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Strubberg AM, Veronese Paniagua DA, Zhao T, Dublin L, Pritchard T, Bayguinov PO, Fitzpatrick JAJ, Madison BB. The Zinc Finger Transcription Factor PLAGL2 Enhances Stem Cell Fate and Activates Expression of ASCL2 in Intestinal Epithelial Cells. Stem Cell Reports 2018; 11:410-424. [PMID: 30017821 PMCID: PMC6092695 DOI: 10.1016/j.stemcr.2018.06.009] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2017] [Revised: 06/11/2018] [Accepted: 06/12/2018] [Indexed: 01/02/2023] Open
Abstract
Intestinal epithelial stem cell (IESC) fate is promoted by two major transcriptional regulators, the TCF4/β-catenin complex and ASCL2, which drive expression of IESC-specific factors, including Lgr5, Ephb2, and Rnf43. Canonical Wnt signaling via TCF4/β-catenin directly transactivates Ascl2, which in turn auto-regulates its own expression. Conversely, Let-7 microRNAs antagonize the IESC lineage by repressing specific mRNA targets. Here, we identify the zinc finger transcription factor PLAGL2 as a Let-7 target that regulates IESC fate. PLAGL2 drives an IESC expression signature, activates Wnt gene expression, and enhances a TCF/LEF reporter in intestinal organoids. In parallel, via cell-autonomous mechanisms, PLAGL2 is required for lineage clonal expansion and directly enhances expression of ASCL2. PLAGL2 also supports enteroid growth and survival in the context of Wnt ligand depletion. PLAGL2 expression is strongly associated with an IESC signature in colorectal cancer and may be responsible for contributing to the aberrant activation of an immature phenotype.
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Affiliation(s)
- Ashlee M Strubberg
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8124, CSRB NT 923, Saint Louis, MO 63110, USA
| | - Daniel A Veronese Paniagua
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8124, CSRB NT 923, Saint Louis, MO 63110, USA
| | - Tingting Zhao
- Department of Breast Surgery, First Hospital of China Medical University, Shenyang 110001, China
| | - Leeran Dublin
- Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - Thomas Pritchard
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8124, CSRB NT 923, Saint Louis, MO 63110, USA
| | - Peter O Bayguinov
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, MO 63110, USA
| | - James A J Fitzpatrick
- Washington University Center for Cellular Imaging, Washington University School of Medicine, Saint Louis, MO 63110, USA; Departments of Cell Biology & Physiology and Neuroscience, Washington University School of Medicine, Saint Louis, MO 63110, USA; Department of Biomedical Engineering, Washington University in St. Louis, Saint Louis, MO 63105, USA
| | - Blair B Madison
- Department of Medicine, Division of Gastroenterology, Washington University School of Medicine, 660 S. Euclid Avenue, Campus Box 8124, CSRB NT 923, Saint Louis, MO 63110, USA.
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Clarke LL, Woode RA, Liu JL, Walker NM, Strubberg AM. Evidence for Altered Non‐Canonical Wnt Signaling and Increased Tight Junction Remodeling in Cftr Knockout (KO) Mouse Small Intestine. FASEB J 2018. [DOI: 10.1096/fasebj.2018.32.1_supplement.747.21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Lane L. Clarke
- Biomedical SciencesUniversity of MissouriColumbiaMO
- Dalton Cardio Research CenterUniversity of MissouriColumbiaMO
| | | | - Jinghua L. Liu
- Dalton Cardio Research CenterUniversity of MissouriColumbiaMO
| | - Nancy M. Walker
- Dalton Cardio Research CenterUniversity of MissouriColumbiaMO
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Strubberg AM, Liu J, Walker NM, Stefanski CD, MacLeod RJ, Magness ST, Clarke LL. Cftr Modulates Wnt/β-Catenin Signaling and Stem Cell Proliferation in Murine Intestine. Cell Mol Gastroenterol Hepatol 2017; 5:253-271. [PMID: 29675451 PMCID: PMC5904038 DOI: 10.1016/j.jcmgh.2017.11.013] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 11/18/2017] [Indexed: 02/06/2023]
Abstract
BACKGROUND & AIMS Cystic fibrosis (CF) patients and CF mouse models have increased risk for gastrointestinal tumors. CF mice show augmented intestinal proliferation of unknown etiology and an altered intestinal environment. We examined the role of the cystic fibrosis transmembrane conductance regulator (Cftr) in Wnt/β-catenin signaling, stem cell proliferation, and its functional expression in the active intestinal stem cell (ISC) population. Dysregulation of intracellular pH (pHi) in CF ISCs was investigated for facilitation of Wnt/β-catenin signaling. METHODS Crypt epithelia from wild-type (WT) and CF mice were compared ex vivo and in intestinal organoids (enteroids) for proliferation and Wnt/β-catenin signaling by standard assays. Cftr in ISCs was assessed by immunoblot of sorted Sox9 enhanced green fluorescent protein(EGFP) intestinal epithelia and pHi regulation by confocal microfluorimetry of leucine-rich G-protein-coupled receptor 5 ISCs. Plasma membrane association of the Wnt transducer Dishevelled 2 (Dvl2) was assessed by fluorescence imaging of live enteroids from WT and CF mice crossed with Dvl2-EGFP/ACTB-tdTomato,-EGFP)Luo/J (RosamT/mG) mice. RESULTS Relative to WT, CF intestinal crypts showed an ∼30% increase in epithelial and Lgr5+ ISC proliferation and increased Wnt/β-catenin signaling. Cftr was expressed in Sox9EGFPLo ISCs and loss of Cftr induced an alkaline pHi in ISCs. CF crypt-base columnar cells showed a generalized increase in plasma membrane Dvl2-EGFP association as compared with WT. Dvl2-EGFP membrane association was charge- and pH-dependent and increased in WT crypt-base columnar cells by Cftr inhibition. CONCLUSIONS CF intestine shows increased ISC proliferation and Wnt/β-catenin signaling. Loss of Cftr increases pHi in ISCs, which stabilizes the plasma membrane association of the Wnt transducer Dvl, likely facilitating Wnt/β-catenin signaling. Absence of Cftr-dependent suppression of ISC proliferation in the CF intestine may contribute to increased risk for intestinal tumors.
