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Kato Y, Fukazawa T, Tanimoto K, Kanawa M, Kojima M, Saeki I, Kurihara S, Touge R, Hirohashi N, Okada S, Hiyama E. Achaete-scute family bHLH transcription factor 2 activation promotes hepatoblastoma progression. Cancer Sci 2024; 115:847-858. [PMID: 38183173 PMCID: PMC10921009 DOI: 10.1111/cas.16051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Revised: 11/16/2023] [Accepted: 12/08/2023] [Indexed: 01/07/2024] Open
Abstract
Achaete-scute family bHLH transcription factor 2 (ASCL2) is highly expressed in hepatoblastoma (HB) tissues, but its role remains unclear. Thus, biological changes in the HB cell line HepG2 in response to induced ASCL2 expression were assessed. ASCL2 expression was induced in HepG2 cells using the Tet-On 3G system, which includes doxycycline. Cell viability, proliferation activity, mobility, and stemness were evaluated using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide, colony-formation, migration, invasion, and sphere-formation assays. Quantitative reverse-transcription polymerase chain reaction was used to assess the expression of markers for proliferation (CCND1 and MYC), epithelial-mesenchymal transition (EMT; SNAI1, TWIST1, and ZEB1), mesenchymal-epithelial transition (CDH1), and stemness (KLF4, POU5F1, and SOX9). Compared with the non-induced HepG2 cells, cells with induced ASCL2 expression showed significant increases in viability, colony number, migration area (%), and sphere number on days 7, 14, 8, and 7, respectively, and invasion area (%) after 90 h. Furthermore, induction of ASCL2 expression significantly upregulated CCND1, MYC, POU5F1, SOX9, and KLF4 expression on days 2, 2, 3, 3, and 5, respectively, and increased the ratios of SNAI1, TWIST1, and ZEB1 to CDH1 on day 5. ASCL2 promoted the formation of malignant phenotypes in HepG2 cells, which may be correlated with the upregulation of the Wnt signaling pathway-, EMT-, and stemness-related genes. ASCL2 activation may therefore be involved in the progression of HB.
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Affiliation(s)
- Yutaka Kato
- Department of Pediatrics, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
| | - Takahiro Fukazawa
- Natural Science Center for Basic Research and DevelopmentHiroshima UniversityHiroshimaJapan
- Division of Medical Research Support, Advanced Research Support CenterEhime UniversityToonJapan
| | - Keiji Tanimoto
- Department of Radiation Disaster Medicine, Research Institute for Radiation Biology and MedicineHiroshima UniversityHiroshimaJapan
| | - Masami Kanawa
- Natural Science Center for Basic Research and DevelopmentHiroshima UniversityHiroshimaJapan
| | - Masato Kojima
- Natural Science Center for Basic Research and DevelopmentHiroshima UniversityHiroshimaJapan
- Department of Surgery, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
- Department of Pediatric SurgeryHiroshima University HospitalHiroshimaJapan
| | - Isamu Saeki
- Department of Surgery, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
- Department of Pediatric SurgeryHiroshima University HospitalHiroshimaJapan
| | - Sho Kurihara
- Department of Surgery, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
- Department of Pediatric SurgeryHiroshima University HospitalHiroshimaJapan
| | - Ryo Touge
- Department of Surgery, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
- Department of Pediatric SurgeryHiroshima University HospitalHiroshimaJapan
| | - Nobuyuki Hirohashi
- Department of Radiation Disaster Medicine, Research Institute for Radiation Biology and MedicineHiroshima UniversityHiroshimaJapan
| | - Satoshi Okada
- Department of Pediatrics, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
| | - Eiso Hiyama
- Natural Science Center for Basic Research and DevelopmentHiroshima UniversityHiroshimaJapan
- Department of Surgery, Graduate School of Biomedical and Health SciencesHiroshima UniversityHiroshimaJapan
- Department of Pediatric SurgeryHiroshima University HospitalHiroshimaJapan
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Cao Y, Liu L, Ma K, Wang W, Lv H, Gao M, Wang X, Zhang X, Ren S, Zhang N, Guo YD. The jasmonate-induced bHLH gene SlJIG functions in terpene biosynthesis and resistance to insects and fungus. J Integr Plant Biol 2022; 64:1102-1115. [PMID: 35293128 DOI: 10.1111/jipb.13248] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Accepted: 03/14/2022] [Indexed: 05/27/2023]
Abstract
