were shared by both cell lines. Surprisingly, Disabled-2 was the only gene identified by the chromatin immunoprecipitation approach that displayed a marked change in expression in the GeneChip assay. Taken together, our approaches give an insight into the complex context-dependent nature of Wnt pathway transcriptional responses and identify Disabled-2 as a potential new direct target for Wnt signalling.

  2. Lariat capping as a tool to manipulate the 5' end of individual yeast mRNA species in vivo

    DEFF Research Database (Denmark)

    Krogh, Nicolai; Pietschmann, Max; Schmid, Manfred

    2017-01-01

    The 5' cap structure of eukaryotic mRNA is critical for its processing, transport, translation, and stability. The many functions of the cap and the fact that most, if not all, mRNA carries the same type of cap makes it difficult to analyze cap function in vivo at individual steps of gene...... in the budding yeast Saccharomyces cerevisiae presumably without cofactors and that lariat capping occurs cotranscriptionally. The lariat-capped reporter mRNA is efficiently exported to the cytoplasm where it is found to be oligoadenylated and evenly distributed. Both the oligoadenylated form and a lariat......-capped mRNA with a templated poly(A) tail translates poorly, underlining the critical importance of the m(7)G cap in translation. Finally, the lariat-capped RNA exhibits a threefold longer half-life compared to its m(7)G-capped counterpart, consistent with a key role for the m(7)G cap in mRNA turnover. Our...

  3. Antagonism between Hedgehog and Wnt signaling pathways regulates tumorigenicity.

    Science.gov (United States)

    Ding, Mei; Wang, Xin

    2017-12-01

    The crosstalk of multiple cellular signaling pathways is crucial in animal development and tissue homeostasis, and its dysregulation may result in tumor formation and metastasis. The Hedgehog (Hh) and Wnt signaling pathways are both considered to be essential regulators of cell proliferation, differentiation and oncogenesis. Recent studies have indicated that the Hh and Wnt signaling pathways are closely associated and involved in regulating embryogenesis and cellular differentiation. Hh signaling acts upstream of the Wnt signaling pathway, and negative regulates Wnt activity via secreted frizzled-related protein 1 (SFRP1), and the Wnt/β-catenin pathway downregulates Hh activity through glioma-associated oncogene homolog 3 transcriptional regulation. This evidence suggests that the imbalance of Hh and Wnt regulation serves a crucial role in cancer-associated processes. The activation of SFRP1, which inhibits Wnt, has been demonstrated to be an important cross-point between the two signaling pathways. The present study reviews the complex interaction between the Hh and Wnt signaling pathways in embryogenesis and tumorigenicity, and the role of SFRP1 as an important mediator associated with the dysregulation of the Hh and Wnt signaling pathways.

  4. C. elegans GATA factors EGL-18 and ELT-6 function downstream of Wnt signaling to maintain the progenitor fate during larval asymmetric divisions of the seam cells.

    Science.gov (United States)

    Gorrepati, Lakshmi; Thompson, Kenneth W; Eisenmann, David M

    2013-05-01

    The C. elegans seam cells are lateral epithelial cells arrayed in a single line from anterior to posterior that divide in an asymmetric, stem cell-like manner during larval development. These asymmetric divisions are regulated by Wnt signaling; in most divisions, the posterior daughter in which the Wnt pathway is activated maintains the progenitor seam fate, while the anterior daughter in which the Wnt pathway is not activated adopts a differentiated hypodermal fate. Using mRNA tagging and microarray analysis, we identified the functionally redundant GATA factor genes egl-18 and elt-6 as Wnt pathway targets in the larval seam cells. EGL-18 and ELT-6 have previously been shown to be required for initial seam cell specification in the embryo. We show that in larval seam cell asymmetric divisions, EGL-18 is expressed strongly in the posterior seam-fated daughter. egl-18 and elt-6 are necessary for larval seam cell specification, and for hypodermal to seam cell fate transformations induced by ectopic Wnt pathway overactivation. The TCF homolog POP-1 binds a site in the egl-18 promoter in vitro, and this site is necessary for robust seam cell expression in vivo. Finally, larval overexpression of EGL-18 is sufficient to drive expression of a seam marker in other hypodermal cells in wild-type animals, and in anterior hypodermal-fated daughters in a Wnt pathway-sensitized background. These data suggest that two GATA factors that are required for seam cell specification in the embryo independently of Wnt signaling are reused downstream of Wnt signaling to maintain the progenitor fate during stem cell-like divisions in larval development.

