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Bhaskara M, Anjorin O, Wang M. Mesenchymal Stem Cell-Derived Exosomal microRNAs in Cardiac Regeneration. Cells 2023; 12:2815. [PMID: 38132135 PMCID: PMC10742005 DOI: 10.3390/cells12242815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/01/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
Mesenchymal stem cell (MSC)-based therapy is one of the most promising modalities for cardiac repair. Accumulated evidence suggests that the therapeutic value of MSCs is mainly attributable to exosomes. MSC-derived exosomes (MSC-Exos) replicate the beneficial effects of MSCs by regulating various cellular responses and signaling pathways implicated in cardiac regeneration and repair. miRNAs constitute an important fraction of exosome content and are key contributors to the biological function of MSC-Exo. MSC-Exo carrying specific miRNAs provides anti-apoptotic, anti-inflammatory, anti-fibrotic, and angiogenic effects within the infarcted heart. Studying exosomal miRNAs will provide an important insight into the molecular mechanisms of MSC-Exo in cardiac regeneration and repair. This significant information can help optimize cell-free treatment and overcome the challenges associated with MSC-Exo therapeutic application. In this review, we summarize the characteristics and the potential mechanisms of MSC-derived exosomal miRNAs in cardiac repair and regeneration.
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Affiliation(s)
| | | | - Meijing Wang
- Department of Surgery, Indiana University School of Medicine, Indianapolis, IN 46202, USA
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2
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Extensive NEUROG3 occupancy in the human pancreatic endocrine gene regulatory network. Mol Metab 2021; 53:101313. [PMID: 34352411 PMCID: PMC8387919 DOI: 10.1016/j.molmet.2021.101313] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 07/27/2021] [Accepted: 07/28/2021] [Indexed: 01/17/2023] Open
Abstract
Objective Mice lacking the bHLH transcription factor (TF) Neurog3 do not form pancreatic islet cells, including insulin-secreting beta cells, the absence of which leads to diabetes. In humans, homozygous mutations of NEUROG3 manifest with neonatal or childhood diabetes. Despite this critical role in islet cell development, the precise function of and downstream genetic programs regulated directly by NEUROG3 remain elusive. Therefore, we mapped genome-wide NEUROG3 occupancy in human induced pluripotent stem cell (hiPSC)–derived endocrine progenitors and determined NEUROG3 dependency of associated genes to uncover direct targets. Methods We generated a novel hiPSC line (NEUROG3-HA-P2A-Venus) where NEUROG3 is HA-tagged and fused to a self-cleaving fluorescent VENUS reporter. We used the CUT&RUN technique to map NEUROG3 occupancy and epigenetic marks in pancreatic endocrine progenitors (PEP) that were differentiated from this hiPSC line. We integrated NEUROG3 occupancy data with chromatin status and gene expression in PEPs as well as their NEUROG3-dependence. In addition, we investigated whether NEUROG3 binds type 2 diabetes mellitus (T2DM)–associated variants at the PEP stage. Results CUT&RUN revealed a total of 863 NEUROG3 binding sites assigned to 1263 unique genes. NEUROG3 occupancy was found at promoters as well as at distant cis-regulatory elements that frequently overlapped within PEP active enhancers. De novo motif analyses defined a NEUROG3 consensus binding motif and suggested potential co-regulation of NEUROG3 target genes by FOXA or RFX transcription factors. We found that 22% of the genes downregulated in NEUROG3−/− PEPs, and 10% of genes enriched in NEUROG3-Venus positive endocrine cells were bound by NEUROG3 and thus likely to be directly regulated. NEUROG3 binds to 138 transcription factor genes, some with important roles in islet cell development or function, such as NEUROD1, PAX4, NKX2-2, SOX4, MLXIPL, LMX1B, RFX3, and NEUROG3 itself, and many others with unknown islet function. Unexpectedly, we uncovered that NEUROG3 targets genes critical for insulin secretion in beta cells (e.g., GCK, ABCC8/KCNJ11, CACNA1A, CHGA, SCG2, SLC30A8, and PCSK1). Thus, analysis of NEUROG3 occupancy suggests that the transient expression of NEUROG3 not only promotes islet destiny in uncommitted pancreatic progenitors, but could also initiate endocrine programs essential for beta cell function. Lastly, we identified eight T2DM risk SNPs within NEUROG3-bound regions. Conclusion Mapping NEUROG3 genome occupancy in PEPs uncovered unexpectedly broad, direct control of the endocrine genes, raising novel hypotheses on how this master regulator controls islet and beta cell differentiation. NEUROG3 CUT&RUN analysis revealed 1263 target genes in human pancreatic endocrine progenitors (PEPs). NEUROG3 binding sites overlap with active chromatin regions in PEPs. 1/5 of the genes downregulated in NEUROG3−/− hESC-derived PEPs are bound by NEUROG3. NEUROG3 targets islet-specific TFs and regulators of insulin secretion. Several T2DM risk alleles lie within NEUROG3-bound regions.
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3
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Rispal J, Escaffit F, Trouche D. Chromatin Dynamics in Intestinal Epithelial Homeostasis: A Paradigm of Cell Fate Determination versus Cell Plasticity. Stem Cell Rev Rep 2020; 16:1062-1080. [PMID: 33051755 PMCID: PMC7667136 DOI: 10.1007/s12015-020-10055-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/05/2020] [Indexed: 12/12/2022]
Abstract
The rapid renewal of intestinal epithelium is mediated by a pool of stem cells, located at the bottom of crypts, giving rise to highly proliferative progenitor cells, which in turn differentiate during their migration along the villus. The equilibrium between renewal and differentiation is critical for establishment and maintenance of tissue homeostasis, and is regulated by signaling pathways (Wnt, Notch, Bmp…) and specific transcription factors (TCF4, CDX2…). Such regulation controls intestinal cell identities by modulating the cellular transcriptome. Recently, chromatin modification and dynamics have been identified as major actors linking signaling pathways and transcriptional regulation in the control of intestinal homeostasis. In this review, we synthesize the many facets of chromatin dynamics involved in controlling intestinal cell fate, such as stemness maintenance, progenitor identity, lineage choice and commitment, and terminal differentiation. In addition, we present recent data underlying the fundamental role of chromatin dynamics in intestinal cell plasticity. Indeed, this plasticity, which includes dedifferentiation processes or the response to environmental cues (like microbiota’s presence or food ingestion), is central for the organ’s physiology. Finally, we discuss the role of chromatin dynamics in the appearance and treatment of diseases caused by deficiencies in the aforementioned mechanisms, such as gastrointestinal cancer, inflammatory bowel disease or irritable bowel syndrome. Graphical abstract ![]()
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Affiliation(s)
- Jérémie Rispal
- LBCMCP, Centre of Integrative Biology (CBI), Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
| | - Fabrice Escaffit
- LBCMCP, Centre of Integrative Biology (CBI), Université de Toulouse, CNRS, UPS, Toulouse, 31062, France.
| | - Didier Trouche
- LBCMCP, Centre of Integrative Biology (CBI), Université de Toulouse, CNRS, UPS, Toulouse, 31062, France
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4
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Lee TY, Cho IS, Bashyal N, Naya FJ, Tsai MJ, Yoon JS, Choi JM, Park CH, Kim SS, Suh-Kim H. ERK Regulates NeuroD1-mediated Neurite Outgrowth via Proteasomal Degradation. Exp Neurobiol 2020; 29:189-206. [PMID: 32606250 PMCID: PMC7344372 DOI: 10.5607/en20021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/16/2020] [Accepted: 06/16/2020] [Indexed: 12/22/2022] Open
Abstract
Neurogenic differentiation 1 (NeuroD1) is a class B basic helix-loop-helix (bHLH) transcription factor and regulates differentiation and survival of neuronal and endocrine cells by means of several protein kinases, including extracellular signal-regulated kinase (ERK). However, the effect of phosphorylation on the functions of NeuroD1 by ERK has sparked controversy based on context-dependent differences across diverse species and cell types. Here, we evidenced that ERK-dependent phosphorylation controlled the stability of NeuroD1 and consequently, regulated proneural activity in neuronal cells. A null mutation at the ERK-dependent phosphorylation site, S274A, increased the half-life of NeuroD1 by blocking its ubiquitin-dependent proteasomal degradation. The S274A mutation did not interfere with either the nuclear translocation of NeuroD1 or its heterodimerization with E47, its ubiquitous partner and class A bHLH transcription factor. However, the S274A mutant increased transactivation of the E-box-mediated gene and neurite outgrowth in F11 neuroblastoma cells, compared to the wild-type NeuroD1. Transcriptome and Gene Ontology enrichment analyses indicated that genes involved in axonogenesis and dendrite development were downregulated in NeuroD1 knockout (KO) mice. Overexpression of the S274A mutant salvaged neurite outgrowth in NeuroD1-deficient mice, whereas neurite outgrowth was minimal with S274D, a phosphomimicking mutant. Our data indicated that a longer protein half-life enhanced the overall activity of NeuroD1 in stimulating downstream genes and neuronal differentiation. We propose that blocking ubiquitin-dependent proteasomal degradation may serve as a strategy to promote neuronal activity by stimulating the expression of neuron-specific genes in differentiating neurons.
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Affiliation(s)
- Tae-Young Lee
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, Graduate School, Ajou University School of Medicine, Suwon 16499, Korea.,Research Center, CelleBrain Ltd., Jeonju 54871, Korea
| | - In-Su Cho
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea
| | - Narayan Bashyal
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, Graduate School, Ajou University School of Medicine, Suwon 16499, Korea
| | - Francisco J Naya
- Department of Biology, Life Science and Engineering Building, Boston University, Boston, MA 00215, USA
| | - Ming-Jer Tsai
- Department of Medicine and Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Jeong Seon Yoon
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea
| | - Jung-Mi Choi
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea
| | - Chang-Hwan Park
- Graduate School of Biomedical Science and Engineering, Hanyang University, Seoul 04763, Korea
| | - Sung-Soo Kim
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, Graduate School, Ajou University School of Medicine, Suwon 16499, Korea
| | - Haeyoung Suh-Kim
- Department of Anatomy, Ajou University School of Medicine, Suwon 16499, Korea.,Department of Biomedical Sciences, Graduate School, Ajou University School of Medicine, Suwon 16499, Korea.,Research Center, CelleBrain Ltd., Jeonju 54871, Korea
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5
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Lipinski M, Muñoz-Viana R, Del Blanco B, Marquez-Galera A, Medrano-Relinque J, Caramés JM, Szczepankiewicz AA, Fernandez-Albert J, Navarrón CM, Olivares R, Wilczyński GM, Canals S, Lopez-Atalaya JP, Barco A. KAT3-dependent acetylation of cell type-specific genes maintains neuronal identity in the adult mouse brain. Nat Commun 2020; 11:2588. [PMID: 32444594 PMCID: PMC7244750 DOI: 10.1038/s41467-020-16246-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2019] [Accepted: 04/22/2020] [Indexed: 02/06/2023] Open
Abstract
The lysine acetyltransferases type 3 (KAT3) family members CBP and p300 are important transcriptional co-activators, but their specific functions in adult post-mitotic neurons remain unclear. Here, we show that the combined elimination of both proteins in forebrain excitatory neurons of adult mice resulted in a rapidly progressing neurological phenotype associated with severe ataxia, dendritic retraction and reduced electrical activity. At the molecular level, we observed the downregulation of neuronal genes, as well as decreased H3K27 acetylation and pro-neural transcription factor binding at the promoters and enhancers of canonical neuronal genes. The combined deletion of CBP and p300 in hippocampal neurons resulted in the rapid loss of neuronal molecular identity without de- or transdifferentiation. Restoring CBP expression or lysine acetylation rescued neuronal-specific transcription in cultured neurons. Together, these experiments show that KAT3 proteins maintain the excitatory neuron identity through the regulation of histone acetylation at cell type-specific promoter and enhancer regions. Neuronal identity maintenance is highly regulated. Here, the authors showed that CBP and p300 safeguard neuronal identity through histone acetylation at promoters and enhancers of neuronal specific genes. The loss of both CBP and p300 impairs gene expression, circuit activity, and behavior in mice.
