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England SJ, Campbell PC, Banerjee S, Bates RL, Grieb G, Fancher WF, Lewis KE. Transcriptional regulators with broad expression in the zebrafish spinal cord. Dev Dyn 2024. [PMID: 38850245 DOI: 10.1002/dvdy.717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2024] [Revised: 04/12/2024] [Accepted: 05/15/2024] [Indexed: 06/10/2024] Open
Abstract
BACKGROUND The spinal cord is a crucial part of the vertebrate CNS, controlling movements and receiving and processing sensory information from the trunk and limbs. However, there is much we do not know about how this essential organ develops. Here, we describe expression of 21 transcription factors and one transcriptional regulator in zebrafish spinal cord. RESULTS We analyzed the expression of aurkb, foxb1a, foxb1b, her8a, homeza, ivns1abpb, mybl2b, myt1a, nr2f1b, onecut1, sall1a, sall3a, sall3b, sall4, sox2, sox19b, sp8b, tsc22d1, wdhd1, zfhx3b, znf804a, and znf1032 in wild-type and MIB E3 ubiquitin protein ligase 1 zebrafish embryos. While all of these genes are broadly expressed in spinal cord, they have distinct expression patterns from one another. Some are predominantly expressed in progenitor domains, and others in subsets of post-mitotic cells. Given the conservation of spinal cord development, and the transcription factors and transcriptional regulators that orchestrate it, we expect that these genes will have similar spinal cord expression patterns in other vertebrates, including mammals and humans. CONCLUSIONS Our data identify 22 different transcriptional regulators that are strong candidates for playing different roles in spinal cord development. For several of these genes, this is the first published description of their spinal cord expression.
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Affiliation(s)
| | - Paul C Campbell
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Santanu Banerjee
- Biological Sciences Department, SUNY-Cortland, Cortland, New York, USA
| | - Richard L Bates
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Ginny Grieb
- Department of Biology, Syracuse University, Syracuse, New York, USA
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2
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Causeret F, Fayon M, Moreau MX, Ne E, Oleari R, Parras C, Cariboni A, Pierani A. Diversity within olfactory sensory derivatives revealed by the contribution of Dbx1 lineages. J Comp Neurol 2023. [PMID: 37125418 DOI: 10.1002/cne.25492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2022] [Revised: 03/06/2023] [Accepted: 04/12/2023] [Indexed: 05/02/2023]
Abstract
In vertebrates, the embryonic olfactory epithelium contains progenitors that will give rise to distinct classes of neurons, including olfactory sensory neurons (OSNs; involved in odor detection), vomeronasal sensory neurons (VSNs; responsible for pheromone sensing), and gonadotropin-releasing hormone (GnRH) neurons that control the hypothalamic-pituitary-gonadal axis. Currently, these three neuronal lineages are usually believed to emerge from uniform pools of progenitors. Here, we found that the homeodomain transcription factor Dbx1 is expressed by neurogenic progenitors in the developing and adult mouse olfactory epithelium. We demonstrate that Dbx1 itself is dispensable for neuronal fate specification and global organization of the olfactory sensory system. Using lineage tracing, we characterize the contribution of Dbx1 lineages to OSN, VSN, and GnRH neuron populations and reveal an unexpected degree of diversity. Furthermore, we demonstrate that Dbx1-expressing progenitors remain neurogenic in the absence of the proneural gene Ascl1. Our work therefore points to the existence of distinct neurogenic programs in Dbx1-derived and other olfactory lineages.
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Affiliation(s)
- Frédéric Causeret
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, France
| | - Maxime Fayon
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, France
| | - Matthieu X Moreau
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, France
| | - Enrico Ne
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, France
| | - Roberto Oleari
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Carlos Parras
- Sorbonne Université, UPMC University Paris 06, Inserm U1127, CNRS UMR 7225, GH Pitié-Salpêtrière, Institut du Cerveau et de la Moelle Épinière, ICM, Paris, France
| | - Anna Cariboni
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, Milan, Italy
| | - Alessandra Pierani
- Université Paris Cité, Imagine Institute, Team Genetics and Development of the Cerebral Cortex, Paris, France
- Université Paris Cité, Institute of Psychiatry and Neuroscience of Paris, INSERM U1266, Paris, France
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3
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Alper SR, Dorsky RI. Unique advantages of zebrafish larvae as a model for spinal cord regeneration. Front Mol Neurosci 2022; 15:983336. [PMID: 36157068 PMCID: PMC9489991 DOI: 10.3389/fnmol.2022.983336] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/18/2022] [Indexed: 11/30/2022] Open
Abstract
The regenerative capacity of the spinal cord in mammals ends at birth. In contrast, teleost fish and amphibians retain this capacity throughout life, leading to the use of the powerful zebrafish model system to identify novel mechanisms that promote spinal cord regeneration. While adult zebrafish offer an effective comparison with non-regenerating mammals, they lack the complete array of experimental approaches that have made this animal model so successful. In contrast, the optical transparency, simple anatomy and complex behavior of zebrafish larvae, combined with the known conservation of pro-regenerative signals and cell types between larval and adult stages, suggest that they may hold even more promise as a system for investigating spinal cord regeneration. In this review, we highlight characteristics and advantages of the larval model that underlie its potential to provide future therapeutic approaches for treating human spinal cord injury.
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Mukaigasa K, Sakuma C, Yaginuma H. The developmental hourglass model is applicable to the spinal cord based on single-cell transcriptomes and non-conserved cis-regulatory elements. Dev Growth Differ 2021; 63:372-391. [PMID: 34473348 PMCID: PMC9293469 DOI: 10.1111/dgd.12750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 08/24/2021] [Accepted: 08/26/2021] [Indexed: 11/27/2022]
Abstract
The developmental hourglass model predicts that embryonic morphology is most conserved at the mid‐embryonic stage and diverges at the early and late stages. To date, this model has been verified by examining the anatomical features or gene expression profiles at the whole embryonic level. Here, by data mining approach utilizing multiple genomic and transcriptomic datasets from different species in combination, and by experimental validation, we demonstrate that the hourglass model is also applicable to a reduced element, the spinal cord. In the middle of spinal cord development, dorsoventrally arrayed neuronal progenitor domains are established, which are conserved among vertebrates. By comparing the publicly available single‐cell transcriptome datasets of mice and zebrafish, we found that ventral subpopulations of post‐mitotic spinal neurons display divergent molecular profiles. We also detected the non‐conservation of cis‐regulatory elements located around the progenitor fate determinants, indicating that the cis‐regulatory elements contributing to the progenitor specification are evolvable. These results demonstrate that, despite the conservation of the progenitor domains, the processes before and after the progenitor domain specification diverged. This study will be helpful to understand the molecular basis of the developmental hourglass model.
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Affiliation(s)
- Katsuki Mukaigasa
- Department of Neuroanatomy and Embryology, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Chie Sakuma
- Department of Neuroanatomy and Embryology, School of Medicine, Fukushima Medical University, Fukushima, Japan
| | - Hiroyuki Yaginuma
- Department of Neuroanatomy and Embryology, School of Medicine, Fukushima Medical University, Fukushima, Japan
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He R, Zhang X, Ding L. DBX2 promotes glioblastoma cell proliferation by regulating REST expression. Curr Pharm Biotechnol 2021; 23:1101-1108. [PMID: 34463226 DOI: 10.2174/1389201022666210830142827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 07/07/2021] [Accepted: 07/08/2021] [Indexed: 11/22/2022]
Abstract
BACKGROUND Glioblastoma (GBM) is the most common but lethal brain cancer with poor prognosis. The developing brain homeobox 2 (DBX2) has been reported to play important roles in tumor growth. However, the mechanisms of DBX2 in GBM are still unknown. OBJECTIVE This study aims to investigate the function and mechanisms of DBX2 in GBM. METHODS The expressions of DBX2 and REST in GBM were measured by analyzing data from databases, and the results were checked by qPCR and/or western blot of GBM cell lines. Cell proliferation was determined by CCK8 assay, immunohistochemistry and colony formation assay. ChIP-qPCR was used to determine the binding sites of DBX2 on REST. RESULTS In this study, we found that the expression of DBX2 was upregulated in the GBM cell lines. The cell proliferation was damaged after blocking DBX2 expression in U87 and U251 GBM cell lines. The expression level of DBX2 had a positive relationship with that of REST. Our ChIP-qPCR results showed that DBX2 is directly bound to the promoter region of REST. Additionally, the increased GBM cell proliferation caused by DBX2 overexpression can be rescued by REST loss of function. CONCLUSION DBX2 could promote cell proliferation of GBM by binding to the promoter region of REST gene and increasing REST expression.