Jasmonic acid (JA) is a key regulator of plant defense responses. Although the transcription factor MYC2, the master regulator of the JA signaling pathway, orchestrates a hierarchical transcriptional cascade that regulates the JA responses, only a few transcriptional regulators involved in this cascade have been described. Here, we identified the basic helix-loop-helix (bHLH) transcription factor gene in tomato (Solanum lycopersicum), METHYL JASMONATE (MeJA)-INDUCED GENE (SlJIG), the expression of which was strongly induced by MeJA treatment. Genetic and molecular biology experiments revealed that SlJIG is a direct target of MYC2. SlJIG knockout plants generated by gene editing had lower terpene contents than the wild type from the lower expression of TERPENE SYNTHASE (TPS) genes, rendering them more appealing to cotton bollworm (Helicoverpa armigera). Moreover, SlJIG knockouts exhibited weaker JA-mediated induction of TPSs, suggesting that SlJIG may participate in JA-induced terpene biosynthesis. Knocking out SlJIG also resulted in attenuated expression of JA-responsive defense genes, which may contribute to the observed lower resistance to cotton bollworm and to the fungus Botrytis cinerea. We conclude that SlJIG is a direct target of MYC2, forms a MYC2-SlJIG module, and functions in terpene biosynthesis and resistance against cotton bollworm and B. cinerea.
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Affiliation(s)
- Yunyun Cao
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- College of Horticulture Science and Engineering, Shandong Agricultural University, Tai'an, 271018, China
| | - Lun Liu
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Kangsheng Ma
- Hubei Insect Resources Utilization and Sustainable Pest Management Key Laboratory, College of Plant Science and Technology, Huazhong Agricultural University, Wuhan, 430070, China
| | - Wenjing Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Hongmei Lv
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Ming Gao
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xinman Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xichun Zhang
- College of Plant Science and Technology, Beijing University of Agriculture, Beijing, 102206, China
| | - Shuxin Ren
- School of Agriculture, Virginia State University, Petersburg, 23806, VA, USA
| | - Na Zhang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
| | - Yang-Dong Guo
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
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Sirp A, Roots K, Nurm K, Tuvikene J, Sepp M, Timmusk T. Functional consequences of TCF4 missense substitutions associated with Pitt-Hopkins syndrome, mild intellectual disability, and schizophrenia. J Biol Chem 2021; 297:101381. [PMID: 34748727 PMCID: PMC8648840 DOI: 10.1016/j.jbc.2021.101381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 10/28/2021] [Accepted: 10/30/2021] [Indexed: 11/24/2022] Open
Abstract
Transcription factor 4 (TCF4) is a basic helix-loop-helix transcription factor essential for neurocognitive development. The aberrations in TCF4 are associated with neurodevelopmental disorders including schizophrenia, intellectual disability, and Pitt-Hopkins syndrome, an autism-spectrum disorder characterized by developmental delay. Several disease-associated missense mutations in TCF4 have been shown to interfere with TCF4 function, but for many mutations, the impact remains undefined. Here, we tested the effects of 12 functionally uncharacterized disease-associated missense mutations and variations in TCF4 using transient expression in mammalian cells, confocal imaging, in vitro DNA-binding assays, and reporter assays. We show that Pitt-Hopkins syndrome-associated missense mutations within the basic helix-loop-helix domain of TCF4 and a Rett-like syndrome-associated mutation in a transcription activation domain result in altered DNA-binding and transcriptional activity of the protein. Some of the missense variations found in schizophrenia patients slightly increase TCF4 transcriptional activity, whereas no effects were detected for missense mutations linked to mild intellectual disability. We in addition find that the outcomes of several disease-related mutations are affected by cell type, TCF4 isoform, and dimerization partner, suggesting that the effects of TCF4 mutations are context-dependent. Together with previous work, this study provides a basis for the interpretation of the functional consequences of TCF4 missense variants.
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Affiliation(s)
- Alex Sirp
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Kaisa Roots
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Kaja Nurm
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia
| | - Jürgen Tuvikene
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia; Protobios LLC, Tallinn, Estonia
| | - Mari Sepp
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia.
| | - Tõnis Timmusk
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Tallinn, Estonia; Protobios LLC, Tallinn, Estonia.
