scholarly journals Amygdala-Based Altered miRNome and Epigenetic Contribution of miR-128-3p in Conferring Susceptibility to Depression-Like Behavior via Wnt Signaling

2020 ◽  
Vol 23 (3) ◽  
pp. 165-177 ◽  
Author(s):  
Bhaskar Roy ◽  
Michael Dunbar ◽  
Juhee Agrawal ◽  
Lauren Allen ◽  
Yogesh Dwivedi
Keyword(s):  
Wnt Signaling ◽  
Target Genes ◽  
Rna Binding ◽  
Statistical Significance ◽  
Neuroblastoma Cell ◽  
Wnt Signaling Pathway ◽  
Target Prediction ◽  
In Vivo Model

Abstract Background Recent studies suggest that microRNAs (miRNAs) can participate in depression pathogenesis by altering a host of genes that are critical in corticolimbic functioning. The present study focuses on examining whether alterations in the miRNA network in the amygdala are associated with susceptibility or resiliency to develop depression-like behavior in rats. Methods Amygdala-specific altered miRNA transcriptomics were determined in a rat depression model following next-generation sequencing method. Target prediction analyses (cis- and trans) and qPCR-based assays were performed to decipher the functional role of altered miRNAs. miRNA-specific target interaction was determined using in vitro transfection assay in neuroblastoma cell line. miRNA-specific findings from the rat in vivo model were further replicated in postmortem amygdala of major depressive disorder (MDD) subjects. Results Changes in miRNome identified 17 significantly upregulated and 8 significantly downregulated miRNAs in amygdala of learned helpless (LH) compared with nonlearned helpless rats. Prediction analysis showed that the majority of the upregulated miRNAs had target genes enriched for the Wnt signaling pathway. Among altered miRNAs, upregulated miR-128-3p was identified as a top hit based on statistical significance and magnitude of change in LH rats. Target validation showed significant downregulation of Wnt signaling genes in amygdala of LH rats. A discernable increase in expression of amygdalar miR-128-3p along with significant downregulation of key target genes from Wnt signaling (WNT5B, DVL, and LEF1) was noted in MDD subjects. Overexpression of miR-128-3p in a cellular model lead to a marked decrease in the expression of Dvl1 and Lef1 genes, confirming them as validated targets of miR-128-3p. Additional evidence suggested that the amygdala-specific diminished expression of transcriptional repressor Snai1 could be potentially linked to induced miR-128-2 expression in LH rats. Furthermore, an amygdala-specific posttranscriptional switching mechanism could be active between miR-128-3p and RNA binding protein Arpp21 to gain control over their target genes such as Lef1. Conclusion Our study suggests that in amygdala a specific set of miRNAs may play an important role in depression susceptibility, which could potentially be mediated through Wnt signaling.

Disruption of CTNNB1/LEF-1 Complex by Small Molecule Inhibitors Induces Apoptosis in B-CLL Cells in Vitro and in Vivo

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. 3163-3163
Author(s):  
Rajesh Kumar Gandhirajan ◽  
Iris Gehrke ◽  
Julian Paesler ◽  
Regina Razavi ◽  
Alexandra Filipovich ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Small Molecule ◽  
Target Genes ◽  
Small Molecule Inhibitors ◽  
Wnt Signaling Pathway ◽  
Lymphocytic Leukemia ◽  
In Vivo Studies ◽  
Parp Cleavage

