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

2014 ◽  
Vol 207 (4) ◽  
pp. 549-567 ◽  
Author(s):  
Mohammed I. Ahmed ◽  
Majid Alam ◽  
Vladimir U. Emelianov ◽  
Krzysztof Poterlowicz ◽  
Ankit Patel ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Hair Follicle ◽  
Wnt Pathway ◽  
Expression Patterns ◽  
Gene Activation ◽  
Wnt Signaling Pathway ◽  
Skin Development ◽  
Cell Functions ◽  
Skin Morphogenesis ◽  
Hair Follicle Development

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

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 Regulation of Wnt Signaling by FOX Transcription Factors in Cancer

Cancers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 3446
Author(s):  
Stefan Koch
Keyword(s):  
Transcription Factors ◽  
Wnt Signaling ◽  
Wnt Pathway ◽  
Treatment Options ◽  
Wnt Signaling Pathway ◽  
Tissue Homeostasis ◽  
Fine Tuning ◽  
Dependent Manner ◽  
Forkhead Box ◽  
Signaling Activity

Aberrant activation of the oncogenic Wnt signaling pathway is a hallmark of numerous types of cancer. However, in many cases, it is unclear how a chronically high Wnt signaling tone is maintained in the absence of activating pathway mutations. Forkhead box (FOX) family transcription factors are key regulators of embryonic development and tissue homeostasis, and there is mounting evidence that they act in part by fine-tuning the Wnt signaling output in a tissue-specific and context-dependent manner. Here, I review the diverse ways in which FOX transcription factors interact with the Wnt pathway, and how the ectopic reactivation of FOX proteins may affect Wnt signaling activity in various types of cancer. Many FOX transcription factors are partially functionally redundant and exhibit a highly restricted expression pattern, especially in adults. Thus, precision targeting of individual FOX proteins may lead to safe treatment options for Wnt-dependent cancers.

THE ROLE OF AGONISTS AND ANTAGONISTS OF THE WNT SIGNALING PATHWAY IN PATIENTS WITH ANDROGENIC ALOPECIA AND ALOPECIA AREATA

2021 ◽  
pp. 87-95
Author(s):  
Samoylova A.V. ◽  
Snimshchikova I.A. ◽  
Plotnikova M.O. ◽  
Yakushkina N.Y.
Keyword(s):  
Wnt Signaling ◽  
Hair Follicle ◽  
Signaling Pathway ◽  
Alopecia Areata ◽  
Intracellular Signaling ◽  
Wnt Signaling Pathway ◽  
Follicle Cells ◽  
Androgenic Alopecia ◽  
Active Population

Alopecia is a common pathology among the active population, which leads not only to cosmetic defects, but also to the development of somatic diseases against the background of traumatic effects and chronic stress. The pathogenetic mechanisms of hair follicle formation are complex and diverse, since numerous factors, including the components of the Wnt signaling pathway, have an effect on its morphogenesis, the study of which is the subject of this study. The search for possible early markers of the development of alopecia led to interest in the study of the main morphogenic proteins of WNT - the signaling pathway (one of the intracellular signaling pathways, which control the development of blood vessels, as well as the growth and division of hair follicle cells) sclerostin and β-catenin among patients with androgenic and alopecia areata. The article presents data on the quantitative content of β-catenin and sclerostin in the blood serum in patients with androgenic and alopecia areata. Their possible pathways of complex interaction and influence on the morphogenesis of the hair follicle and the activity of the Wnt-signaling pathway have been analyzed, and the relationship between changes in the level of morphogenic proteins of the WNT-signaling pathway with sex and the course of the disease has been described. Establishment of the prognostic role of morphogenic proteins of the WNT signaling pathway in androgenic and alopecia areata will allow not only identify the personal risk of disease progression and to determine approaches to targeted therapy, but to develop and introduce updated diagnostic screening into dermatological practice.