  5. The development of clinical activity in relapsing-remitting MS is associated with a decrease of FasL mRNA and an increase of Fas mRNA in peripheral blood

    NARCIS (Netherlands)

    Lopatinskaya, L.; Boxel van-Dezaire, A.H.H.; Barkhof, F.; Polman, C.H.; Lucas, C.J.; Nagelkerken, L.

    2003-01-01

    In this longitudinal study, we examined the expression of Fas, FasL, CCR3, CCR5 and CXCR3 mRNA in peripheral blood mononuclear cells (PBMCs) of secondary progressive (SP) and relapsing-remitting (RR) multiple sclerosis (MS) patients. In RR patients, FasL, CCR3 and CCR5 mRNA levels were increased

  6. Effects of Wnt3a on proliferation and differentiation of human epidermal stem cells

    International Nuclear Information System (INIS)

    Jia Liwei; Zhou Jiaxi; Peng Sha; Li Juxue; Cao Yujing; Duan Enkui

    2008-01-01

    Epidermal stem cells maintain development and homeostasis of mammalian epidermis throughout life. However, the molecular mechanisms involved in the proliferation and differentiation of epidermal stem cells are far from clear. In this study, we investigated the effects of Wnt3a and Wnt/β-catenin signaling on proliferation and differentiation of human fetal epidermal stem cells. We found both Wnt3a and active β-catenin, two key members of the Wnt/β-catenin signaling, were expressed in human fetal epidermis and epidermal stem cells. In addition, Wnt3a protein can promote proliferation and inhibit differentiation of epidermal stem cells in vitro culture. Our results suggest that Wnt/β-catenin signaling plays important roles in human fetal skin development and homeostasis, which also provide new insights on the molecular mechanisms of oncogenesis in human epidermis

  7. Effect of 3,3',5-triiodothyronine and 3,5-diiodothyronine on progesterone production, cAMP synthesis, and mRNA expression of STAR, CYP11A1, and HSD3B genes in granulosa layer of chicken preovulatory follicles.

    Science.gov (United States)

    Sechman, A; Pawlowska, K; Hrabia, A

    2011-10-01

    In vitro studies were performed to assess whether stimulatory effects of triiodothyronine (T3) on progesterone (P4) production in a granulosa layer (GL) of chicken preovulatory follicles are associated with 3',5'-cyclic adenosine monophosphate (cAMP) synthesis and mRNA expression of STAR protein, CYP11A1, and HSD3B. Effects of 3,5-diiodothyronine (3,5-T2) on steroidogenic function in these follicles were also investigated. The GL of F3 to F1 follicles was incubated in medium supplemented with T3 or 3,5-T2, LH, or forskolin (F), and a combination of each iodothyronine with LH or F. Levels of P4 and cAMP in culture media were determined by RIA. Expression of genes involved in P4 synthesis (ie, STAR protein, CYP11A1, and HSD3B) in the GL of F3 to F1 follicles incubated in medium with T3 or 3,5-T2 and their combination with LH was performed by real-time PCR. Triiodothyronine increased basal and LH- and F-stimulated P4 secretion by preovulatory follicles. The 3,5-T2 elevated P4 synthesis by F3, had no effect on F2 follicles, and diminished P4 production by the GL of F1 follicles. It had no effect on LH-stimulated P4 production; however, it augmented F-stimulated P4 production by F2 and F1 follicles. Although T3 did not affect basal and F-stimulated cAMP synthesis by the GL of preovulatory follicles, it increased LH-stimulated synthesis of this nucleotide. However, 3,5-T2 elevated F-stimulated cAMP synthesis in F3 and F2 follicles; it did not change basal and LH-stimulated cAMP production. Triiodothyronine decreased basal STAR and CYP11A1 mRNAs in F3 follicles, increased them in F1 follicles, and elevated HSD3B mRNA levels in F1 follicles. Triiodothyronine augmented LH-stimulated STAR, CYP11A1, and HSD3B mRNA levels in F2 and CYP11A1 in F1 follicles. However, T3 decreased LH-stimulated STAR and HSD3B mRNA levels in F1 follicles. The 3,5-T2 did not affect basal STAR and CYP11A1 mRNA expression in all investigated follicles; however, it decreased LH-stimulated STAR