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Affiliation(s)
- Michal Lipinski
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Rafael Muñoz-Viana
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Beatriz Del Blanco
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Angel Marquez-Galera
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Juan Medrano-Relinque
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - José M Caramés
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Andrzej A Szczepankiewicz
- Nencki Institute of Experimental Biology, Polish Academy of Science, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Jordi Fernandez-Albert
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Carmen M Navarrón
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Roman Olivares
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Grzegorz M Wilczyński
- Nencki Institute of Experimental Biology, Polish Academy of Science, 3 Pasteur Street, 02-093, Warsaw, Poland
| | - Santiago Canals
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Jose P Lopez-Atalaya
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain
| | - Angel Barco
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Avenida Santiago Ramón y Cajal, s/n, Sant Joan d'Alacant, 03550, Alicante, Spain.
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6
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Kersigo J, Gu L, Xu L, Pan N, Vijayakuma S, Jones T, Shibata SB, Fritzsch B, Hansen MR. Effects of Neurod1 Expression on Mouse and Human Schwannoma Cells. Laryngoscope 2020; 131:E259-E270. [PMID: 32438526 DOI: 10.1002/lary.28671] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 03/11/2020] [Accepted: 03/18/2020] [Indexed: 12/22/2022]
Abstract
OBJECTIVES The objective was to explore the effect of the proneuronal transcription factor neurogenic differentiation 1 (Neurod1, ND1) on Schwann cells (SC) and schwannoma cell proliferation. METHODS Using a variety of transgenic mouse lines, we investigated how expression of Neurod1 effects medulloblastoma (MB) growth, schwannoma tumor progression, vestibular function, and SC cell proliferation. Primary human vestibular schwannoma (VS) cell cultures were transduced with adenoviral vectors expressing Neurod1. Cell proliferation was assessed by 5-ethynyl-2'-deoxyuridine (EdU) uptake. STUDY DESIGN Basic science investigation. RESULTS Expression of Neurod1 reduced the growth of slow-growing but not fast-growing MB models. Gene transfer of Neurod1 in human schwannoma cultures significantly reduced cell proliferation in dose-dependent way. Deletion of the neurofibromatosis type 2 (Nf2) tumor-suppressor gene via Cre expression in SCs led to increased intraganglionic SC proliferation and mildly reduced vestibular sensory-evoked potentials (VsEP) responses compared to age-matched wild-type littermates. The effect of Neurod1-induced expression on intraganglionic SC proliferation in animals lacking Nf2 was mild and highly variable. Sciatic nerve axotomy significantly increased SC proliferation in wild-type and Nf2-null animals, and expression of Neurod1 reduced the proliferative capacity of both wild-type and Nf2-null SCs following nerve injury. CONCLUSION Expression of Neurod1 reduces slow-growing MB progression and reduces human SC proliferation in primary VS cultures. In a genetic mouse model of schwannomas, we find some effects of Neurod1 expression; however, the high variability indicates that more tightly regulated Neurod1 expression levels that mimic our in vitro data are needed to fully validate Neurod1 effects on schwannoma progression. LEVEL OF EVIDENCE NA Laryngoscope, 131:E259-E270, 2021.
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Affiliation(s)
- Jennifer Kersigo
- Department of Biology, University of Lowa, Lowa City, Lowa, U.S.A
| | - Lintao Gu
- Department of Otolaryngology, University of Lowa, Lowa City, Lowa, U.S.A.,Decibel Pharmaceutical, Boston, Massachusetts, U.S.A
| | - Linjing Xu
- Department of Otolaryngology, University of Lowa, Lowa City, Lowa, U.S.A
| | - Ning Pan
- Department of Biology, University of Lowa, Lowa City, Lowa, U.S.A.,Department of Special Education & Communication Disorders, University of Nebraska, Lincoln, Nebraska, U.S.A
| | - Sarath Vijayakuma
- Department of Otolaryngology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China
| | - Timothy Jones
- Department of Otolaryngology, The First Affiliated Hospital of Shandong First Medical University, Jinan, Shandong, China
| | - Seiji B Shibata
- Department of Otolaryngology, University of Lowa, Lowa City, Lowa, U.S.A
| | - Bernd Fritzsch
- Department of Biology, University of Lowa, Lowa City, Lowa, U.S.A.,Department of Otolaryngology, University of Lowa, Lowa City, Lowa, U.S.A
| | - Marlan R Hansen
- Department of Otolaryngology, University of Lowa, Lowa City, Lowa, U.S.A
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7
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Tsakmaki A, Fonseca Pedro P, Pavlidis P, Hayee B, Bewick GA. ISX-9 manipulates endocrine progenitor fate revealing conserved intestinal lineages in mouse and human organoids. Mol Metab 2020; 34:157-173. [PMID: 32180555 PMCID: PMC7036449 DOI: 10.1016/j.molmet.2020.01.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 01/08/2020] [Accepted: 01/21/2020] [Indexed: 01/17/2023] Open
Abstract
Objective Enteroendocrine cells (EECs) survey the gut luminal environment and coordinate hormonal, immune and neuronal responses to it. They exhibit well-characterised physiological roles ranging from the control of local gut function to whole body metabolism, but little is known regarding the regulatory networks controlling their differentiation, especially in the human gut. The small molecule isoxazole-9 (ISX-9) has been shown to stimulate neuronal and pancreatic beta-cell differentiation, both closely related to EEC differentiation. Our aim was to use ISX-9 as a tool to explore EEC differentiation. Methods We investigated the effects of ISX-9 on EEC differentiation in mouse and human intestinal organoids, using real-time quantitative polymerase chain reaction (RT-qPCR), fluorescent-activated cell sorting, immunostaining and single-cell RNA sequencing. Results ISX-9 increased the number of neurogenin3-RFP (Ngn3)-positive endocrine progenitor cells and upregulated NeuroD1 and Pax4, transcription factors that play roles in mouse EEC specification. Single-cell analysis showed induction of Pax4 expression in a developmentally late Ngn3+ population of cells and potentiation of genes associated with progenitors biased toward serotonin-producing enterochromaffin (EC) cells. Further, we observed enrichment of organoids with functional EC cells that was partly dependent on stimulation of calcium signalling in a population of cells residing outside the crypt base. Inducible Pax4 overexpression, in ileal organoids, uncovered its importance as a component of early human endocrine specification and highlighted the potential existence of two major endocrine lineages, the early appearing enterochromaffin lineage and the later developing peptidergic lineage which contains classical gut hormone cell types. Conclusion Our data provide proof-of-concept for the controlled manipulation of specific endocrine lineages with small molecules, whilst also shedding new light on human EEC differentiation and its similarity to the mouse. Given their diverse roles, understanding endocrine lineage plasticity and its control could have multiple therapeutic implications. ISX-9 promotes flux through the Ngn3 lineage and enriches it with enterochromaffin cells. ISX-9 engages an enterochromaffin biased transcriptional programme in endocrine fated cells. Enterochromaffin bias is partly dependent on calcium signalling in progenitor cells. ISX-9 reveals conserved gut endocrine specification between mouse and human. Pax4 overexpression in human ileum organoids mimics the effects of ISX-9 on EC bias.
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Affiliation(s)
- Anastasia Tsakmaki
- Diabetes Research Group, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Patricia Fonseca Pedro
- Diabetes Research Group, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Polychronis Pavlidis
- Centre for Inflammation Biology and Cancer Immunology, King's College London, London, UK
| | - Bu'Hussain Hayee
- Department of Gastroenterology, King's College Hospital NHS Foundation Trust, London, UK
| | - Gavin A Bewick
- Diabetes Research Group, School of Life Course Sciences, Faculty of Life Science and Medicine, King's College London, London, UK.
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8
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Li HJ, Ray SK, Pan N, Haigh J, Fritzsch B, Leiter AB. Intestinal Neurod1 expression impairs paneth cell differentiation and promotes enteroendocrine lineage specification. Sci Rep 2019; 9:19489. [PMID: 31862906 PMCID: PMC6925293 DOI: 10.1038/s41598-019-55292-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Accepted: 11/25/2019] [Indexed: 12/12/2022] Open
Abstract
Transcription factor Neurod1 is required for enteroendocrine progenitor differentiation and maturation. Several earlier studies indicated that ectopic expression of Neurod1 converted non- neuronal cells into neurons. However, the functional consequence of ectopic Neurod1 expression has not been examined in the GI tract, and it is not known whether Neurod1 can similarly switch cell fates in the intestine. We generated a mouse line that would enable us to conditionally express Neurod1 in intestinal epithelial cells at different stages of differentiation. Forced expression of Neurod1 throughout intestinal epithelium increased the number of EECs as well as the expression of EE specific transcription factors and hormones. Furthermore, we observed a substantial reduction of Paneth cell marker expression, although the expressions of enterocyte-, tuft- and goblet-cell specific markers are largely not affected. Our earlier study indicated that Neurog3+ progenitor cells give rise to not only EECs but also Goblet and Paneth cells. Here we show that the conditional expression of Neurod1 restricts Neurog3+ progenitors to adopt Paneth cell fate, and promotes more pronounced EE cell differentiation, while such effects are not seen in more differentiated Neurod1+ cells. Together, our data suggest that forced expression of Neurod1 programs intestinal epithelial cells more towards an EE cell fate at the expense of the Paneth cell lineage and the effect ceases as cells mature to EE cells.
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Affiliation(s)
- Hui Joyce Li
- Division of Gastroenterology, Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA
| | - Subir K Ray
- Division of Gastroenterology, Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA
| | - Ning Pan
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
- Decibel Pharmaceutical, Boston, MA, USA
| | - Jody Haigh
- Department of Biomedical, Molecular Biology, Ghent University, Ghent, Belgium
| | - Bernd Fritzsch
- Department of Biology, University of Iowa, Iowa City, IA, 52242, USA
| | - Andrew B Leiter
- Division of Gastroenterology, Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA, 01605, USA.