A Wnt signaling pathway controls hox gene expression and neuroblast migration in C. elegans

Development ◽  
1999 ◽  
Vol 126 (1) ◽  
pp. 37-49 ◽  
Author(s):  
J.N. Maloof ◽  
J. Whangbo ◽  
J.M. Harris ◽  
G.D. Jongeward ◽  
C. Kenyon
Keyword(s):  
Gene Expression ◽  
Wnt Signaling ◽  
Wnt Pathway ◽  
Hox Genes ◽  
Wnt Signaling Pathway ◽  
Beta Catenin ◽  
Hox Gene ◽  
C Elegans ◽  
Neuroblast Migration ◽  
Pathway Gene

The specification of body pattern along the anteroposterior (A/P) body axis is achieved largely by the actions of conserved clusters of Hox genes. Limiting expression of these genes to localized regional domains and controlling the precise patterns of expression within those domains is critically important for normal patterning. Here we report that egl-20, a C. elegans gene required to activate expression of the Hox gene mab-5 in the migratory neuroblast QL, encodes a member of the Wnt family of secreted glycoproteins. We have found that a second Wnt pathway gene, bar-1, which encodes a beta-catenin/Armadillo-like protein, is also required for activation of mab-5 expression in QL. In addition, we describe the gene pry-1, which is required to limit expression of the Hox genes lin-39, mab-5 and egl-5 to their correct local domains. We find that egl-20, pry-1 and bar-1 all function in a linear genetic pathway with conserved Wnt signaling components, suggesting that a conserved Wnt pathway activates expression of mab-5 in the migratory neuroblast QL. Moreover, we find that members of this Wnt signaling system play a major role in both the general and fine-scale control of Hox gene expression in other cell types along the A/P axis.

LncRNAs in Secondary Hair Follicle of Cashmere Goat: Identification, Expression, and Their Regulatory Network in Wnt Signaling Pathway

2017 ◽  
Vol 29 (3) ◽  
pp. 199-211 ◽  
Author(s):  
Wen L. Bai ◽  
Su J. Zhao ◽  
Ze Y. Wang ◽  
Yu B. Zhu ◽  
Yun L. Dang ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Hair Follicle ◽  
Signaling Pathway ◽  
Regulatory Network ◽  
Wnt Signaling Pathway ◽  
Cashmere Goat

scholarly journals A Context-Dependent Role for the RNF146 Ubiquitin Ligase in Wingless/Wnt Signaling in Drosophila

Genetics ◽  
2018 ◽  
Vol 211 (3) ◽  
pp. 913-923 ◽  
Author(s):  
Zhenghan Wang ◽  
Ofelia Tacchelly-Benites ◽  
Geoffrey P. Noble ◽  
Megan K. Johnson ◽  
Jean-Philippe Gagné ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Ubiquitin Ligase ◽  
Wnt Pathway ◽  
Gene Activation ◽  
Negative Regulator ◽  
Compensatory Mechanisms ◽  
E3 Ligases ◽  
Pathway Activation ◽  
Wingless Signaling

Aberrant activation of the Wnt signal transduction pathway triggers the development of colorectal cancer. The ADP-ribose polymerase Tankyrase (TNKS) mediates proteolysis of Axin—a negative regulator of Wnt signaling—and provides a promising therapeutic target for Wnt-driven diseases. Proteolysis of TNKS substrates is mediated through their ubiquitination by the poly-ADP-ribose (pADPr)-dependent RING-domain E3 ubiquitin ligase RNF146/Iduna. Like TNKS, RNF146 promotes Axin proteolysis and Wnt pathway activation in some cultured cell lines, but in contrast with TNKS, RNF146 is dispensable for Axin degradation in colorectal carcinoma cells. Thus, the contexts in which RNF146 is essential for TNKS-mediated Axin destabilization and Wnt signaling remain uncertain. Herein, we tested the requirement for RNF146 in TNKS-mediated Axin proteolysis and Wnt pathway activation in a range of in vivo settings. Using null mutants in Drosophila, we provide genetic and biochemical evidence that Rnf146 and Tnks function in the same proteolysis pathway in vivo. Furthermore, like Tnks, Drosophila Rnf146 promotes Wingless signaling in multiple developmental contexts by buffering Axin levels to ensure they remain below the threshold at which Wingless signaling is inhibited. However, in contrast with Tnks, Rnf146 is dispensable for Wingless target gene activation and the Wingless-dependent control of intestinal stem cell proliferation in the adult midgut during homeostasis. Together, these findings demonstrate that the requirement for Rnf146 in Tnks-mediated Axin proteolysis and Wingless pathway activation is dependent on physiological context, and suggest that, in some cell types, functionally redundant pADPr-dependent E3 ligases or other compensatory mechanisms promote the Tnks-dependent proteolysis of Axin in both mammalian and Drosophila cells.

scholarly journals Small RNA Sequencing Reveals Differentially Expressed miRNAs in Necrotizing Enterocolitis in Rats

