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Bou-Rouphael J, Doulazmi M, Eschstruth A, Abdou A, Durand BC. Cerebellar granular neuron progenitors exit their germinative niche via BarH-like1 activity mediated partly by inhibition of T-cell factor. Development 2024; 151:dev202234. [PMID: 38860486 DOI: 10.1242/dev.202234] [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: 12/26/2023] [Accepted: 06/04/2024] [Indexed: 06/12/2024]
Abstract
Cerebellar granule neuron progenitors (GNPs) originate from the upper rhombic lip (URL), a germinative niche in which developmental defects produce human diseases. T-cell factor (TCF) responsiveness and Notch dependence are hallmarks of self-renewal in neural stem cells. TCF activity, together with transcripts encoding proneural gene repressors hairy and enhancer of split (Hes/Hey), are detected in the URL; however, their functions and regulatory modes are undeciphered. Here, we established amphibian as a pertinent model for studying vertebrate URL development. The amphibian long-lived URL is TCF active, whereas the external granular layer (EGL) is non-proliferative and expresses hes4 and hes5 genes. Using functional and transcriptomic approaches, we show that TCF activity is necessary for URL emergence and maintenance. We establish that the transcription factor Barhl1 controls GNP exit from the URL, acting partly through direct TCF inhibition. Identification of Barhl1 target genes suggests that, besides TCF, Barhl1 inhibits transcription of hes5 genes independently of Notch signaling. Observations in amniotes suggest a conserved role for Barhl in maintenance of the URL and/or EGL via co-regulation of TCF, Hes and Hey genes.
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Affiliation(s)
- Johnny Bou-Rouphael
- Sorbonne Université, CNRS UMR7622, Institut de Biologie Paris-Seine (IBPS) - Laboratoire de Biologie du Développement, 75005 Paris, France
| | - Mohamed Doulazmi
- Sorbonne Université, CNRS UMR8256, Institut de Biologie Paris-Seine (IBPS) - Laboratoire Adaptation Biologique et Vieillissement, 75005 Paris, France
| | - Alexis Eschstruth
- Sorbonne Université, CNRS UMR7622, Institut de Biologie Paris-Seine (IBPS) - Laboratoire de Biologie du Développement, 75005 Paris, France
| | - Asna Abdou
- Sorbonne Université, CNRS UMR7622, Institut de Biologie Paris-Seine (IBPS) - Laboratoire de Biologie du Développement, 75005 Paris, France
| | - Béatrice C Durand
- Sorbonne Université, CNRS UMR7622, Institut de Biologie Paris-Seine (IBPS) - Laboratoire de Biologie du Développement, 75005 Paris, France
- Sorbonne Université, CNRS UMR8256, Institut de Biologie Paris-Seine (IBPS) - Laboratoire Adaptation Biologique et Vieillissement, 75005 Paris, France
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2
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Ibeagha-Awemu EM, Bissonnette N, Bhattarai S, Wang M, Dudemaine PL, McKay S, Zhao X. Whole Genome Methylation Analysis Reveals Role of DNA Methylation in Cow's Ileal and Ileal Lymph Node Responses to Mycobacterium avium subsp. paratuberculosis Infection. Front Genet 2021; 12:797490. [PMID: 34992636 PMCID: PMC8724574 DOI: 10.3389/fgene.2021.797490] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Accepted: 11/22/2021] [Indexed: 12/27/2022] Open
Abstract
Johne's Disease (JD), caused by Mycobacterium avium subsp paratuberculosis (MAP), is an incurable disease of ruminants and other animal species and is characterized by an imbalance of gut immunity. The role of MAP infection on the epigenetic modeling of gut immunity during the progression of JD is still unknown. This study investigated the DNA methylation patterns in ileal (IL) and ileal lymph node (ILLN) tissues from cows diagnosed with persistent subclinical MAP infection over a one to 4 years period. DNA samples from IL and ILLN tissues from cows negative (MAPneg) (n = 3) or positive for MAP infection (MAPinf) (n = 4) were subjected to whole genome bisulfite sequencing. A total of 11,263 and 62,459 differentially methylated cytosines (DMCs), and 1259 and 8086 differentially methylated regions (DMRs) (FDR<0.1) were found between MAPinf and MAPneg IL and ILLN tissues, respectively. The DMRs were found on 394 genes (denoted DMR genes) in the IL and on 1305 genes in the ILLN. DMR genes with hypermethylated promoters/5'UTR [3 (IL) and 88 (ILLN)] or hypomethylated promoters/5'UTR [10 (IL) and 25 (ILLN)] and having multiple functions including response to stimulus/immune response (BLK, BTC, CCL21, AVPR1A, CHRNG, GABRA4, TDGF1), cellular processes (H2AC20, TEX101, GLA, NCKAP5L, RBM27, SLC18A1, H2AC20BARHL2, NLGN3, SUV39H1, GABRA4, PPA1, UBE2D2) and metabolic processes (GSTO2, H2AC20, SUV39H1, PPA1, UBE2D2) are potential DNA methylation candidate genes of MAP infection. The ILLN DMR genes were enriched for more biological process (BP) gene ontology (GO) terms (n = 374), most of which were related to cellular processes (27.6%), biological regulation (16.6%), metabolic processes (15.4%) and response to stimulus/immune response (8.2%) compared to 75 BP GO terms (related to cellular processes, metabolic processes and transport, and system development) enriched for IL DMR genes. ILLN DMR genes were enriched for more pathways (n = 47) including 13 disease pathways compared with 36 enriched pathways, including 7 disease/immune pathways for IL DMR genes. In conclusion, the results show tissue specific responses to MAP infection with more epigenetic changes (DMCs and DMRs) in the ILLN than in the IL tissue, suggesting that the ILLN and immune processes were more responsive to regulation by methylation of DNA relative to IL tissue. Our data is the first to demonstrate a potential role for DNA methylation in the pathogenesis of MAP infection in dairy cattle.