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9
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Jin W, Mulas F, Gaertner B, Sui Y, Wang J, Matta I, Zeng C, Vinckier N, Wang A, Nguyen-Ngoc KV, Chiou J, Kaestner KH, Frazer KA, Carrano AC, Shih HP, Sander M. A Network of microRNAs Acts to Promote Cell Cycle Exit and Differentiation of Human Pancreatic Endocrine Cells. iScience 2019; 21:681-694. [PMID: 31733514 PMCID: PMC6889369 DOI: 10.1016/j.isci.2019.10.063] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 09/30/2019] [Accepted: 10/28/2019] [Indexed: 12/12/2022] Open
Abstract
Pancreatic endocrine cell differentiation is orchestrated by the action of transcription factors that operate in a gene regulatory network to activate endocrine lineage genes and repress lineage-inappropriate genes. MicroRNAs (miRNAs) are important modulators of gene expression, yet their role in endocrine cell differentiation has not been systematically explored. Here we characterize miRNA-regulatory networks active in human endocrine cell differentiation by combining small RNA sequencing, miRNA over-expression, and network modeling approaches. Our analysis identified Let-7g, Let-7a, miR-200a, miR-127, and miR-375 as endocrine-enriched miRNAs that drive endocrine cell differentiation-associated gene expression changes. These miRNAs are predicted to target different transcription factors, which converge on genes involved in cell cycle regulation. When expressed in human embryonic stem cell-derived pancreatic progenitors, these miRNAs induce cell cycle exit and promote endocrine cell differentiation. Our study delineates the role of miRNAs in human endocrine cell differentiation and identifies miRNAs that could facilitate endocrine cell reprogramming.
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Affiliation(s)
- Wen Jin
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Francesca Mulas
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Bjoern Gaertner
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yinghui Sui
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Jinzhao Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Ileana Matta
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Chun Zeng
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Nicholas Vinckier
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Allen Wang
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Kim-Vy Nguyen-Ngoc
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Joshua Chiou
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Kelly A Frazer
- Department of Pediatrics, Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Andrea C Carrano
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA
| | - Hung-Ping Shih
- Department of Translational Research and Cellular Therapeutics, Diabetes and Metabolic Research Institute, Beckman Research Institute, City of Hope, Duarte, CA 91010, USA
| | - Maike Sander
- Departments of Pediatrics and Cellular & Molecular Medicine, Pediatric Diabetes Research Center, University of California, San Diego, La Jolla, CA 92093, USA.
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10
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Manu KA, Cao PHA, Chai TF, Casey PJ, Wang M. p21cip1/waf1 Coordinate Autophagy, Proliferation and Apoptosis in Response to Metabolic Stress. Cancers (Basel) 2019; 11:cancers11081112. [PMID: 31382612 PMCID: PMC6721591 DOI: 10.3390/cancers11081112] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2019] [Revised: 07/25/2019] [Accepted: 07/30/2019] [Indexed: 12/12/2022] Open
Abstract
Cancer cells possess metabolic properties that are different from benign cells. These unique characteristics have become attractive targets that are being actively investigated for cancer therapy. p21cip1/waf1, also known as Cyclin-Dependent Kinase inhibitor 1A, is encoded by the CDKN1A gene. It is a major p53 target gene involved in cell cycle progression that has been extensively evaluated. To date, p21 has been reported to regulate various cell functions, both dependent and independent of p53. Besides regulating the cell cycle, p21 also modulates apoptosis, induces senescence, and maintains cellular quiescence in response to various stimuli. p21 transcription is induced in response to stresses, including those from oxidative and chemotherapeutic treatment. A recent study has shown that in response to metabolic stresses such as nutrient and energy depletion, p21 expression is induced to regulate various cell functions. Despite the biological significance, the mechanism of p21 regulation in cancer adaptation to metabolic stress is underexplored and thus represents an exciting field. This review focuses on the recent development of p21 regulation in response to metabolic stress and its impact in inducing cell cycle arrest and death in cancer cells.
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Affiliation(s)
- Kanjoormana Aryan Manu
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Pham Hong Anh Cao
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Tin Fan Chai
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
| | - Patrick J Casey
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore
- Department of Pharmacology and Cancer Biology, Duke University School of Medicine, Durham, NC 27710, USA
| | - Mei Wang
- Program in Cancer and Stem Cell Biology, Duke-NUS Graduate Medical School, Singapore 169857, Singapore.
- Department of Biochemistry, National University of Singapore, Singapore 117596, Singapore.
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11
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Solorzano-Vargas RS, Bjerknes M, Wu SV, Wang J, Stelzner M, Dunn JCY, Dhawan S, Cheng H, Georgia S, Martín MG. The cellular regulators PTEN and BMI1 help mediate NEUROGENIN-3-induced cell cycle arrest. J Biol Chem 2019; 294:15182-15192. [PMID: 31341016 DOI: 10.1074/jbc.ra119.008926] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2019] [Revised: 06/25/2019] [Indexed: 11/06/2022] Open
Abstract
Neurogenin-3 (NEUROG3) is a helix-loop-helix (HLH) transcription factor involved in the production of endocrine cells in the intestine and pancreas of humans and mice. However, the human NEUROG3 loss-of-function phenotype differs subtly from that in mice, but the reason for this difference remains poorly understood. Because NEUROG3 expression precedes exit of the cell cycle and the expression of endocrine cell markers during differentiation, we investigated the effect of lentivirus-mediated overexpression of the human NEUROG3 gene on the cell cycle of BON4 cells and various human nonendocrine cell lines. NEUROG3 overexpression induced a reversible cell cycle exit, whereas expression of a neuronal lineage homolog, NEUROG1, had no such effect. In endocrine lineage cells, the cellular quiescence induced by short-term NEUROG3 expression required cyclin-dependent kinase inhibitor 1A (CDKN1A)/p21CIP1 expression. Expression of endocrine differentiation markers required sustained NEUROG3 expression in the quiescent, but not in the senescent, state. Inhibition of the phosphatase and tensin homolog (PTEN) pathway reversed quiescence by inducing cyclin-dependent kinase 2 (CDK2) and reducing p21CIP1 and NEUROG3 protein levels in BON4 cells and human enteroids. We discovered that NEUROG3 expression stimulates expression of CDKN2a/p16INK4a and BMI1 proto-oncogene polycomb ring finger (BMI1), with the latter limiting expression of the former, delaying the onset of CDKN2a/p16INK4a -driven cellular senescence. Furthermore, NEUROG3 bound to the promoters of both CDKN1a/p21CIP1 and BMI1 genes, and BMI1 attenuated NEUROG3 binding to the CDKN1a/p21CIP1 promoter. Our findings reveal how human NEUROG3 integrates inputs from multiple signaling pathways and thereby mediates cell cycle exit at the onset of differentiation.
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Affiliation(s)
- R Sergio Solorzano-Vargas
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel Children's Hospital and the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Matthew Bjerknes
- Department of Medicine, Medical Sciences Building, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - S Vincent Wu
- Veterans Affairs Greater Los Angeles Healthcare System, and Department of Medicine, University of California, Los Angeles, Los Angeles, California 90073
| | - Jiafang Wang
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel Children's Hospital and the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
| | - Matthias Stelzner
- Division of General Surgery, Department of Surgery, University of California, Los Angeles, Los Angeles, California 90095
| | - James C Y Dunn
- Division of Pediatric Surgery, Department of Surgery, Stanford University School of Medicine, Stanford, California 94305
| | - Sangeeta Dhawan
- Department of Translational Research and Cellular Therapeutics, City of Hope, Duarte, California 91010
| | - Hazel Cheng
- Department of Medicine, Medical Sciences Building, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Senta Georgia
- Department of Pediatrics, Division of Endocrinology, Children's Hospital of Los Angeles, University of Southern California, Los Angeles, Los Angeles, California 90027
| | - Martín G Martín
- Department of Pediatrics, Division of Gastroenterology and Nutrition, Mattel Children's Hospital and the David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California 90095
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12
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Analysis of pituitary adenoma expression patterns suggests a potential role for the NeuroD1 transcription factor in neuroendocrine tumor-targeting therapies. Oncotarget 2019; 10:289-312. [PMID: 30719226 PMCID: PMC6349459 DOI: 10.18632/oncotarget.26513] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2018] [Accepted: 12/10/2018] [Indexed: 11/25/2022] Open
Abstract
NeuroD1’s roles in the pathogenesis of pituitary adenomas and in the biology of the normal adult pituitary gland have been insufficiently researched. Much of the work investigating its expression patterns has yielded contradictory results. Objective: morphological study of NeuroD1 transcription factor expression in different types of pituitary adenomas and in normal adult human pituitary glands. Materials and methods: This study analyzed 48 pituitary adenomas and nine normal pituitary glands. In all cases, immunohistochemical study was performed with antibodies to NeuroD1, 6 hormones of adenohypophysis, Ki-67, and CK7. We used confocal laser scanning microscopy, electron microscopy and electron immunocytochemistry. Results: NeuroD1 expression was detected in all cases of plurihormonal adenomas, mammosomatotropinomas, corticotropinomas, prolactinomas, gonadotropinomas, null-cell pituitary adenomas, and in normal pituitary glands. The average numbers of NeuroD1 expressing cells in normal adenohypophysis specimens were significantly lower than in the adenomas overall (p=0.006). NeuroD1 expression was confirmed by several methods (in prolactinomas, by double stain immunohistochemistry; in mammosomatotropinomas, by double stain immunohistochemistry, confocal laser scanning microscopy, and electron immunocytochemistry; and in somatotropinomas, by electron immunocytochemistry). Conclusion: Immunohistochemistry, confocal microscopy, and double label electron immunocytochemistry confirmed NeuroD1’s key role in the pathogenesis of pituitary tumors, regardless of their hormonal state. Its expression level in pituitary adenomas is significantly higher than in the normal pituitary gland and has no reliable correlation with any studied hormones or Ki-67. These findings suggest that NeuroD1 should be investigated further as a potential molecular target in tumor-targeting therapies.
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13
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Buchanan KL, Bohórquez DV. You Are What You (First) Eat. Front Hum Neurosci 2018; 12:323. [PMID: 30150928 PMCID: PMC6099179 DOI: 10.3389/fnhum.2018.00323] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2018] [Accepted: 07/25/2018] [Indexed: 01/15/2023] Open
Abstract
As far back as we can remember, we eat. In fact, we eat before we can remember. Our first meal is amniotic fluid. We swallow it during the first trimester of gestation, and with that, we expose our gut to a universe of molecules. These early molecules have a profound influence on gut and brain function. For example, the taste of the amniotic fluid changes based on the mother's diet. Indeed, recent findings suggest that food preferences begin in utero. Likewise, a baby's first exposure to bacteria, previously thought to be during birth, appears to be in utero as well. And just as postnatal food and microbiota are implicated in brain function and dysfunction, prenatal nutrients and microbes may have a long-lasting impact on the development of the gut-brain neural circuits processing food, especially considering their plasticity during this vulnerable period. Here, we use current literature to put forward concepts needed to understand how the gut first meets the brain, and how this encounter may help us remember food.
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Affiliation(s)
| | - Diego V. Bohórquez
- Department of Medicine, Duke University, Durham, NC, United States
- Department of Neurobiology, Duke University, Durham, NC, United States
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14
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Ferguson SW, Wang J, Lee CJ, Liu M, Neelamegham S, Canty JM, Nguyen J. The microRNA regulatory landscape of MSC-derived exosomes: a systems view. Sci Rep 2018; 8:1419. [PMID: 29362496 PMCID: PMC5780426 DOI: 10.1038/s41598-018-19581-x] [Citation(s) in RCA: 230] [Impact Index Per Article: 38.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2017] [Accepted: 01/04/2018] [Indexed: 02/08/2023] Open
Abstract
Mesenchymal stem cell (MSC)-derived exosomes mediate tissue regeneration in a variety of diseases including ischemic heart injury, liver fibrosis, and cerebrovascular disease. Despite an increasing number of studies reporting the therapeutic effects of MSC exosomes, the underlying molecular mechanisms and their miRNA complement are poorly characterized. Here we microRNA (miRNA)-profiled MSC exosomes and conducted a network analysis to identify the dominant biological processes and pathways modulated by exosomal miRNAs. At a system level, miRNA-targeted genes were enriched for (cardio)vascular and angiogenesis processes in line with observed cardiovascular regenerative effects. Targeted pathways were related to Wnt signaling, pro-fibrotic signaling via TGF-β and PDGF, proliferation, and apoptosis. When tested, MSC exosomes reduced collagen production by cardiac fibroblasts, protected cardiomyocytes from apoptosis, and increased angiogenesis in HUVECs. The intrinsic beneficial effects were further improved by virus-free enrichment of MSC exosomes with network-informed regenerative miRNAs capable of promoting angiogenesis and cardiomyocyte proliferation. The data presented here help define the miRNA landscape of MSC exosomes, establish their biological functions through network analyses at a system level, and provide a platform for modulating the overall phenotypic effects of exosomes.