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Ren-qiang Yu ◽  
Min Wang ◽  
Shan-yu Jiang ◽  
Ying-hui Zhang ◽  
Xiao-yu Zhou ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Rna Sequencing ◽  
Necrotizing Enterocolitis ◽  
Small Rna ◽  
Mirna Expression ◽  
Expression Patterns ◽  
Wnt Signaling Pathway ◽  
Differentially Expressed ◽  
Small Rna Sequencing

Necrotizing enterocolitis (NEC) is the leading cause of death due to gastrointestinal disease in preterm infants. The role of miRNAs in NEC is still unknown. The objective of this study was to identify differentially expressed (DE) miRNAs in rats with NEC and analyze their possible roles. In this study, a NEC rat model was established using Sprague-Dawley rat pups. Small RNA sequencing was used to analyze the miRNA expression profiles in the NEC and control rats. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses were carried out to identify target mRNAs for the DE miRNAs and to explore their potential roles. The DE miRNAs were verified by real-time quantitative PCR (RT-qPCR). The status of intestinal injury and the elevated levels of inflammatory cytokines in the NEC group confirmed that the NEC model was successfully established. The 16 miRNAs were found to be differentially expressed between the NEC group and the control group of rats. Bioinformatics analysis indicated that the parental genes of the DE miRNAs were predominantly implicated in the phosphorylation, cell migration, and protein phosphorylation processes. Moreover, the DE miRNAs were mainly found to be involved in the pathways of axon guidance, endocytosis, and focal adhesion, as well as in the Wnt signaling pathway, which is related to colitis. The expression patterns of the candidate miRNAs (rno-miR-27a-5p and rno-miR-187-3p), as assessed by RT-qPCR, were in accordance with the expression patterns obtained by miRNA-sequencing. The miRNA/mRNA/pathway network revealed that rno-miR-27a-5p and rno-miR-187-3p might be involved in NEC via the Wnt signaling pathway. We found an altered miRNA expression pattern in rats with NEC. We hypothesize that rno-miR-27a-5p and rno-miR-187-3p might mediate the NEC pathophysiological processes via the Wnt signaling pathway.

scholarly journals Replicating Adenoviruses That Target Tumors with Constitutive Activation of the wnt Signaling Pathway

2001 ◽  
Vol 75 (6) ◽  
pp. 2857-2865 ◽  
Author(s):  
Michele Brunori ◽  
Maddalena Malerba ◽  
Haruhiko Kashiwazaki ◽  
Richard Iggo
Keyword(s):  
Wnt Signaling ◽  
Cancer Cells ◽  
Wnt Pathway ◽  
Wnt Signaling Pathway ◽  
Lung Model ◽  
Colorectal Tumors ◽  
Colon Tumors ◽  
Treat All

ABSTRACT Despite important advances in understanding the molecular basis of cancer, few treatments have been devised which rationally target known causal oncogenic defects. Selectively replicating viruses have a major advantage over nonreplicating viruses to target these defects because the therapeutic effect of the injected virus is augmented by virus produced within the tumor. To permit rational targeting of colon tumors, we have developed replicating adenoviruses that express the viral E1B and E2 genes from promoters controlled by the Tcf4 transcription factor. Tcf4 is constitutively activated by mutations in the adenomatous polyposis coli and β-catenin genes in virtually all colon tumors and is constitutively repressed by Groucho and CtBP in normal tissue. The Tcf-E2 and Tcf-E1B promoters are active in many, but not all, cell lines with activation of the wnt pathway. Viruses with Tcf regulation of E2 expression replicate normally in SW480 colon cancer cells but show a 50- to 100-fold decrease in replication in H1299 lung cancer cells and WI38 normal fibroblasts. Activation of wnt signaling by transduction of a stable β-catenin mutant into normal fibroblasts renders the cells permissive for virus replication. Insertion of Tcf4 sites in the E1B promoter has only small effects on replication in vitro but significantly reduces the inflammatory response in a rodent lung model in vivo. Replicating adenoviruses with Tcf regulation of both E1B and E2 transcription are potentially useful for the treatment of liver metastases from colorectal tumors, but additional changes will be required to produce a virus that can be used to treat all colon tumors.