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Nurm K, Sepp M, Castany-Pladevall C, Creus-Muncunill J, Tuvikene J, Sirp A, Vihma H, Blake DJ, Perez-Navarro E, Timmusk T. Isoform-Specific Reduction of the Basic Helix-Loop-Helix Transcription Factor TCF4 Levels in Huntington's Disease. eNeuro 2021; 8:ENEURO. [PMID: 34518368 DOI: 10.1523/ENEURO.0197-21.2021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 08/19/2021] [Accepted: 08/22/2021] [Indexed: 11/21/2022] Open
Abstract
Huntington's disease (HD) is an inherited neurodegenerative disorder with onset of characteristic motor symptoms at midlife, preceded by subtle cognitive and behavioral disturbances. Transcriptional dysregulation emerges early in the disease course and is considered central to HD pathogenesis. Using wild-type (wt) and HD knock-in mouse striatal cell lines we observed a HD genotype-dependent reduction in the protein levels of transcription factor 4 (TCF4), a member of the basic helix-loop-helix (bHLH) family with critical roles in brain development and function. We characterized mouse Tcf4 gene structure and expression of alternative mRNAs and protein isoforms in cell-based models of HD, and in four different brain regions of male transgenic HD mice (R6/1) from young to mature adulthood. The largest decrease in the levels of TCF4 at mRNA and specific protein isoforms were detected in the R6/1 mouse hippocampus. Translating this finding to human disease, we found reduced expression of long TCF4 isoforms in the postmortem hippocampal CA1 area and in the cerebral cortex of HD patients. Additionally, TCF4 protein isoforms showed differential synergism with the proneural transcription factor ASCL1 in activating reporter gene transcription in hippocampal and cortical cultured neurons. Induction of neuronal activity increased these synergistic effects in hippocampal but not in cortical neurons, suggesting brain region-dependent differences in TCF4 functions. Collectively, this study demonstrates isoform-specific changes in TCF4 expression in HD that could contribute to the progressive impairment of transcriptional regulation and neuronal function in this disease.
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Lim SD, Mayer JA, Yim WC, Cushman JC. Plant tissue succulence engineering improves water-use efficiency, water-deficit stress attenuation and salinity tolerance in Arabidopsis. Plant J 2020; 103:1049-1072. [PMID: 32338788 DOI: 10.1111/tpj.14783] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Revised: 04/01/2020] [Accepted: 04/14/2020] [Indexed: 05/25/2023]
Abstract
Tissue succulence (ratio of tissue water/leaf area or dry mass) or the ability to store water within living tissues is among the most successful adaptations to drought in the plant kingdom. This taxonomically widespread adaptation helps plants avoid the damaging effects of drought, and is often associated with the occupancy of epiphytic, epilithic, semi-arid and arid environments. Tissue succulence was engineered in Arabidopsis thaliana by overexpression of a codon-optimized helix-loop-helix transcription factor (VvCEB1opt ) from wine grape involved in the cell expansion phase of berry development. VvCEB1opt -overexpressing lines displayed significant increases in cell size, succulence and decreased intercellular air space. VvCEB1opt -overexpressing lines showed increased instantaneous and integrated water-use efficiency (WUE) due to reduced stomatal conductance caused by reduced stomatal aperture and density resulting in increased attenuation of water-deficit stress. VvCEB1opt -overexpressing lines also showed increased salinity tolerance due to reduced salinity uptake and dilution of internal Na+ and Cl- as well as other ions. Alterations in transporter activities were further suggested by media and apoplastic acidification, hygromycin B tolerance and changes in relative transcript abundance patterns of various transporters with known functions in salinity tolerance. Engineered tissue succulence might provide an effective strategy for improving WUE, drought avoidance or attenuation, salinity tolerance, and for crassulacean acid metabolism biodesign.
