scholarly journals Developmentally regulated Tcf7l2 splice variants mediate transcriptional repressor functions during eye formation

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Rodrigo M Young ◽  
Kenneth B Ewan ◽  
Veronica P Ferrer ◽  
Miguel L Allende ◽  
Jasminka Godovac-Zimmermann ◽  
...  
Keyword(s):  
Wnt Pathway ◽  
Splice Variants ◽  
Gene Promoters ◽  
Developmentally Regulated ◽  
Reporter Assays ◽  
Tcf7l2 Variant ◽  
Transcriptional Output ◽  
Biological Outcomes ◽  
Eye Formation

Tcf7l2 mediates Wnt/β-Catenin signalling during development and is implicated in cancer and type-2 diabetes. The mechanisms by which Tcf7l2 and Wnt/β-Catenin signalling elicit such a diversity of biological outcomes are poorly understood. Here, we study the function of zebrafish tcf7l2 alternative splice variants and show that only variants that include exon five or an analogous human tcf7l2 variant can effectively provide compensatory repressor function to restore eye formation in embryos lacking tcf7l1a/tcf7l1b function. Knockdown of exon five specific tcf7l2 variants in tcf7l1a mutants also compromises eye formation, and these variants can effectively repress Wnt pathway activity in reporter assays using Wnt target gene promoters. We show that the repressive activities of exon5-coded variants are likely explained by their interaction with Tle co-repressors. Furthermore, phosphorylated residues in Tcf7l2 coded exon5 facilitate repressor activity. Our studies suggest that developmentally regulated splicing of tcf7l2 can influence the transcriptional output of the Wnt pathway.

scholarly journals Developmentally regulated tcf7l2 splice variants mediate transcriptional repressor functions during eye formation

2019 ◽  
Author(s):  
Rodrigo M. Young ◽  
Kenneth B. Ewan ◽  
Veronica P. Ferrer ◽  
Miguel L. Allende ◽  
Jasminka Godovac-Zimmermann ◽  
...  
Keyword(s):  
Wnt Pathway ◽  
Splice Variants ◽  
Gene Promoters ◽  
Developmentally Regulated ◽  
Alternatively Spliced ◽  
Reporter Assays ◽  
Transcriptional Output ◽  
Biological Outcomes ◽  
Eye Formation

AbstractTcf7l2 mediates Wnt/β-Catenin signalling during development and is implicated in cancer and type-2 diabetes. The mechanisms by which Tcf7l2 and Wnt/β-Catenin signalling elicits such a diversity of biological outcomes are poorly understood. Here, we study alternatively spliced tcf7l2 in zebrafish and show that only splice variants that include exon 5 and an analogous human tcf7l2 variant can effectively provide compensatory repressor function to restore eye formation in embryos lacking tcf7l1a/tcf7l1b function. Knockdown of exon 5 specific tcf7l2 variants in tcf7l1a mutants also compromises eye formation and these variants can effectively repress Wnt pathway activity in reporter assays using Wnt target gene promoters. We show that the repressive activities of exon5-coded variants are likely explained by their interaction with Tle co-repressors. Furthermore, phosphorylated residues in Tcf7l2 coded exon5 facilitate repressor activity. Our studies suggest that developmentally regulated splicing of tcf7l2 can influence the transcriptional output of the Wnt pathway.

scholarly journals Author response: Developmentally regulated Tcf7l2 splice variants mediate transcriptional repressor functions during eye formation

2019 ◽  
Author(s):  
Rodrigo M Young ◽  
Kenneth B Ewan ◽  
Veronica P Ferrer ◽  
Miguel L Allende ◽  
Jasminka Godovac-Zimmermann ◽  
...  
Keyword(s):  
Splice Variants ◽  
Transcriptional Repressor ◽  
Author Response ◽  
Developmentally Regulated ◽  
Eye Formation

1983-P: WNT Pathway and Bone Fragility in Postmenopausal Women with Type 2 Diabetes

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 1983-P
Author(s):  
ALESSANDRA PICCOLI ◽  
FRANCESCA CANNATA ◽  
FABRIZIO RUSSO ◽  
VALENTINA L. GRETO ◽  
CAMILLA ISGRÒ ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Postmenopausal Women ◽  
Wnt Pathway ◽  
Bone Fragility

Search for Pharmacoepigenetic Correlations in Type 2 Diabetes Under Sulfonylurea Treatment