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Affiliation(s)
- Eveline M. Ibeagha-Awemu
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| | - Nathalie Bissonnette
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| | - Suraj Bhattarai
- Department of Animal and Veterinary Sciences, University of Vermont, Burlington, VT, United States
| | - Mengqi Wang
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| | - Pier-Luc Dudemaine
- Sherbrooke Research and Development Centre, Agriculture and Agri-Food Canada, Sherbrooke, QC, Canada
| | - Stephanie McKay
- Department of Animal and Veterinary Sciences, University of Vermont, Burlington, VT, United States
| | - Xin Zhao
- Department of Animal Science, McGill University, Ste-Anne-Be-Bellevue, QC, Canada
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3
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Bou-Rouphael J, Durand BC. T-Cell Factors as Transcriptional Inhibitors: Activities and Regulations in Vertebrate Head Development. Front Cell Dev Biol 2021; 9:784998. [PMID: 34901027 PMCID: PMC8651982 DOI: 10.3389/fcell.2021.784998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Accepted: 10/28/2021] [Indexed: 11/22/2022] Open
Abstract
Since its first discovery in the late 90s, Wnt canonical signaling has been demonstrated to affect a large variety of neural developmental processes, including, but not limited to, embryonic axis formation, neural proliferation, fate determination, and maintenance of neural stem cells. For decades, studies have focused on the mechanisms controlling the activity of β-catenin, the sole mediator of Wnt transcriptional response. More recently, the spotlight of research is directed towards the last cascade component, the T-cell factor (TCF)/Lymphoid-Enhancer binding Factor (LEF), and more specifically, the TCF/LEF-mediated switch from transcriptional activation to repression, which in both embryonic blastomeres and mouse embryonic stem cells pushes the balance from pluri/multipotency towards differentiation. It has been long known that Groucho/Transducin-Like Enhancer of split (Gro/TLE) is the main co-repressor partner of TCF/LEF. More recently, other TCF/LEF-interacting partners have been identified, including the pro-neural BarH-Like 2 (BARHL2), which belongs to the evolutionary highly conserved family of homeodomain-containing transcription factors. This review describes the activities and regulatory modes of TCF/LEF as transcriptional repressors, with a specific focus on the functions of Barhl2 in vertebrate brain development. Specific attention is given to the transcriptional events leading to formation of the Organizer, as well as the roles and regulations of Wnt/β-catenin pathway in growth of the caudal forebrain. We present TCF/LEF activities in both embryonic and neural stem cells and discuss how alterations of this pathway could lead to tumors.
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Affiliation(s)
| | - Béatrice C. Durand
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Campus Pierre et Marie Curie, Paris, France
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4
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Albadri S, Armant O, Aljand-Geschwill T, Del Bene F, Carl M, Strähle U, Poggi L. Expression of a Barhl1a reporter in subsets of retinal ganglion cells and commissural neurons of the developing zebrafish brain. Sci Rep 2020; 10:8814. [PMID: 32483163 PMCID: PMC7264323 DOI: 10.1038/s41598-020-65435-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 05/05/2020] [Indexed: 12/03/2022] Open
Abstract
Promoting the regeneration or survival of retinal ganglion cells (RGCs) is one focus of regenerative medicine. Homeobox Barhl transcription factors might be instrumental in these processes. In mammals, only barhl2 is expressed in the retina and is required for both subtype identity acquisition of amacrine cells and for the survival of RGCs downstream of Atoh7, a transcription factor necessary for RGC genesis. The underlying mechanisms of this dual role of Barhl2 in mammals have remained elusive. Whole genome duplication in the teleost lineage generated the barhl1a and barhl2 paralogues. In the Zebrafish retina, Barhl2 functions as a determinant of subsets of amacrine cells lineally related to RGCs independently of Atoh7. In contrast, barhl1a expression depends on Atoh7 but its expression dynamics and function have not been studied. Here we describe for the first time a Barhl1a reporter line in vivo showing that barhl1a turns on exclusively in subsets of RGCs and their post-mitotic precursors. We also show transient expression of barhl1a:GFP in diencephalic neurons extending their axonal projections as part of the post-optic commissure, at the time of optic chiasm formation. This work sets the ground for future studies on RGC subtype identity, axonal projections and genetic specification of Barhl1a-positive RGCs and commissural neurons.
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Affiliation(s)
- Shahad Albadri
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany.,Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Olivier Armant
- Institute of Biological and Chemical Systems, Biological Information Processing Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | | | - Filippo Del Bene
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, Paris, France
| | - Matthias Carl
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Uwe Strähle
- Institute of Biological and Chemical Systems, Biological Information Processing Karlsruhe Institute of Technology, Eggenstein-Leopoldshafen, Germany
| | - Lucia Poggi
- Centre for Organismal Studies, University of Heidelberg, Heidelberg, Germany. .,Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy.