Abstract Deregulated WNT signaling has been implicated in variety of tumors. Previous findings suggest critical components of WNT signaling pathway (WNTs, FZD and LEF-1) are overepxressed in B-cell chronic lymphocytic leukemia (CLL) at the m-RNA level. β-catenin (CTNNB1)/LEF-1 transcription activation complex is the key component of WNT signaling which governs the expression of WNT target genes. Critical genes like C-MYC, survivin (SURV), cyclin D1 (CCND1) and LEF-1 which are also overexpressed in CLL are downstream targets of this pathway. In the current study we attempted to inhibit CTNNB1/LEF-1 interaction in CLL cells using the novel small molecule inhibitors CGP049090 and PKF115-584 and observed the survival potential both in vivo and in vitro. Substantial overexpression of LEF-1 and dephospho-CTNNB1, in CLL cells was observed when compared to healthy CD19 positive B cells and PBMCs suggests activation of WNT signaling in CLL. The LC50 calculated from 30 CLL patients was 1.18 μM for CGP049090 and 1.10 μM for PKF115-584 by the ATP based assay. This was confirmed by the DiSC assay LC50 of 0.33 μM (CGP049090) and 0.23 μM (PKF115-584) for primary B-CLL cells (n=3). Both substances showed little effects on normal PBMCs (n=5) as seen from the LC50 values of 90.92 μM and 39.88 μM for CGP049090 and PKF115-584, respectively. Time course experiments indicate activation of caspase 8, 9, 3 & 7, PARP cleavage and paralleled by downregulation of known inhibitors of apoptosis (IAPs) MCL-1, XIAP and BCL-2 leading to apoptosis. Co-immune precipitation of CTNNB1/LEF-1 complex was inhibited in the presence of CGP049090 and PKF115-584 suggesting the specificity of the interaction. Cellular uptake of PKF115-584 and cytoplasmic co-localisation with lef-1 was observed by fluorescence microscopy. In vivo studies reveal that both substances are highly tolerable and effective in eradicating tumor growth in xenografts. The tumor inhibitory rate (IRmax) was found to be 78% and 63.8% for CGP049090 and PKF115-584, respectively. These results indicate that LEF-1 is a promising target for B-CLL therapy as CGP049090 and PKF115-584 effectively induce apoptosis within micromolar concentrations in CLL cells but do not affect healthy cells at these doses. Downregulation of WNT target genes and IAPs hasten the apoptotic mechanism. Moreover, and these inhibitors are highly effective and tolerable in vivo which identifies both compounds as promising drugs for targeted therapy in CLL.

Abstract 361: Activation of Wnt Pathway in Macrophages During Atherosclerosis Regression

2015 ◽  
Vol 35 (suppl_1) ◽  
Author(s):  
Prashanthi Menon ◽  
Yulia Vengrenyuk ◽  
Yoscar Ogando ◽  
Stephen Ramsey ◽  
Elizabeth Gold ◽  
...  
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Mouse Models ◽  
Target Genes ◽  
Wnt Signaling Pathway ◽  
Macrophage Migration ◽  
Canonical Wnt Signaling ◽  
Canonical Wnt

Introduction and Objective: Transcriptome analysis of plaque macrophages in two different mouse models of atherosclerosis regression revealed an over representation of consensus binding site sequences for the T-cell factor (TCF)/Lymphoid enhancer binding factor (LEF) family of transcription factors, suggesting canonical Wnt signaling pathway activation during regression in vivo. The canonical Wnt/β-catenin signaling pathway is important for cardiac development and regulates processes such as migration, invasion and tissue repair. However, its function in plaque macrophages is unclear. The objective of the study was to understand the role of canonical Wnt signaling in macrophages during regression using in vivo and in vitro approaches. Methods and Results: Immunohistochemistry of atherosclerotic arterial sections in mouse models of atherosclerosis regression (Reversa and aortic arch transplant) showed a significant increase in β-catenin expression in regressing vs. progressing macrophages. Elevated transcript levels of canonical Wnt downstream targets Ctnnb1, Lrp1 and Gja1 were detected in regressing plaque macrophages isolated by laser capture microdissection (LCM). Canonical Wnt signaling was further investigated in Wnt3a-stimulated primary bone marrow-derived macrophages (BMDM) in vitro, revealing upregulation of pathway target genes Ctnnb1 and Axin2. Furthermore, immunofluorescence analysis of BMDM stimulated with Wnt3a showed increased nuclear expression of β-catenin. Macrophage cell migration evaluated by scratch wound assay revealed a significant increase in migration in Wnt3a-treated vs. untreated BMDM. Conclusions: Our findings demonstrate that canonical Wnt signaling is activated in regressing plaque macrophages and regulates macrophage migration in vitro. Future studies are aimed at understanding the mechanism by which Wnt modulates macrophage migration.

