scholarly journals Wnt7b Activates Canonical Signaling in Epithelial and Vascular Smooth Muscle Cells through Interactions with Fzd1, Fzd10, and LRP5

2005 ◽  
Vol 25 (12) ◽  
pp. 5022-5030 ◽  
Author(s):  
Zhishan Wang ◽  
Weiguo Shu ◽  
Min Min Lu ◽  
Edward E. Morrisey
Keyword(s):  
Cell Surface ◽  
Wnt Signaling ◽  
Airway Epithelium ◽  
Lung Development ◽  
Wnt Pathway ◽  
Vascular Development ◽  
Placental Development ◽  
Surface Receptors ◽  
Wnt Ligands ◽  
Canonical Wnt

ABSTRACT Wnt7b is a Wnt ligand that has been demonstrated to play critical roles in several developmental processes, including lung airway and vascular development and chorion-allantois fusion during placental development. Wnt signaling involves the binding of Wnt ligands to cell surface receptors of the frizzled family and coreceptors of the LRP5/6 family. However, little is known of the ligand-receptor specificity exhibited by different Wnts, Fzds, and LRPs in Wnt signaling. Expression analysis of Fzds and LRP5/6 in the developing lung and vasculature showed that Fzd1, -4, -7, and -10 and LRP5/6 are expressed in tissue-specific patterns during lung development. Fzd1, -4, and -7 are expressed primarily in the developing lung mesenchyme, and Fzd10 is expressed in airway epithelium. LRP5 and LRP6 are expressed in airway epithelium during lung development, whereas LRP5 but not LRP6 expression is observed in the muscular component of large blood vessels, including the aorta. Cell transfection studies demonstrate that Wnt7b can activate the canonical Wnt pathway but not the noncanonical Wnt pathway in a cell-specific manner. Biochemical analysis demonstrates that Wnt7b can bind to Fzd1 and -10 on the cell surface and cooperatively activate canonical Wnt signaling with these receptors in the presence of LRP5. Together, these data demonstrate that Wnt7b signals through Fzd1 and -10 and LRP5 and implicate these Wnt coreceptors in the regulation of lung airway and vascular development.

scholarly journals R-Spondin Family Members Regulate the Wnt Pathway by a Common Mechanism

2008 ◽  
Vol 19 (6) ◽  
pp. 2588-2596 ◽  
Author(s):  
Kyung-Ah Kim ◽  
Marie Wagle ◽  
Karolyn Tran ◽  
Xiaoming Zhan ◽  
Melissa A. Dixon ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Wnt Pathway ◽  
Expression Patterns ◽  
Family Members ◽  
Wnt Signaling Pathway ◽  
Direct Consequence ◽  
Common Mechanism ◽  
Wnt Ligands ◽  
Canonical Wnt

The R-Spondin (RSpo) family of secreted proteins is implicated in the activation of the Wnt signaling pathway. Despite the high structural homology between the four members, expression patterns and phenotypes in knockout mice have demonstrated striking differences. Here we dissected and compared the molecular and cellular function of all RSpo family members. Although all four RSpo proteins activate the canonical Wnt pathway, RSpo2 and 3 are more potent than RSpo1, whereas RSpo4 is relatively inactive. All RSpo members require Wnt ligands and LRP6 for activity and amplify signaling of Wnt3A, Wnt1, and Wnt7A, suggesting that RSpo proteins are general regulators of canonical Wnt signaling. Like RSpo1, RSpo2-4 antagonize DKK1 activity by interfering with DKK1 mediated LRP6 and Kremen association. Analysis of RSpo deletion mutants indicates that the cysteine-rich furin domains are sufficient and essential for the amplification of Wnt signaling and inhibition of DKK1, suggesting that Wnt amplification by RSpo proteins may be a direct consequence of DKK1 inhibition. Together, these findings indicate that RSpo proteins modulate the Wnt pathway by a common mechanism and suggest that coexpression with specific Wnt ligands and DKK1 may determine their biological specificity in vivo.

scholarly journals Hyperactivated Wnt-β-catenin signaling in the absence of sFRP1 and sFRP5 disrupts trophoblast differentiation through repression of Ascl2

BMC Biology ◽  
2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Haili Bao ◽  
Dong Liu ◽  
Yingchun Xu ◽  
Yang Sun ◽  
Change Mu ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Wnt Pathway ◽  
Giant Cells ◽  
Placental Development ◽  
Trophoblast Differentiation ◽  
Human Trophoblast ◽  
Canonical Wnt Pathway ◽  
Trophoblast Stem ◽  
Canonical Wnt ◽  
The Impact