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5
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Sena E, Bou-Rouphael J, Rocques N, Carron-Homo C, Durand BC. Mcl1 protein levels and Caspase-7 executioner protease control axial organizer cells survival. Dev Dyn 2020; 249:847-866. [PMID: 32141178 DOI: 10.1002/dvdy.169] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 02/05/2020] [Accepted: 02/29/2020] [Indexed: 11/07/2022] Open
Abstract
BACKGROUND Organizing centers are groups of specialized cells that secrete morphogens, thereby influencing development of their neighboring territories. Apoptosis is a form of programmed cell death reported to limit the size of organizers. Little is known about the identity of intracellular signals driving organizer cell death. Here we investigated in Xenopus the role of both the anti-apoptotic protein Myeloid-cell-leukemia 1 (Mcl1) and the cysteine proteases Caspase-3 and Caspase-7 in formation of the axial organizing center-the notochord-that derives from the Spemann organizer, and participates in the induction and patterning of the neuroepithelium. RESULTS We confirm a role for apoptosis in establishing the axial organizer in early neurula. We show that the expression pattern of mcl1 is coherent with a role for this gene in early notochord development. Using loss of function approaches, we demonstrate that Mcl1 depletion decreases neuroepithelium width and increases notochord cells apoptosis, a process that relies on Caspase-7, and not on Caspase-3, activity. Our data provide evidence that Mcl1 protein levels physiologically control notochord cells' survival and that Caspase-7 is the executioner protease in this developmental process. CONCLUSIONS Our study reveals new functions for Mcl1 and Caspase-7 in formation of the axial signalling center.
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Affiliation(s)
- Elena Sena
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France
| | - Johnny Bou-Rouphael
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
| | - Nathalie Rocques
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France
| | - Clémence Carron-Homo
- Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
| | - Béatrice C Durand
- Institut Curie, PSL Research University, Orsay, France.,Université Paris Sud, Orsay, France.,Sorbonne Université, CNRS UMR7622, IBPS Developmental Biology Laboratory, Paris, France
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6
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Yang Y, An C, Yao Y, Cao Z, Gu T, Xu Q, Chen G. Intron polymorphisms of MAGI-1 and ACSF2 and effects on their expression in different goose breeds. Gene 2019; 701:82-88. [PMID: 30902784 DOI: 10.1016/j.gene.2019.02.102] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 10/27/2022]
Abstract
The goose is one of the most important waterfowl, having lowing laying rate. Previous studies have shown the SNPs in the introns of MAGI-1 (Record-106975) and ACSF2 (Record-106582) significantly associated with egg production in geese. However, the mechanism of those SNPs influencing egg production remains unclear. In this study, the three goose breeds (Yangzhou geese, Zhedong white geese, and Carlos geese) with obviously different egg production were selected, and the allele frequency distribution and functions of those SNPs were investigated. The results suggested that the allele frequency distribution of ACSF2 was significantly different among the three goose breeds (χc2 = 92.377, Pc = 2.29 × 10-22), with the C allele appearing at frequencies of 0.29 in the Yangzhou geese and 0.94 in the Carlos geese. In contrast, the allele frequencies of MAGI-1 were not significantly different among the different goose breeds. Quantitative Reverse Transcription PCR (qRT-PCR) showed that the expression of MAGI-1 with the AG genotype individuals was significantly higher than those of the AA and GG genotype. For ACSF2, the CC genotype had significantly higher expression than both the AC genotype and the AA genotype. The luciferase reporter analysis revealed that the site-directed mutation ACSF2 (A>C) significantly drove the expression activity. Further analysis suggested that the mutation altered the binding site of the transcription factor BARHL2. Binding of BARHL2 to the ACSF2 intron was confirmed by electrophoretic mobility shift assay (EMSA) analysis. Thus, our findings revealed the A>C mutation of ACSF2 (Record-106582) could promote the expression by regulating the binding of BARHL2, resulting in differences in egg performance, which provided molecular insights into the effect of the polymorphism in ACSF2 on egg performance in geese.
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Affiliation(s)
- Yaozong Yang
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Chen An
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Ying Yao
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Zhengfeng Cao
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Tiantian Gu
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China
| | - Qi Xu
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.
| | - Guohong Chen
- Key Laboratory of Animal Genetics and Breeding and Molecular Design of Jiangsu Province, College of Animal Science and Technology, Yangzhou University, Yangzhou, Jiangsu, China.
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7
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Georgiadis P, Gavriil M, Rantakokko P, Ladoukakis E, Botsivali M, Kelly RS, Bergdahl IA, Kiviranta H, Vermeulen RCH, Spaeth F, Hebbels DGAJ, Kleinjans JCS, de Kok TMCM, Palli D, Vineis P, Kyrtopoulos SA. DNA methylation profiling implicates exposure to PCBs in the pathogenesis of B-cell chronic lymphocytic leukemia. ENVIRONMENT INTERNATIONAL 2019; 126:24-36. [PMID: 30776747 PMCID: PMC7063446 DOI: 10.1016/j.envint.2019.01.068] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/01/2018] [Revised: 01/17/2019] [Accepted: 01/28/2019] [Indexed: 05/03/2023]
Abstract
OBJECTIVES To characterize the impact of PCB exposure on DNA methylation in peripheral blood leucocytes and to evaluate the corresponding changes in relation to possible health effects, with a focus on B-cell lymphoma. METHODS We conducted an epigenome-wide association study on 611 adults free of diagnosed disease, living in Italy and Sweden, in whom we also measured plasma concentrations of 6 PCB congeners, DDE and hexachlorobenzene. RESULTS We identified 650 CpG sites whose methylation correlates strongly (FDR < 0.01) with plasma concentrations of at least one PCB congener. Stronger effects were observed in males and in Sweden. This epigenetic exposure profile shows extensive and highly statistically significant overlaps with published profiles associated with the risk of future B-cell chronic lymphocytic leukemia (CLL) as well as with clinical CLL (38 and 28 CpG sites, respectively). For all these sites, the methylation changes were in the same direction for increasing exposure and for higher disease risk or clinical disease status, suggesting an etiological link between exposure and CLL. Mediation analysis reinforced the suggestion of a causal link between exposure, changes in DNA methylation and disease. Disease connectivity analysis identified multiple additional diseases associated with differentially methylated genes, including melanoma for which an etiological link with PCB exposure is established, as well as developmental and neurological diseases for which there is corresponding epidemiological evidence. Differentially methylated genes include many homeobox genes, suggesting that PCBs target stem cells. Furthermore, numerous polycomb protein target genes were hypermethylated with increasing exposure, an effect known to constitute an early marker of carcinogenesis. CONCLUSIONS This study provides mechanistic evidence in support of a link between exposure to PCBs and the etiology of CLL and underlines the utility of omic profiling in the evaluation of the potential toxicity of environmental chemicals.