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Affiliation(s)
- Ruixing He
- Neurosurgery Department, the Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University, Jiangsu. China
| | - Xiaotian Zhang
- Neurosurgery Department, Hongze Huai'an District People's Hospital, Jiangsu. China
| | - Lianshu Ding
- Neurosurgery Department, the Affiliated Huai'an No.1 People's Hospital of Nanjing Medical University, Jiangsu. China
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6
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Juárez-Morales JL, Weierud F, England SJ, Demby C, Santos N, Grieb G, Mazan S, Lewis KE. Evolution of lbx spinal cord expression and function. Evol Dev 2021; 23:404-422. [PMID: 34411410 DOI: 10.1111/ede.12387] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Revised: 06/04/2021] [Accepted: 06/21/2021] [Indexed: 11/29/2022]
Abstract
Ladybird homeobox (Lbx) transcription factors have crucial functions in muscle and nervous system development in many animals. Amniotes have two Lbx genes, but only Lbx1 is expressed in spinal cord. In contrast, teleosts have three lbx genes and we show here that zebrafish lbx1a, lbx1b, and lbx2 are expressed by distinct spinal cell types, and that lbx1a is expressed in dI4, dI5, and dI6 interneurons, as in amniotes. Our data examining lbx expression in Scyliorhinus canicula and Xenopus tropicalis suggest that the spinal interneuron expression of zebrafish lbx1a is ancestral, whereas lbx1b has acquired a new expression pattern in spinal cord progenitor cells. lbx2 spinal expression was probably acquired in the ray-finned lineage, as this gene is not expressed in the spinal cords of either amniotes or S. canicula. We also show that the spinal function of zebrafish lbx1a is conserved with mouse Lbx1. In zebrafish lbx1a mutants, there is a reduction in the number of inhibitory spinal interneurons and an increase in the number of excitatory spinal interneurons, similar to mouse Lbx1 mutants. Interestingly, the number of inhibitory spinal interneurons is also reduced in lbx1b mutants, although in this case the number of excitatory interneurons is not increased. lbx1a;lbx1b double mutants have a similar spinal interneuron phenotype to lbx1a single mutants. Taken together these data suggest that lbx1b and lbx1a may be required in succession for correct specification of dI4 and dI6 spinal interneurons, although only lbx1a is required for suppression of excitatory fates in these cells.
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Affiliation(s)
| | - Frida Weierud
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK
| | | | - Celia Demby
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Nicole Santos
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Ginny Grieb
- Department of Biology, Syracuse University, Syracuse, New York, USA
| | - Sylvie Mazan
- Biologie Intégrative des Organismes Marins, UMR 7232 CNRS, Observatoire Océanologique, Sorbonne Université, Banyuls-sur-Mer, France
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7
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Zhang X, Wang Y, Zhao S, Qin Q, Zhang M, Jiang Y, Zhu H, Li H. Low expression of developing brain homeobox 2 (Dbx2) may serve as a biomarker to predict poor prognosis in endometrial cancer. Am J Transl Res 2021; 13:4738-4748. [PMID: 34150054 PMCID: PMC8205784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 02/02/2021] [Indexed: 06/12/2023]
Abstract
OBJECTIVE For investigating Dbx2's expression in endometrial cancer (EC) and its effect on prognosis of patients with EC. METHODS A comparison was performed in the Cancer Genome Atlas (TCGA) database in terms of the expression profiling of EC and the survival data. To obtain differential expression genes (DEGs), Volcano plot and Venn analysis were adopted. DEGs function was performed by carrying out the GO annotation analysis (GO) and gene set enrichment analysis (GSEA). In clinical EC samples, PCR was applied to the verification of Dbx2's expression. RESULTS Dbx2 was a downregulated expression in tumor tissues. Dbx2 can have a poor prognosis role in EC by regulating the apoptotic signaling pathway and the immune pathway. Lower expression of Dbx2 was related to lymph node metastasis and FIGO stage. CONCLUSION Dbx2 is downregulated in endometrial cancer, which serves as a biomarker to predict poor prognosis.
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Affiliation(s)
- Xinlu Zhang
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Yaping Wang
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Shujun Zhao
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
- Zhengzhou Key Laboratory of Gynecological Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Qiaohong Qin
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
- Zhengzhou Key Laboratory of Gynecological Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Min Zhang
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Yi Jiang
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Hai Zhu
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
| | - Hongyu Li
- Gynecologic Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
- Zhengzhou Key Laboratory of Gynecological Oncology, The Third Affiliated Hospital of Zhengzhou UniversityZhengzhou 450000, Henan, P. R. China
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8
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Tsai TYC, Sikora M, Xia P, Colak-Champollion T, Knaut H, Heisenberg CP, Megason SG. An adhesion code ensures robust pattern formation during tissue morphogenesis. Science 2020; 370:113-116. [PMID: 33004519 PMCID: PMC7879479 DOI: 10.1126/science.aba6637] [Citation(s) in RCA: 48] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Accepted: 07/27/2020] [Indexed: 12/14/2022]
Abstract
Animal development entails the organization of specific cell types in space and time, and spatial patterns must form in a robust manner. In the zebrafish spinal cord, neural progenitors form stereotypic patterns despite noisy morphogen signaling and large-scale cellular rearrangements during morphogenesis and growth. By directly measuring adhesion forces and preferences for three types of endogenous neural progenitors, we provide evidence for the differential adhesion model in which differences in intercellular adhesion mediate cell sorting. Cell type-specific combinatorial expression of different classes of cadherins (N-cadherin, cadherin 11, and protocadherin 19) results in homotypic preference ex vivo and patterning robustness in vivo. Furthermore, the differential adhesion code is regulated by the sonic hedgehog morphogen gradient. We propose that robust patterning during tissue morphogenesis results from interplay between adhesion-based self-organization and morphogen-directed patterning.
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Affiliation(s)
- Tony Y-C Tsai
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston MA 02115, USA
| | - Mateusz Sikora
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuberg, Austria
| | - Peng Xia
- Institute of Science and Technology Austria, Am Campus 1, 3400 Klosterneuberg, Austria
| | - Tugba Colak-Champollion
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | - Holger Knaut
- Skirball Institute of Biomolecular Medicine, New York University School of Medicine, 540 First Avenue, New York, NY 10016, USA
| | | | - Sean G Megason
- Department of Systems Biology, Harvard Medical School, 200 Longwood Avenue, Boston MA 02115, USA.
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Moskalev AA, Shaposhnikov MV, Zemskaya NV, Koval LА, Schegoleva EV, Guvatova ZG, Krasnov GS, Solovev IA, Sheptyakov MA, Zhavoronkov A, Kudryavtseva AV. Transcriptome Analysis of Long-lived Drosophila melanogaster E(z) Mutants Sheds Light on the Molecular Mechanisms of Longevity. Sci Rep 2019; 9:9151. [PMID: 31235842 PMCID: PMC6591219 DOI: 10.1038/s41598-019-45714-x] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Accepted: 06/11/2019] [Indexed: 12/15/2022] Open
Abstract
The E(z) histone methyltransferase heterozygous mutation in Drosophila is known to increase lifespan and stress resistance. However, the longevity mechanisms of E(z) mutants have not been revealed. Using genome-wide transcriptome analysis, we demonstrated that lifespan extension, increase of resistance to hyperthermia, oxidative stress and endoplasmic reticulum stress, and fecundity enhancement in E(z) heterozygous mutants are accompanied by changes in the expression level of 239 genes (p < 0.05). Our results demonstrated sex-specific effects of E(z) mutation on gene expression, which, however, did not lead to differences in lifespan extension in both sexes. We observed that a mutation in an E(z) gene leads to perturbations in gene expression, most of which participates in metabolism, such as Carbohydrate metabolism, Lipid metabolism, Drug metabolism, Nucleotide metabolism. Age-dependent changes in the expression of genes involved in pathways related to immune response, cell cycle, and ribosome biogenesis were found.