Abstract Background Wnt signaling is a critical determinant for the maintenance and differentiation of stem/progenitor cells, including trophoblast stem cells during placental development. Hyperactivation of Wnt signaling has been shown to be associated with human trophoblast diseases. However, little is known about the impact and underlying mechanisms of excessive Wnt signaling during placental trophoblast development. Results In the present work, we observed that two inhibitors of Wnt signaling, secreted frizzled-related proteins 1 and 5 (Sfrp1 and Sfrp5), are highly expressed in the extraembryonic trophoblast suggesting possible roles in early placental development. Sfrp1 and Sfrp5 double knockout mice exhibited disturbed trophoblast differentiation in the placental ectoplacental cone (EPC), which contains the precursors of trophoblast giant cells (TGCs) and spongiotrophoblast cells. In addition, we employed mouse models expressing a truncated β-catenin with exon 3 deletion globally and trophoblast-specifically, as well as trophoblast stem cell lines, and unraveled that hyperactivation of canonical Wnt pathway exhausted the trophoblast precursor cells in the EPC, resulting in the overabundance of giant cells at the expense of spongiotrophoblast cells. Further examination uncovered that hyperactivation of canonical Wnt pathway disturbed trophoblast differentiation in the EPC via repressing Ascl2 expression. Conclusions Our investigations provide new insights that the homeostasis of canonical Wnt-β-catenin signaling is essential for EPC trophoblast differentiation during placental development, which is of high clinical relevance, since aberrant Wnt signaling is often associated with trophoblast-related diseases.

scholarly journals Wnt Signaling in Vascular Calcification

2021 ◽  
Vol 8 ◽  
Author(s):  
Kaylee Bundy ◽  
Jada Boone ◽  
C. LaShan Simpson
Keyword(s):  
Cardiovascular Disease ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Vascular Calcification ◽  
Arterial Wall ◽  
Wnt Signaling Pathway ◽  
Phenotypic Switch ◽  
Wnt Ligands ◽  
And Function ◽  
Canonical Wnt

Cardiovascular disease is a worldwide epidemic and considered the leading cause of death globally. Due to its high mortality rates, it is imperative to study the underlying causes and mechanisms of the disease. Vascular calcification, or the buildup of hydroxyapatite within the arterial wall, is one of the greatest contributors to cardiovascular disease. Medial vascular calcification is a predictor of cardiovascular events such as, but not limited to, hypertension, stiffness, and even heart failure. Vascular smooth muscle cells (VSMCs), which line the arterial wall and function to maintain blood pressure, are hypothesized to undergo a phenotypic switch into bone-forming cells during calcification, mimicking the manner by which mesenchymal stem cells differentiate into osteoblast cells throughout osteogenesis. RunX2, a transcription factor necessary for osteoblast differentiation and a target gene of the Wnt signaling pathway, has also shown to be upregulated when calcification is present, implicating that the Wnt cascade may be a key player in the transdifferentiation of VSMCs. It is important to note that the phenotypic switch of VSMCs from a healthy, contractile state to a proliferative, synthetic state is necessary in response to the vascular injury surrounding calcification. The lingering question, however, is if VSMCs acquire this synthetic phenotype through the Wnt pathway, how and why does this signaling occur? This review seeks to highlight the potential role of the canonical Wnt signaling pathway within vascular calcification based on several studies and further discuss the Wnt ligands that specifically aid in VSMC transdifferentiation.

Wnt7b regulates mesenchymal proliferation and vascular development in the lung

Development ◽  
2002 ◽  
Vol 129 (20) ◽  
pp. 4831-4842 ◽  
Author(s):  
Weiguo Shu ◽  
Yue Qin Jiang ◽  
Min Min Lu ◽  
Edward E. Morrisey
Keyword(s):  
Smooth Muscle ◽  
Airway Epithelium ◽  
Lung Development ◽  
Perinatal Death ◽  
Vascular Development ◽  
Wnt Signaling Pathway ◽  
Lung Hypoplasia ◽  
Coding Region ◽  
Newborn Mice ◽  
Pulmonary Vessels