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Affiliation(s)
- Scott W Ferguson
- Department of Pharmaceutical Sciences, School of Pharmacy, University at Buffalo, The State University of New York, Buffalo, NY, 14214, USA
| | - Jinli Wang
- Department of Pharmaceutical Sciences, School of Pharmacy, University at Buffalo, The State University of New York, Buffalo, NY, 14214, USA
| | - Christine J Lee
- Department of Pharmaceutical Sciences, School of Pharmacy, University at Buffalo, The State University of New York, Buffalo, NY, 14214, USA
| | - Maixian Liu
- Department of Pharmaceutical Sciences, School of Pharmacy, University at Buffalo, The State University of New York, Buffalo, NY, 14214, USA
| | - Sriram Neelamegham
- Department of Chemical and Biological Engineering, Department of Biomedical Engineering, Clinical and Translational Research Center of the University at Buffalo, The State University of New York, Buffalo, NY, 14260, USA
| | - John M Canty
- Department of Medicine, Department of Physiology and Biophysics, Department of Biomedical Engineering, The Clinical and Translational Research Center of the University at Buffalo, Buffalo, New York and the VA Western New York Healthcare System, Buffalo, NY, 14214, USA
| | - Juliane Nguyen
- Department of Pharmaceutical Sciences, School of Pharmacy, University at Buffalo, The State University of New York, Buffalo, NY, 14214, USA.
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15
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Parvin R, Saito-Hakoda A, Shimada H, Shimizu K, Noro E, Iwasaki Y, Fujiwara K, Yokoyama A, Sugawara A. Role of NeuroD1 on the negative regulation of Pomc expression by glucocorticoid. PLoS One 2017; 12:e0175435. [PMID: 28406939 PMCID: PMC5391015 DOI: 10.1371/journal.pone.0175435] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2016] [Accepted: 03/24/2017] [Indexed: 01/20/2023] Open
Abstract
The mechanism of the negative regulation of proopiomelanocortin gene (Pomc) by glucocorticoids (Gcs) is still unclear in many points. Here, we demonstrated the involvement of neurogenic differentiation factor 1 (NeuroD1) in the Gc-mediated negative regulation of Pomc. Murine pituitary adrenocorticotropic hormone (ACTH) producing corticotroph tumor-derived AtT20 cells were treated with dexamethasone (DEX) (1-100 nM) and cultured for 24 hrs. Thereafter, Pomc mRNA expression was studied by quantitative real-time PCR and rat Pomc promoter (-703/+58) activity was examined by luciferase assay. Both Pomc mRNA expression and Pomc promoter activity were inhibited by DEX in a dose-dependent manner. Deletion and point mutant analyses of Pomc promoter suggested that the DEX-mediated transcriptional repression was mediated via E-box that exists at -376/-371 in the promoter. Since NeuroD1 is known to bind to and activate E-box of the Pomc promoter, we next examined the effect of DEX on NeuroD1 expression. Interestingly, DEX dose-dependently inhibited NeuroD1 mRNA expression, mouse NeuroD1 promoter (-2.2-kb) activity, and NeuroD1 protein expression in AtT20 cells. In addition, we confirmed the inhibitory effect of DEX on the interaction of NeuroD1 and E-box on Pomc promoter by chromatin immunoprecipitation (ChIP) assay. Finally, overexpression of mouse NeuroD1 could rescue the DEX-mediated inhibition of Pomc mRNA expression and Pomc promoter activity. Taken together, it is suggested that the suppression of NeuroD1 expression and the inhibition of NeuroD1/E-box interaction may play an important role in the Gc-mediated negative regulation of Pomc.
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Affiliation(s)
- Rehana Parvin
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Akiko Saito-Hakoda
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Hiroki Shimada
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Kyoko Shimizu
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Erika Noro
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | | | - Ken Fujiwara
- Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan
| | - Atsushi Yokoyama
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
| | - Akira Sugawara
- Department of Molecular Endocrinology, Tohoku University Graduate School of Medicine, Sendai, Miyagi, Japan
- * E-mail:
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16
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Ratanasirintrawoot S, Israsena N. Stem Cells in the Intestine: Possible Roles in Pathogenesis of Irritable Bowel Syndrome. J Neurogastroenterol Motil 2016; 22:367-82. [PMID: 27184041 PMCID: PMC4930294 DOI: 10.5056/jnm16023] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/04/2016] [Accepted: 03/08/2016] [Indexed: 12/13/2022] Open
Abstract
Irritable bowel syndrome is one of the most common functional gastrointestinal (GI) disorders that significantly impair quality of life in patients. Current available treatments are still not effective and the pathophysiology of this condition remains unclearly defined. Recently, research on intestinal stem cells has greatly advanced our understanding of various GI disorders. Alterations in conserved stem cell regulatory pathways such as Notch, Wnt, and bone morphogenic protein/TGF-β have been well documented in diseases such as inflammatory bowel diseases and cancer. Interaction between intestinal stem cells and various signals from their environment is important for the control of stem cell self-renewal, regulation of number and function of specific intestinal cell types, and maintenance of the mucosal barrier. Besides their roles in stem cell regulation, these signals are also known to have potent effects on immune cells, enteric nervous system and secretory cells in the gut, and may be responsible for various aspects of pathogenesis of functional GI disorders, including visceral hypersensitivity, altered gut motility and low grade gut inflammation. In this article, we briefly summarize the components of these signaling pathways, how they can be modified by extrinsic factors and novel treatments, and provide evidenced support of their roles in the inflammation processes. Furthermore, we propose how changes in these signals may contribute to the symptom development and pathogenesis of irritable bowel syndrome.
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Affiliation(s)
- Sutheera Ratanasirintrawoot
- Stem Cell and Cell Therapy Research Unit, Chulalongkorn University, Bangkok, Thailand.,Department of Research Affairs, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
| | - Nipan Israsena
- Stem Cell and Cell Therapy Research Unit, Chulalongkorn University, Bangkok, Thailand.,Department of Pharmacology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand
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17
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Lorenzi F, Babaei-Jadidi R, Sheard J, Spencer-Dene B, Nateri AS. Fbxw7-associated drug resistance is reversed by induction of terminal differentiation in murine intestinal organoid culture. MOLECULAR THERAPY-METHODS & CLINICAL DEVELOPMENT 2016; 3:16024. [PMID: 27110583 PMCID: PMC4830362 DOI: 10.1038/mtm.2016.24] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/12/2015] [Revised: 01/29/2016] [Accepted: 02/19/2016] [Indexed: 12/12/2022]
Abstract
Colorectal cancer (CRC) is one of the top three cancer-related causes of death worldwide. FBXW7 is a known tumor-suppressor gene, commonly mutated in CRC and in a variety of other epithelial tumors. Low expression of FBXW7 is also associated with poor prognosis. Loss of FBXW7 sensitizes cancer cells to certain drugs, while making them more resistant to other types of chemotherapies. However, is not fully understood how epithelial cells within normal gut and primary tumors respond to potential cancer therapeutics. We have studied genetically engineered mice in which the fbxw7 gene is conditionally knocked-out in the intestine (fbxw7∆G). To further investigate the mechanism of Fbxw7-action, we grew intestinal crypts from floxed-fbxw7 (fbxw7fl/fl) and fbxw7ΔG mice, in a Matrigel-based organoid (mini-gut) culture. The fbxw7ΔG organoids exhibited rapid budding events in the crypt region. Furthermore, to test organoids for drug response, we exposed day 3 intestinal organoids from fbxw7fl/fl and fbxw7∆G mice, to various concentrations of 5-fluorouracil (5-FU) for 72 hours. 5-FU triggers phenotypic differences in organoids including changing shape, survival, resistance, and death. 5-FU however, rescues the drug-resistance phenotype of fbxw7ΔG through the induction of terminal differentiation. Our results support the hypothesis that a differentiating therapy successfully targets FBXW7-mutated CRC cells.
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Affiliation(s)
- Federica Lorenzi
- Cancer Genetics and Stem Cell Group, Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham , Nottingham, UK
| | - Roya Babaei-Jadidi
- Cancer Genetics and Stem Cell Group, Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham , Nottingham, UK
| | - Jonathan Sheard
- CM Technologies Oy I, Institute for Biomedical Technology, University of Tampere , Tampere, Finland
| | - Bradley Spencer-Dene
- Experimental Pathology Laboratory, Cancer Research UK London Research Institute, The Francis Crick Institute, Lincoln's Inn Fields Laboratory , London, UK
| | - Abdolrahman S Nateri
- Cancer Genetics and Stem Cell Group, Cancer Biology Unit, Division of Cancer and Stem Cells, School of Medicine, University of Nottingham , Nottingham, UK
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18
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Aprea J, Nonaka-Kinoshita M, Calegari F. Generation and characterization of Neurod1-CreER(T2) mouse lines for the study of embryonic and adult neurogenesis. Genesis 2014; 52:870-8. [PMID: 24913893 DOI: 10.1002/dvg.22797] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Revised: 04/18/2014] [Accepted: 06/02/2014] [Indexed: 12/13/2022]
Abstract
Neurod1 is a transcription factor involved in several developmental programs of the gastrointestinal tract, pancreas, neurosensory, and central nervous system. In the brain, Neurod1 has been shown to be essential for neurogenesis as well as migration, maturation, and survival of newborn neurons during development and adulthood. Interestingly, Neurod1 expression is maintained in a subset of fully mature neurons where its function remains unclear. To study the role of Neurod1, systems are required that allow the temporal and spatial genetic manipulation of Neurod1-expressing cells. To this aim, we have generated four Neurod1-CreER(T2) mouse lines in which CreER(T2) expression, although at different levels, is restricted within areas of physiological Neurod1 expression and Neurod1 positive cells. In particular, the different levels of CreER(T2) expression in different mouse lines offers the opportunity to select the one that is more suited for a given experimental approach. Hence, our Neurod1-CreER(T2) lines provide valuable new tools for the manipulation of newborn neurons during development and adulthood as well as for studying the subpopulation of mature neurons that retain Neurod1 expression throughout life. In this context, we here report that Neurod1 is not only expressed in immature newborn neurons of the adult hippocampus, as already described, but also in fully mature granule cells of the dentate gyrus.