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Affiliation(s)
- Alexey A Moskalev
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia. .,Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia. .,Moscow Institute of Physics and Technology, Dolgoprudny, Russia.
| | | | - Nadezhda V Zemskaya
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
| | - Liubov А Koval
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
| | - Eugenia V Schegoleva
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
| | - Zulfiya G Guvatova
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - George S Krasnov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
| | - Ilya A Solovev
- Institute of Biology of Komi Science Center of Ural Branch of RAS, Syktyvkar, Russia
| | | | | | - Anna V Kudryavtseva
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Moscow, Russia
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Hu YT, Li BF, Zhang PJ, Wu D, Li YY, Li ZW, Shen L, Dong B, Gao J, Zhu X. Dbx2 exhibits a tumor-promoting function in hepatocellular carcinoma cell lines via regulating Shh-Gli1 signaling. World J Gastroenterol 2019; 25:923-940. [PMID: 30833799 PMCID: PMC6397724 DOI: 10.3748/wjg.v25.i8.923] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 12/25/2018] [Accepted: 12/28/2018] [Indexed: 02/06/2023] Open
Abstract
BACKGROUND Hepatocellular carcinoma (HCC) is the fifth most common cancer worldwide. HCC patients suffer from a high mortality-to-incidence ratio and low cure rate since we still have no specific and effective treatment. Although tremendous advances have been made in the investigation of HCC, the specific mechanisms of the progression of this disease are still only partially established. Hence, more research is needed to elucidate the underlying potential mechanisms to develop effective strategies for HCC.
AIM To determine the role of developing brain homeobox 2 (Dbx2) gene in promoting the development of HCC.
METHODS Dbx2 expression in clinical specimens and HCC cell lines was detected by Western blot (WB) and immunohistochemistry. Gain and loss of Dbx2 function assays were performed in vitro and in vivo. Cell viability assays were used to investigate cell growth, flow cytometry was employed to assess cell cycle and apoptosis, and trans-well assays were conducted to evaluate cell migration, invasion, and metastasis. The expression of key molecules in the sonic hedgehog (Shh) signaling was determined by WB.
RESULTS Compared to matched adjacent non-tumorous tissues, Dbx2 was overexpressed in 5 HCC cell lines and 76 surgically resected HCC tissues. Dbx2 overexpression was correlated with large tumor size. Both gain and loss of function assays indicated that Dbx2 promoted HCC cell proliferation by facilitating the transition from G1 to S phase, attenuating apoptosis and promoted HCC proliferation, migration, and invasion in vitro and in vivo. Mechanistically, Dbx2 modulated Shh signaling by enhancing FTCH1 and GLi1 expression in HCC cells that overexpressed Dbx2, which was reversed in HCC cells with Dbx2 knockdown.
CONCLUSION Our results indicate that Dbx2 is significantly upregulated in HCC tissues and plays significant roles in proliferation and metastasis of HCC cells by activating the Shh pathway.
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Affiliation(s)
- Yan-Ting Hu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Bei-Fang Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Peng-Jun Zhang
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Interventional Therapy, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Di Wu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Interventional Therapy, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Yan-Yan Li
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | | | - Lin Shen
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Bin Dong
- Key laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Pathology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Jing Gao
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Gastrointestinal Oncology, Peking University Cancer Hospital and Institute, Beijing 100142, China
| | - Xu Zhu
- Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education/Beijing), Department of Interventional Therapy, Peking University Cancer Hospital and Institute, Beijing 100142, China
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11
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Lee KK, Lee JG, Park CS, Lee SH, Raja N, Yun HS, Lee JS, Lee CS. Bone-targeting carbon dots: effect of nitrogen-doping on binding affinity. RSC Adv 2019; 9:2708-2717. [PMID: 35520477 PMCID: PMC9059868 DOI: 10.1039/c8ra09729a] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Accepted: 01/01/2019] [Indexed: 11/23/2022] Open
Abstract
Novel fluorescent carbon dots (CDs) for bone imaging were fabricated via a facile hydrothermal method using alendronate in the absence of a nitrogen-doping precursor to enhance bone affinity. One-step synthesized alendronate-based CDs (Alen-CDs) had strong binding activity for calcium-deficient hydroxyapatite (CDHA, the mineral component of bones) scaffold, rat femur, and bone structures of live zebrafish. This was attributed to the bisphosphonate group present on the CD surface, even after carbonization. For comparison, the surface effects of nitrogen-doped CDs obtained using ethylenediamine (EDA), i.e., Alen-EDA-CDs, were also investigated, focusing on the targeting ability of distinct surface functional groups when compared with Alen-CDs. An in vivo study to assess the impact on bone affinity revealed that Alen-CDs effectively accumulated in the bone structures of live zebrafish larvae after microinjections, as well as in the bone tissues of femur extracted from rats. Moreover, Alen-CD-treated zebrafish larvae had superior toleration, retaining skeletal fluorescence for 7 days post-injection (dpi). The sustainable capability, surpassing that of Alizarin Red S, suggests that Alen-CDs have the potential for targeted drug delivery to damaged bone tissues and provides motivation for additional in vivo investigations. To our knowledge, this is the first in vitro, ex vivo, and in vivo demonstration of direct bone-targeted deliveries, supporting the use of fluorescent CDs in the treatment of various bone diseases such as osteoporosis, Paget's disease, and metastatic bone cancer. Fluorescent carbon dots selectively bind to skull tissues with high affinity, including a strong binding activity for calcium deficient hydroxyapatite, and rat femur, for bone targeted imaging.![]()
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Affiliation(s)
- Kyung Kwan Lee
- Hazards Monitoring BNT Research Center
- Korea Research Institute of Bioscience and Biotechnology (KRIBB)
- Daejeon 34141
- Republic of Korea
- Department of Chemical Engineering and Applied Chemistry
| | - Jae-Geun Lee
- Disease Target Structure Research Center
- Korea Research Institute of Bioscience and Biotechnology (KRIBB)
- Daejeon
- Republic of Korea
- Department of Biotechnology
| | - Chul Soon Park
- Department of Polymer Engineering
- Chonnam National University
- Gwangju 61186
- Republic of Korea
| | - Sun Hyeok Lee
- Hazards Monitoring BNT Research Center
- Korea Research Institute of Bioscience and Biotechnology (KRIBB)
- Daejeon 34141
- Republic of Korea
- Department of Biotechnology
| | - Naren Raja
- Department of Biotechnology
- University of Science & Technology (UST)
- Daejeon 34113
- Republic of Korea
- Powder and Ceramics Division
| | - Hui-suk Yun
- Department of Biotechnology
- University of Science & Technology (UST)
- Daejeon 34113
- Republic of Korea
- Powder and Ceramics Division
| | - Jeong-Soo Lee
- Disease Target Structure Research Center
- Korea Research Institute of Bioscience and Biotechnology (KRIBB)
- Daejeon
- Republic of Korea
- Department of Biotechnology
| | - Chang-Soo Lee
- Hazards Monitoring BNT Research Center
- Korea Research Institute of Bioscience and Biotechnology (KRIBB)
- Daejeon 34141
- Republic of Korea
- Department of Biotechnology
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12
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Peng Z, Miyanji EH, Zhou Y, Pardo J, Hettiarachchi SD, Li S, Blackwelder PL, Skromne I, Leblanc RM. Carbon dots: promising biomaterials for bone-specific imaging and drug delivery. NANOSCALE 2017; 9:17533-17543. [PMID: 29110000 PMCID: PMC5691292 DOI: 10.1039/c7nr05731h] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
Bone-related diseases and dysfunctions are heavy burdens on our increasingly aged society. One important strategy to relieve this problem is through early detection and treatment of bone-related diseases. Towards this goal, there has been constant interest in developing novel bone-specific materials for imaging and drug delivery. Currently, however, materials that have high affinity and specificity towards bone are very limited. Carbon dots (C-dots) synthesized from carbon nanopowder bind to calcified bones in vivo with high affinity and specificity. In this study we show that bone binding is highly unique to a specific type of C-dot, and that this binding is non-toxic. Significantly, C-dots derived from other raw materials did not show any bone binding properties. These differences are attributed to the differences in surface chemistry of C-dot preparations, highlighting the heterogeneous nature of C-dots. Importantly, bone-binding by carbon nanopowder derived C-dots is not significantly altered by chemical functionalization of their surface. These unique properties indicate the potential applications of carbon nanopowder-derived C-dots as highly bone-specific bioimaging agents and drug carriers.