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Affiliation(s)
- Sung Don Lim
- Department of Applied Plant Sciences, Kangwon National University, Chuncheon, 24341, Republic of Korea
| | | | - Won Cheol Yim
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557-0330, USA
| | - John C Cushman
- Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV, 89557-0330, USA
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Lim SD, Yim WC, Liu D, Hu R, Yang X, Cushman JC. A Vitis vinifera basic helix-loop-helix transcription factor enhances plant cell size, vegetative biomass and reproductive yield. Plant Biotechnol J 2018; 16:1595-1615. [PMID: 29520945 PMCID: PMC6096725 DOI: 10.1111/pbi.12898] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 01/22/2018] [Indexed: 05/03/2023]
Abstract
Strategies for improving plant size are critical targets for plant biotechnology to increase vegetative biomass or reproductive yield. To improve biomass production, a codon-optimized helix-loop-helix transcription factor (VvCEB1opt ) from wine grape was overexpressed in Arabidopsis thaliana resulting in significantly increased leaf number, leaf and rosette area, fresh weight and dry weight. Cell size, but typically not cell number, was increased in all tissues resulting in increased vegetative biomass and reproductive organ size, number and seed yield. Ionomic analysis of leaves revealed the VvCEB1opt -overexpressing plants had significantly elevated, K, S and Mo contents relative to control lines. Increased K content likely drives increased osmotic potential within cells leading to greater cellular growth and expansion. To understand the mechanistic basis of VvCEB1opt action, one transgenic line was genotyped using RNA-Seq mRNA expression profiling and revealed a novel transcriptional reprogramming network with significant changes in mRNA abundance for genes with functions in delayed flowering, pathogen-defence responses, iron homeostasis, vesicle-mediated cell wall formation and auxin-mediated signalling and responses. Direct testing of VvCEB1opt -overexpressing plants showed that they had significantly elevated auxin content and a significantly increased number of lateral leaf primordia within meristems relative to controls, confirming that cell expansion and organ number proliferation were likely an auxin-mediated process. VvCEB1opt overexpression in Nicotiana sylvestris also showed larger cells, organ size and biomass demonstrating the potential applicability of this innovative strategy for improving plant biomass and reproductive yield in crops.
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Affiliation(s)
- Sung Don Lim
- Department of Biochemistry and Molecular BiologyUniversity of Nevada, RenoRenoNVUSA
| | - Won Choel Yim
- Department of Biochemistry and Molecular BiologyUniversity of Nevada, RenoRenoNVUSA
| | - Degao Liu
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTNUSA
| | - Rongbin Hu
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTNUSA
| | - Xiaohan Yang
- Biosciences DivisionOak Ridge National LaboratoryOak RidgeTNUSA
| | - John C. Cushman
- Department of Biochemistry and Molecular BiologyUniversity of Nevada, RenoRenoNVUSA
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Perron A, Nishikawa Y, Iwata J, Shimojo H, Takaya J, Kobayashi K, Imayoshi I, Mbenza NM, Takenoya M, Kageyama R, Kodama Y, Uesugi M. Small-molecule screening yields a compound that inhibits the cancer-associated transcription factor Hes1 via the PHB2 chaperone. J Biol Chem 2018. [PMID: 29523683 DOI: 10.1074/jbc.ra118.002316] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The transcription factor Hes family basic helix-loop-helix transcription factor 1 (Hes1) is a downstream effector of Notch signaling and plays a crucial role in orchestrating developmental processes during the embryonic stage. However, its aberrant signaling in adulthood is linked to the pathogenesis of cancer. In the present study, we report the discovery of small organic molecules (JI051 and JI130) that impair the ability of Hes1 to repress transcription. Hes1 interacts with the transcriptional corepressor transducing-like enhancer of split 1 (TLE1) via an interaction domain comprising two tryptophan residues, prompting us to search a chemical library of 1,800 small molecules enriched for indole-like π-electron-rich pharmacophores for a compound that blocks Hes1-mediated transcriptional repression. This screening identified a lead compound whose extensive chemical modification to improve potency yielded JI051, which inhibited HEK293 cell proliferation with an EC50 of 0.3 μm Unexpectedly, using immunomagnetic isolation and nanoscale LC-MS/MS, we found that JI051 does not bind TLE1 but instead interacts with prohibitin 2 (PHB2), a cancer-associated protein chaperone. We also found that JI051 stabilizes PHB2's interaction with Hes1 outside the nucleus, inducing G2/M cell-cycle arrest. Of note, JI051 dose-dependently reduced cell growth of the human pancreatic cancer cell line MIA PaCa-2, and JI130 treatment significantly reduced tumor volume in a murine pancreatic tumor xenograft model. These results suggest a previously unrecognized role for PHB2 in the regulation of Hes1 and may inform potential strategies for managing pancreatic cancer.