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Affiliation(s)
- Julieta Aprea
- DFG-Research Center and Cluster of Excellence for Regenerative Therapies, Dresden, Germany
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19
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CtBP and associated LSD1 are required for transcriptional activation by NeuroD1 in gastrointestinal endocrine cells. Mol Cell Biol 2014; 34:2308-17. [PMID: 24732800 DOI: 10.1128/mcb.01600-13] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
Gene expression programs required for differentiation depend on both DNA-bound transcription factors and surrounding histone modifications. Expression of the basic helix-loop-helix (bHLH) protein NeuroD1 is restricted to endocrine cells in the gastrointestinal (GI) tract, where it is important for endocrine differentiation. RREB1 (RAS-responsive element binding protein 1), identified as a component of the CtBP corepressor complex, binds to nearby DNA elements to associate with NeuroD and potentiate transcription of a NeuroD1 target gene. Transcriptional activation by RREB1 depends on recruitment of CtBP with its associated proteins, including LSD1, through its PXDLS motifs. The mechanism of transcriptional activation by CtBP has not been previously characterized. Here we found that activation was dependent on the histone H3 lysine 9 (H3K9) demethylase activity of LSD1, which removes repressive methyl marks from dimethylated H3K9 (H3K9Me2), to facilitate subsequent H3K9 acetylation by the NeuroD1-associated histone acetyltransferase, P300/CBP-associated factor (PCAF). The secretin, β-glucokinase, insulin I, and insulin II genes, four known direct targets of NeuroD1 in intestinal and pancreatic endocrine cells, all show similar promoter occupancy by CtBP-associated proteins and PCAF, with acetylation of H3K9. This work may indicate a mechanism for selective regulation of transcription by CtBP and LSD1 involving their association with specific transcription factors and cofactors to drive tissue-specific transcription.
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20
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Nakajima T, Aratani S, Nakazawa M, Hirose T, Fujita H, Nishioka K. Implications of transcriptional coactivator CREB binding protein complexes in rheumatoid arthritis. Mod Rheumatol 2014. [DOI: 10.3109/s10165-003-0258-1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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21
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ZeRuth GT, Takeda Y, Jetten AM. The Krüppel-like protein Gli-similar 3 (Glis3) functions as a key regulator of insulin transcription. Mol Endocrinol 2013; 27:1692-705. [PMID: 23927931 DOI: 10.1210/me.2013-1117] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Transcriptional regulation of insulin in pancreatic β-cells is mediated primarily through enhancer elements located within the 5' upstream regulatory region of the preproinsulin gene. Recently, the Krüppel-like transcription factor, Gli-similar 3 (Glis3), was shown to bind the insulin (INS) promoter and positively influence insulin transcription. In this report, we examined in detail the synergistic activation of insulin transcription by Glis3 with coregulators, CREB-binding protein (CBP)/p300, pancreatic and duodenal homeobox 1 (Pdx1), neuronal differentiation 1 (NeuroD1), and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A (MafA). Our data show that Glis3 expression, the binding of Glis3 to GlisBS, and its recruitment of CBP are required for optimal activation of the insulin promoter in pancreatic β-cells not only by Glis3, but also by Pdx1, MafA, and NeuroD1. Mutations in the GlisBS or small interfering RNA-directed knockdown of GLIS3 diminished insulin promoter activation by Pdx1, NeuroD1, and MafA, and neither Pdx1 nor MafA was able to stably associate with the insulin promoter when the GlisBS were mutated. In addition, a GlisBS mutation in the INS promoter implicated in the development of neonatal diabetes similarly abated activation by Pdx1, NeuroD1, and MafA that could be reversed by increased expression of exogenous Glis3. We therefore propose that recruitment of CBP/p300 by Glis3 provides a scaffold for the formation of a larger transcriptional regulatory complex that stabilizes the binding of Pdx1, NeuroD1, and MafA complexes to their respective binding sites within the insulin promoter. Taken together, these results indicate that Glis3 plays a pivotal role in the transcriptional regulation of insulin and may serve as an important therapeutic target for the treatment of diabetes.
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Affiliation(s)
- Gary T ZeRuth
- Division of Intramural Research, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709.
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22
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Flasse LC, Stern DG, Pirson JL, Manfroid I, Peers B, Voz ML. The bHLH transcription factor Ascl1a is essential for the specification of the intestinal secretory cells and mediates Notch signaling in the zebrafish intestine. Dev Biol 2013; 376:187-97. [PMID: 23352790 DOI: 10.1016/j.ydbio.2013.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 01/09/2013] [Accepted: 01/11/2013] [Indexed: 11/24/2022]
Abstract
Notch signaling has a fundamental role in stem cell maintenance and in cell fate choice in the intestine of different species. Canonically, Notch signaling represses the expression of transcription factors of the achaete-scute like (ASCL) or atonal related protein (ARP) families. Identifying the ARP/ASCL genes expressed in the gastrointestinal tract is essential to build the regulatory cascade controlling the differentiation of gastrointestinal progenitors into the different intestinal cell types. The expression of the ARP/ASCL factors was analyzed in zebrafish to identify, among all the ARP/ASCL factors found in the zebrafish genome, those expressed in the gastrointestinal tract. ascl1a was found to be the earliest factor detected in the intestine. Loss-of-function analyses using the pia/ascl1a mutant, revealed that ascl1a is crucial for the differentiation of all secretory cells. Furthermore, we identify a battery of transcription factors expressed during secretory cell differentiation and downstream of ascl1a. Finally, we show that the repression of secretory cell fate by Notch signaling is mediated by the inhibition of ascl1a expression. In conclusion, this work identifies Ascl1a as a key regulator of the secretory cell lineage in the zebrafish intestine, playing the same role as Atoh1 in the mouse intestine. This highlights the diversity in the ARP/ASCL family members acting as cell fate determinants downstream from Notch signaling.
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Affiliation(s)
- Lydie C Flasse
- Unit of Molecular Biology and Genetic Engineering, Giga-Research, University of Liège, 1 avenue de l'Hôpital B34, B-4000 Sart-Tilman (Liège), Belgium
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Notch signaling differentially regulates the cell fate of early endocrine precursor cells and their maturing descendants in the mouse pancreas and intestine. Dev Biol 2012; 371:156-69. [PMID: 22964416 DOI: 10.1016/j.ydbio.2012.08.023] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2012] [Revised: 06/27/2012] [Accepted: 08/15/2012] [Indexed: 11/20/2022]
Abstract
Notch signaling inhibits differentiation of endocrine cells in the pancreas and intestine. In a number of cases, the observed inhibition occurred with Notch activation in multipotential cells, prior to the initiation of endocrine differentiation. It has not been established how direct activation of Notch in endocrine precursor cells affects their subsequent cell fate. Using conditional activation of Notch in cells expressing Neurogenin3 or NeuroD1, we examined the effects of Notch in both organs, on cell fate of early endocrine precursors and maturing endocrine-restricted cells, respectively. Notch did not preclude the differentiation of a limited number of endocrine cells in either organ when activated in Ngn3(+) precursor cells. In addition, in the pancreas most Ngn3(+) cells adopted a duct but not acinar cell fate; whereas in intestinal Ngn3(+) cells, Notch favored enterocyte and goblet cell fates, while selecting against endocrine and Paneth cell differentiation. A small fraction of NeuroD1(+) cells in the pancreas retain plasticity to respond to Notch, giving rise to intraislet ductules as well as cells with no detectable pancreatic lineage markers that appear to have limited ultrastructural features of both endocrine and duct cells. These results suggest that Notch directly regulates cell fate decisions in multipotential early endocrine precursor cells. Some maturing endocrine-restricted NeuroD1(+) cells in the pancreas switch to the duct lineage in response to Notch, indicating previously unappreciated plasticity at such a late stage of endocrine differentiation.
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Ninov N, Borius M, Stainier DYR. Different levels of Notch signaling regulate quiescence, renewal and differentiation in pancreatic endocrine progenitors. Development 2012; 139:1557-67. [PMID: 22492351 DOI: 10.1242/dev.076000] [Citation(s) in RCA: 163] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Genetic studies have implicated Notch signaling in the maintenance of pancreatic progenitors. However, how Notch signaling regulates the quiescent, proliferative or differentiation behaviors of pancreatic progenitors at the single-cell level remains unclear. Here, using single-cell genetic analyses and a new transgenic system that allows dynamic assessment of Notch signaling, we address how discrete levels of Notch signaling regulate the behavior of endocrine progenitors in the zebrafish intrapancreatic duct. We find that these progenitors experience different levels of Notch signaling, which in turn regulate distinct cellular outcomes. High levels of Notch signaling induce quiescence, whereas lower levels promote progenitor amplification. The sustained downregulation of Notch signaling triggers a multistep process that includes cell cycle entry and progenitor amplification prior to endocrine differentiation. Importantly, progenitor amplification and differentiation can be uncoupled by modulating the duration and/or extent of Notch signaling downregulation, indicating that these processes are triggered by distinct levels of Notch signaling. These data show that different levels of Notch signaling drive distinct behaviors in a progenitor population.
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Affiliation(s)
- Nikolay Ninov
- Department of Biochemistry and Biophysics, Programs in Developmental and Stem Cell Biology, Genetics and Human Genetics, Diabetes Center, and Liver Center, University of California, San Francisco, San Francisco, CA 94158, USA.
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25
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Li HJ, Ray SK, Singh NK, Johnston B, Leiter AB. Basic helix-loop-helix transcription factors and enteroendocrine cell differentiation. Diabetes Obes Metab 2011; 13 Suppl 1:5-12. [PMID: 21824251 PMCID: PMC3467197 DOI: 10.1111/j.1463-1326.2011.01438.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
For over 30 years it has been known that enteroendocrine cells derive from common precursor cells in the intestinal crypts. Until recently little was understood about the events that result in commitment to endocrine differentiation or the eventual segregation of over 10 different hormone-expressing cell types in the gastrointestinal tract. Enteroendocrine cells arise from pluripotent intestinal stem cells. Differentiation of enteroendocrine cells is controlled by the sequential expression of three basic helix-loop-helix transcription factors, Math1, Neurogenin 3 (Neurog3) and NeuroD. Math1 expression is required for specification and segregation of the intestinal secretory lineage (Paneth, goblet,and enteroendocrine cells) from the absorptive enterocyte lineage. Neurog3 expression represents the earliest stage of enteroendocrine differentiation and in its absence enteroendocrine cells fail to develop. Subsequent expression of NeuroD appears to represent a later stage of differentiation for maturing enteroendocrine cells. Enteroendocrine cell fate is inhibited by the Notch signalling pathway, which appears to inhibit both Math1 and Neurog3. Understanding enteroendocrine cell differentiation will become increasingly important for identifying potential future targets for common diseases such as diabetes and obesity.