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Affiliation(s)
- Panagiotis Georgiadis
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., Athens 11635, Greece
| | - Marios Gavriil
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., Athens 11635, Greece
| | - Panu Rantakokko
- National Institute for Health and Welfare, Department of Health Security, Environmental Health unit, P.O. Box 95, Kuopio, Finland
| | - Efthymios Ladoukakis
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., Athens 11635, Greece
| | - Maria Botsivali
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., Athens 11635, Greece
| | - Rachel S Kelly
- MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College London, UK
| | - Ingvar A Bergdahl
- Department of Biobank Research, and Occupational and Environmental Medicine, Department of Public Health and Clinical Medicine, Umeå University, Sweden
| | - Hannu Kiviranta
- MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College London, UK
| | - Roel C H Vermeulen
- Institute for Risk Assessment Sciences (IRAS), Utrecht University, Utrecht, Netherlands
| | - Florentin Spaeth
- Department of Radiation Sciences, Oncology, Umeå University, Sweden
| | | | | | | | - Domenico Palli
- The Institute for Cancer Research and Prevention, Florence, Italy
| | - Paolo Vineis
- MRC-HPA Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Faculty of Medicine, Imperial College London, UK
| | - Soterios A Kyrtopoulos
- National Hellenic Research Foundation, Institute of Biology, Medicinal Chemistry and Biotechnology, 48 Vas. Constantinou Ave., Athens 11635, Greece.
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Zhang Y, Zhang L, Fan X, Yang W, Yu B, Kou J, Li F. Captopril attenuates TAC-induced heart failure via inhibiting Wnt3a/β-catenin and Jak2/Stat3 pathways. Biomed Pharmacother 2019; 113:108780. [PMID: 30889487 DOI: 10.1016/j.biopha.2019.108780] [Citation(s) in RCA: 69] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2018] [Revised: 02/28/2019] [Accepted: 03/13/2019] [Indexed: 12/23/2022] Open
Abstract
Captopril (Cap) as angiotensin-converting enzyme inhibitor (ACEi) is commonly used to treat hypertension and some types of congestive heart failure. However, few studies reported on whether Cap exerts a protective effect on myocardial apoptosis induced by transverse aortic constriction (TAC). This study aimed at investigating the possible mechanism of Cap on myocardial apoptosis induced by pressure overload. Results showed that Cap significantly decreased heart-to-body weight ratios (HBWR). Cap markedly improved cardiac function, and reduced inner diameter of ascending aorta (Asc Ao) in TAC mice as shown by echocardiography. Enzyme-linked immunosorbent assay (ELISA) results demonstrated that Cap treatment also markedly decreased the level of N-terminal pro-B-type natriuretic peptide (NT-proBNP), atrial natriuretic peptide (ANP), tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Cardiac pathological changes and fibrosis have been improved after Cap treatment as shown by hematoxylin-eosin (H&E) staining and Masson's trichrome staining. Moreover, Terminal deoxynucleotidyl transferase-mediated dexoxyuridine triphosphate nick-end labeling (TUNEL) staining result indicated Cap treatment also significantly inhibited cardiac apoptosis. Western Blot results showed that Cap obviously decreased the expression of cleaved capase-3, Bax, phosphorylated Jak2 (p-Jak2), phosphorylated Stat3 (p-Stat3), Wnt3a and β-catenin proteins, as well as increased Bcl-2 expression. In conclusion, Cap showed a protective effect on TAC-induced cardiac apoptosis, which could be attributed to the inhibition of Wnt3a/β-catenin signaling pathway. Cap also attenuated myocardial hypertrophy induced by TAC via suppression of Jak2/Stat3 pathway.
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Affiliation(s)
- Yu Zhang
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Ling Zhang
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Xiaoxue Fan
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Weiwei Yang
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Boyang Yu
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China
| | - Junping Kou
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.
| | - Fang Li
- Jiangsu Key Laboratory of TCM Evaluation and Translational Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing, China.