Although the Wnt signaling pathway regulates inductive interactions between epithelial and mesenchymal cells, little is known of the role that this pathway plays during lung development. Wnt7b is expressed in the airway epithelium, suggesting a possible role for Wnt-mediated signaling in the regulation of lung development. To test this hypothesis, we have mutated Wnt7b in the germline of mice by replacement of the first exon with the lacZ-coding region. Wnt7blacZ–/– mice exhibit perinatal death due to respiratory failure. Defects in early mesenchymal proliferation leading to lung hypoplasia are observed in Wnt7blacZ–/– embryos. In addition, Wnt7blacZ–/– embryos and newborn mice exhibit severe defects in the smooth muscle component of the major pulmonary vessels. These defects lead to rupture of the major vessels and hemorrhage in the lungs after birth. These results demonstrate that Wnt7b signaling is required for proper lung mesenchymal growth and vascular development.

scholarly journals Loss of FLCN inhibits canonical WNT signaling via TFE3

2019 ◽  
Vol 28 (19) ◽  
pp. 3270-3281 ◽  
Author(s):  
John C Kennedy ◽  
Damir Khabibullin ◽  
Thomas Hougard ◽  
Julie Nijmeh ◽  
Wei Shi ◽  
...  
Keyword(s):  
Wnt Pathway ◽  
Lower Lobe ◽  
Fetal Lung ◽  
Lung Fibroblasts ◽  
Pulmonary Cysts ◽  
Wnt Ligands ◽  
Neonatal Lung ◽  
Canonical Wnt ◽  
Human Fetal Lung ◽  
Bhd Syndrome

Abstract Lower lobe predominant pulmonary cysts occur in up to 90% of patients with Birt–Hogg–Dubé (BHD) syndrome, but the key pathologic cell type and signaling events driving this distinct phenotype remain elusive. Through examination of the LungMAP database, we found that folliculin (FLCN) is highly expressed in neonatal lung mesenchymal cells. Using RNA-Seq, we found that inactivation of Flcn in mouse embryonic fibroblasts leads to changes in multiple Wnt ligands, including a 2.8-fold decrease in Wnt2. This was associated with decreased TCF/LEF activity, a readout of canonical WNT activity, after treatment with a GSK3-α/β inhibitor. Similarly, FLCN deficiency in HEK293T cells decreased WNT pathway activity by 76% post-GSK3-α/β inhibition. Inactivation of FLCN in human fetal lung fibroblasts (MRC-5) led to ~ 100-fold decrease in Wnt2 expression and a 33-fold decrease in Wnt7b expression—two ligands known to be necessary for lung development. Furthermore, canonical WNT activity was decreased by 60%. Classic WNT targets such as AXIN2 and BMP4, and WNT enhanceosome members including TCF4, LEF1 and BCL9 were also decreased after GSK3-α/β inhibition. FLCN-deficient MRC-5 cells failed to upregulate LEF1 in response to GSK3-α/β inhibition. Finally, we found that a constitutively active β-catenin could only partially rescue the decreased WNT activity phenotype seen in FLCN-deficient cells, whereas silencing the transcription factor TFE3 completely reversed this phenotype. In summary, our data establish FLCN as a critical regulator of the WNT pathway via TFE3 and suggest that FLCN-dependent defects in WNT pathway developmental cues may contribute to lung cyst pathogenesis in BHD.

Wnt Production in Dental Epithelium Is Crucial for Tooth Differentiation

2019 ◽  
Vol 98 (5) ◽  
pp. 580-588 ◽  
Author(s):  
Y. Xiong ◽  
Y. Fang ◽  
Y. Qian ◽  
Y. Liu ◽  
X. Yang ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Tooth Development ◽  
Wnt Signaling Pathway ◽  
Conditional Knockout ◽  
Canonical Wnt Signaling ◽  
Odontoblast Differentiation ◽  
Wnt Ligands ◽  
Dental Epithelium ◽  
Canonical Wnt