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Key Words
- CBC, crypt-base columnar cell
- CCH, carbachol
- CF, cystic fibrosis
- Cftr, cystic fibrosis transmembrane conductance regulator
- Cystic Fibrosis
- DEP, Dishevelled, Egl-10, and Pleckstrin
- Dishevelled
- Dvl, Dishevelled
- EGFP, enhanced green fluorescent protein
- EdU, 5-ethynyl-2’-deoxyuridine
- Fz, Frizzled
- GI, gastrointestinal
- ISC, intestinal stem cell
- Intracellular pH
- KO, knockout
- Lgr5, leucine-rich G-protein–coupled receptor 5
- Neoplasia
- Organoids
- PBS, phosphate-buffered saline
- PDZ, Post synaptic density protein, Drosophila disc large tumor suppressor, and Zonula occludens-1 protein
- PH3, phospho-histone H3
- ROI, region of interest
- WT, wild type
- pHi, intracellular pH
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Affiliation(s)
- Ashlee M. Strubberg
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Jinghua Liu
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Nancy M. Walker
- Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Casey D. Stefanski
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - R. John MacLeod
- Department of Biomedical and Molecular Sciences, Queen’s University, Kingston, Ontario, Canada
| | - Scott T. Magness
- Department of Medicine, Department of Cell and Molecular Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina
| | - Lane L. Clarke
- Department of Biomedical Sciences, University of Missouri, Columbia, Missouri,Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri,Correspondence Address correspondence to: Lane L. Clarke, DVM, PhD, 324D Dalton Cardiovascular Research Center, University of Missouri, 134 Research Park Drive, Columbia, Missouri 65211-3300. fax: (573) 884–4232.
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Abstract
MicroRNAs (miRNAs) are small single-stranded RNAs that repress mRNA translation
and trigger mRNA degradation. Of the ∼1900 miRNA-encoding genes present
in the human genome, ∼250 miRNAs are reported to have changes in
abundance or altered functions in colorectal cancer. Thousands of studies have
documented aberrant miRNA levels in colorectal cancer, with some miRNAs reported
to actively regulate tumorigenesis. A recurrent phenomenon with miRNAs is their
frequent participation in feedback loops, which probably serve to reinforce or
magnify biological outcomes to manifest a particular cellular phenotype. Here,
we review the roles of oncogenic miRNAs (oncomiRs), tumor suppressive miRNAs
(anti-oncomiRs) and miRNA regulators in colorectal cancer. Given their stability
in patient-derived samples and ease of detection with standard and novel
techniques, we also discuss the potential use of miRNAs as biomarkers in the
diagnosis of colorectal cancer and as prognostic indicators of this disease.
MiRNAs also represent attractive candidates for targeted therapies because their
function can be manipulated through the use of synthetic antagonists and miRNA
mimics. Summary: This Review provides an overview of some important
microRNAs and their roles in colorectal cancer.