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9
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Sena E, Rocques N, Borday C, Amin HSM, Parain K, Sitbon D, Chesneau A, Durand BC. Barhl2 maintains T-cell factors as repressors, and thereby switches off the Wnt/β-Catenin response driving Spemann organizer formation. Development 2019; 146:dev.173112. [DOI: 10.1242/dev.173112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 04/11/2019] [Indexed: 12/19/2022]
Abstract
A hallmark of Wnt/β-Catenin signaling is the extreme diversity of its transcriptional response, which varies depending on cell and developmental context. What controls this diversity is poorly understood. In all cases, the switch from transcriptional repression to activation depends on a nuclear increase in β-Catenin, which detaches the transcription factor T-cell Factor-7 like 1 (Tcf7l1) bound to Groucho (Gro) transcriptional co-repressors from its DNA binding sites and transiently converts Tcf7/Lymphoid enhancer binding factor 1 (Lef1) into a transcriptional activator. One of the earliest and evolutionarily conserved functions of Wnt/β-Catenin signaling is the induction of the blastopore lip organizer. Here, we demonstrate that the evolutionarily conserved BarH-like homeobox-2 (Barhl2) protein stabilizes the Tcf7l1-Gro complex and maintains repressed expression of Tcf target genes by a mechanism that depends on histone deacetylase 1 (Hdac-1) activity. In this way, Barhl2 switches off the Wnt/β-Catenin-dependent early transcriptional response, thereby limiting the formation of the organizer in time and/or space. This study reveals a novel nuclear inhibitory mechanism of Wnt/Tcf signaling that switches off organizer fate determination.
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Affiliation(s)
- Elena Sena
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
| | - Nathalie Rocques
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
| | - Caroline Borday
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Harem Sabr Muhamad Amin
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 CNRS 8197, INSERM U1024 46 rue d'Ulm 75005, Paris F-75005, France
| | - Karine Parain
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - David Sitbon
- Institut Curie, PSL Research University, CNRS, UMR3664, Equipe Labellisée Ligue contre le Cancer, Paris, France
| | - Albert Chesneau
- Paris-Saclay Institute of Neuroscience, CNRS, Université Paris Sud, Université Paris-Saclay, 91405 Orsay, France
| | - Béatrice C. Durand
- Institut Curie, Research Division, PSL Research University, Université Paris Sud, CNRS UMR 3347, INSERM U1021, Centre Universitaire, Bâtiment 110 F-91405 Orsay Cedex
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 CNRS 8197, INSERM U1024 46 rue d'Ulm 75005, Paris F-75005, France
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Pan S, Zhao X, Wang X, Tian X, Wang Y, Fan R, Feng N, Zhang S, Gu X, Jia M, Li J, Yang L, Wang K, Guo H, Pei J. Sfrp1 attenuates TAC-induced cardiac dysfunction by inhibiting Wnt signaling pathway- mediated myocardial apoptosis in mice. Lipids Health Dis 2018; 17:202. [PMID: 30153824 PMCID: PMC6114876 DOI: 10.1186/s12944-018-0832-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/19/2018] [Indexed: 01/12/2023] Open
Abstract
Background Hemodynamic overload causes cardiac hypertrophy leading to heart failure. Wnt signaling pathway was reported activated in heart failure. Secreted frizzled related protein 1 (Sfrp1) is a suppressor of Wnt signaling activation. The aim of the present study was to investigate the protective effect of Sfrp1 on hemodynamic overload- induced cardiac dysfunction. Methods A mice transverse aortic constriction (TAC)- induced heart failure model was established. A recombinant adeno-associated virus 9 (AAV9) vector was used to deliver Sfrp1 gene into myocardium. Fluorescence and immunohistochemistry staining was used to evaluate the effectiveness of viral vector delivery. Invasive hemodynamic examination was used to evaluate cardiac systolic and diastolic functions. Myocardium apoptosis was detected by TUNEL assay. The expression levels of Sfrp1, β-catenin, caspase3, Bax, Bcl-2 and c-Myc were measured by Western blotting. Results Increased mean arterial pressure and impaired cardiac function confirmed the establishment of TAC model. Sfrp1 protein expression was effectively increased in myocardium of mice treated with AAV9-Sfrp1 viral vector. The viral vector administration improved both systolic and diastolic cardiac functions by reducing myocardial apoptosis in TAC mice. The expression levels of β-catenin, caspase3 and Bax were significantly reduced while the expression levels of Bcl-2 and c-Myc were dramatically increased in myocardium by the viral vector treatment in TAC mice. Conclusions AAV9 viral vector delivered sfrp1 expression gene into myocardium, which attenuated TAC-induced cardiac dysfunction by inhibiting Wnt signaling pathway activation- mediated apoptosis.
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Affiliation(s)
- Shuo Pan
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China.,1st Department of Cardiology, People's Hospital of Shaanxi Province, Xi'an, Shaanxi Province, China
| | - Xiujuan Zhao
- Ultrasonic Center, Northwest Women and Children's Hospital, Xi'an, Shaanxi Province, China
| | - Xu Wang
- Student Brigade, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Xin Tian
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Yuanbo Wang
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Rong Fan
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Na Feng
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Shumiao Zhang
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Xiaoming Gu
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Min Jia
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Juan Li
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Lu Yang
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Kaiyan Wang
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China
| | - Haitao Guo
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China.
| | - Jianming Pei
- Department of Physiology, National Key Discipline of Cell Biology, Fourth Military Medical University, Xi'an, Shaanxi Province, China.