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Affiliation(s)
| | | | | | | | - Andrew B. Leiter
- Corresponding author: Andrew B. Leiter M.D., Ph.D., Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street LRB217, Worcester, MA 01605, Telephone: (508) 856-8101, Fax: (508) 856-4770,
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26
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Yuan Y, Lee LTO, Ng SS, Chow BKC. Extragastrointestinal functions and transcriptional regulation of secretin and secretin receptors. Ann N Y Acad Sci 2011; 1220:23-33. [DOI: 10.1111/j.1749-6632.2011.05987.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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27
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Stein R. Insulin Gene Transcription: Factors Involved in Cell Type–Specific and Glucose‐Regulated Expression in Islet β Cells are Also Essential During Pancreatic Development. Compr Physiol 2011. [DOI: 10.1002/cphy.cp070202] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
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Zhang H, Wang WP, Guo T, Yang JC, Chen P, Ma KT, Guan YF, Zhou CY. The LIM-homeodomain protein ISL1 activates insulin gene promoter directly through synergy with BETA2. J Mol Biol 2009; 392:566-77. [PMID: 19619559 DOI: 10.1016/j.jmb.2009.07.036] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 06/05/2009] [Accepted: 07/11/2009] [Indexed: 10/20/2022]
Abstract
The LIM-homeodomain transcription factor ISL1 (islet factor 1) is essential for pancreatic islet cell and dorsal mesenchyme development. Mutations in ISL1 are associated with maturity-onset diabetes of the young and type 2 diabetes. Whether ISL1 plays a role in the insulin gene expression has not been fully elucidated. In the present study, we show that ISL1 can synergistically activate insulin gene transcription with BETA2 in pancreatic beta cells. The protein-protein interactions of ISL1 and BETA2 are directly mediated by the LIM domains of ISL1 and the basic helix-loop-helix domain of BETA2. Deletion of the two LIM domains of ISL1 enhances the transcriptional activation of the insulin gene, indicating a key role for the homeodomain in activating the insulin promoter. Furthermore, ISL1 can bind with the A3/4 box in the rat insulin gene capital I, Ukrainian promoter through its homeodomain. ISL1 expression is up-regulated at the mRNA level in type 2 diabetes (db/db mouse model) but down-regulated by dexamethasone in rat insulinoma cells. These results suggest that ISL1 is a transcriptional activator for insulin gene expression, and the interactions of ISL1 with BETA2 are required for the transcriptional activity of the insulin gene. Reduction in Isl1 gene expression appears to be involved in the impairment of insulin expression mediated by dexamethasone.
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Affiliation(s)
- Hui Zhang
- Department of Biochemistry and Molecular Biology, Peking University, Beijing, China
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30
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Kaneto H, Matsuoka TA, Kawashima S, Yamamoto K, Kato K, Miyatsuka T, Katakami N, Matsuhisa M. Role of MafA in pancreatic beta-cells. Adv Drug Deliv Rev 2009; 61:489-96. [PMID: 19393272 DOI: 10.1016/j.addr.2008.12.015] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2008] [Accepted: 12/15/2008] [Indexed: 01/01/2023]
Abstract
Pancreatic beta-cell-specific insulin gene expression is regulated by a variety of pancreatic transcription factors and the conserved A3, C1 and E1 elements in the insulin gene enhancer region are very important for activation of insulin gene. Indeed, PDX-1 binding to the A3 element and NeuroD binding to the E1 element are crucial for insulin gene transcription. Recently, C1 element-binding transcription factor was identified as MafA, which is a basic-leucine zipper transcription factor and functions as a potent transactivator for the insulin gene. Under diabetic conditions, chronic hyperglycemia gradually deteriorates pancreatic beta-cell function, which is accompanied by decreased expression and/or DNA binding activities of MafA and PDX-1. Furthermore, MafA overexpression, together with PDX-1 and NeuroD, markedly induces insulin biosynthesis in various non-beta-cells and thereby is a useful tool to efficiently induce insulin-producing surrogate beta-cells. These results suggest that MafA plays a crucial role in pancreatic beta-cells and could be a novel therapeutic target for diabetes.
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31
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Cho JH, Kwon IS, Kim S, Ghil SH, Tsai MJ, Kim YS, Lee YD, Suh-Kim H. Overexpression of BETA2/NeuroD induces neurite outgrowth in F11 neuroblastoma cells. J Neurochem 2008. [DOI: 10.1046/j.1471-4159.2001.00230.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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32
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Lee LTO, Lam IPY, Chow BKC. A functional variable number of tandem repeats is located at the 5' flanking region of the human secretin gene plays a downregulatory role in expression. J Mol Neurosci 2008; 36:125-31. [PMID: 18566919 DOI: 10.1007/s12031-008-9083-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2008] [Accepted: 03/28/2008] [Indexed: 11/26/2022]
Abstract
Secretin is a peptide hormone playing multiple functions in the brain-gut axis. In this report, we investigated, by promoter analysis, the potential function of the variable of tandem repeats (VNTR), located at the 5' upstream region of the human secretin gene, and we demonstrated for the first time that this VNTR could downregulate transcription of the human secretin gene in a promoter-specific manner. The efficiency of VNTR in silencing the promoter was found to be directly related the number of repetitive units residing within. We also showed the deoxyribonucleic acid sequence as well as the length polymorphism of the VNTR of 76 Chinese individuals. These results collectively suggest that VNTR could potentially be a functional regulator to control the expression of the human secretin gene in different individuals.
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Affiliation(s)
- Leo T O Lee
- School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China
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33
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Lam IPY, Siu FKY, Chu JYS, Chow BKC. Multiple actions of secretin in the human body. INTERNATIONAL REVIEW OF CYTOLOGY 2008; 265:159-90. [PMID: 18275888 DOI: 10.1016/s0074-7696(07)65004-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The discovery of secretin initiated the field of endocrinology. Over the past century, multiple gastrointestinal functions of secretin have been extensively studied, and it was discovered that the principal function of this peptide in the gastrointestinal system is to facilitate digestion and to provide protection. In view of the late identification of secretin and the secretin receptor in various tissues, including the central nervous system, the pleiotropic functions of secretin have more recently been an area of intense focus. Secretin is a classical hormone, and recent studies clearly showed secretin's involvement in neural and neuroendocrine pathways, although the neuroactivity and neural regulation of its release are yet to be elucidated. This chapter reviews our current understanding of the pleiotropic actions of secretin with a special focus on the hormonal and neural interdependent pathways that mediate these actions.
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Affiliation(s)
- Ian P Y Lam
- Department of Zoology, University of Hong Kong, Hong Kong, China
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Eun B, Lee Y, Hong S, Kim J, Lee HW, Kim K, Sun W, Kim H. Hes6 controls cell proliferation via interaction with cAMP-response element-binding protein-binding protein in the promyelocytic leukemia nuclear body. J Biol Chem 2007; 283:5939-49. [PMID: 18160400 DOI: 10.1074/jbc.m707683200] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Hes6 is a basic helix-loop-helix transcription factor that functions in the differentiation of pluripotent progenitor cells and during tumorigenesis. However, the molecular mechanism for its function is largely unknown. Here we show that Hes6 is a component of the promyelocytic leukemia nuclear body (PML-NB) complex in the nuclei and that Hes6 inhibits cell proliferation through induction of p21 cyclin-dependent kinase inhibitor. We further show that Hes6 directly interacts with CREB-binding protein (CBP), one of the key components of PML-NB, via its basic domain. This association is critical for p21 induction through multiple mechanisms, including chromatin remodeling and p53 acetylation. Taken together, these results suggest that the Hes6-CBP complex in PML-NB may influence the proliferation of cells via p53-dependent and -independent pathways.
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Affiliation(s)
- Bokkee Eun
- College of Medicine, Brain Korea 21, Korea University, Seoul 136-705, Korea
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35
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Ray SK, Leiter AB. The basic helix-loop-helix transcription factor NeuroD1 facilitates interaction of Sp1 with the secretin gene enhancer. Mol Cell Biol 2007; 27:7839-47. [PMID: 17875929 PMCID: PMC2169158 DOI: 10.1128/mcb.00438-07] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The basic helix-loop-helix transcription factor NeuroD1 is required for late events in neuronal differentiation, for maturation of pancreatic beta cells, and for terminal differentiation of enteroendocrine cells expressing the hormone secretin. NeuroD1-null mice demonstrated that this protein is essential for expression of the secretin gene in the murine intestine, and yet it is a relatively weak transcriptional activator by itself. The present study shows that Sp1 and NeuroD1 synergistically activate transcription of the secretin gene. NeuroD1, but not its widely expressed dimerization partner E12, physically interacts with the C-terminal 167 amino acids of Sp1, which include its DNA binding zinc fingers. NeuroD1 stabilizes Sp1 DNA binding to an adjacent Sp1 binding site on the promoter to generate a higher-order DNA-protein complex containing both proteins and facilitates Sp1 occupancy of the secretin promoter in vivo. NeuroD-dependent transcription of the genes encoding the hormones insulin and proopiomelanocortin is potentiated by lineage-specific homeodomain proteins. The stabilization of binding of the widely expressed transcription factor Sp1 to the secretin promoter by NeuroD represents a distinct mechanism from other NeuroD target genes for increasing NeuroD-dependent transcription.
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Affiliation(s)
- Subir K Ray
- Department of Medicine, Division of Gastroenterology, University of Massachusetts Medical School, Worcester, Massachusetts 01605, USA
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36
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Wang Y, Ray SK, Hinds PW, Leiter AB. The retinoblastoma protein, RB, is required for gastrointestinal endocrine cells to exit the cell cycle, but not for hormone expression. Dev Biol 2007; 311:478-86. [PMID: 17936268 DOI: 10.1016/j.ydbio.2007.08.052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 07/26/2007] [Accepted: 08/28/2007] [Indexed: 11/26/2022]
Abstract
Important functions of the RB family proteins include inhibition of cell cycle progression and regulation of terminal differentiation. We have examined the role of RB and the related protein, p107, in regulating cell cycle activity and differentiation of gastrointestinal endocrine cells, a relatively quiescent cell population, by conditionally disrupting the RB gene in neurogenin3 (Ngn3)-expressing cells in both p107(+/+) and p107(-/-) mice. Endocrine cells in the small intestine, colon, pancreas, and stomach were present in normal numbers in RB and RB-p107 mutants except for an increase in serotonin cells and decrease in ghrelin cells in the antral stomach. Deletion of RB resulted in a dramatic increase in proliferating serotonin cells in the antral stomach and intestine, whereas other enteroendocrine cell types exhibited much lower cell cycle activity or remained quiescent. The related p107 protein appears dispensable for enteroendocrine differentiation and does not functionally compensate for the loss of RB. Our results suggest that RB is required for enteroendocrine cells, particularly serotonin cells, to undergo cell cycle arrest as they terminally differentiate. RB has relatively subtle effects on enteroendocrine cell differentiation and is not required for the expression of the normal repertoire of hormones in the gastrointestinal tract.
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Affiliation(s)
- Yang Wang
- Division of Gastroenterology, GRASP Digestive Disease Center, Tufts-New England Medical Center, Boston, MA 02111, USA
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37
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López-Díaz L, Jain RN, Keeley TM, VanDussen KL, Brunkan CS, Gumucio DL, Samuelson LC. Intestinal Neurogenin 3 directs differentiation of a bipotential secretory progenitor to endocrine cell rather than goblet cell fate. Dev Biol 2007; 309:298-305. [PMID: 17706959 PMCID: PMC2679162 DOI: 10.1016/j.ydbio.2007.07.015] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 07/12/2007] [Accepted: 07/16/2007] [Indexed: 01/24/2023]
Abstract
Neurogenin 3 is essential for enteroendocrine cell development; however, it is unknown whether this transcription factor is sufficient to induce an endocrine program in the intestine or how it affects the development of other epithelial cells originating from common progenitors. In this study, the mouse villin promoter was used to drive Neurogenin 3 expression throughout the developing epithelium to measure the affect on cell fate. Although the general morphology of the intestine was unchanged, transgenic founder embryos displayed increased numbers of cells expressing the pan-endocrine marker chromogranin A. Accordingly, expression of several hormones and pro-endocrine transcription factors was increased in the transgenics suggesting that Neurogenin 3 stimulated a program of terminal enteroendocrine cell development. To test whether increased endocrine cell differentiation affected the development of other secretory cell lineages, we quantified goblet cells, the only other secretory cell formed in embryonic intestine. The Neurogenin 3-expressing transgenics had decreased numbers of goblet cells in correspondence to the increase in endocrine cells, with no change in the total secretory cell numbers. Thus, our data suggest that Neurogenin 3 can redirect the differentiation of bipotential secretory progenitors to endocrine rather than goblet cell fate.