2018 ◽  
Vol 127 (04) ◽  
pp. 226-233 ◽  
Author(s):  
Makrina Karaglani ◽  
Georgia Ragia ◽  
Maria Panagopoulou ◽  
Ioanna Balgkouranidou ◽  
Evangelia Nena ◽  
...  
Keyword(s):  
Dna Methylation ◽  
Gene Promoter ◽  
Katp Channels ◽  
Protective Role ◽  
Gene Promoters ◽  
Specific Pcr ◽  
Abcc8 Gene ◽  
First Time ◽  
E23k Polymorphism

AbstractSulfonylureas are insulin secretagogues which act in pancreatic β cells by blocking the KATP channels encoded by KCNJ11 and ABCC8 genes. In the present study, a pharmacoepigenetic approach was applied for the first time, investigating the correlation of KCNJ11 and ABCC8 gene promoter methylation with sulfonylureas-induced mild hypoglycemic events as well as the KCNJ11 E23K genotype. Sodium bisulfite-treated genomic DNA of 171 sulfonylureas treated T2DM patients previously genotyped for KCNJ11 E23K, including 88 that had experienced drug-associated hypoglycemia and 83 that had never experienced hypoglycemia, were analyzed for DNA methylation of KCNJ11 and ABCC8 gene promoters via quantitative Methylation-Specific PCR. KCNJ11 methylation was detected in 19/88 (21.6%) of hypoglycemic and in 23/83 (27.7%) of non-hypoglycemic patients (p=0.353), while ABCC8 methylation in 6/83 (7.2%) of non-hypoglycemic and none (0/88) of the hypoglycemic patients (p=0.012). Methylation in at least one promoter (KCNJ11 or ABCC8) was significantly associated with non-hypoglycemic patients who are carriers of KCNJ11 EK allele (p=0.030). Our data suggest that ABCC8 but not KCNJ11 methylation is associated to hypoglycemic events in sulfonylureas-treated T2DM patients. Furthermore, it is demonstrated that the KCNJ11 E23K polymorphism in association to either of the two genes’ DNA methylation may have protective role against sulfonylurea-induced hypoglycemia.

Abstract MP171: Transcription Start Site Profiling Defines Promoter and Enhancer Regions for Cardiomyopathy Genes

2020 ◽  
Vol 127 (Suppl_1) ◽  
Author(s):  
Anthony M Gacita ◽  
Lisa Dellefave-Castillo ◽  
Patrick G Page ◽  
David Y Barefield ◽  
Andrew Wasserstrom ◽  
...  
Keyword(s):  
Heart Failure ◽  
Genetic Variation ◽  
Cardiac Tissue ◽  
Autosomal Dominant ◽  
Gene Promoters ◽  
Regulatory Regions ◽  
Genome Wide ◽  
Reporter Assays ◽  
Transcriptional Start Sites ◽  
Putative Enhancer

Background: Mutations in more than 100 genes lead to dilated, hypertrophic and other forms of cardiomyopathy. Autosomal dominant mutations in the MYH7 and LMNA genes cause autosomal dominant hypertrophic and dilated cardiomyopathy, respectively. Individual mutations display a range of clinical expression from severe early onset disease to minimal or no symptoms. Genetic variation in noncoding gene regulatory regions including enhancers is expected to modify expression of cardiomyopathy genes and disease expressivity. In addition, heart failure is associated a fetal gene re-expression program, mediated by genetic regulatory regions. The contribution of noncoding genetic variation to cardiomyopathy and heart failure has been hampered by limited genome wide descriptions of human cardiac regulatory regions. Methods and Results: We used C ap A nalysis of G ene E xpression by sequencing (CAGE-seq) to profile the transcriptional start sites in healthy and failed human hearts. CAGE-seq detects the unidirectional signals of gene promoters and the bidirectional signal of transcribed enhancer regions. We identified ~17,000 transcriptional start sites associated with gene promoters and ~1,500 putative enhancer regions active in cardiac tissue. These CAGE-defined regulatory regions carried histone modifications and transcription factor binding properties characteristic of enhancers or promoters. We specifically identified promoter switching and differential enhancer usage between healthy and failed hearts. We intersected CAGE-defined enhancers with additional epigenomic datasets to identify regulatory regions for MYH7 and LMNA genes. We identified 13 putative enhancer regions and validated the functionality of a subset of these regulatory regions using reporter assays and gene editing. Conclusions: This CAGE-seq dataset defines the regulatory environment for heart failure. These promoter and enhancer regions could be used to target heart-failure associated gene expression changes. Additionally, this data can be used to identify enhancer regions regulating cardiomyopathy genes.

scholarly journals The type 2 anti-Müllerian hormone receptor has splice variants that are dominant-negative inhibitors

FEBS Letters ◽  
2013 ◽  
Vol 587 (12) ◽  
pp. 1749-1753 ◽  
Author(s):  
Floriane M. Imhoff ◽  
Dee Yang ◽  
Suneeth F. Mathew ◽  
Andrew N. Clarkson ◽  
Yui Kawagishi ◽  
...  
Keyword(s):  
Hormone Receptor ◽  
Splice Variants ◽  
Dominant Negative

Transcription Factor Integration from Pathways Regulating Adult Blood Stem Cell Production and Self-Renewal.