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Sena E, Feistel K, Durand BC. An Evolutionarily Conserved Network Mediates Development of the zona limitans intrathalamica, a Sonic Hedgehog-Secreting Caudal Forebrain Signaling Center. J Dev Biol 2016; 4:jdb4040031. [PMID: 29615594 PMCID: PMC5831802 DOI: 10.3390/jdb4040031] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2016] [Revised: 09/29/2016] [Accepted: 10/13/2016] [Indexed: 12/16/2022] Open
Abstract
Recent studies revealed new insights into the development of a unique caudal forebrain-signaling center: the zona limitans intrathalamica (zli). The zli is the last brain signaling center to form and the first forebrain compartment to be established. It is the only part of the dorsal neural tube expressing the morphogen Sonic Hedgehog (Shh) whose activity participates in the survival, growth and patterning of neuronal progenitor subpopulations within the thalamic complex. Here, we review the gene regulatory network of transcription factors and cis-regulatory elements that underlies formation of a shh-expressing delimitated domain in the anterior brain. We discuss evidence that this network predates the origin of chordates. We highlight the contribution of Shh, Wnt and Notch signaling to zli development and discuss implications for the fact that the morphogen Shh relies on primary cilia for signal transduction. The network that underlies zli development also contributes to thalamus induction, and to its patterning once the zli has been set up. We present an overview of the brain malformations possibly associated with developmental defects in this gene regulatory network (GRN).
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Affiliation(s)
- Elena Sena
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
| | - Kerstin Feistel
- Institute of Zoology, University of Hohenheim, Garbenstr. 30, 70593 Stuttgart, Germany.
| | - Béatrice C Durand
- Institut Curie, Université Paris Sud, INSERM U1021, CNRS UMR3347, Centre Universitaire, Bâtiment 110, F-91405 Orsay Cedex, France.
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12
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BARHL2 Methylation Using Gastric Wash DNA or Gastric Juice Exosomal DNA is a Useful Marker For Early Detection of Gastric Cancer in an H. pylori-Independent Manner. Clin Transl Gastroenterol 2016; 7:e184. [PMID: 27441821 PMCID: PMC5543484 DOI: 10.1038/ctg.2016.40] [Citation(s) in RCA: 57] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/26/2016] [Indexed: 12/12/2022] Open
Abstract
OBJECTIVES The main purpose of this study was to develop a methylation analysis pipeline by using gastric wash-derived DNA and/or gastric juice-derived exosomal DNA (exoDNA), and to evaluate its suitability for the early detection of gastric cancer (GC) in clinical settings. METHODS We analyzed alterations of BarH-like 2 homeobox protein (BARHL2) in GC cell lines and tissues, as well as in DNA obtained from 128 gastric washes and 30 gastric juice-derived exosomes. GC cell lines were transfected with plasmids encoding BARHL2 and subjected to proliferation, colony formation, and gene expression analyses. RESULTS High levels of BARHL2 methylation were detected in three of seven GC cell lines; consistent with this, these cell lines expressed low levels of BARHL2. Treatment of these cell lines with 5-aza-2'-deoxycytidine restored BARHL2 expression. Levels of BARHL2 methylation in 18 normal and 14 atrophic gastritis samples were low irrespective of Helicobacter pylori infection. High levels of BARHL2 methylation were observed in gastric wash-derived DNA obtained from early GC patients before endoscopic resection (ER), but methylation was significantly lower after curative ER. Analysis using gastric juice-derived exoDNA samples revealed that BARHL2 methylation yielded an area under the curve of 0.923 with 90% sensitivity and 100% specificity with respect to discriminating GC patients from non-GC controls. BARHL2 nuclear immunoreactivity was found in all normal gastric epithelial cells and in cells from patients with gastritis and adenoma. In contrast, loss of BARHL2 expression was observed in the vast majority of the GC tissues. Finally, transfection of BARHL2 into MKN7 and MKN45 cell lines significantly inhibited their proliferation and ability to form colonies. CONCLUSIONS Methylation analysis of BARHL2 using gastric wash-derived DNA and/or gastric juice-derived exoDNA could be useful for early detection of GC in clinical settings.
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13
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Durand BC. Stem cell-like Xenopus Embryonic Explants to Study Early Neural Developmental Features In Vitro and In Vivo. J Vis Exp 2016:e53474. [PMID: 26863402 DOI: 10.3791/53474] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Understanding the genetic programs underlying neural development is an important goal of developmental and stem cell biology. In the amphibian blastula, cells from the roof of the blastocoel are pluripotent. These cells can be isolated, and programmed to generate various tissues through manipulation of genes expression or induction by morphogens. In this manuscript protocols are described for the use of Xenopus laevis blastocoel roof explants as an assay system to investigate key in vivo and in vitro features of early neural development. These protocols allow the investigation of fate acquisition, cell migration behaviors, and cell autonomous and non-autonomous properties. The blastocoel roof explants can be cultured in a serum-free defined medium and grafted into host embryos. This transplantation into an embryo allows the investigation of the long-term lineage commitment, the inductive properties, and the behavior of transplanted cells in vivo. These assays can be exploited to investigate molecular mechanisms, cellular processes and gene regulatory networks underlying neural development. In the context of regenerative medicine, these assays provide a means to generate neural-derived cell types in vitro that could be used in drug screening.