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Affiliation(s)
- Zhili Peng
- College of Pharmacy and Chemistry, Dali University, Dali, Yunnan, 671000, P. R. China
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
| | - Esmail H. Miyanji
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
| | - Yiqun Zhou
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
| | - Joel Pardo
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
| | - Sajini D. Hettiarachchi
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
| | - Shanghao Li
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
- MP Biomedicals, 3 Hutton Center Dr. #100, Santa Ana, CA 92707, United States
| | - Patricia L. Blackwelder
- Center for Advanced Microscopy and Marine Geosciences, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
- Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania, Florida, 33004, United States
| | - Isaac Skromne
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
- Departmnt of Biology, University of Richmond, 28 Westhampton Way, Richmond, Virginia, 23173, United States
| | - Roger M. Leblanc
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida, 33146, United States
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13
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Roberson S, Halpern ME. Convergence of signaling pathways underlying habenular formation and axonal outgrowth in zebrafish. Development 2017; 144:2652-2662. [PMID: 28619821 DOI: 10.1242/dev.147751] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 06/07/2017] [Indexed: 12/20/2022]
Abstract
The habenular nuclei are a conserved integrating center in the vertebrate epithalamus, where they modulate diverse behaviors. Despite their importance, our understanding of habenular development is incomplete. Time-lapse imaging and fate mapping demonstrate that the dorsal habenulae (dHb) of zebrafish are derived from dbx1b-expressing (dbx1b+ ) progenitors, which transition into cxcr4b-expressing neuronal precursors. The precursors give rise to differentiated neurons, the axons of which innervate the midbrain interpeduncular nucleus (IPN). Formation of the dbx1b+ progenitor population relies on the activity of the Shh, Wnt and Fgf signaling pathways. Wnt and Fgf function additively to generate dHb progenitors. Surprisingly, Wnt signaling also negatively regulates fgf8a, confining expression to a discrete dorsal diencephalic domain. Moreover, the Wnt and Fgf pathways have opposing roles in transcriptional regulation of components of the Cxcr4-chemokine signaling pathway. The chemokine pathway, in turn, directs the posterior outgrowth of dHb efferents toward the IPN and, when disrupted, results in ectopic, anteriorly directed axonal projections. The results define a signaling network underlying the generation of dHb neurons and connectivity with their midbrain target.
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Affiliation(s)
- Sara Roberson
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA.,Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
| | - Marnie E Halpern
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA .,Department of Embryology, Carnegie Institution for Science, Baltimore, MD 21218, USA
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14
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Danesin C, Soula C. Moving the Shh Source over Time: What Impact on Neural Cell Diversification in the Developing Spinal Cord? J Dev Biol 2017; 5:jdb5020004. [PMID: 29615562 PMCID: PMC5831764 DOI: 10.3390/jdb5020004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Revised: 03/29/2017] [Accepted: 04/06/2017] [Indexed: 12/18/2022] Open
Abstract
A substantial amount of data has highlighted the crucial influence of Shh signalling on the generation of diverse classes of neurons and glial cells throughout the developing central nervous system. A critical step leading to this diversity is the establishment of distinct neural progenitor cell domains during the process of pattern formation. The forming spinal cord, in particular, has served as an excellent model to unravel how progenitor cells respond to Shh to produce the appropriate pattern. In recent years, considerable advances have been made in our understanding of important parameters that control the temporal and spatial interpretation of the morphogen signal at the level of Shh-receiving progenitor cells. Although less studied, the identity and position of Shh source cells also undergo significant changes over time, raising the question of how moving the Shh source contributes to cell diversification in response to the morphogen. Here, we focus on the dynamics of Shh-producing cells and discuss specific roles for these time-variant Shh sources with regard to the temporal events occurring in the receiving field.
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Affiliation(s)
- Cathy Danesin
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31520 Toulouse, France.
| | - Cathy Soula
- Centre de Biologie du Développement (CBD) CNRS/UPS, Centre de Biologie Intégrative (CBI), Université de Toulouse, 31520 Toulouse, France.
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15
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Juárez-Morales JL, Martinez-De Luna RI, Zuber ME, Roberts A, Lewis KE. Zebrafish transgenic constructs label specific neurons in Xenopus laevis spinal cord and identify frog V0v spinal neurons. Dev Neurobiol 2017; 77:1007-1020. [PMID: 28188691 DOI: 10.1002/dneu.22490] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2016] [Revised: 01/26/2017] [Accepted: 02/08/2017] [Indexed: 12/19/2022]
Abstract
A correctly functioning spinal cord is crucial for locomotion and communication between body and brain but there are fundamental gaps in our knowledge of how spinal neuronal circuitry is established and functions. To understand the genetic program that regulates specification and functions of this circuitry, we need to connect neuronal molecular phenotypes with physiological analyses. Studies using Xenopus laevis tadpoles have increased our understanding of spinal cord neuronal physiology and function, particularly in locomotor circuitry. However, the X. laevis tetraploid genome and long generation time make it difficult to investigate how neurons are specified. The opacity of X. laevis embryos also makes it hard to connect functional classes of neurons and the genes that they express. We demonstrate here that Tol2 transgenic constructs using zebrafish enhancers that drive expression in specific zebrafish spinal neurons label equivalent neurons in X. laevis and that the incorporation of a Gal4:UAS amplification cassette enables cells to be observed in live X. laevis tadpoles. This technique should enable the molecular phenotypes, morphologies and physiologies of distinct X. laevis spinal neurons to be examined together in vivo. We have used an islet1 enhancer to label Rohon-Beard sensory neurons and evx enhancers to identify V0v neurons, for the first time, in X. laevis spinal cord. Our work demonstrates the homology of spinal cord circuitry in zebrafish and X. laevis, suggesting that future work could combine their relative strengths to elucidate a more complete picture of how vertebrate spinal cord neurons are specified, and function to generate behavior. © 2017 Wiley Periodicals, Inc. Develop Neurobiol 77: 1007-1020, 2017.
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Affiliation(s)
- José L Juárez-Morales
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244.,Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, United Kingdom
| | - Reyna I Martinez-De Luna
- The Center for Vision Research, Department of Ophthalmology, SUNY Upstate Medical University, Institute for Human Performance, 505 Irving Ave. Syracuse, New York, 13210
| | - Michael E Zuber
- The Center for Vision Research, Department of Ophthalmology, SUNY Upstate Medical University, Institute for Human Performance, 505 Irving Ave. Syracuse, New York, 13210
| | - Alan Roberts
- School of Biological Sciences, Bristol University, 24 Tyndall Avenue, Bristol, BS8 1TQ, United Kingdom
| | - Katharine E Lewis
- Department of Biology, Syracuse University, 107 College Place, Syracuse, New York, 13244
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16
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Li S, Skromne I, Peng Z, Dallman J, Al-Youbi AO, Bashammakh AS, El-Shahawi MS, Leblanc RM. "Dark" carbon dots specifically "light-up" calcified zebrafish bones. J Mater Chem B 2016; 4:7398-7405. [PMID: 32263740 DOI: 10.1039/c6tb02241c] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Because accidents, disease and aging compromise the structural and physiological functions of bones, the development of an in vivo bone imaging test is critical to identify, detect and diagnose bone related development and dysfunctions. Recent advances in fluorescence instrumentation offer a new alternative for traditional bone imaging methods. However, the development of new in vivo bone imaging fluorescence materials has significantly lagged behind. Here we show that carbon dot nanoparticles (C-dots) with low quantum yield ("dark") bind to calcified bone structures of live zebrafish larvae with high affinity and selectivity. Binding resulted in a strong enhancement of luminescence that was not observed in other tissues, including non-calcified endochondral elements. Retention of C-dots by bones was very stable, long lasting, and with no detectable toxicity. Furthermore, we found C-dots to be a suitable carrier to deliver fluorescein to bones. These observations support a novel and revolutionary use of C-dots as highly specific bioagents for bone imaging and diagnosis, and as bone-specific drug delivery vehicles.
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Affiliation(s)
- Shanghao Li
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, Florida 33146, USA.