scholarly journals The microRNA miR-8 is a conserved negative regulator of Wnt signaling

2008 ◽  
Vol 105 (40) ◽  
pp. 15417-15422 ◽  
Author(s):  
Jennifer A. Kennell ◽  
Isabelle Gerin ◽  
Ormond A. MacDougald ◽  
Ken M. Cadigan
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathway ◽  
Target Genes ◽  
Wnt Signaling Pathway ◽  
Negative Regulator ◽  
Animal Development ◽  
Protein Levels ◽  
Evolutionarily Conserved ◽  
Multiple Levels

Wnt signaling plays many important roles in animal development. This evolutionarily conserved signaling pathway is highly regulated at all levels. To identify regulators of the Wnt/Wingless (Wg) pathway, we performed a genetic screen in Drosophila. We identified the microRNA miR-8 as an inhibitor of Wg signaling. Expression of miR-8 potently antagonizes Wg signaling in vivo, in part by directly targeting wntless, a gene required for Wg secretion. In addition, miR-8 inhibits the pathway downstream of the Wg signal by repressing TCF protein levels. Another positive regulator of the pathway, CG32767, is also targeted by miR-8. Our data suggest that miR-8 potently antagonizes the Wg pathway at multiple levels, from secretion of the ligand to transcription of target genes. In addition, mammalian homologues of miR-8 promote adipogenesis of marrow stromal cells by inhibiting Wnt signaling. These findings indicate that miR-8 family members play an evolutionarily conserved role in regulating the Wnt signaling pathway.

scholarly journals Dickkopf Wnt signaling pathway inhibitor 1 regulates the differentiation of mouse embryonic stem cells in vitro and in vivo

2015 ◽  
Vol 13 (1) ◽  
pp. 720-730 ◽  
Author(s):  
LIPING OU ◽  
LIAOQIONG FANG ◽  
HEJING TANG ◽  
HAI QIAO ◽  
XIAOMEI ZHANG ◽  
...  
Keyword(s):  
Stem Cells ◽  
Embryonic Stem Cells ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Wnt Signaling Pathway ◽  
Embryonic Stem ◽  
Mouse Embryonic Stem Cells

RNA binding by Sxl proteins in vitro and in vivo

1994 ◽  
Vol 14 (7) ◽  
pp. 4975-4990
Author(s):  
M E Samuels ◽  
D Bopp ◽  
R A Colvin ◽  
R F Roscigno ◽  
M A Garcia-Blanco ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Target Genes ◽  
Rna Binding ◽  
Polytene Chromosomes ◽  
Regulatory Sequences ◽  
Acceptor Site ◽  
Nuclear Extracts ◽  
Preferential Binding

Sxl has been proposed to regulate splicing of specific target genes by directly interacting with their pre-mRNAs. We have therefore examined the RNA-binding properties of Sxl protein in vitro and in vivo. Gel shift and UV cross-linking assays with a purified recombinant MBP-Sxl fusion protein demonstrated preferential binding to RNAs containing poly(U) tracts, and the protein footprinted over the poly(U) region. The protein did not appear to recognize either branch point or AG dinucleotide sequences, but an adenosine residue at the 5' end of the poly(U) tract enhanced binding severalfold. MBP-Sxl formed two shifted complexes on a tra regulated acceptor site RNA; the doubly shifted form may have been stabilized by protein-protein interactions. Consistent with its proposed role in pre-mRNA processing, in nuclear extracts Sxl was found in large ribonucleoprotein (RNP) complexes which sedimented significantly faster than bulk heterogeneous nuclear RNP and small nuclear RNPs. Anti-Sxl staining of polytene chromosomes showed Sxl protein at a number of chromosomal locations, among which was the Sxl locus itself. Sxl protein could also be targeted to a new chromosomal site carrying a transgene containing splicing regulatory sequences from the Sxl gene, following transcriptional induction. After prolonged heat shock, all Sxl protein was restricted to the heat-induced puff at the hs93D locus. In contrast, a presumptive small nuclear RNP protein was observed at several heat puffs following shock.

scholarly journals Rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal antibodies against DKK2 for cancer therapy