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Affiliation(s)
- Beatrice C Durand
- Institut Curie; UMR 3387, CNRS; PSL Research University; Université Paris-Sud;
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Adiponectin promotes pancreatic cancer progression by inhibiting apoptosis via the activation of AMPK/Sirt1/PGC-1α signaling. Oncotarget 2015; 5:4732-45. [PMID: 25051362 PMCID: PMC4148095 DOI: 10.18632/oncotarget.1963] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Adiponectin is an adipocyte-secreted adipokine with pleiotropic actions. Clinical evidence has shown that serum adiponectin levels are increased and that adiponectin can protect pancreatic beta cells against apoptosis, which suggests that adiponectin may play an anti-apoptotic role in pancreatic cancer (PC). Here, we investigated the effects of adiponectin on PC development and elucidated the underlying molecular mechanisms. Adiponectin deficiency markedly attenuated pancreatic tumorigenesis in vivo. We found that adiponectin significantly inhibited the apoptosis of both human and mouse pancreatic cancer cells via adipoR1, but not adipoR2. Furthermore, adiponectin can increase AMP-activated protein kinase (AMPK) phosphorylation and NAD-dependent deacetylase sirtuin-1 (Sirt1) of PC cells. Knockdown of AMPK or Sirt1 can increase the apoptosis in PC cells. AMPK up-regulated Sirt1, and Sirt1 can inversely phosphorylate AMPK. Further studies have shown that Sirt1 can deacetylate peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC1α), which can increase the expression levels of mitochondrial genes. Thus, adiponectin exerts potent anti-apoptotic effects on PC cells via the activation of AMPK/Sirt1/PGC1α signaling. Finally, adiponectin can elevate β-catenin levels. Taken together, these novel findings reveal an unconventional role of adiponectin in promoting pancreatic cancers, and suggest that the effects of adiponectin on tumorigenesis are highly tissue-dependent.
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15
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Zhang S, Li J, Lea R, Vleminckx K, Amaya E. Fezf2 promotes neuronal differentiation through localised activation of Wnt/β-catenin signalling during forebrain development. Development 2015; 141:4794-805. [PMID: 25468942 PMCID: PMC4299278 DOI: 10.1242/dev.115691] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Brain regionalisation, neuronal subtype diversification and circuit connectivity are crucial events in the establishment of higher cognitive functions. Here we report the requirement for the transcriptional repressor Fezf2 for proper differentiation of neural progenitor cells during the development of the Xenopus forebrain. Depletion of Fezf2 induces apoptosis in postmitotic neural progenitors, with concomitant reduction in forebrain size and neuronal differentiation. Mechanistically, we found that Fezf2 stimulates neuronal differentiation by promoting Wnt/β-catenin signalling in the developing forebrain. In addition, we show that Fezf2 promotes activation of Wnt/β-catenin signalling by repressing the expression of two negative regulators of Wnt signalling, namely lhx2 and lhx9. Our findings suggest that Fezf2 plays an essential role in controlling when and where neuronal differentiation occurs within the developing forebrain and that it does so by promoting local Wnt/β-catenin signalling via a double-repressor model.
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Affiliation(s)
- Siwei Zhang
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Jingjing Li
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Robert Lea
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
| | - Kris Vleminckx
- Department for Biomedical Molecular Biology, Ghent University, B-9052 Ghent, Belgium
| | - Enrique Amaya
- The Healing Foundation Centre, Faculty of Life Sciences, University of Manchester, Manchester M13 9PT, UK
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Juraver-Geslin HA, Durand BC. Early development of the neural plate: new roles for apoptosis and for one of its main effectors caspase-3. Genesis 2015; 53:203-24. [PMID: 25619400 DOI: 10.1002/dvg.22844] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 01/07/2015] [Indexed: 12/12/2022]
Abstract
Despite its tremendous complexity, the vertebrate nervous system emerges from a homogenous layer of neuroepithelial cells, the neural plate. Its formation relies on the time- and space-controlled progression of developmental programs. Apoptosis is a biological process that removes superfluous and potentially dangerous cells and is implemented through the activation of a molecular pathway conserved during evolution. Apoptosis and an unconventional function of one of its main effectors, caspase-3, contribute to the patterning and growth of the neuroepithelium. Little is known about the intrinsic and extrinsic cues controlling activities of the apoptotic machinery during development. The BarH-like (Barhl) proteins are homeodomain-containing transcription factors. The observations in Caenorhabditis elegans, Xenopus, and mice document that Barhl proteins act in cell survival and as cell type-specific regulators of a caspase-3 function that limits neural progenitor proliferation. In this review, we discuss the roles and regulatory modes of the apoptotic machinery in the development of the neural plate. We focus on the Barhl2, the Sonic Hedgehog, and the Wnt pathways and their activities in neural progenitor survival and proliferation.
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Affiliation(s)
- Hugo A Juraver-Geslin
- Department of Basic Science, Craniofacial Biology, College of Dentistry, New York University, New York, New York
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17
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PFKFB4 controls embryonic patterning via Akt signalling independently of glycolysis. Nat Commun 2015; 6:5953. [PMID: 25601028 DOI: 10.1038/ncomms6953] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 11/26/2014] [Indexed: 12/25/2022] Open
Abstract
How metabolism regulators play roles during early development remains elusive. Here we show that PFKFB4 (6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 4), a glycolysis regulator, is critical for controlling dorsal ectoderm global patterning in gastrulating frog embryos via a non-glycolytic function. PFKFB4 is required for dorsal ectoderm progenitors to proceed towards more specified fates including neural and non-neural ectoderm, neural crest or placodes. This function is mediated by Akt signalling, a major pathway that integrates cell homeostasis and survival parameters. Restoring Akt signalling rescues the loss of PFKFB4 in vivo. In contrast, glycolysis is not essential for frog development at this stage. Our study reveals the existence of a PFKFB4-Akt checkpoint that links cell homeostasis to the ability of progenitor cells to undergo differentiation, and uncovers glycolysis-independent functions of PFKFB4.