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Affiliation(s)
- Amelie Perron
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Uji, Kyoto 611-0011
| | | | - Jun Iwata
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
| | - Hiromi Shimojo
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Uji, Kyoto 611-0011; Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Junichiro Takaya
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
| | - Kumiko Kobayashi
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Itaru Imayoshi
- Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan; Graduate School of Biostudies, Kyoto University, Kyoto 606-8507, Japan
| | - Naasson M Mbenza
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011
| | - Mihoko Takenoya
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Uji, Kyoto 611-0011
| | - Ryoichiro Kageyama
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Uji, Kyoto 611-0011; Institute for Frontier Life and Medical Sciences, Kyoto University, Kyoto 606-8507, Japan
| | - Yuzo Kodama
- Department of Gastroenterology and Hepatology, Graduate School of Medicine.
| | - Motonari Uesugi
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011; Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Uji, Kyoto 611-0011.
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Miyazaki M, Miyazaki K, Chen K, Jin Y, Turner J, Moore AJ, Saito R, Yoshida K, Ogawa S, Rodewald HR, Lin YC, Kawamoto H, Murre C. The E-Id Protein Axis Specifies Adaptive Lymphoid Cell Identity and Suppresses Thymic Innate Lymphoid Cell Development. Immunity 2017; 46:818-834.e4. [PMID: 28514688 DOI: 10.1016/j.immuni.2017.04.022] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Revised: 02/26/2017] [Accepted: 04/27/2017] [Indexed: 01/24/2023]
Abstract
Innate and adaptive lymphoid development is orchestrated by the activities of E proteins and their antagonist Id proteins, but how these factors regulate early T cell progenitor (ETP) and innate lymphoid cell (ILC) development remains unclear. Using multiple genetic strategies, we demonstrated that E proteins E2A and HEB acted in synergy in the thymus to establish T cell identity and to suppress the aberrant development of ILCs, including ILC2s and lymphoid-tissue-inducer-like cells. E2A and HEB orchestrated T cell fate and suppressed the ILC transcription signature by activating the expression of genes associated with Notch receptors, T cell receptor (TCR) assembly, and TCR-mediated signaling. E2A and HEB acted in ETPs to establish and maintain a T-cell-lineage-specific enhancer repertoire, including regulatory elements associated with the Notch1, Rag1, and Rag2 loci. On the basis of these and previous observations, we propose that the E-Id protein axis specifies innate and adaptive lymphoid cell fate.
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Vijayakumar P, Datta S, Dolan L. ROOT HAIR DEFECTIVE SIX-LIKE4 (RSL4) promotes root hair elongation by transcriptionally regulating the expression of genes required for cell growth. New Phytol 2016; 212:944-953. [PMID: 27452638 PMCID: PMC5111604 DOI: 10.1111/nph.14095] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 06/05/2016] [Indexed: 05/07/2023]
Abstract
ROOT HAIR DEFECTIVE SIX-LIKE4 (RSL4) is necessary and sufficient for root hair elongation in Arabidopsis thaliana. Root hair length is determined by the duration for which RSL4 protein is present in the developing root hair. The aim of this research was to identify genes regulated by RSL4 that affect root hair growth. To identify genes regulated by RSL4, we identified genes whose expression was elevated by induction of RSL4 activity in the presence of an inhibitor of translation. Thirty-four genes were identified as putative targets of RSL transcriptional regulation, and the results suggest that the activities of SUPPRESSOR OF ACTIN (SAC1), EXOCSYT SUBUNIT 70A1 (EXO70A1), PEROXIDASE7 (PRX7) and CALCIUM-DEPENDENT PROTEIN KINASE11 (CPK11) are required for root hair elongation. These data indicate that RSL4 controls cell growth by controlling the expression of genes encoding proteins involved in cell signalling, cell wall modification and secretion.