2020 ◽  
Vol 3 (2) ◽  
pp. 63-70 ◽  
Author(s):  
Rongqing Zhao ◽  
Qian Xiao ◽  
Maohua Li ◽  
Wenlin Ren ◽  
Chenxi Xia ◽  
...  
Keyword(s):  
Monoclonal Antibodies ◽  
Tumor Growth ◽  
Wnt Signaling ◽  
Rational Design ◽  
Polyclonal Antibodies ◽  
Wnt Signaling Pathway ◽  
Keyhole Limpet Hemocyanin ◽  
Linear Epitopes

Abstract Dickkopf-related protein 2 (DKK2)is a member of the Dickkopf family in Wnt signaling pathway. Recently, we found that antibodies against DKK2 could activate natural killer (NK) and CD8+ T cells in tumors and inhibit tumor growth. In this paper, we report the rational design of peptides for identification of linear epitopes and generation of neutralizing monoclonal anti-DKK2 antibodies. To break the immune tolerance, we designed and chemically synthesized six peptides corresponding to different regions of DKK2 as immunogens and found five of them could generate mouse polyclonal antibodies that can bind to the active recombinant human DKK2 protein. Neutralizing mouse monoclonal antibodies (5F8 and 1A10) against human DKK2 were successfully developed by immunizing the mice with two different peptides (34KLNSIKSSL42 and 240KVWKDATYS248) conjugated to Keyhole limpet hemocyanin (KLH). The monoclonal antibodies not only abolish DKK2’s suppression of Wnt signaling in vitro but also inhibits tumor growth in vivo. Currently, those two mAbs are undergoing humanization as immunotherapy candidates and may offer a new drug for treatment of human cancers.

scholarly journals The Wnt signaling pathway effector TCF7L2 is upregulated by insulin and represses hepatic gluconeogenesis

2012 ◽  
Vol 303 (9) ◽  
pp. E1166-E1176 ◽  
Author(s):  
Wilfred Ip ◽  
Weijuan Shao ◽  
Yu-ting Alex Chiang ◽  
Tianru Jin
Keyword(s):  
Gene Expression ◽  
Type 2 Diabetes ◽  
Transcription Factor ◽  
Wnt Signaling ◽  
Wnt Signaling Pathway ◽  
Glucose Production ◽  
Hepatic Gluconeogenesis

Certain single nucleotide polymorphisms (SNPs) in transcription factor 7-like 2 (TCF7L2) are strongly associated with the risk of type 2 diabetes. TCF7L2 and β-catenin (β-cat) form the bipartite transcription factor cat/TCF in stimulating Wnt target gene expression. cat/TCF may also mediate the effect of other signaling cascades, including that of cAMP and insulin in cell-type specific manners. As carriers of TCF7L2 type 2 diabetes risk SNPs demonstrated increased hepatic glucose production, we aimed to determine whether TCF7L2 expression is regulated by nutrient availability and whether TCF7L2 and Wnt regulate hepatic gluconeogenesis. We examined hepatic Wnt activity in the TOPGAL transgenic mouse, assessed hepatic TCF7L2 expression in mice upon feeding, determined the effect of insulin on TCF7L2 expression and β-cat Ser675 phosphorylation, and investigated the effect of Wnt activation and TCF7L2 knockdown on gluconeogenic gene expression and glucose production in hepatocytes. Wnt activity was observed in pericentral hepatocytes in the TOPGAL mouse, whereas TCF7L2 expression was detected in human and mouse hepatocytes. Insulin and feeding stimulated hepatic TCF7L2 expression in vitro and in vivo, respectively. In addition, insulin activated β-cat Ser675 phosphorylation. Wnt activation by intraperitoneal lithium injection repressed hepatic gluconeogenic gene expression in vivo, whereas lithium or Wnt-3a reduced gluconeogenic gene expression and glucose production in hepatic cells in vitro. Small interfering RNA-mediated TCF7L2 knockdown increased glucose production and gluconeogenic gene expression in cultured hepatocytes. These observations suggest that Wnt signaling and TCF7L2 are negative regulators of hepatic gluconeogenesis, and TCF7L2 is among the downstream effectors of insulin in hepatocytes.