Blood ◽  
2008 ◽  
Vol 112 (11) ◽  
pp. sci-14-sci-14
Author(s):  
Leonard I. Zon
Keyword(s):  
Stem Cell ◽  
Signaling Pathways ◽  
Binding Sites ◽  
Wnt Pathway ◽  
Dominant Negative ◽  
Transgenic Zebrafish ◽  
Self Renewal ◽  
Hematopoietic Stem ◽  
Transcriptional Output ◽  
Multiple Signaling

Self-renewal of hematopoietic stem cells (HSCs) involves multiple signaling and transcription factors. We recently showed that prostaglandin (PG) E2 regulates the induction and engraftment of vertebrate HSC pathways. Yet, the targets and transcriptional output of the PGE2 pathway remains to be defined. The wnt pathway similarly affects HSC formation; activation of wnt signaling in heat-shock inducible transgenic zebrafish led to enhanced HSC formation, while inhibition of wnt/β-catenin signaling at the membrane level (dickkopf), in the cytosol (axin) or in the nucleus (dominant negative TCF), reduced HSC numbers. Using wnt transcriptional reporter zebrafish with multimerized TCF-binding sites. PGE2 was found to increase activity during embryonic development, demonstrating a direct interaction between these signaling pathways. The transcriptional output of the wnt pathway is linked to the interaction of TCF with β-catenin. Based on the transcriptional increase in multimerized TCF binding sites in vivo, we had hypothesized that prostaglandin signaling directly stimulates β-catenin activation. β-catenin is known to be phosphorylated on critical residues that modulate its activity. In marrow-derived cells, we demonstrate that prostaglandin increases a cyclic AMP pathway that leads to the PKA phosphorylation of β-catenin, thereby increasing its transcriptional activity. In HSCs, the interaction of multiple signaling pathways with transcriptional output is a method for modulating self-renewal in the stem cell pool as well as tissue differentiation.

The Type2 EWS-Fli1 protein causes a greater up-regulation of elements of the human stromelysin 3 promoter compared with EWS-Fli1 Type 1 and Fli1

2006 ◽  
Vol 24 (18_suppl) ◽  
pp. 9538-9538
Author(s):  
B. S. Ubhi
Keyword(s):  
Vector System ◽  
Expression Vectors ◽  
Luciferase Reporter ◽  
Gene Promoters ◽  
Promoter Element ◽  
Nih3t3 Cells ◽  
Reporter Vector ◽  
Disease Pattern

9538 Background: The role of EWS-Fli1 in the pathogenesis of Ewing’s sarcoma has been extensively investigated. This translocation is found in 85% of Ewing’s tumours. The translocation brings together two genes, EWS and Fli1. EWS is thought to have homology with RNA polymerase whilst Fli1 is a member of the ETS family of transcription factors. The EWS-Fli1 translocation was previously thought to result in an increase in Fli1 activity at target gene promoters including human stromelysin 1. Mutants of the human stromelysin promoter were therefore constructed and cloned into the pGL-3 luciferase reporter vector system and co-transfected with either EWS-Fli1 (type 1 or 2) and/or Fli1 expression vectors. We had previously detemined that EWS-Fli1 appeared to have greater activity at the 5’ end of the stromelysin promoter compared with Fli1.This system was therefore used to investigate the activity of EWS Fli1 type1, Ews-Fli1 type 2 and Fli1 on a 5’ element of the human stromelysin 1 promoter (containing the 5’ 335bp of the promoter). Methods: 1μg of the reporter vector strom-3’Δ5 (containing the 5’ 335bp of the human stromelysin 1 promoter) was co-transfected into NIH3T3 cells with 1μg of the expression vectors ES-TPF10 (EWS-Fli1 Type1),ES-RDP20 (EWS-Fli1 type 2) or Fli1-DH6 (Fli1). The cells were incubated at 37oC in 5% CO2 for 24 hours before being lysed and assayed for luciferase activity. Conclusions: Ews-Fli1 (type 1 and 2) caused a higher level of stimulation of this promoter element compared with Fli1. Interestingly, the type 2 translocation caused a significantly higher level of expression of this promoter element compared with type 1, a finding which may reflect the disease pattern observed clinically. [Table: see text] No significant financial relationships to disclose.

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