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17
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Karaz S, Courgeon M, Lepetit H, Bruno E, Pannone R, Tarallo A, Thouzé F, Kerner P, Vervoort M, Causeret F, Pierani A, D'Onofrio G. Neuronal fate specification by the Dbx1 transcription factor is linked to the evolutionary acquisition of a novel functional domain. EvoDevo 2016; 7:18. [PMID: 27525057 PMCID: PMC4983035 DOI: 10.1186/s13227-016-0055-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 07/27/2016] [Indexed: 12/18/2022] Open
Abstract
Background Dbx1 is a homeodomain transcription factor involved in neuronal fate specification belonging to a widely conserved family among bilaterians. In mammals, Dbx1 was proposed to act as a transcriptional repressor by interacting with the Groucho corepressors to allow the specification of neurons involved in essential biological functions such as locomotion or breathing. Results Sequence alignments of Dbx1 proteins from different species allowed us to identify two conserved domains related to the Groucho-dependent Engrailed repressor domain (RD), as well as a newly described domain composed of clusterized acidic residues at the C-terminus (Cter) which is present in tetrapods but also several invertebrates. Using a heterologous luciferase assay, we showed that the two putative repressor domains behave as such in a Groucho-dependent manner, whereas the Cter does not bear any intrinsic transcriptional activity. Consistently with in vitro data, we found that both RDs are involved in cell fate specification using in vivo electroporation experiments in the chick spinal cord. Surprisingly, we show that the Cter domain is required for Dbx1 function in vivo, acting as a modulator of its repressive activity and/or imparting specificity. Conclusion Our results strongly suggest that the presence of a Cter domain among tetrapods is essential for Dbx1 to regulate neuronal diversity and, in turn, nervous system complexity. Electronic supplementary material The online version of this article (doi:10.1186/s13227-016-0055-5) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Sonia Karaz
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Maximilien Courgeon
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Hélène Lepetit
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Eugenia Bruno
- Dept. BEOM, Stazione Zoologica A. Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Raimondo Pannone
- Dept. BEOM, Stazione Zoologica A. Dohrn, Villa Comunale, 80121 Naples, Italy
| | - Andrea Tarallo
- Dept. BEOM, Stazione Zoologica A. Dohrn, Villa Comunale, 80121 Naples, Italy
| | - France Thouzé
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Pierre Kerner
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Michel Vervoort
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Frédéric Causeret
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Alessandra Pierani
- Institut Jacques Monod, CNRS UMR 7592, Université Paris Diderot, Sorbonne Paris Cité, 75205 Paris Cedex, France
| | - Giuseppe D'Onofrio
- Dept. BEOM, Stazione Zoologica A. Dohrn, Villa Comunale, 80121 Naples, Italy
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18
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Ghosh S, Hui SP. Regeneration of Zebrafish CNS: Adult Neurogenesis. Neural Plast 2016; 2016:5815439. [PMID: 27382491 PMCID: PMC4921647 DOI: 10.1155/2016/5815439] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Accepted: 04/18/2016] [Indexed: 12/13/2022] Open
Abstract
Regeneration in the animal kingdom is one of the most fascinating problems that have allowed scientists to address many issues of fundamental importance in basic biology. However, we came to know that the regenerative capability may vary across different species. Among vertebrates, fish and amphibians are capable of regenerating a variety of complex organs through epimorphosis. Zebrafish is an excellent animal model, which can repair several organs like damaged retina, severed spinal cord, injured brain and heart, and amputated fins. The focus of the present paper is on spinal cord regeneration in adult zebrafish. We intend to discuss our current understanding of the cellular and molecular mechanism(s) that allows formation of proliferating progenitors and controls neurogenesis, which involve changes in epigenetic and transcription programs. Unlike mammals, zebrafish retains radial glia, a nonneuronal cell type in their adult central nervous system. Injury induced proliferation involves radial glia which proliferate, transcribe embryonic genes, and can give rise to new neurons. Recent technological development of exquisite molecular tools in zebrafish, such as cell ablation, lineage analysis, and novel and substantial microarray, together with advancement in stem cell biology, allowed us to investigate how progenitor cells contribute to the generation of appropriate structures and various underlying mechanisms like reprogramming.
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Affiliation(s)
- Sukla Ghosh
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
| | - Subhra Prakash Hui
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, 92 A. P. C. Road, Kolkata 700009, India
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19
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Li S, Peng Z, Dallman J, Baker J, Othman AM, Blackwelder PL, Leblanc RM. Crossing the blood-brain-barrier with transferrin conjugated carbon dots: A zebrafish model study. Colloids Surf B Biointerfaces 2016; 145:251-256. [PMID: 27187189 DOI: 10.1016/j.colsurfb.2016.05.007] [Citation(s) in RCA: 82] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/02/2016] [Accepted: 05/04/2016] [Indexed: 12/22/2022]
Abstract
Drug delivery to the central nervous system (CNS) in biological systems remains a major medical challenge due to the tight junctions between endothelial cells known as the blood-brain-barrier (BBB). Here we use a zebrafish model to explore the possibility of using transferrin-conjugated carbon dots (C-Dots) to ferry compounds across the BBB. C-Dots have previously been reported to inhibit protein fibrillation, and they are also used to deliver drugs for disease treatment. In terms of the potential medical application of C-Dots for the treatment of CNS diseases, one of the most formidable challenges is how to deliver them inside the CNS. To achieve this in this study, human transferrin was covalently conjugated to C-Dots. The conjugates were then injected into the vasculature of zebrafish to examine the possibility of crossing the BBB in vivo via transferrin receptor-mediated endocytosis. The experimental observations suggest that the transferrin-C-Dots can enter the CNS while C-Dots alone cannot.
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Affiliation(s)
- Shanghao Li
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33146, United States
| | - Zhili Peng
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33146, United States
| | - Julia Dallman
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33146, United States
| | - James Baker
- Department of Biology, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33146, United States
| | - Abdelhameed M Othman
- Department of Chemistry, Faculty of Science in Yanbu, Taibah University, Yanbu, Saudi Arabia; Department of Environmental Biotechnology, Genetic Engineering and Biotechnology, University of Sadat City, Sadat City, Egypt
| | - Patrica L Blackwelder
- University of Miami Center for Advanced Microscopy and Marine Geosciences, 1301 Memorial Drive, University of Miami, Coral Gables, FL, 33146, United States; Nova Southeastern University Oceanographic Center, 8000 North Ocean Drive, Dania, FL, 33004, United States
| | - Roger M Leblanc
- Department of Chemistry, University of Miami, 1301 Memorial Drive, Coral Gables, FL, 33146, United States.
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20
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Juárez-Morales JL, Schulte CJ, Pezoa SA, Vallejo GK, Hilinski WC, England SJ, de Jager S, Lewis KE. Evx1 and Evx2 specify excitatory neurotransmitter fates and suppress inhibitory fates through a Pax2-independent mechanism. Neural Dev 2016; 11:5. [PMID: 26896392 PMCID: PMC4759709 DOI: 10.1186/s13064-016-0059-9] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/04/2016] [Indexed: 01/04/2023] Open
Abstract
BACKGROUND For neurons to function correctly in neuronal circuitry they must utilize appropriate neurotransmitters. However, even though neurotransmitter specificity is one of the most important and defining properties of a neuron we still do not fully understand how neurotransmitter fates are specified during development. Most neuronal properties are determined by the transcription factors that neurons express as they start to differentiate. While we know a few transcription factors that specify the neurotransmitter fates of particular neurons, there are still many spinal neurons for which the transcription factors specifying this critical phenotype are unknown. Strikingly, all of the transcription factors that have been identified so far as specifying inhibitory fates in the spinal cord act through Pax2. Even Tlx1 and Tlx3, which specify the excitatory fates of dI3 and dI5 spinal neurons work at least in part by down-regulating Pax2. METHODS In this paper we use single and double mutant zebrafish embryos to identify the spinal cord functions of Evx1 and Evx2. RESULTS We demonstrate that Evx1 and Evx2 are expressed by spinal cord V0v cells and we show that these cells develop into excitatory (glutamatergic) Commissural Ascending (CoSA) interneurons. In the absence of both Evx1 and Evx2, V0v cells still form and develop a CoSA morphology. However, they lose their excitatory fate and instead express markers of a glycinergic fate. Interestingly, they do not express Pax2, suggesting that they are acquiring their inhibitory fate through a novel Pax2-independent mechanism. CONCLUSIONS Evx1 and Evx2 are required, partially redundantly, for spinal cord V0v cells to become excitatory (glutamatergic) interneurons. These results significantly increase our understanding of the mechanisms of neuronal specification and the genetic networks involved in these processes.
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Affiliation(s)
- José L Juárez-Morales
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - Claus J Schulte
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Sofia A Pezoa
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - Grace K Vallejo
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - William C Hilinski
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.,Department of Neuroscience and Physiology, SUNY Upstate Medical University, 505 Irving Avenue, Syracuse, NY, 13210, USA
| | - Samantha J England
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA
| | - Sarah de Jager
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge, CB2 3DY, UK
| | - Katharine E Lewis
- Department of Biology, Syracuse University, 107 College Place, Syracuse, NY, 13244, USA.