scholarly journals Modulation of Calretinin Expression in Human Mesothelioma Cells Reveals the Implication of the FAK and Wnt Signaling Pathways in Conferring Chemoresistance towards Cisplatin

2019 ◽  
Vol 20 (21) ◽  
pp. 5391 ◽  
Author(s):  
Wörthmüller ◽  
Salicio ◽  
Oberson ◽  
Blum ◽  
Schwaller
Keyword(s):  
Wnt Signaling ◽  
Signaling Pathways ◽  
Signaling Pathway ◽  
Expression System ◽  
Single Agent ◽  
Wnt Signaling Pathway ◽  
Tumor Formation ◽  
Mesenchymal Transition

Malignant mesothelioma (MM) is an aggressive asbestos-linked neoplasm, characterized by dysregulation of signaling pathways. Due to intrinsic or acquired chemoresistance, MM treatment options remain limited. Calretinin is a Ca2+-binding protein expressed during MM tumorigenesis that activates the FAK signaling pathway, promoting invasion and epithelial-to-mesenchymal transition. Constitutive calretinin downregulation decreases MM cells’ growth and survival, and impairs tumor formation in vivo. In order to evaluate early molecular events occurring during calretinin downregulation, we generated a tightly controlled IPTG-inducible expression system to modulate calretinin levels in vitro. Calretinin downregulation significantly reduced viability and proliferation of MM cells, attenuated FAK signaling and reduced the invasive phenotype of surviving cells. Importantly, surviving cells showed a higher resistance to cisplatin due to increased Wnt signaling. This resistance was abrogated by the Wnt signaling pathway inhibitor 3289-8625. In various MM cell lines and regardless of calretinin expression levels, blocking of FAK signaling activated the Wnt signaling pathway and vice versa. Thus, blocking both pathways had the strongest impact on MM cell proliferation and survival. Chemoresistance mechanisms in MM cells have resulted in a failure of single-agent therapies. Targeting of multiple components of key signaling pathways, including Wnt signaling, might be the future method-of-choice to treat MM.

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.

scholarly journals The endocannabinoid anandamide inhibits cholangiocarcinoma growth via activation of the noncanonical Wnt signaling pathway

2008 ◽  
Vol 295 (6) ◽  
pp. G1150-G1158 ◽  
Author(s):  
Sharon DeMorrow ◽  
Heather Francis ◽  
Eugenio Gaudio ◽  
Julie Venter ◽  
Antonio Franchitto ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Tumor Growth ◽  
Wnt Signaling ◽  
Signaling Pathway ◽  
Calcium Release ◽  
Wnt Signaling Pathway ◽  
Xenograft Model ◽  
Orphan Receptor

Cholangiocarcinomas are cancers that have poor prognosis and limited treatment options. The noncanonical Wnt pathway is mediated predominantly by Wnt 5a, which activates a Ca2+-dependent pathway involving protein kinase C, or a Ca2+-independent pathway involving the orphan receptor Ror2 and subsequent activation of Jun NH2-terminal kinase (JNK). This pathway is associated with growth-suppressing effects in numerous cell types. We have shown that anandamide decreases cholangiocarcinoma growth in vitro. Therefore, we determined the effects of anandamide on cholangiocarcinoma tumor growth in vivo using a xenograft model and evaluated the effects of anandamide on the noncanonical Wnt signaling pathways. Chronic administration of anandamide decreased tumor growth and was associated with increased Wnt 5a expression in vitro and in vivo. Treatment of cholangiocarcinoma cells with recombinant Wnt 5a decreased cell proliferation in vitro. Neither anandamide nor Wnt 5a affected intracellular calcium release, but both increased the JNK phosphorylation. Stable knockdown of Wnt 5a or Ror2 expression in cholangiocarcinoma cells abolished the effects of anandamide on cell proliferation and JNK activation. Modulation of the endocannabinoid system may be important in cholangiocarcinoma treatment. The antiproliferative actions of the noncanonical Wnt signaling pathway warrants further investigation to dissect the mechanism by which this may occur.

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