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Affiliation(s)
- Lymari López-Díaz
- Cellular and Molecular Biology Graduate Program, The University of Michigan, Ann Arbor, MI 48109-0622
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Renu N. Jain
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Theresa M. Keeley
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Kelli L. VanDussen
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Cynthia S. Brunkan
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Deborah L. Gumucio
- Cellular and Molecular Biology Graduate Program, The University of Michigan, Ann Arbor, MI 48109-0622
- Department of Cell and Developmental Biology, The University of Michigan, Ann Arbor, MI 48109-0622
| | - Linda C. Samuelson
- Cellular and Molecular Biology Graduate Program, The University of Michigan, Ann Arbor, MI 48109-0622
- Department of Molecular and Integrative Physiology, The University of Michigan, Ann Arbor, MI 48109-0622
- Corresponding author: Linda Samuelson, Department of Molecular and Integrative Physiology, The University of Michigan, 2041 BSRB, 109 Zina Pitcher Pl, Ann Arbor, MI 48109-2200, Phone: (734) 764-9448, Fax: (734) 763-1166,
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Wang Y, Giel-Moloney M, Rindi G, Leiter AB. Enteroendocrine precursors differentiate independently of Wnt and form serotonin expressing adenomas in response to active beta-catenin. Proc Natl Acad Sci U S A 2007; 104:11328-33. [PMID: 17592150 PMCID: PMC2040898 DOI: 10.1073/pnas.0702665104] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Wnt signaling is required for the maintenance of intestinal stem cells and self-renewal of the intestinal epithelium. Intestinal cancers are frequently associated with mutations that activate the Wnt pathway. The role of Wnt signaling on differentiation of lineage-specific precursors in the intestine is not well characterized. Here, we show that specification of enteroendocrine but not Paneth cells occurs independently of Wnt signals by conditional deletion of beta-catenin in immature cells expressing the transcription factor, neurogenin 3. In addition, we determined whether neurogenin 3-expressing cells respond to abnormal Wnt signaling. Activation of the Wnt pathway by conditionally deleting exon 3 of the beta-catenin gene at an early stage of enteroendocrine cell differentiation induced small-intestinal adenomas expressing serotonin, a feature not previously described in other tumors induced by Wnt in mice. In contrast, excision of exon 3 of beta-catenin at a later stage of enteroendocrine differentiation did not produce tumors. These results provide direct evidence that some intestinal lineages are specified independently of the Wnt pathway and may lead to a better understanding of the spectrum of neuroendocrine differentiation frequently seen in human gastrointestinal cancer.
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Affiliation(s)
- Yang Wang
- *Division of Gastroenterology, GRASP Digestive Disease Center, Tufts–New England Medical Center, Boston, MA 02111; and
| | - Maryann Giel-Moloney
- *Division of Gastroenterology, GRASP Digestive Disease Center, Tufts–New England Medical Center, Boston, MA 02111; and
| | - Guido Rindi
- Dipartimento di Patologia e Medicina di Laboratorio, Sezione di Anatomia Patologica, Università degli Studi, Via Gramsci 14, I-43100 Parma, Italy
| | - Andrew B. Leiter
- *Division of Gastroenterology, GRASP Digestive Disease Center, Tufts–New England Medical Center, Boston, MA 02111; and
- To whom correspondence should be sent at the present address:
Division of Gastroenterology, Department of Medicine, University of Massachusetts Medical School, Worcester, MA 01605. E-mail:
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Gierl MS, Karoulias N, Wende H, Strehle M, Birchmeier C. The zinc-finger factor Insm1 (IA-1) is essential for the development of pancreatic beta cells and intestinal endocrine cells. Genes Dev 2006; 20:2465-78. [PMID: 16951258 PMCID: PMC1560419 DOI: 10.1101/gad.381806] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
The pancreatic and intestinal primordia contain epithelial progenitor cells that generate many cell types. During development, specific programs of gene expression restrict the developmental potential of such progenitors and promote their differentiation. The Insm1 (insulinoma-associated 1, IA-1) gene encodes a Zinc-finger factor that was discovered in an insulinoma cDNA library. We show that pancreatic and intestinal endocrine cells express Insm1 and require Insm1 for their development. In the pancreas of Insm1 mutant mice, endocrine precursors are formed, but only few insulin-positive beta cells are generated. Instead, endocrine precursor cells accumulate that express none of the pancreatic hormones. A similar change is observed in the development of intestine, where endocrine precursor cells are formed but do not differentiate correctly. A hallmark of endocrine cell differentiation is the accumulation of proteins that participate in secretion and vesicle transport, and we find many of the corresponding genes to be down-regulated in Insm1 mutant mice. Insm1 thus controls a gene expression program that comprises hormones and proteins of the secretory machinery. Our genetic analysis has revealed a key role of Insm1 in differentiation of pancreatic and intestinal endocrine cells.
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Affiliation(s)
- Mathias S Gierl
- Max-Delbrück-Center for Molecular Medicine, Berlin 13125, Germany
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40
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Abstract
During development, several populations of progenitor cells in the dorsal telencephalon generate a large variety of neurons which acquire distinct morphologies and physiological properties and serve distinct functions in the mammalian cortex. This paper reviews recent work that has identified (i) key molecules involved in the specification and differentiation of cortical neurons, (ii) novel genes which distinguish distinct subsets of cortical progenitors and may be involved in the diversification of cortical neurons present in different cortical layers, and (iii) mechanisms involved in the generation of different projection neuronal subtypes in the well-studied model of layer 5 of the rodent cortex.
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Affiliation(s)
- Francois Guillemot
- Division of Molecular Neurobiology, National Institute for Medical Research, The Ridgeway, Mill Hill, NW7 1AA London, UK
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41
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Paquin A, Barnabé-Heider F, Kageyama R, Miller FD. CCAAT/enhancer-binding protein phosphorylation biases cortical precursors to generate neurons rather than astrocytes in vivo. J Neurosci 2006; 25:10747-58. [PMID: 16291948 PMCID: PMC6725854 DOI: 10.1523/jneurosci.2662-05.2005] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
The intracellular mechanisms that bias mammalian neural precursors to generate neurons versus glial cells are not well understood. We demonstrated previously that the growth factor-regulated mitogen-activated protein kinase kinase (MEK) and its downstream target, the CCAAT/enhancer-binding protein (C/EBP) family of transcription factors, are essential for neurogenesis in cultured cortical precursor cells (Ménard et al., 2002). Here, we examined a role for this pathway during cortical cell fate determination in vivo using in utero electroporation of the embryonic cortex. These studies demonstrate that inhibition of the activity of either MEK or the C/EBPs inhibits the genesis of neurons in vivo. Moreover, the MEK pathway mediates phosphorylation of C/EBPbeta in cortical precursors, and expression of a C/EBPbeta construct in which the MEK pathway phosphorylation sites are mutated inhibits neurogenesis. Conversely, expression of a C/EBPbeta construct, in which the same sites are mutated to glutamate and therefore are "constitutively" phosphorylated, enhances neurogenesis in the early embryonic cortex. A subpopulation of precursors in which C/EBP activity is inhibited are maintained as cycling precursors in the ventricular/subventricular zone of the cortex until early in postnatal life, when they have an enhanced propensity to generate astrocytes, presumably in response to gliogenic signals in the neonatal environment. Thus, activation of an MEK-C/EBP pathway in cortical precursors in vivo biases them to become neurons and against becoming astrocytes, thereby acting as a growth factor-regulated switch.
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Affiliation(s)
- Annie Paquin
- Developmental Biology, Hospital for Sick Children, 555 University Avenue, Toronto, Ontario, Canada
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42
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Oliveira CSV, Hauache OM, Vieira JGH, Maciel RMB, Sjöroos M, Canani LH, Velho G, Gross JL, Reis AF. The Ala45Thr polymorphism of NEUROD1 is associated with type 1 diabetes in Brazilian women. DIABETES & METABOLISM 2005; 31:599-602. [PMID: 16357810 DOI: 10.1016/s1262-3636(07)70237-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
BACKGROUND NEUROD1 encodes a transcription factor expressed in the endocrine pancreas, and involved in beta-cell development, function and mechanisms of apoptosis. In this study, we investigated the association of a frequent polymorphism in exon 2 of NEUROD1 (G > A; Ala45Thr) with Type 1 diabetes in Brazilian subjects. METHODS A population/association study comprising 246 unrelated Type 1 diabetic and 275 nondiabetic white Brazilian subjects. The Ala45Thr variant was genotyped by a PCR-RFLP method. RESULTS The frequency of the Thr allele was significantly higher in patients with Type 1 diabetes than in controls (42.3% vs 35.3%, P=0.02). Stratification by gender showed that homozygosity for the Thr allele was associated with Type 1 diabetes in women with odds ratio of 3.66 (95% C.I. 1.43-10.11, P=0.009) as compared to homozygosity for the Ala allele. This effect was not observed in men. CONCLUSIONS We found a gender-specific association of the Ala45Thr variant of NEUROD1 with Type 1 diabetes in Brazilian women. Our results suggest that gender as well as ethnicity might modulate the association of NEUROD1 with Type 1 diabetes.
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Affiliation(s)
- C S V Oliveira
- Laboratory of Molecular Endocrinology, Federal University of São Paulo, 01333-011 São Paulo-SP, Brazil
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43
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Hauck AL, Swanson KS, Kenis PJA, Leckband DE, Gaskins HR, Schook LB. Twists and turns in the development and maintenance of the mammalian small intestine epithelium. ACTA ACUST UNITED AC 2005; 75:58-71. [PMID: 15838920 DOI: 10.1002/bdrc.20032] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Experimental studies during the last decade have revealed a number of signaling pathways that are critical for the development and maintenance of the intestinal epithelium and that demonstrate the molecular basis for a variety of diseases. The Notch-Delta, Wnt, Hedge Hog, TGF-beta, and other signaling pathways have been shown to form and steadily maintain the crypt-villus system, generating the proper quantities of highly-specialized cells, and ultimately defining the architectural shape of the system. Based on the characterized phenotypes and functional defects of mice resulting from various targeted knockouts, and overexpression and misexpressions of genes, a picture is emerging of the sequence of gene expression events from within the epithelium, and in the underlying mesenchyme that contribute to the regulation of cell differentiation and proliferation. This review focuses on the contributions of multiple signaling pathways to intestinal epithelial proliferation, differentiation, and structural organization, as well as the possible opportunities for cross-talk between pathways. The Notch pathway's potential ability to maintain and regulate the intestinal epithelial stem cell is discussed, in addition to its role as the primary mediator of lineage specification. Recent research that has shed light on the function of Wnt signaling and epithelial-mesenchymal cross-talk during embryonic and postnatal development is examined, along with data on the interplay of heparan sulfate proteoglycans in the signaling process.