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21
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Kuan YS, Roberson S, Akitake CM, Fortuno L, Gamse J, Moens C, Halpern ME. Distinct requirements for Wntless in habenular development. Dev Biol 2015; 406:117-128. [PMID: 26116173 PMCID: PMC4639407 DOI: 10.1016/j.ydbio.2015.06.006] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 06/05/2015] [Indexed: 01/24/2023]
Abstract
Secreted Wnt proteins play pivotal roles in development, including regulation of cell proliferation, differentiation, progenitor maintenance and tissue patterning. The transmembrane protein Wntless (Wls) is necessary for secretion of most Wnts and essential for effective Wnt signaling. During a mutagenesis screen to identify genes important for development of the habenular nuclei in the dorsal forebrain, we isolated a mutation in the sole wls gene of zebrafish and confirmed its identity with a second, independent allele. Early embryonic development appears normal in homozygous wls mutants, but they later lack the ventral habenular nuclei, form smaller dorsal habenulae and otic vesicles, have truncated jaw and fin cartilages and lack swim bladders. Activation of a reporter for β-catenin-dependent transcription is decreased in wls mutants, indicative of impaired signaling by the canonical Wnt pathway, and expression of Wnt-responsive genes is reduced in the dorsal diencephalon. Wnt signaling was previously implicated in patterning of the zebrafish brain and in the generation of left-right (L-R) differences between the bilaterally paired dorsal habenular nuclei. Outside of the epithalamic region, development of the brain is largely normal in wls mutants and, despite their reduced size, the dorsal habenulae retain L-R asymmetry. We find that homozygous wls mutants show a reduction in two cell populations that contribute to the presumptive dorsal habenulae. The results support distinct temporal requirements for Wls in habenular development and reveal a new role for Wnt signaling in the regulation of dorsal habenular progenitors.
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Affiliation(s)
- Yung-Shu Kuan
- Department of Embryology, Carnegie Institution for Science, USA
| | - Sara Roberson
- Department of Embryology, Carnegie Institution for Science, USA
- Department of Biology, Johns Hopkins University, USA
| | - Courtney M. Akitake
- Department of Embryology, Carnegie Institution for Science, USA
- Department of Biology, Johns Hopkins University, USA
| | - Lea Fortuno
- Department of Embryology, Carnegie Institution for Science, USA
| | - Joshua Gamse
- Department of Biological Sciences, Vanderbilt University, USA
| | - Cecilia Moens
- Division of Basic Sciences, Fred Hutchinson Cancer Research Center, USA
| | - Marnie E. Halpern
- Department of Embryology, Carnegie Institution for Science, USA
- Department of Biology, Johns Hopkins University, USA
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22
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Dean BJ, Erdogan B, Gamse JT, Wu SY. Dbx1b defines the dorsal habenular progenitor domain in the zebrafish epithalamus. Neural Dev 2014; 9:20. [PMID: 25212830 PMCID: PMC4164515 DOI: 10.1186/1749-8104-9-20] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2014] [Accepted: 09/01/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND The conserved habenular nuclei function as a relay system connecting the forebrain with the brain stem. They play crucial roles in various cognitive behaviors by modulating cholinergic, dopaminergic and serotonergic activities. Despite the renewed interest in this conserved forebrain region because of its importance in regulating aversion and reward behaviors, the formation of the habenular nuclei during embryogenesis is poorly understood due to their small size and deep location in the brain, as well as the lack of known markers for habenular progenitors. In zebrafish, the bilateral habenular nuclei are subdivided into dorsal and ventral compartments, are particularly large and found on the dorsal surface of the brain, which facilitates the study of their development. RESULTS Here we examine the expression of a homeodomain transcription factor, dbx1b, and its potential to serve as an early molecular marker of dorsal habenular progenitors. Detailed spatiotemporal expression profiles demonstrate that the expression domain of dbx1b correlates with the presumptive habenular region, and dbx1b-expressing cells are proliferative along the ventricle. A lineage-tracing experiment using the Cre-lox system confirms that all or almost all dorsal habenular neurons are derived from dbx1b-expressing cells. In addition, mutant analysis and pharmacological treatments demonstrate that both initiation and maintenance of dbx1b expression requires precise regulation by fibroblast growth factor (FGF) signaling. CONCLUSIONS We provide clear evidence in support of dbx1b marking the progenitor populations that give rise to the dorsal habenulae. In addition, the expression of dbx1b in the dorsal diencephalon is tightly controlled by FGF signaling.
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Affiliation(s)
| | | | | | - Shu-Yu Wu
- Department of Biological Sciences, Vanderbilt University, Box 351634 Station B, Nashville, TN 37235-1634, USA.
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23
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Li L, Chen H, Yin C, Yang C, Wang B, Zheng S, Zhang J, Fan W. Mapping breakpoints of a familial chromosome insertion (18,7) (q22.1; q36.2q21.11) to DPP6 and CACNA2D1 genes in an azoospermic male. Gene 2014; 547:43-9. [PMID: 24937803 DOI: 10.1016/j.gene.2014.06.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2014] [Revised: 06/03/2014] [Accepted: 06/05/2014] [Indexed: 11/16/2022]
Abstract
It is widely accepted that the incidence of chromosomal aberration is 10-15.2% in the azoospermic male; however, the exact genetic damages are currently unknown for more than 40% of azoospermia. To elucidate the causative gene defects, we used the next generation sequencing (NGS) to map the breakpoints of a chromosome insertion from an azoospermic male who carries a balanced, maternally inherited karyotype 46, XY, inv ins (18,7) (q22.1; q36.2q21.11). The analysis revealed that the breakage in chromosome 7 disrupts two genes, dipeptidyl aminopeptidase-like protein 6 (DPP6) and contactin-associated protein-like 2 (CACNA2D1), the former participates in regulation of voltage-gated potassium channels, and the latter is one of the components in voltage-gated calcium channels. The deletion and duplication were not identified equal or beyond 100 kb, but 4 homologous DNA elements were verified proximal to the breakpoints. One of the proband's sisters inherited the same aberrant karyotype and experienced recurrent miscarriages and consecutive fetus death, while in contrast, another sister with a normal karyotype experienced normal labor and gave birth to healthy babies. The insertional translocation is confirmed with FISH and the Y-chromosome microdeletions were excluded by genetic testing. This is the first report describing chromosome insertion inv ins (18,7) and attributes DPP6 and CACNA2D1 to azoospermia.
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Affiliation(s)
- Lin Li
- Institute of Medical Genetics, Linyi People's Hospital, Shandong 276003, China
| | - Haixiao Chen
- BGI, 11-2 Building, Northern Industry District, Shenzhen 518083, China
| | - Chenxing Yin
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Hebei University School of Life Sciences, Baoding, Hebei 071002, China
| | - Chuanchun Yang
- BGI, 11-2 Building, Northern Industry District, Shenzhen 518083, China
| | - Bei Wang
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Hebei University School of Life Sciences, Baoding, Hebei 071002, China
| | - Shuqi Zheng
- Institute of Medical Genetics, Linyi People's Hospital, Shandong 276003, China
| | - Jixia Zhang
- Institute of Medical Genetics, Linyi People's Hospital, Shandong 276003, China
| | - Wufang Fan
- Key Laboratory of Medicinal Chemistry and Molecular Diagnosis, Hebei University School of Life Sciences, Baoding, Hebei 071002, China
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24
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Briona LK, Dorsky RI. Radial glial progenitors repair the zebrafish spinal cord following transection. Exp Neurol 2014; 256:81-92. [PMID: 24721238 DOI: 10.1016/j.expneurol.2014.03.017] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2013] [Revised: 03/22/2014] [Accepted: 03/25/2014] [Indexed: 01/21/2023]
Abstract
In mammals, spinal cord injury results in permanent sensory-motor loss due in part to a failure in reinitiating local neurogenesis. However, zebrafish show robust neuronal regeneration and functional recovery even after complete spinal cord transection. Postembryonic neurogenesis is dependent upon resident multipotent progenitors, which have been identified in multiple vertebrates. One candidate cell population for injury repair expresses Dbx1, which has been shown to label multipotent progenitors in mammals. In this study, we use specific markers to show that cells expressing a dbx1a:GFP reporter in the zebrafish spinal cord are radial glial progenitors that continue to generate neurons after embryogenesis. We also use a novel larval spinal cord transection assay to show that dbx1a:GFP(+) cells exhibit a proliferative and neurogenic response to injury, and contribute newly-born neurons to the regenerative blastema. Together, our data indicate that dbx1a:GFP(+) radial glia may be stem cells for the regeneration of interneurons following spinal cord injury in zebrafish.
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Affiliation(s)
- Lisa K Briona
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84112, USA.
| | - Richard I Dorsky
- Department of Neurobiology & Anatomy, University of Utah, Salt Lake City, UT 84112, USA.