Inhibition of Wnt Pathway Signaling by Thalidomide and Revlimid: Studies in a Drosophila Model System.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 3356-3356
Author(s):  
A. Keith Stewart ◽  
Yuan Xiao Zhu ◽  
Maryan Yahyapour ◽  
Armen Manoukian ◽  
Sam E. Scanga
Keyword(s):  
Wnt Signaling ◽  
Cell Lines ◽  
Wnt Pathway ◽  
High Throughput Sequencing ◽  
Cellular Proliferation ◽  
Wnt Signaling Pathway ◽  
Myeloma Cell ◽  
Lacz Expression ◽  
Western Blots ◽  
Drosophila Model

Abstract High throughput sequencing, gene expression profiling and protein biochemistry in myeloma have all consistently revealed elevated expression of wnt signaling pathways in malignant plasma cells. Indeed, downregulation of the Wnt pathway in myeloma cells has recently been shown to inhibit myeloma cellular proliferation. Preliminary pharmacogenomic studies have also suggested that hyperactivation of the wnt signaling antagonist DKK-1 is associated with response to the immunomodulators thalidomide and revlimid. The mechanism of action for these therapeutically active drugs is however by no means clear as multiple biologic consequences of treatment have been proposed. We report here use of a drosophila model to examine wnt signaling inhibition by these pharmaceuticals. We employed a unique drosophila larval imaginal disc culture system in which wnt pathway activity is monitored through control of LacZ expression by the distalless promoter. In this system 10uM of both thalidomide and revlimid reproducibly inhibit lacZ expression when compared with vehicle controls. Western blots of larva confirmed downregulation of expression of armadillo (the drosophila b-catenin homologue) by both drugs but particularly revlimid. Lithium Chloride is an inhibitor of the drosphila GSK3b homologue shaggy and thus mimics wnt signaling by stabilizing b-catenin. The effect of Lithium could not be overcome by thalidomide or revlimid indicating that the action of these drugs is upstream of shaggy (or GSK3). Next we employed a fly transgenic for wingless which is embryonic lethal. By adding either drug to larval culture medium the lethality of wingless expression was reversed. Indeed drosophila embryos fed thalidomide exhibited developmental plate abnormalities. We next sought evidence that similar effects were evident in revlimid treated human myeloma. As previously reported most myeloma cell lines studied expressed b-catenin and this protein was downregulated by revlimid treatment of human myeloma cell lines co-incident with inhibition of growth as measured by MTT assay. We sought, but failed to find evidence of up-regulation of the wnt signaling pathway antagonist DKK-1 using an ELISA assay on pre and post treatment serum samples in patients responding to thalidomide.The implications of wnt signaling inhibition as a primary or secondary readout of therapeutic efficiency in MM may be of substantial importance in subsequent design of drug therapies or combination therapies.

scholarly journals Wnt/β-Catenin/Tcf Signaling Induces the Transcription of Axin2, a Negative Regulator of the Signaling Pathway

2002 ◽  
Vol 22 (4) ◽  
pp. 1172-1183 ◽  
Author(s):  
Eek-hoon Jho ◽  
Tong Zhang ◽  
Claire Domon ◽  
Choun-Ki Joo ◽  
Jean-Noel Freund ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Wnt Pathway ◽  
Genomic Sequence ◽  
Wnt Signaling Pathway ◽  
Genomic Region ◽  
Negative Regulator ◽  
Mobility Shift ◽  
Specific Expression

ABSTRACT Axin2/Conductin/Axil and its ortholog Axin are negative regulators of the Wnt signaling pathway, which promote the phosphorylation and degradation of β-catenin. While Axin is expressed ubiquitously, Axin2 mRNA was seen in a restricted pattern during mouse embryogenesis and organogenesis. Because many sites of Axin2 expression overlapped with those of several Wnt genes, we tested whether Axin2 was induced by Wnt signaling. Endogenous Axin2 mRNA and protein expression could be rapidly induced by activation of the Wnt pathway, and Axin2 reporter constructs, containing a 5.6-kb DNA fragment including the promoter and first intron, were also induced. This genomic region contains eight Tcf/LEF consensus binding sites, five of which are located within longer, highly conserved noncoding sequences. The mutation or deletion of these Tcf/LEF sites greatly diminished induction by β-catenin, and mutation of the Tcf/LEF site T2 abolished protein binding in an electrophoretic mobility shift assay. These results strongly suggest that Axin2 is a direct target of the Wnt pathway, mediated through Tcf/LEF factors. The 5.6-kb genomic sequence was sufficient to direct the tissue-specific expression of d2EGFP in transgenic embryos, consistent with a role for the Tcf/LEF sites and surrounding conserved sequences in the in vivo expression pattern of Axin2. Our results suggest that Axin2 participates in a negative feedback loop, which could serve to limit the duration or intensity of a Wnt-initiated signal.

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