  8. Medulloblastoma in China: clinicopathologic analyses of SHH, WNT, and non-SHH/WNT molecular subgroups reveal different therapeutic responses to adjuvant chemotherapy.

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    Zhen-Yu Zhang

    Full Text Available Medulloblastoma (MB is one of the most common primary central nervous system tumors in children. Data is lacking of a large cohort of medulloblastoma patients in China. Also, our knowledge on the sensitivity of different molecular subgroups of MB to adjuvant radiation therapy (RT or chemotherapy (CHT is still limited. The authors performed a retrospective study of 173 medulloblastoma patients treated at two institutions from 2002 to 2011. Formalin-fixed paraffin embedded (FFPE tissues were available in all the cases and sections were stained to classify histological and molecular subgroups. Univariate and multivariate analyses were used to investigate prognostic factors. Of 173 patients, there were 118 children and 55 adults, 112 males and 61 females. Estimated 5-year overall survival (OS rates for all patients, children and adults were 52%, 48% and 63%, respectively. After multivariate analysis, postoperative primary radiation therapy (RT and chemotherapy (CHT were revealed as favorable prognostic factors influencing OS and EFS. Postoperative primary chemotherapy (CHT was found significantly improving the survival of children (p<0.001 while it was not a significant prognostic factor for adult patients. Moreover, patients in WNT subtype had better OS (p = 0.028 than others (SHH and Non-SHH/WNT subtypes given postoperative adjuvant therapies. Postoperative primary RT was found to be a strong prognostic factor influencing the survival in all histological and molecular subgroups (p<0.001. Postoperative primary CHT was found significantly to influence the survival of classic medulloblastoma (CMB (OS p<0.001, EFS p<0.001, SHH subgroup (OS p = 0.020, EFS p = 0.049 and WNT subgroup (OS p = 0.003, EFS p = 0.016 but not in desmoplastic/nodular medulloblastoma (DMB (OS p = 0.361, EFS p = 0.834 and Non-SHH/WNT subgroup (OS p = 0.127, EFS p = 0.055. Our study showed postoperative primary CHT significantly influence the

  9. Functional Consequences of 17q21.31/WNT3-WNT9B Amplification in hPSCs with Respect to Neural Differentiation

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    Chun-Ting Lee

    2015-02-01

    Full Text Available Human pluripotent stem cell (hPSC lines exhibit repeated patterns of genetic variation, which can alter in vitro properties as well as suitability for clinical use. We examined associations between copy-number variations (CNVs on chromosome 17 and hPSC mesodiencephalic dopaminergic (mDA differentiation. Among 24 hPSC lines, two karyotypically normal lines, BG03 and CT3, and BG01V2, with trisomy 17, exhibited amplification of the WNT3/WNT9B region and rapid mDA differentiation. In hPSC lines with amplified WNT3/WNT9B, basic fibroblast growth factor (bFGF signaling through mitogen-activated protein kinase (MAPK/ERK amplifies canonical WNT signaling by phosphorylating LRP6, resulting in enhanced undifferentiated proliferation. When bFGF is absent, noncanonical WNT signaling becomes dominant due to upregulation of SIAH2, enhancing JNK signaling and promoting loss of pluripotency. When bFGF is present during mDA differentiation, stabilization of canonical WNT signaling causes upregulation of LMX1A and mDA induction. Therefore, CNVs in 17q21.31, a “hot spot” for genetic variation, have multiple and complex effects on hPSC cellular phenotype.