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Affiliation(s)
| | - Sourav Datta
- Department of Plant SciencesUniversity of OxfordOxfordOX1 3RBUK
| | - Liam Dolan
- Department of Plant SciencesUniversity of OxfordOxfordOX1 3RBUK
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Bohrer C, Schachtrup C. ID(ealizing) control of adult subventricular zone neural stem/precursor cell differentiation for CNS regeneration. Neurogenesis (Austin) 2016; 3:e1223532. [PMID: 27882335 DOI: 10.1080/23262133.2016.1223532] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 07/26/2016] [Accepted: 08/05/2016] [Indexed: 10/20/2022]
Abstract
The adult central nervous system (CNS) was considered a comparatively static tissue with little cell turnover. It is now well established that there is more plasticity than previously thought and that astrocytes act as neural stem/precursor cells (NSPCs) in the subventricular zone (SVZ). The discovery that these NSPCs can give rise to a limited number of new neurons, reactive astrocytes and oligodendrocytes contributing to brain repair in CNS disease, has raised hopes toward harnessing these cells for therapeutic interventions. Here, we will discuss the transcriptional control of adult NSPC differentiation into astrocytes in CNS disease focusing on the helix-loop-helix transcription factor protein family. In our recent study, we reported that elevated BMP-2 levels are translated into an increase in Id3 expression in adult NSPC subpopulations after cortical injury. Id3 then heterodimerizes with the basic helix-loop-helix transcription factor E47 and releases the E47-mediated repression of astrocyte-specific gene expression. Consequently, adult NSPCs preferentially differentiate into astrocytes. We believe that understanding the in vivo differentiation potential and the molecular underpinnings of NSPCs in the adult mammalian brain will help us to evaluate their contributions to brain repair and may lead to new concepts in treating human CNS diseases.
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Affiliation(s)
- Christian Bohrer
- Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg, Germany; Faculty of Biology, University of Freiburg, Germany
| | - Christian Schachtrup
- Faculty of Medicine, Institute of Anatomy and Cell Biology, University of Freiburg , Germany
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Kazanjian A, Noah T, Brown D, Burkart J, Shroyer NF. Atonal homolog 1 is required for growth and differentiation effects of notch/gamma-secretase inhibitors on normal and cancerous intestinal epithelial cells. Gastroenterology 2010; 139:918-28, 928.e1-6. [PMID: 20621629 PMCID: PMC3197859 DOI: 10.1053/j.gastro.2010.05.081] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/24/2009] [Revised: 05/13/2010] [Accepted: 05/21/2010] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS The atonal homolog 1 (Atoh1) transcription factor is required for intestinal secretory (goblet, Paneth, enteroendocrine) cell differentiation. Notch/gamma-secretase inhibitors (GSIs) block proliferation and induce secretory cell differentiation in the intestine. We used genetic analyses of mice to determine whether Atoh1 mediates the effects of GSIs in normal and cancerous intestinal epithelia. METHODS We studied mice with intestine-specific disruption of Atoh1 (Atoh1(Deltaintestine)), the adenomatosis polyposis coli (APC)(min) mutation, both mutations (Atoh1(Deltaintestine); APC(min)), or littermate controls; mice were given GSI or vehicle. Colorectal cancer (CRC) cell lines were treated with GSI or vehicle and with small hairpin RNAs to reduce ATOH1. Differentiation and homeostasis were assessed by protein, RNA, and histologic analyses. RESULTS GSIs failed to induce secretory cell differentiation or apoptosis or decrease proliferation of Atoh1-null progenitor cells, compared with wild-type cells. Exposure of APC(min) adenomas to GSIs decreased proliferation and increased secretory cell numbers in an Atoh1-dependent manner. In CRC cells treated with GSI, ATOH1 levels were correlated inversely with proliferation. ATOH1 was required for secretory cell gene expression in cell lines and in mice. CONCLUSIONS ATOH1 is required for all effects of GSIs in intestinal crypts and adenomas; Notch has no unique function in intestinal progenitors and cancer cells other than to regulate ATOH1 expression. Reducing ATOH1 activity might mitigate intestinal toxicity from systemic GSI therapy for nonintestinal diseases. Among gastrointestinal malignancies, ATOH1 mediates the effects of GSIs, so ATOH1 expression levels might predict responses to these inhibitors. We propose that only the subset of CRCs that retain ATOH1 expression will respond to GSIs.