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Affiliation(s)
- Ashlee M Strubberg
- Division of Gastroenterology, Washington University School of Medicine, Washington University, Saint Louis, MO 63110, USA
| | - Blair B Madison
- Division of Gastroenterology, Washington University School of Medicine, Washington University, Saint Louis, MO 63110, USA
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Walker NM, Liu J, Stein SR, Strubberg AM, Clarke LL. Reply: Epithelial alkalinity and hyperproliferation in the Cftr KO intestine. Am J Physiol Gastrointest Liver Physiol 2016; 310:G1184. [PMID: 27281735 DOI: 10.1152/ajpgi.00161.2016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 04/22/2016] [Indexed: 01/31/2023]
Affiliation(s)
- Nancy M Walker
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Jinghua Liu
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Sydney R Stein
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Ashlee M Strubberg
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
| | - Lane L Clarke
- Department of Biomedical Sciences, Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri
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Walker NM, Liu J, Stein SR, Stefanski CD, Strubberg AM, Clarke LL. Cellular chloride and bicarbonate retention alters intracellular pH regulation in Cftr KO crypt epithelium. Am J Physiol Gastrointest Liver Physiol 2016; 310:G70-80. [PMID: 26542396 PMCID: PMC4719062 DOI: 10.1152/ajpgi.00236.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 10/29/2015] [Indexed: 01/31/2023]
Abstract
Cystic fibrosis (CF) is caused by mutations in the CF transmembrane conductance regulator (CFTR), an anion channel providing a major pathway for Cl(-) and HCO3 (-) efflux across the apical membrane of the epithelium. In the intestine, CF manifests as obstructive syndromes, dysbiosis, inflammation, and an increased risk for gastrointestinal cancer. Cftr knockout (KO) mice recapitulate CF intestinal disease, including intestinal hyperproliferation. Previous studies using Cftr KO intestinal organoids (enteroids) indicate that crypt epithelium maintains an alkaline intracellular pH (pHi). We hypothesized that Cftr has a cell-autonomous role in downregulating pHi that is incompletely compensated by acid-base regulation in its absence. Here, 2',7'-bis(2-carboxyethyl)-5(6)-carboxyfluorescein microfluorimetry of enteroids showed that Cftr KO crypt epithelium sustains an alkaline pHi and resistance to cell acidification relative to wild-type. Quantitative real-time PCR revealed that Cftr KO enteroids exhibit downregulated transcription of base (HCO3 (-))-loading proteins and upregulation of the basolateral membrane HCO3 (-)-unloader anion exchanger 2 (Ae2). Although Cftr KO crypt epithelium had increased Ae2 expression and Ae2-mediated Cl(-)/HCO3 (-) exchange with maximized gradients, it also had increased intracellular Cl(-) concentration relative to wild-type. Pharmacological reduction of intracellular Cl(-) concentration in Cftr KO crypt epithelium normalized pHi, which was largely Ae2-dependent. We conclude that Cftr KO crypt epithelium maintains an alkaline pHi as a consequence of losing both Cl(-) and HCO3 (-) efflux, which impairs pHi regulation by Ae2. Retention of Cl(-) and an alkaline pHi in crypt epithelium may alter several cellular processes in the proliferative compartment of Cftr KO intestine.
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Affiliation(s)
- Nancy M. Walker
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and
| | - Jinghua Liu
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and
| | - Sydney R. Stein
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and
| | - Casey D. Stefanski
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and ,2Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Ashlee M. Strubberg
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and ,2Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Lane L. Clarke
- 1Dalton Cardiovascular Research Center, University of Missouri, Columbia, Missouri; and ,2Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
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Liu J, Walker NM, Ootani A, Strubberg AM, Clarke LL. Defective goblet cell exocytosis contributes to murine cystic fibrosis-associated intestinal disease. J Clin Invest 2015; 125:1056-68. [PMID: 25642775 DOI: 10.1172/jci73193] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 12/18/2014] [Indexed: 01/12/2023] Open
Abstract
Cystic fibrosis (CF) intestinal disease is associated with the pathological manifestation mucoviscidosis, which is the secretion of tenacious, viscid mucus that plugs ducts and glands of epithelial-lined organs. Goblet cells are the principal cell type involved in exocytosis of mucin granules; however, little is known about the exocytotic process of goblet cells in the CF intestine. Using intestinal organoids from a CF mouse model, we determined that CF goblet cells have altered exocytotic dynamics, which involved intrathecal granule swelling that was abruptly followed by incomplete release of partially decondensated mucus. Some CF goblet cells exhibited an ectopic granule location and distorted cellular morphology, a phenotype that is consistent with retrograde intracellular granule movement during exocytosis. Increasing the luminal concentration of bicarbonate, which mimics CF transmembrane conductance regulator-mediated anion secretion, increased spontaneous degranulation in WT goblet cells and improved exocytotic dynamics in CF goblet cells; however, there was still an apparent incoordination between granule decondensation and exocytosis in the CF goblet cells. Compared with those within WT goblet cells, mucin granules within CF goblet cells had an alkaline pH, which may adversely affect the polyionic composition of the mucins. Together, these findings indicate that goblet cell dysfunction is an epithelial-autonomous defect in the CF intestine that likely contributes to the pathology of mucoviscidosis and the intestinal manifestations of obstruction and inflammation.
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