  10. [Effect of Biejiajian Pills on Wnt/β-catenin signal pathway and DKK-1 and FrpHe gene expressions in hepatocellular carcinoma cells].

    Science.gov (United States)

    He, Songqi; Cheng, Yang; Zhu, Yun; Fan, Qin; Sun, Haitao; Jia, Wenyan

    2013-01-01

    To investigate the effect of Biejiajian Pills on Wnt signal pathway and its inhibitory gene (DKK-1 and FrpHe) expressions and explore the mechanism underlying the action of Biejiajian Pills to suppress the invasiveness of hepatocellular carcinoma. Twenty-four Wistar rats were randomized equally into 3 groups for gavage of normal saline and Biejiajian Pills at 20- and 10-fold clinical doses for 3 days. Blood samples were then collected from the rats, and the serum was separated and added in HepG2 cell cultures. After 48 h of culture, the cells were collected to determine the cellular content of β-catenin protein using flow cytometry and detect DKK-1 and FrpHe mRNA expressions using qRT-PCR. HepG2 cells cultured in the presence of sera from rats fed with Biejiajian Pills showed significantly lowered β-catenin protein expression and obvious down-regulation of DKK-1 mRNA expression, and the effect was correlated with the doses of the drug administered. The expression of FrpHe mRNA showed no significant differences between the 3 groups. Biejiajian Pills can effectively inhibit the invasiveness and migration of hepatocellular carcinoma cells, which is closely related to decreased expressions of β-catenin and DKK-1 to cause block of the Wnt/β-catenin signal pathway.

  11. Unraveling the Wnt secretion pathway

    NARCIS (Netherlands)

    Harterink, M.

    2011-01-01

    The Wnt family of signaling proteins has essential functions in development and adult tissue homeostasis throughout the animal kingdom. Although signaling cascades triggered by Wnt proteins have been extensively studied, much remains to be learned about how Wnts are produced and secreted and how

  12. Winding through the WNT pathway during cellular development and demise.

    Science.gov (United States)

    Li, F; Chong, Z Z; Maiese, K

    2006-01-01

    In slightly over a period of twenty years, our comprehension of the cellular and molecular mechanisms that govern the Wnt signaling pathway continue to unfold. The Wnt proteins were initially implicated in viral carcinogenesis experiments associated with mammary tumors, but since this period investigations focusing on the Wnt pathways and their transmembrane receptors termed Frizzled have been advanced to demonstrate the critical nature of Wnt for the development of a variety of cell populations as well as the potential of the Wnt pathway to avert apoptotic injury. In particular, Wnt signaling plays a significant role in both the cardiovascular and nervous systems during embryonic cell patterning, proliferation, differentiation, and orientation. Furthermore, modulation of Wnt signaling under specific cellular influences can either promote or prevent the early and late stages of apoptotic cellular injury in neurons, endothelial cells, vascular smooth muscle cells, and cardiomyocytes. A number of downstream signal transduction pathways can mediate the biological response of the Wnt proteins that include Dishevelled, beta-catenin, intracellular calcium, protein kinase C, Akt, and glycogen synthase kinase-3beta. Interestingly, these cellular cascades of the Wnt-Frizzled pathways can participate in several neurodegenerative, vascular, and cardiac disorders and may be closely integrated with the function of trophic factors. Identification of the critical elements that modulate the Wnt-Frizzled signaling pathway should continue to unlock the potential of Wnt pathway for the development of new therapeutic options against neurodegenerative and vascular diseases.