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Juraver-Geslin HA, Gómez-Skarmeta JL, Durand BC. The conserved barH-like homeobox-2 gene barhl2 acts downstream of orthodentricle-2 and together with iroquois-3 in establishment of the caudal forebrain signaling center induced by Sonic Hedgehog. Dev Biol 2014; 396:107-20. [PMID: 25281935 DOI: 10.1016/j.ydbio.2014.09.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2014] [Revised: 08/13/2014] [Accepted: 09/23/2014] [Indexed: 01/01/2023]
Abstract
In this study, we investigated the gene regulatory network that governs formation of the Zona limitans intrathalamica (ZLI), a signaling center that secretes Sonic Hedgehog (Shh) to control the growth and regionalization of the caudal forebrain. Using loss- and gain-of-function, explants and grafting experiments in amphibians, we demonstrate that barhl2 acts downstream of otx2 and together with the iroquois (irx)-3 gene in establishment of the ZLI compartment initiated by Shh influence. We find that the presumptive (pre)-ZLI domain expresses barhl2, otx2 and irx3, whereas the thalamus territory caudally bordering the pre-ZLI expresses barhl2, otx2 and irx1/2 and early on irx3. We demonstrate that Barhl2 activity is required for determination of the ZLI and thalamus fates and that within the p2 alar plate the ratio of Irx3 to Irx1/2 contributes to ZLI specification and size determination. We show that when continuously exposed to Shh, neuroepithelial cells coexpressing barhl2, otx2 and irx3 acquire two characteristics of the ZLI compartment-the competence to express shh and the ability to segregate from anterior neural plate cells. In contrast, neuroepithelial cells expressing barhl2, otx2 and irx1/2, are not competent to express shh. Noteworthy in explants, under Shh influence, ZLI-like cells segregate from thalamic-like cells. Our study establishes that Barhl2 activity plays a key role in p2 alar plate patterning, specifically ZLI formation, and provides new insights on establishment of the signaling center of the caudal forebrain.
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Affiliation(s)
- Hugo A Juraver-Geslin
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 46 rue d'Ulm 75005, Paris F-75005, France; INSERM, U1024, Paris F-75005, France; CNRS, UMR 8197, Paris F-75005, France; S1.7 46 rue d'Ulm, 75005 Paris, France
| | - José Luis Gómez-Skarmeta
- Centro Andaluz de Biología del Desarrollo-CSIC/Universidad Pablo de Olavide, Carretera de Utrera, Km1, 41013 Sevilla, Spain
| | - Béatrice C Durand
- Ecole Normale Supérieure, Institut de Biologie de l'ENS, IBENS, S1.7 46 rue d'Ulm 75005, Paris F-75005, France; INSERM, U1024, Paris F-75005, France; CNRS, UMR 8197, Paris F-75005, France; S1.7 46 rue d'Ulm, 75005 Paris, France.
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Wnt signal specifies the intrathalamic limit and its organizer properties by regulating Shh induction in the alar plate. J Neurosci 2013; 33:3967-80. [PMID: 23447606 DOI: 10.1523/jneurosci.0726-12.2013] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
The structural complexity of the brain depends on precise molecular and cellular regulatory mechanisms orchestrated by regional morphogenetic organizers. The thalamic organizer is the zona limitans intrathalamica (ZLI), a transverse linear neuroepithelial domain in the alar plate of the diencephalon. Because of its production of Sonic hedgehog, ZLI acts as a morphogenetic signaling center. Shh is expressed early on in the prosencephalic basal plate and is then gradually activated dorsally within the ZLI. The anteroposterior positioning and the mechanism inducing Shh expression in ZLI cells are still partly unknown, being a subject of controversial interpretations. For instance, separate experimental results have suggested that juxtaposition of prechordal (rostral) and epichordal (caudal) neuroepithelium, anteroposterior encroachment of alar lunatic fringe (L-fng) expression, and/or basal Shh signaling is required for ZLI specification. Here we investigated a key role of Wnt signaling in the molecular regulation of ZLI positioning and Shh expression, using experimental embryology in ovo in the chick. Early Wnt expression in the ZLI regulates Gli3 and L-fng to generate a permissive territory in which Shh is progressively induced by planar signals of the basal plate.
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Abstract
Within the developing vertebrate retina, particular subtypes of amacrine cells (ACs) tend to arise from progenitors expressing the basic helix-loop-helix (bHLH) transcription factor, Atoh7, which is necessary for the early generation of retinal ganglion cells (RGCs). All ACs require the postmitotic expression of the bHLH pancreas transcription factor Ptf1a; however, Ptf1a alone is not sufficient to give subtype identities. Here we use functional and in vivo time-lapse studies in the zebrafish retina to investigate on the developmental programs leading to ACs specification within the subsequent divisions of Atoh7-positive progenitors. We find evidences that the homeobox transcription factor Barhl2 is an AC subtype identity-biasing factor that turns on within Atoh7-positive descendants. In vivo lineage tracing reveals that particular modes of cell division tend to generate Barhl2-positive precursors from sisters of RGCs. Additionally, Atoh7 indirectly impacts these division modes to regulate the right number of barhl2-expressing cells. We finally find that Atoh7 itself influences the subtypes of Barhl2-dependent ACs. Together, the results from our study uncover lineage-related and molecular logic of subtype specification in the vertebrate retina, by showing that specific AC subtypes arise via a particular mode of cell division and a transcriptional network cascade involving the sequential expression of first atoh7 followed by ptf1a and then barhl2.
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Rgs19 regulates mouse palatal fusion by modulating cell proliferation and apoptosis in the MEE. Mech Dev 2012; 129:244-54. [DOI: 10.1016/j.mod.2012.07.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 07/18/2012] [Accepted: 07/18/2012] [Indexed: 01/12/2023]
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