The Wnt ligands display varied spatiotemporal expression in the epithelium and mesenchyme in the developing tooth. Thus far, the actions of these differentially expressed Wnt ligands on tooth development are not clear. Shh expression specifies the odontogenic epithelium during initiation and is consistently restricted to the dental epithelium during tooth development. In this study, we inactivate Wntless ( Wls), the key regulator for Wnt trafficking, by Shh-Cre to investigate how the Wnt ligands produced in the dental epithelium lineage act on tooth development. We find that conditional knockout of Wls by Shh-Cre leads to defective ameloblast and odontoblast differentiation. WlsShh-Cre teeth display reduced canonical Wnt signaling activity in the inner enamel epithelium and the underlying mesenchyme at the early bell stage, as exhibited by target gene expression and BAT-gal staining. The expression of Wnt5a and Wnt10b is not changed in WlsShh-Cre teeth. By contrast, Wnt10a expression is significantly increased in response to epithelial Wls deficiency. In addition, the expression of Hedgehog signaling pathway components Shh, Gli1, and Patched1 was greatly decreased in WlsShh-Cre teeth. Epithelial Wls loss of function in Shh lineage also leads to aberrant cell proliferation in dental epithelium and mesenchyme at embryonic day 16.5; however, the cell apoptosis is unaffected. Moreover, we find that Decorin and Col1a1, the key markers for odontoblast differentiation that are downregulated in WlsShh-Cre teeth, act as direct downstream targets of the canonical Wnt signaling pathway by chromatin immunoprecipitation analysis. Additionally, Decorin and Col1a1 expression can be increased by lithium chloride (LiCl) treatment in the in vitro tooth explants. Taken together, our results suggest that the spatial expression of Wnt ligands within the dental epithelial lineage regulates the differentiation of tooth structures in later stages.

scholarly journals Wnt Signaling in Cancer Metabolism and Immunity

Cancers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 904 ◽  
Author(s):  
Sara El-Sahli ◽  
Ying Xie ◽  
Lisheng Wang ◽  
Sheng Liu
Keyword(s):  
Wnt Signaling ◽  
Cancer Cells ◽  
Cancer Metabolism ◽  
Metabolic Reprogramming ◽  
Tumor Initiating Cells ◽  
Tumor Plasticity ◽  
Anti Cancer ◽  
Wnt Ligands ◽  
Canonical Wnt

The Wingless (Wnt)/β-catenin pathway has long been associated with tumorigenesis, tumor plasticity, and tumor-initiating cells called cancer stem cells (CSCs). Wnt signaling has recently been implicated in the metabolic reprogramming of cancer cells. Aberrant Wnt signaling is considered to be a driver of metabolic alterations of glycolysis, glutaminolysis, and lipogenesis, processes essential to the survival of bulk and CSC populations. Over the past decade, the Wnt pathway has also been shown to regulate the tumor microenvironment (TME) and anti-cancer immunity. Wnt ligands released by tumor cells in the TME facilitate the immune evasion of cancer cells and hamper immunotherapy. In this review, we illustrate the role of the canonical Wnt/β-catenin pathway in cancer metabolism and immunity to explore the potential therapeutic approach of targeting Wnt signaling from a metabolic and immunological perspective.

scholarly journals When Wnts antagonize Wnts

2003 ◽  
Vol 162 (5) ◽  
pp. 753-756 ◽  
Author(s):  
Gilbert Weidinger ◽  
Randall T. Moon
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathways ◽  
Limb Bud ◽  
Zebrafish Embryos ◽  
Previous Hypothesis ◽  
Distal Mouse ◽  
Wnt Ligands ◽  
Mouse Limb ◽  
Ectopic Activation ◽  
Canonical Wnt

Secreted Wnt ligands appear to activate a variety of signaling pathways. Two papers in this issue now present genetic evidence that “noncanonical” Wnt signaling inhibits the “canonical” Wnt/β-catenin pathway. Westfall et al. (2003a) show that zebrafish embryos lacking maternal Wnt-5 function are dorsalized due to ectopic activation of β-catenin, whereas Topol et al. (2003) report that chondrogenesis in the distal mouse limb bud depends on inhibition of Wnt/β-catenin signaling by a paralogue of Wnt-5. These studies present the first genetic confirmation of the previous hypothesis that vertebrate Wnt signaling pathways can act in an antagonistic manner.

scholarly journals Reduced Affinity to and Inhibition by DKK1 Form a Common Mechanism by Which High Bone Mass-Associated Missense Mutations in LRP5 Affect Canonical Wnt Signaling

2005 ◽  
Vol 25 (12) ◽  
pp. 4946-4955 ◽  
Author(s):  
Minrong Ai ◽  
Sheri L. Holmen ◽  
Wim Van Hul ◽  
Bart O. Williams ◽  
Matthew L. Warman
Keyword(s):  
Cell Surface ◽  
Bone Mass ◽  
Wnt Signaling ◽  
Common Mechanism ◽  
Missense Mutations ◽  
Canonical Wnt Signaling ◽  
High Bone Mass ◽  
Mutant Proteins ◽  
High Bone ◽  
Canonical Wnt