  13. Green tea increases anti-inflammatory tristetraprolin and decreases pro-inflammatory tumor necrosis factor mRNA levels in rats

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    Roussel Anne M

    2007-01-01

    Full Text Available Abstract Background Tristetraprolin (TTP/ZFP36 family proteins have anti-inflammatory activity by binding to and destabilizing pro-inflammatory mRNAs such as Tnf mRNA, and represent a potential therapeutic target for inflammation-related diseases. Tea has anti-inflammatory properties but the molecular mechanisms have not been completely elucidated. We hypothesized that TTP and/or its homologues might contribute to the beneficial effects of tea as an anti-inflammatory product. Methods Quantitative real-time PCR was used to investigate the effects of green tea (0, 1, and 2 g solid extract/kg diet on the expression of Ttp family genes (Ttp/Tis11/Zfp36, Zfp36l1/Tis11b, Zfp36l2/Tis11d, Zfp36l3, pro-inflammatory genes (Tnf, Csf2/Gm-csf, Ptgs2/Cox2, and Elavl1/Hua/Hur and Vegf genes in liver and muscle of rats fed a high-fructose diet known to induce insulin resistance, oxidative stress, inflammation, and TNF-alpha levels. Results Ttp and Zfp36l1 mRNAs were the major forms in both liver and skeletal muscle. Ttp, Zfp36l1, and Zfp36l2 mRNA levels were more abundant in the liver than those in the muscle. Csf2/Gm-csf and Zfp36l3 mRNAs were undetectable in both tissues. Tea (1 g solid extract/kg diet increased Ttp mRNA levels by 50–140% but Tnf mRNA levels decreased by 30% in both tissues, and Ptgs2/Cox2 mRNA levels decreased by 40% in the muscle. Tea (2 g solid extract/kg diet increased Elavl1/Hua/Hur mRNA levels by 40% in the liver but did not affect any of the other mRNA levels in liver or muscle. Conclusion These results show that tea can modulate Ttp mRNA levels in animals and suggest that a post-transcriptional mechanism through TTP could partially account for tea's anti-inflammatory properties. The results also suggest that drinking adequate amounts of green tea may play a role in the prevention of inflammation-related diseases.

  14. 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

    2011-01-01

    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

  15. Maternal plasma levels of cell-free β-HCG mRNA as a prenatal diagnostic indicator of placenta accrete.

    Science.gov (United States)

    Zhou, J; Li, J; Yan, P; Ye, Y H; Peng, W; Wang, S; Wang, X Tong

    2014-09-01

    Several biomarkers, including maternal serum creatinine kinase and α-fetoprotein, have been described as potential tools for the diagnosis of placental abnormalities. This study aimed to determine whether maternal plasma mRNA levels of the β subunit of human chorionic gonadotropin (β-HCG) could predict placenta accreta prenatally. Sixty-eight singleton pregnant women with prior cesarean deliveries (CDs) were classified into three groups: normal placentation (35 women, control group); placenta previa alone (21 women, placenta previa group); and both placenta previa and placenta accreta (12 women, placenta previa/accreta group). Maternal plasma concentrations of cell-free β-HCG mRNA were measured by real-time reverse-transcription polymerase chain reaction and were expressed as multiples of the median (MoM). Cell-free β-HCG mRNA concentrations (MoM, range) were significantly higher in women with placenta accreta (3.65, 2.78-7.19) than in women with placenta previa (0.94, 0.00-2.97) or normal placentation (1.00, 0.00-2.69) (Steel-Dwass test, P accreta group, the concentration of cell-free β-HCG mRNA was significantly higher among women who underwent CDs with hysterectomy (4.41, 3.49-7.19) than among women whose CDs did not result in hysterectomy (3.20, 2.78-3.70) (Mann-Whitney U test, P = 0.012). An increased level of cell-free β-HCG mRNA in the maternal plasma of women with placenta accreta may arise from direct uteroplacental transfer of cell-free placental mRNA molecules. The concentration of cell-free β-HCG mRNA in maternal plasma may be applicable to the prenatal diagnosis of placenta accreta, especially to identify women with placenta accreta likely to require hysterectomy. Copyright © 2014 Elsevier Ltd. All rights reserved.