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Affiliation(s)
- Andrew L Hauck
- Department of Cell and Structural Biology, University of Illinois, Urbana, Illinois 61801, USA
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Liu KJ, Harland RM. Inhibition of neurogenesis by SRp38, a neuroD-regulated RNA-binding protein. Development 2005; 132:1511-23. [PMID: 15728676 DOI: 10.1242/dev.01703] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Although serine-arginine rich (SR) proteins have often been implicated in the positive regulation of splicing, recent studies have shown that one unusual SR protein, SRp38, serves, contrastingly, as a splicing repressor during mitosis and stress response. We have identified a novel developmental role for SRp38 in the regulation of neural differentiation. SRp38 is expressed in the neural plate during embryogenesis and is transcriptionally induced by the neurogenic bHLH protein neuroD. Overexpression of SRp38 inhibits primary neuronal differentiation at a step between neurogenin and neuroD activity. This repression of neuronal differentiation requires activation of the Notch pathway. Conversely, depletion of SRp38 activity results in a dysregulation of neurogenesis. Finally, SRp38 can interact with the peptidyltransferase center of 28S rRNA, suggesting that SRp38 activity may act, in part, via regulation of ribosome biogenesis or function. Strikingly, recent studies of several cell cycle regulators during primary neurogenesis have also revealed a crucial control step between neurogenin and neuroD. SRp38 may mediate one component of this control by maintaining splicing and translational silencing in undifferentiated neural cells.
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Affiliation(s)
- Karen J Liu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720, USA
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45
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Batsché E, Moschopoulos P, Desroches J, Bilodeau S, Drouin J. Retinoblastoma and the related pocket protein p107 act as coactivators of NeuroD1 to enhance gene transcription. J Biol Chem 2005; 280:16088-95. [PMID: 15701640 DOI: 10.1074/jbc.m413427200] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Gene inactivation studies have suggested that the product of the retinoblastoma gene, Rb, is particularly limiting in pituitary pro-opiomelanocortin (POMC)-expressing cell lineages. Indeed, in Rb knock-out mice, these cells develop tumors with high frequency. To understand the implication of limiting Rb expression in these cells, we investigated the action of Rb and its related pocket proteins, p107 and p130, on POMC gene transcription. This led to the identification of the neurogenic basic helix-loop-helix transcription factor, NeuroD1, as a target of Rb action. Rb and to a lesser extent p107, but not p130, enhance NeuroD1-dependent transcription, and this activity appears to depend on direct protein interactions between the Rb pocket and the helix-loop-helix domain of NeuroD1. In vivo, NeuroD is found in a complex that includes Rb and also the orphan nuclear receptor NGFI-B, which mediates corticotropin-releasing hormone activation of POMC transcription. The formation of a similar complex in vitro requires the presence of Rb as a bridge between NeuroD and NGFI-B. In POMC-expressing AtT-20 cells, Rb and p107 are present on the POMC promoter and inhibition of their expression through small interfering RNA decreases POMC mRNA levels. The action of Rb and its related proteins on POMC transcription may contribute to the establishment and/or maintenance of the differentiation phenotype.
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Affiliation(s)
- Eric Batsché
- Laboratoire de génétique moléculaire, Institut de recherches cliniques de Montréal (IRCM), Montréal, Québec H2W 1R7, Canada
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Lay JM, Bane G, Brunkan CS, Davis J, Lopez-Diaz L, Samuelson LC. Enteroendocrine cell expression of a cholecystokinin gene construct in transgenic mice and cultured cells. Am J Physiol Gastrointest Liver Physiol 2005; 288:G354-61. [PMID: 15486342 DOI: 10.1152/ajpgi.00356.2004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
CCK is predominantly expressed in subsets of endocrine cells in the intestine and neurons in the brain. We evaluated the expression of a CCK gene construct in transgenic mice and cultured cells to identify a genomic region that directs correct tissue- and cell-specific expression in enteroendocrine cells. The CCKL1 transgene contained 6.4 kb of mouse Cck fused to lacZ. Expression was evaluated in three transgenic lines (J11, J12, J14) by measurement of beta-galactosidase in tissue homogenates and frozen sections. Correct tissue-specific expression was observed, with beta-galactosidase activity detected in intestine and brain. However, there were differences seen in cell-specific expression in the intestine. Line J14 exhibited expression in CCK-endocrine cells, with expressing cells arising at the normal time during fetal development. However, transgene expression in line J12 intestine was limited to neurons of the enteric nervous system, which reflect an early fetal expression pattern for CCK. Analysis of an additional 15 transgenic founder mice demonstrated intestinal expression in 40% of transgenics, with expressing mice following either an endocrine cell pattern or a neuronal pattern in approximately equal numbers. CCKL1 transfection analysis in cultured cells also demonstrated enteroendocrine cell expression, with 100-fold enhanced activity in the enteroendocrine cell line STC-1 compared with nonendocrine cell lines. The results suggest that the minimal cis-regulatory DNA elements necessary for appropriate CCK expression in enteroendocrine cells reside within the 6.4-kb mouse genomic fragment.
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Affiliation(s)
- Jean M Lay
- Department of Molecular and Integrative Physiology, The University of Michigan, 7761 Med Sci II, Ann Arbor, MI 48109-0622, USA
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Kaneto H, Matsuoka TA, Nakatani Y, Miyatsuka T, Matsuhisa M, Hori M, Yamasaki Y. A crucial role of MafA as a novel therapeutic target for diabetes. J Biol Chem 2005; 280:15047-52. [PMID: 15664997 DOI: 10.1074/jbc.m412013200] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
MafA, a recently isolated pancreatic beta-cell-specific transcription factor, is a potent activator of insulin gene transcription. In this study, we show that MafA overexpression, together with PDX-1 (pancreatic and duodenal homeobox factor-1) and NeuroD, markedly increases insulin gene expression in the liver. Consequently, substantial amounts of insulin protein were induced by such combination. Furthermore, in streptozotocin-induced diabetic mice, MafA overexpression in the liver, together with PDX-1 and NeuroD, dramatically ameliorated glucose tolerance, while combination of PDX-1 and NeuroD was much less effective. These results suggest a crucial role of MafA as a novel therapeutic target for diabetes.
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Affiliation(s)
- Hideaki Kaneto
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871, Japan.
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Seo S, Richardson GA, Kroll KL. The SWI/SNF chromatin remodeling protein Brg1 is required for vertebrate neurogenesis and mediates transactivation of Ngn and NeuroD. Development 2004; 132:105-15. [PMID: 15576411 DOI: 10.1242/dev.01548] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Chromatin remodeling complexes play crucial roles in transcription and are implicated in processes including cell proliferation, differentiation and embryonic patterning. Brg1 is the catalytic subunit of the SWI/SNF chromatin remodeling complex and shows neural-enriched expression. Although early lethality of Brg1-null mice reflects its importance in embryogenesis, this phenotype precluded further study of specific Brg1-dependent developmental processes. Here, we have identified a requirement of Brg1 for both Xenopus primary neurogenesis and neuronal differentiation of mammalian P19 embryonic carcinoma cells. In Xenopus, loss of Brg1 function did not affect neural induction or neural cell fate determination. However, the Sox2-positive, proliferating neural progenitor cell population was expanded, and expression of a terminally differentiated neuronal marker, N-tubulin, was diminished upon loss of Brg1 activity, suggesting that Brg1 is required for neuronal differentiation. The ability of the bHLH transcription factors Ngnr1 and NeuroD to drive neuronal differentiation was also abolished by loss of Brg1 function, indicating that Brg1 is essential for the proneural activities of Ngnr1 and NeuroD. Consistent with this, dominant-negative interference with Brg1 function in P19 cells suppressed neuronal differentiation promoted by NeuroD2, showing the requirement of Brg1 for neuronal differentiation is conserved in mammalian cells. Finally, we discovered that Brg1 physically associates with both Ngnr1 and NeuroD and that interference with Brg1 function blocks Neurogenin3- and NeuroD2-mediated reporter gene transactivation. Together, our results demonstrate that Brg1 (and by inference the SWI/SNF complex) is required for neuronal differentiation by mediating the transcriptional activities of proneural bHLH proteins.
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MESH Headings
- Animals
- Basic Helix-Loop-Helix Transcription Factors
- Blotting, Western
- Brain/embryology
- Cell Cycle
- Cell Differentiation
- Cell Line, Tumor
- Cell Lineage
- Cell Proliferation
- Chromatin/metabolism
- Cloning, Molecular
- DNA Helicases
- DNA, Complementary/metabolism
- Drosophila Proteins/metabolism
- Drosophila Proteins/physiology
- Gene Expression Regulation, Developmental
- Histones/metabolism
- Immunohistochemistry
- Immunoprecipitation
- In Situ Nick-End Labeling
- Luciferases/metabolism
- Mice
- Microscopy, Fluorescence
- Models, Genetic
- Nerve Tissue Proteins/metabolism
- Neurons/metabolism
- Neuropeptides/metabolism
- Nuclear Proteins/metabolism
- Nuclear Proteins/physiology
- Oligonucleotides/chemistry
- Phenotype
- Phylogeny
- Plasmids/metabolism
- Protein Binding
- RNA/metabolism
- RNA-Binding Proteins/metabolism
- RNA-Binding Proteins/physiology
- Ribonucleoprotein, U1 Small Nuclear/metabolism
- Ribonucleoprotein, U1 Small Nuclear/physiology
- Time Factors
- Transcription Factors/metabolism
- Transcription Factors/physiology
- Transcription, Genetic
- Transcriptional Activation
- Tubulin/metabolism
- Xenopus
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Affiliation(s)
- Seongjin Seo
- Department of Molecular Biology and Pharmacology, Washington University School of Medicine, 660 South Euclid Avenue, St Louis, MO 63110, USA
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Lee CS, Kaestner KH. Clinical endocrinology and metabolism. Development of gut endocrine cells. Best Pract Res Clin Endocrinol Metab 2004; 18:453-62. [PMID: 15533769 DOI: 10.1016/j.beem.2004.08.008] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
During development, the definitive endoderm differentiates into several gastrointestinal epithelial lineages, including enteroendocrine cells. The enteroendocrine lineage consists of at least 15 different cell types that are categorized based on their morphology, location and peptide hormone expression. The mechanisms regulating enteroendocrine cell differentiation are likely to be critical not only in embryonic development, but also during the constant renewal of gut epithelia in the adult. The identification of transcription factors and regulatory DNA elements required for cell type-specific gene expression in various endocrine cell types has broadened our understanding of the regulatory networks controlling the spatial and temporal activation of enteroendocrine differentiation programs. This chapter will review recent studies of transcription factors during enteroendocrine cell differentiation, with a focus on the central role for the Notch signaling pathway in enteroendocrine cell fate decisions.
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Affiliation(s)
- Catherine S Lee
- Department of Genetics and Penn Diabetes Center, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
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50
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Cho JH, Tsai MJ. The role of BETA2/NeuroD1 in the development of the nervous system. Mol Neurobiol 2004; 30:35-47. [PMID: 15247487 DOI: 10.1385/mn:30:1:035] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2003] [Accepted: 12/19/2003] [Indexed: 11/11/2022]
Abstract
BETA2/NeuroD1 is a member of the basic helix-loop-helix (bHLH) transcription factor family, which has been shown to play a major role in development of the nervous system and formation of the endocrine system. Gain-of-function studies have indicated that BETA2/NeuroD1 is important for the neurogenesis of Xenopus embryos and several neurogenic cell lines. Disruption of the gene encoding BETA2/NeuroD1 leads to severe abnormalities of the developing mouse central nervous system as well as the peripheral nervous system. The focus of this article is on the recent progress in understanding the role of BETA2/NeuroD1 in the development of the nervous system.
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Affiliation(s)
- Jang-Hyeon Cho
- Department of Molecular and Cellular Biology, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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