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25
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Achim K, Salminen M, Partanen J. Mechanisms regulating GABAergic neuron development. Cell Mol Life Sci 2014; 71:1395-415. [PMID: 24196748 PMCID: PMC11113277 DOI: 10.1007/s00018-013-1501-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 12/17/2022]
Abstract
Neurons using gamma-aminobutyric acid (GABA) as their neurotransmitter are the main inhibitory neurons in the mature central nervous system (CNS) and show great variation in their form and function. GABAergic neurons are produced in all of the main domains of the CNS, where they develop from discrete regions of the neuroepithelium. Here, we review the gene expression and regulatory mechanisms controlling the main steps of GABAergic neuron development: early patterning of the proliferative neuroepithelium, production of postmitotic neural precursors, establishment of their identity and migration. By comparing the molecular regulation of these events across CNS, we broadly identify three regions utilizing distinct molecular toolkits for GABAergic fate determination: telencephalon-anterior diencephalon (DLX2 type), posterior diencephalon-midbrain (GATA2 type) and hindbrain-spinal cord (PTF1A and TAL1 types). Similarities and differences in the molecular regulatory mechanisms reveal the core determinants of a GABAergic neuron as well as provide insights into generation of the vast diversity of these neurons.
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Affiliation(s)
- Kaia Achim
- EMBL Heidelberg, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Marjo Salminen
- Department of Veterinary Biosciences, University of Helsinki, Agnes Sjobergin katu 2, PO Box 66, 00014 Helsinki, Finland
| | - Juha Partanen
- Department of Biosciences, University of Helsinki, Viikinkaari 5, PO Box 56, 00014 Helsinki, Finland
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26
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Beck AP, Watt RM, Bonner J. Dissection and lateral mounting of zebrafish embryos: analysis of spinal cord development. J Vis Exp 2014:e50703. [PMID: 24637734 PMCID: PMC4140612 DOI: 10.3791/50703] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
The zebrafish spinal cord is an effective investigative model for nervous system research for several reasons. First, genetic, transgenic and gene knockdown approaches can be utilized to examine the molecular mechanisms underlying nervous system development. Second, large clutches of developmentally synchronized embryos provide large experimental sample sizes. Third, the optical clarity of the zebrafish embryo permits researchers to visualize progenitor, glial, and neuronal populations. Although zebrafish embryos are transparent, specimen thickness can impede effective microscopic visualization. One reason for this is the tandem development of the spinal cord and overlying somite tissue. Another reason is the large yolk ball, which is still present during periods of early neurogenesis. In this article, we demonstrate microdissection and removal of the yolk in fixed embryos, which allows microscopic visualization while preserving surrounding somite tissue. We also demonstrate semipermanent mounting of zebrafish embryos. This permits observation of neurodevelopment in the dorso-ventral and anterior-posterior axes, as it preserves the three-dimensionality of the tissue.
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27
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England S, Batista MF, Mich JK, Chen JK, Lewis KE. Roles of Hedgehog pathway components and retinoic acid signalling in specifying zebrafish ventral spinal cord neurons. Development 2012; 138:5121-34. [PMID: 22069186 DOI: 10.1242/dev.066159] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
In mouse, Hedgehog (Hh) signalling is required for most ventral spinal neurons to form. Here, we analyse the spinal cord phenotype of zebrafish maternal-zygotic smoothened (MZsmo) mutants that completely lack Hh signalling. We find that most V3 domain cells and motoneurons are lost, whereas medial floorplate still develops normally and V2, V1 and V0v cells form in normal numbers. This phenotype resembles that of mice that lack both Hh signalling and Gli repressor activity. Ventral spinal cord progenitor domain transcription factors are not expressed at 24 hpf in zebrafish MZsmo mutants. However, pMN, p2 and p1 domain markers are expressed at early somitogenesis stages in these mutants. This suggests that Gli repressor activity does not extend into zebrafish ventral spinal cord at these stages, even in the absence of Hh signalling. Consistent with this, ectopic expression of Gli3R represses ventral progenitor domain expression at these early stages and knocking down Gli repressor activity rescues later expression. We investigated whether retinoic acid (RA) signalling specifies ventral spinal neurons in the absence of Hh signalling. The results suggest that RA is required for the correct number of many different spinal neurons to form. This is probably mediated, in part, by an effect on cell proliferation. However, V0v, V1 and V2 cells are still present, even in the absence of both Hh and RA signalling. We demonstrate that Gli1 has a Hh-independent role in specifying most of the remaining motoneurons and V3 domain cells in embryos that lack Hh signalling, but removal of Gli1 activity does not affect more dorsal neurons.
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Affiliation(s)
- Samantha England
- Biology Department, Syracuse University, 107 College Place, Syracuse, NY 13244, USA
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28
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Ma P, Zhao S, Zeng W, Yang Q, Li C, Lv X, Zhou Q, Mao B. Xenopus Dbx2 is involved in primary neurogenesis and early neural plate patterning. Biochem Biophys Res Commun 2011; 412:170-4. [PMID: 21806971 DOI: 10.1016/j.bbrc.2011.07.068] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2011] [Accepted: 07/18/2011] [Indexed: 12/19/2022]
Abstract
The evolutionarily conserved Dbx homeodomain-containing proteins play important roles in the development of vertebrate central nervous system. In mouse, Dbx and Nkx6 have been suggested to be cross-repressive partners involved in the patterning of ventral neural tube. Here, we have isolated Xenopus Dbx2 and studied its developmental expression and function during neural development. Like XDbx1, from mid-neurula stage on, XDbx2 is expressed in stripes between the primary motoneurons and interneurons. At the tailbud stages, it is detected in the middle region of the neural tube. XDbx2 acts as a transcriptional repressor in vitro and over-expression of XDbx2 inhibits primary neurogenesis in Xenopus embryos. Over-expression of XDbx genes represses the expression of XNkx6.2 and vise versa. Knockdown of either XDbx1, XDbx2 or both by specific morpholinos induces lateral expansion of XNkx6.2 expression domains. These data reveal conserved roles for Dbx in primary neurogenesis and dorsoventral neural patterning in Xenopus.
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Affiliation(s)
- Pengcheng Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming 650223, China
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29
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Harrison MRM, Georgiou AS, Spaink HP, Cunliffe VT. The epigenetic regulator Histone Deacetylase 1 promotes transcription of a core neurogenic programme in zebrafish embryos. BMC Genomics 2011; 12:24. [PMID: 21226904 PMCID: PMC3032698 DOI: 10.1186/1471-2164-12-24] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2010] [Accepted: 01/12/2011] [Indexed: 12/29/2022] Open
Abstract
Background The epigenetic regulator Histone Deacetylase 1 (Hdac1) is required for specification and patterning of neurones and myelinating glia during development of the vertebrate central nervous system (CNS). This co-ordinating function for Hdac1 is evolutionarily conserved in zebrafish and mouse, but the mechanism of action of Hdac1 in the developing CNS is not well-understood. Results A genome-wide comparative analysis of the transcriptomes of Hdac1-deficient and wild-type zebrafish embryos was performed, which identified an extensive programme of gene expression that is regulated by Hdac1 in the developing embryo. Using time-resolved expression profiling of embryos, we then identified a small subset of 54 genes within the Hdac1-regulated transcriptome that specifically exhibit robust and sustained Hdac1-dependent expression from early neurogenesis onwards. 18 of these 54 stringently Hdac1-regulated genes encode DNA-binding transcription factors that are implicated in promoting neuronal specification and CNS patterning, including the proneural bHLH proteins Ascl1a and Ascl1b, as well as Neurod4 and Neurod. Relatively few genes are strongly repressed by Hdac1 but expression of the Notch target gene her6 is attenuated by Hdac1 in specific sub-regions of the developing CNS, from early stages of neurogenesis onwards. Selected members of the stringently Hdac1-regulated group of genes were tested for Hdac1 binding to their promoter-proximal cis-regulatory elements. Surprisingly, we found that Hdac1 is specifically and stably associated with DNA sequences within the promoter region of ascl1b during neurogenesis, and that this Hdac1-ascl1b interaction is abolished in hdac1 mutant embryos. Conclusions We conclude that Hdac1 regulates histone acetylation and methylation in the developing zebrafish embryo and promotes the sustained, co-ordinate transcription of a small set of transcription factor genes that control expansion and diversification of cell fates within the developing CNS. Our in vivo chromatin immunoprecipitation results also suggest a specific function for Hdac1 in directly regulating transcription of a key member of this group of genes, ascl1b, from the beginning of neurogenesis onwards. Taken together, our observations indicate a novel role for Hdac1 as a positive regulator of gene transcription during development of the vertebrate CNS, in addition to its more well-established function in transcriptional repression.