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Affiliation(s)
- Avedis Kazanjian
- Cincinnati Children’s Hospital Medical Center, Division of Gastroenterology, Hepatology, and Nutrition
| | - Taeko Noah
- Cincinnati Children’s Hospital Medical Center, Division of Gastroenterology, Hepatology, and Nutrition
| | | | - Jarred Burkart
- Cincinnati Children’s Hospital Medical Center, Summer Undergraduate Research Fellowship program
| | - Noah F. Shroyer
- Cincinnati Children’s Hospital Medical Center, Division of Gastroenterology, Hepatology, and Nutrition,Cincinnati Children’s Hospital Medical Center, Division Developmental Biology,University of Cincinnati, College of Medicine
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Moon JI, Birren SJ. Target-dependent inhibition of sympathetic neuron growth via modulation of a BMP signaling pathway. Dev Biol 2008; 315:404-17. [PMID: 18272145 PMCID: PMC2287379 DOI: 10.1016/j.ydbio.2007.12.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2007] [Revised: 12/19/2007] [Accepted: 12/29/2007] [Indexed: 12/17/2022]
Abstract
Target-derived factors modulate many aspects of peripheral neuron development including neuronal growth, survival, and maturation. Less is known about how initial target contact regulates changes in gene expression associated with these developmental processes. One early consequence of contact between growing sympathetic neurons and their cardiac myocyte targets is the inhibition of neuronal outgrowth. Analysis of neuronal gene expression following this contact revealed coordinate regulation of a bone morphogenetic protein (BMP)-dependent growth pathway in which basic helix-loop-helix transcription factors and downstream neurofilament expression contribute to the growth dynamics of developing sympathetic neurons. BMP2 had dose-dependent growth-promoting effects on sympathetic neurons cultured in the absence, but not the presence, of myocyte targets, suggesting that target contact alters neuronal responses to BMP signaling. Target contact also induced the expression of matrix Gla protein (MGP), a regulator of BMP function in the vascular system. Increased MGP expression inhibited BMP-dependent neuronal growth and MGP expression increased in sympathetic neurons during the period of target contact in vivo. These experiments establish MGP as a novel regulator of BMP function in the nervous system, and define developmental transitions in BMP responses during sympathetic development.
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Affiliation(s)
- Jung-Il Moon
- Department of Biology, National Center for Behavioral Genomics, Brandeis University, Waltham, MA 02254-9110, USA
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Abstract
Nex1/MATH-2 is a neurogenic basic Helix-Loop-Helix (bHLH) transcription factor that belongs to the NeuroD subfamily. Its expression parallels that of the GAP-43 gene and peaks during brain development, when neurite outgrowth and synaptogenesis are highly active. We previously observed a direct correlation between the levels of expression of Nex1 and GAP-43 proteins, which resulted in extensive neurite outgrowth and neuronal differentiation of PC12 cells in the absence of nerve growth factor. Since the GAP-43 gene is a target for bHLH regulation, we investigated whether Nex1 could regulate the activity of the GAP-43 promoter. We found that among the members of the NeuroD subfamily, Nex1 promoted maximal activity of the GAP-43 promoter. The Nex1-mediated activity is restricted to the conserved E1-E2 cluster located near the major transcription start sites. By electrophoretic mobility shift assay and site-directed mutagenesis, we showed that Nex1 binds as homodimers and that the E1 E-box is a high affinity binding site. We further found that Nex1 released the ME1 E-protein-mediated repression in a concentration dependent manner. Thus, the E1-E2 cluster has a dual function: it can mediate activation or repression depending on the interacting bHLH proteins. Finally, a series of N-terminal and C-terminal deletions revealed that Nex1 transcriptional activity is linked to two distinct transactivation domains, TAD1 and TAD2, with TAD1 being unique to Nex1. Together, our results suggest that Nex1 may engage in selective interactions with components of the core transcriptional machinery whose assembly is dictated by the architecture of the GAP-43 promoter and cellular environment.
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Affiliation(s)
- Martine Uittenbogaard
- Department of Anatomy and Cell Biology, George Washington University Medical Center, Washington DC, USA
| | - Debra L. Martinka
- Department of Anatomy and Cell Biology, George Washington University Medical Center, Washington DC, USA
- Program of Neuroscience, George Washington University Medical Center, Washington DC, USA
| | - Anne Chiaramello
- Department of Anatomy and Cell Biology, George Washington University Medical Center, Washington DC, USA
- Program of Neuroscience, George Washington University Medical Center, Washington DC, USA
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