  16. Curcumin increased the differentiation rate of neurons in neural stem cells via wnt signaling in vitro study.

    Science.gov (United States)

    Chen, Fei; Wang, Haoxiang; Xiang, Xin; Yuan, Jichao; Chu, Weihua; Xue, Xingsen; Zhu, Haitao; Ge, Hongfei; Zou, Mingming; Feng, Hua; Lin, Jiangkai

    2014-12-01

    The objective of the present study was to clarify the relationship between the neuroprotective effects of curcumin and the classical wnt signaling pathway. Using Sprague-Dawley rats at a gestational age of 14.5 d, we isolated neural stem cells from the anterior two-thirds of the fetal rat brain. The neural stem cells were passaged three times using the half media replacement method and identified using cellular immunofluorescence. After passaging for three generations, we cultured cells in media without basic fibroblast growth factor and epidermal growth factor. Then we treated cells in five different ways, including a blank control group, a group treated with IWR1 (10 μmol/L), a group treated with curcumin (500 nmol/L), a group treated with IWR1 + curcumin, and a group treated with dimethyl sulfoxide (10 μmol/L). We then measured the protein and RNA expression levels for wnt3a and β-catenin using Western blotting and Reverse transcription-polymerase chain reaction (RT-PCR). Western-blotting: after the third generation of cells had been treated for 72 h, we observed that wnt3a and β-catenin expression was significantly increased in the group receiving 500 nmol/L curcumin but not in the other groups. Furthermore, cells in the IWR1-treated group showed decreased wnt3a and β-catenin expression, and wnt3a and β-catenin was also decreased in the IWR1 + 500 nmol/L curcumin group. No obvious change was observed in the dimethyl sulfoxide group. RT-PCR showed similar changes to those observed with the Western blotting experiments. Our study suggests that curcumin can activate the wnt signaling pathway, which provides evidence that curcumin exhibits a neuroprotective effect through the classical wnt signaling pathway. Copyright © 2014 Elsevier Inc. All rights reserved.

  17. GnRH mRNA levels in male three-spined sticklebacks, Gasterosteus aculeatus, under different reproductive conditions.

    Science.gov (United States)

    Shao, Yi Ta; Tseng, Yung Che; Chang, Chia-Hao; Yan, Hong Young; Hwang, Pung Pung; Borg, Bertil

    2015-02-01

    In vertebrates, reproduction is regulated by the brain-pituitary-gonad (BPG) axis, where the gonadotropin-releasing hormone (GnRH) is one of the key components. However, very little is known about the possible role of GnRH in the environmental and feedback control of fish reproduction. To investigate this, full-length gnrh2 (chicken GnRH II) and gnrh3 (salmon GnRH) sequences of male three-spined sticklebacks (Gasterosteus aculeatus), which are clustered with the taxa of the same GnRH type as other Euteleostei, were cloned and annotated. gnrh1 is absent in this species. The mRNA levels of gnrh2 and gnrh3 in the sticklebacks' brain were measured under breeding and post-breeding conditions as well as in castrated and sham-operated breeding fish and castrated/sham-operated fish kept under long-day (LD 16:8) and short-day (LD 8:16) conditions. Fully breeding males had considerably higher mRNA levels of gnrh2 and gnrh3 in the thalamus (Th) and in the telencephalon and preoptic area (T+POA), respectively, than post-breeding males. Sham-operated breeding males have higher gnrh3 mRNA levels than the corresponding castrated males. Moreover, higher gnrh2 mRNA levels in the Th and higher gnrh3 mRNA levels in the T+POA and hypothalamus (HypTh) were also found in long-day sham-operated males than in sham-operated fish kept under an inhibitory short day photoperiod. Nevertheless, gnrh2 and gnrh3 mRNA levels were not up-regulated in castrated males kept under long-day photoperiod, which suggests that positive feedbacks on the brain-pituitary-gonad axis are necessary for this response. Copyright © 2014 Elsevier Inc. All rights reserved.