ABSTRACT The low-density-lipoprotein receptor-related protein 5 (LRP5), a coreceptor in the canonical Wnt signaling pathway, has been implicated in human disorders of low and high bone mass. Loss-of-function mutations cause the autosomal recessive osteoporosis-pseudoglioma syndrome, and heterozygous missense mutations in families segregating autosomal dominant high bone mass (HBM) phenotypes have been identified. We expressed seven different HBM-LRP5 missense mutations to delineate the mechanism by which they alter Wnt signaling. None of the mutations caused activation of the receptor in the absence of ligand. Each mutant receptor was able to reach the cell surface, albeit at differing amounts, and transduce exogenously supplied Wnt1 and Wnt3a signal. All HBM mutant proteins had reduced physical interaction with and reduced inhibition by DKK1. These data suggest that HBM mutant proteins can transit to the cell surface in sufficient quantity to transduce Wnt signal and that the likely mechanism for the HBM mutations' physiologic effects is via reduced affinity to and inhibition by DKK1.

Noncanonical Wnt5a Is Induced by HTLV-1 bZIP Factor, and Supports Proliferation and Migration of Adult T-Cell Leukemia Cell.

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 2405-2405
Author(s):  
Jun-ichirou Yasunaga ◽  
Guangyong Ma ◽  
Jun Fan ◽  
Masao Matsuoka
Keyword(s):  
T Cell ◽  
Wnt Signaling ◽  
Wnt Pathway ◽  
T Cell Leukemia ◽  
Cell Leukemia ◽  
Adult T Cell Leukemia ◽  
Canonical Wnt Pathway ◽  
Bzip Factor ◽  
And Migration ◽  
Canonical Wnt

Abstract Abstract 2405 Adult T-cell leukemia (ATL) is a fatal malignancy of CD4-positive T-cells caused by human T-cell leukemia virus type1 (HTLV-1). HTLV-1 bZIP factor (HBZ) is encoded in the minus strand of HTLV-1 provirus, and is consistently expressed in HTLV-1-infected cells. It has been shown that HBZ promotes proliferation of T-cells, and HBZ-expressing transgenic mice develop T-cell lymphomas and systemic inflammations, suggesting that HBZ has the critical roles in pathogenesis of HTLV-1. However, the molecular mechanisms of HBZ-induced oncogenesis have not been clarified yet. The Wnt signaling is a highly conserved cellular signaling pathway in eukaryotes and the Wnt ligands have been found to trigger multiple pathways of Wnt signaling. The most well-studied cascade is the Wnt/β-catenin pathway (also known as the canonical Wnt pathway), which is β-catenin-dependent and mainly controls cell differentiation, proliferation, and apoptosis. Aberrant activation of the canonical Wnt pathway has been linked to many cancers. In contrast, it is known that the noncanonical Wnt pathway antagonizes the canonical pathway, while a representative noncanonical Wnt ligand, Wnt5a, is suggested to have both oncogenic and tumor suppressive properties in several malignancies. The significance of those Wnt pathways in HTLV-1-associated oncogenesis is still obscure. In this study, we found that HBZ markedly suppressed the canonical Wnt/β-catenin pathway. As a mechanism of HBZ-mediated Wnt suppression, we found that HBZ targets LEF1 and TCF1, the key transcription factors of the pathway, and impairs its DNA-binding ability. In contrast, HTLV-1 Tax protein interacted with Dvl and DAPLE, which are the regulators of the canonical Wnt signaling, and activated the pathway. Indeed, the canonical Wnt activation is not observed in ATL cells, and enforced activation of β-catenin in ATL cells inhibited cellular proliferation, implying that activation of the canonical Wnt pathway might have suppressive effect on ATL cells. On the other hand, HBZ induces the transcription of the noncanonical Wnt5a by enhancing its promoter activity. In addition, Wnt5a transcription level in ATL cells is significantly higher than in HTLV-1-uninifected control cells. Knockdown of Wnt5a impairs both proliferation and migration of ATL cells, suggesting that HBZ-induced Wnt5a supports development and progression of ATL. Our results implicate novel roles of HBZ in ATL leukemogenesis through dysregulation of both the canonical and noncanonical Wnt pathways. Disclosures: No relevant conflicts of interest to declare.

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