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Affiliation(s)
- Michael R M Harrison
- MRC Centre for Developmental and Biomedical Genetics, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, United Kingdom
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30
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Winterbottom EF, Illes JC, Faas L, Isaacs HV. Conserved and novel roles for the Gsh2 transcription factor in primary neurogenesis. Development 2010; 137:2623-31. [DOI: 10.1242/dev.047159] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The Gsx genes encode members of the ParaHox family of homeodomain transcription factors, which are expressed in the developing central nervous system in members of all major groups of bilaterians. The Gsx genes in Xenopus show similar patterns of expression to their mammalian homologues during late development. However, they are also expressed from early neurula stages in an intermediate region of the open neural plate where primary interneurons form. The Gsx homologue in the protostome Drosophila is expressed in a corresponding intermediate region of the embryonic neuroectoderm, and is essential for the correct specification of the neuroblasts that arise from it, suggesting that Gsx genes may have played a role in intermediate neural specification in the last common bilaterian ancestor. Here, we show that manipulation of Gsx function disrupts the differentiation of primary interneurons. We demonstrate that, despite their similar expression patterns, the uni-directional system of interactions between homeodomain transcription factors from the Msx, Nkx and Gsx families in the Drosophila neuroectoderm is not conserved between their homologues in the Xenopus open neural plate. Finally, we report the identification of Dbx1 as a direct target of Gsh2-mediated transcriptional repression, and show that a series of cross-repressive interactions, reminiscent of those that exist in the amniote neural tube, act between Gsx, Dbx and Nkx transcription factors to pattern the medial aspect of the central nervous system at open neural plate stages in Xenopus.
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Affiliation(s)
| | - Jean C. Illes
- Area 11, Department of Biology, University of York, York YO10 5YW, UK
| | - Laura Faas
- Area 11, Department of Biology, University of York, York YO10 5YW, UK
| | - Harry V. Isaacs
- Area 11, Department of Biology, University of York, York YO10 5YW, UK
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31
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Gribble SL, Nikolaus OB, Carver MS, Hoshijima K, Dorsky RI. Chromosomal position mediates spinal cord expression of a dbx1a enhancer. Dev Dyn 2010; 238:2929-35. [PMID: 19842185 DOI: 10.1002/dvdy.22122] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Dbx homeodomain proteins are important for the production of multiple spinal cord cell types. To examine the regulation of Dbx genes in more detail, we have generated transgenic zebrafish in which fluorescent protein expression is driven by predicted dbx1a enhancers. We identified three areas of sequence conservation upstream of the dbx1a coding sequence and generated fluorescent reporter constructs driven by these predicted enhancer elements and the endogenous dbx1a promoter. In multiple stable insertions of a 3.5-kb enhancer fragment, we observed that there was additional reporter expression in the dorsal spinal cord not normally observed by dbx1a in situ hybridization. In addition, these lines exhibited only transient reporter expression, unlike the endogenous gene. Surprisingly, a single insertion line expressed the reporter in the endogenous pattern, indicating that other local regulatory elements modulate gene expression through the 3.5-kb enhancer.
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Affiliation(s)
- Suzanna L Gribble
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, Utah 84132-3401, USA
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32
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Lacin H, Zhu Y, Wilson BA, Skeath JB. dbx mediates neuronal specification and differentiation through cross-repressive, lineage-specific interactions with eve and hb9. Development 2009; 136:3257-66. [PMID: 19710170 DOI: 10.1242/dev.037242] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Individual neurons adopt and maintain defined morphological and physiological phenotypes as a result of the expression of specific combinations of transcription factors. In particular, homeodomain-containing transcription factors play key roles in determining neuronal subtype identity in flies and vertebrates. dbx belongs to the highly divergent H2.0 family of homeobox genes. In vertebrates, Dbx1 and Dbx2 promote the development of a subset of interneurons, some of which help mediate left-right coordination of locomotor activity. Here, we identify and show that the single Drosophila ortholog of Dbx1/2 contributes to the development of specific subsets of interneurons via cross-repressive, lineage-specific interactions with the motoneuron-promoting factors eve and hb9 (exex). dbx is expressed primarily in interneurons of the embryonic, larval and adult central nervous system, and these interneurons tend to extend short axons and be GABAergic. Interestingly, many Dbx(+) interneurons share a sibling relationship with Eve(+) or Hb9(+) motoneurons. The non-overlapping expression of dbx and eve, or dbx and hb9, within pairs of sibling neurons is initially established as a result of Notch/Numb-mediated asymmetric divisions. Cross-repressive interactions between dbx and eve, and dbx and hb9, then help maintain the distinct expression profiles of these genes in their respective pairs of sibling neurons. Strict maintenance of the mutually exclusive expression of dbx relative to that of eve and hb9 in sibling neurons is crucial for proper neuronal specification, as misexpression of dbx in motoneurons dramatically hinders motor axon outgrowth.
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Affiliation(s)
- Haluk Lacin
- Program in Developmental Biology, Washington University School of Medicine, St Louis, MO 63110, USA
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33
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Cerda GA, Hargrave M, Lewis KE. RNA profiling of FAC-sorted neurons from the developing zebrafish spinal cord. Dev Dyn 2009; 238:150-61. [PMID: 19097188 DOI: 10.1002/dvdy.21818] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
In this report, we describe a successful protocol for isolating and expression-profiling live fluorescent-protein-labelled neurons from zebrafish embryos. As a proof-of-principle for this method, we FAC-sorted and RNA-profiled GFP-labelled spinal CiA interneurons and compared the expression profile of these cells to those of post-mitotic spinal neurons in general and to all trunk cells. We show that RNA of sufficient quality and quantity to uncover both expected and novel transcription profiles via Affymetrix microarray analysis can be extracted from 5,700 to 20,000 FAC-sorted cells. As part of this study, we also further confirm the genetic homology of mammalian and zebrafish V1 interneurons, by demonstrating that zebrafish V1 cells (CiAs) express genes that encode for the transcription factors Lhx1a and Lhx5. This protocol for dissociating, sorting and RNA-profiling neurons from organogenesis-stage zebrafish embryos should also be applicable to other developing organs and tissues and potentially other model organisms.
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Affiliation(s)
- Gustavo A Cerda
- Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, United Kingdom
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34
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Gribble SL, Kim HS, Bonner J, Wang X, Dorsky RI. Tcf3 inhibits spinal cord neurogenesis by regulating sox4a expression. Development 2009; 136:781-9. [PMID: 19176587 DOI: 10.1242/dev.027995] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The Lef/Tcf factor Tcf3 is expressed throughout the developing vertebrate central nervous system (CNS), but its function and transcriptional targets are uncharacterized. Tcf3 is thought to mediate canonical Wnt signaling, which functions in CNS patterning, proliferation and neurogenesis. In this study, we examine Tcf3 function in the zebrafish spinal cord, and find that this factor does not play a general role in patterning, but is required for the proper expression of Dbx genes in intermediate progenitors. In addition, we show that Tcf3 is required to inhibit premature neurogenesis in spinal progenitors by repressing sox4a, a known mediator of spinal neurogenesis. Both of these functions are mediated by Tcf3 independently of canonical Wnt signaling. Together, our data indicate a novel mechanism for the regulation of neurogenesis by Tcf3-mediated repression.
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Affiliation(s)
- Suzanna L Gribble
- Department of Neurobiology and Anatomy, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
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35
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Recent Papers on Zebrafish and Other Aquarium Fish Models. Zebrafish 2007. [DOI: 10.1089/zeb.2007.9977] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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36
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Proliferation and patterning are mediated independently in the dorsal spinal cord downstream of canonical Wnt signaling. Dev Biol 2007; 313:398-407. [PMID: 18062957 DOI: 10.1016/j.ydbio.2007.10.041] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2007] [Revised: 10/23/2007] [Accepted: 10/25/2007] [Indexed: 01/16/2023]
Abstract
Canonical Wnt signaling can regulate proliferation and patterning in the developing spinal cord, but the relationship between these functions has remained elusive. It has been difficult to separate the distinct activities of Wnts because localized changes in proliferation could conceivably alter patterning, and gain and loss of function experiments have resulted in both types of defects. To resolve this issue we have investigated canonical Wnt signaling in the zebrafish spinal cord using multiple approaches. We demonstrate that Wnt signaling is required initially for proliferation throughout the entire spinal cord, and later for patterning dorsal progenitor domains. Furthermore, we find that spinal cord patterning is normal in embryos after cell division has been pharmacologically blocked. Finally, we determine the transcriptional mediators of Wnt signaling that are responsible for patterning and proliferation. We show that tcf7 gene knockdown results in dorsal patterning defects without decreasing the mitotic index in dorsal domains. In contrast, tcf3 gene knockdown results in a reduced mitotic index without affecting dorsal patterning. Together, our work demonstrates that proliferation and patterning in the developing spinal cord are separable events that are regulated independently by Wnt signaling.
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