  18. A novel gene's role in an ancient mechanism: secreted Frizzled-related protein 1 is a critical component in the anterior-posterior Wnt signaling network that governs the establishment of the anterior neuroectoderm in sea urchin embryos.

    Science.gov (United States)

    Khadka, Anita; Martínez-Bartolomé, Marina; Burr, Stephanie D; Range, Ryan C

    2018-01-01

    The anterior neuroectoderm (ANE) in many deuterostome embryos (echinoderms, hemichordates, urochordates, cephalochordates, and vertebrates) is progressively restricted along the anterior-posterior axis to a domain around the anterior pole. In the sea urchin embryo, three integrated Wnt signaling branches (Wnt/β-catenin, Wnt/JNK, and Wnt/PKC) govern this progressive restriction process, which begins around the 32- to 60-cell stage and terminates by the early gastrula stage. We previously have established that several secreted Wnt modulators of the Dickkopf and secreted Frizzled-related protein families (Dkk1, Dkk3, and sFRP-1/5) are expressed within the ANE and play important roles in modulating the Wnt signaling network during this process. In this study, we use morpholino and dominant-negative interference approaches to characterize the function of a novel Frizzled-related protein, secreted Frizzled-related protein 1 (sFRP-1), during ANE restriction. sFRP-1 appears to be related to a secreted Wnt modulator, sFRP3/4, that is essential to block Wnt signaling and establish the ANE in vertebrates. Here, we show that the sea urchin sFRP3/4 orthologue is not expressed during ANE restriction in the sea urchin embryo. Instead, our results indicate that ubiquitously expressed maternal sFRP-1 and Fzl1/2/7 signaling act together as early as the 32- to 60-cell stage to antagonize the ANE restriction mechanism mediated by Wnt/β-catenin and Wnt/JNK signaling. Then, starting from the blastula stage, Fzl5/8 signaling activates zygotic sFRP-1 within the ANE territory, where it works with the secreted Wnt antagonist Dkk1 (also activated by Fzl5/8 signaling) to antagonize Wnt1/Wnt8-Fzl5/8-JNK signaling in a negative feedback mechanism that defines the outer ANE territory boundary. Together, these data indicate that maternal and zygotic sFRP-1 protects the ANE territory by antagonizing the Wnt1/Wnt8-Fzl5/8-JNK signaling pathway throughout ANE restriction, providing precise

  19. A Glimpse of the Pathogenetic Mechanisms of Wnt/β-Catenin Signaling in Diabetic Nephropathy

    Directory of Open Access Journals (Sweden)

    Li Xiao

    2013-01-01

    Full Text Available The Wnt family of proteins belongs to a group of secreted lipid-modified glycoproteins with highly conserved cysteine residues. Prior results indicate that Wnt/β-catenin signaling plays a prominent role in cell differentiation, adhesion, survival, and apoptosis and is involved in organ development, tumorigenesis, and tissue fibrosis, among other functions. Accumulating evidence has suggested that Wnt/β-catenin exhibits a pivotal function in the progression of diabetic nephropathy (DN. In this review, we focused on discussing the dual role of Wnt/β-catenin in apoptosis and epithelial mesenchymal transition (EMT formation of mesangial cells. Moreover, we also elucidated the effect of Wnt/β-catenin in podocyte dysfunction, tubular EMT formation, and renal fibrosis under DN conditions. In addition, the molecular mechanisms involved in this process are introduced. This information provides a novel molecular target of Wnt/β-catenin for the protection of kidney damage and in delay of the progression of DN.

  20. Small, synthetic, GC-rich mRNA stem-loop modules 5' proximal to the AUG start-codon predictably tune gene expression in yeast.

    Science.gov (United States)

    Lamping, Erwin; Niimi, Masakazu; Cannon, Richard D

    2013-07-29

    A large range of genetic tools has been developed for the optimal design and regulation of complex metabolic pathways in bacteria. However, fewer tools exist in yeast that can precisely tune the expression of individual enzymes in novel metabolic pathways suitable for industrial-scale production of non-natural compounds. Tuning expression levels is critical for reducing the metabolic burden of over-expressed proteins, the accumulation of toxic intermediates, and for redirecting metabolic flux from native pathways involving essential enzymes without negatively affecting the viability of the host. We have developed a yeast membrane protein hyper-expression system with critical advantages over conventional, plasmid-based, expression systems. However, expression levels are sometimes so high that they adversely affect protein targeting/folding or the growth and/or phenotype of the host. Here we describe the use of small synthetic mRNA control modules that allowed us to predictably tune protein expression levels to any desired level. Down-regulation of expression was achieved by engineering small GC-rich mRNA stem-loops into the 5' UTR that inhibited translation initiation of the yeast ribosomal 43S preinitiation complex (PIC). Exploiting the fact that the yeast 43S PIC has great difficulty scanning through GC-rich mRNA stem-loops, we created yeast strains containing 17 different RNA stem-loop modules in the 5' UTR that expressed varying amounts of the fungal multidrug efflux pump reporter Cdr1p from Candida albicans. Increasing the length of mRNA stem-loops (that contained only GC-pairs) near the AUG start-codon led to a surprisingly large decrease in Cdr1p expression; ~2.7-fold for every additional GC-pair added to the stem, while the mRNA levels remained largely unaffected. An mRNA stem-loop of seven GC-pairs (∆G = -15.8 kcal/mol) reduced Cdr1p expression levels by >99%, and even the smallest possible stem-loop of only three GC-pairs (∆G = -4.4 kcal/mol) inhibited

  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. An in vitro fatty acylation assay reveals a mechanism for Wnt recognition by the acyltransferase Porcupine.

    Science.gov (United States)

    Asciolla, James J; Miele, Matthew M; Hendrickson, Ronald C; Resh, Marilyn D

    2017-08-18

    Wnt proteins are a family of secreted signaling proteins that play key roles in regulating cell proliferation in both embryonic and adult tissues. Production of active Wnt depends on attachment of palmitoleate, a monounsaturated fatty acid, to a conserved serine by the acyltransferase Porcupine (PORCN). Studies of PORCN activity relied on cell-based fatty acylation and signaling assays as no direct enzyme assay had yet been developed. Here, we present the first in vitro assay that accurately recapitulates PORCN-mediated fatty acylation of a Wnt substrate. The critical feature is the use of a double disulfide-bonded Wnt peptide that mimics the two-dimensional structure surrounding the Wnt acylation site. PORCN-mediated Wnt acylation was abolished when the Wnt peptide was treated with DTT, and did not occur with a linear (non-disulfide-bonded) peptide, or when the double disulfide-bonded Wnt peptide contained Ala substituted for the Ser acylation site. We exploited this in vitro Wnt acylation assay to provide direct evidence that the small molecule LGK974, which is in clinical trials for managing Wnt-driven tumors, is a bona fide PORCN inhibitor whose IC 50 for inhibition of Wnt fatty acylation in vitro closely matches that for inhibition of Wnt signaling. Side-by-side comparison of PORCN and Hedgehog acyltransferase (HHAT), two enzymes that attach 16-carbon fatty acids to secreted proteins, revealed that neither enzyme will accept the other's fatty acyl-CoA or peptide substrates. These findings illustrate the unique enzyme-substrate selectivity exhibited by members of the membrane-bound O -acyl transferase family. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. MicroRNA-1297 inhibits prostate cancer cell proliferation and invasion by targeting the AEG-1/Wnt signaling pathway

    International Nuclear Information System (INIS)

    Liang, Xuan; Li, Hecheng; Fu, Delai; Chong, Tie; Wang, Ziming; Li, Zhaolun

    2016-01-01

    MicroRNAs (miRNAs) have been known to be implicated in tumorigenic programs. miR-1297 has been reported to be dysregulated and involved in cancer progression in many types of human cancers. However, the expression level and the role of miR-1297 in prostate cancer remain u