51
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Delbaere J, Vancamp P, Van Herck SLJ, Bourgeois NMA, Green MJ, Wingate RJT, Darras VM. MCT8 deficiency in Purkinje cells disrupts embryonic chicken cerebellar development. J Endocrinol 2017; 232:259-272. [PMID: 27879339 DOI: 10.1530/joe-16-0323] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 11/21/2016] [Indexed: 01/17/2023]
Abstract
Inactivating mutations in the human SLC16A2 gene encoding the thyroid hormone transporter monocarboxylate transporter 8 (MCT8) result in the Allan-Herndon-Dudley syndrome accompanied by severe locomotor deficits. The underlying mechanisms of the associated cerebellar maldevelopment were studied using the chicken as a model. Electroporation of an MCT8-RNAi vector into the cerebellar anlage of a 3-day-old embryo allowed knockdown of MCT8 in Purkinje cell precursors. This resulted in the downregulation of the thyroid hormone-responsive gene RORα and the Purkinje cell-specific differentiation marker LHX1/5 at day 6. MCT8 knockdown also results in a smaller and less complex dendritic tree at day 18 suggesting a pivotal role of MCT8 for cell-autonomous Purkinje cell maturation. Early administration of the thyroid hormone analogue 3,5,3'-triiodothyroacetic acid partially rescued early Purkinje cell differentiation. MCT8-deficient Purkinje cells also induced non-autonomous effects as they led to a reduced granule cell precursor proliferation, a thinner external germinal layer and a loss of PAX6 expression. By contrast, at day 18, the external germinal layer thickness was increased, with an increase in presence of Axonin-1-positive post-mitotic granule cells in the initial stage of radial migration. The concomitant accumulation of presumptive migrating granule cells in the molecular layer, suggests that inward radial migration to the internal granular layer is stalled. In conclusion, early MCT8 deficiency in Purkinje cells results in both cell-autonomous and non-autonomous effects on cerebellar development and indicates that MCT8 expression is essential from very early stages of development, providing a novel insight into the ontogenesis of the Allan-Herndon-Dudley syndrome.
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Affiliation(s)
- Joke Delbaere
- Laboratory of Comparative EndocrinologyDepartment of Biology, KU Leuven, Leuven, Belgium
| | - Pieter Vancamp
- Laboratory of Comparative EndocrinologyDepartment of Biology, KU Leuven, Leuven, Belgium
| | - Stijn L J Van Herck
- Laboratory of Comparative EndocrinologyDepartment of Biology, KU Leuven, Leuven, Belgium
| | - Nele M A Bourgeois
- Laboratory of Comparative EndocrinologyDepartment of Biology, KU Leuven, Leuven, Belgium
| | - Mary J Green
- Medical Research Council Centre for Developmental NeurobiologyKing's College London, London, UK
| | - Richard J T Wingate
- Medical Research Council Centre for Developmental NeurobiologyKing's College London, London, UK
| | - Veerle M Darras
- Laboratory of Comparative EndocrinologyDepartment of Biology, KU Leuven, Leuven, Belgium
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52
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Lim FT, Ogawa S, Smith AI, Parhar IS. Proteomics Identification of Potential Candidates Involved in Cell Proliferation for Early Stage of Brain Regeneration in the Adult Zebrafish. Zebrafish 2017; 14:10-22. [DOI: 10.1089/zeb.2016.1319] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Affiliation(s)
- Fei Tieng Lim
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - Satoshi Ogawa
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Bandar Sunway, Malaysia
| | - A. Ian Smith
- Department of Biochemistry and Molecular Biology, School of Biomedical Sciences, Faculty of Medicine, Nursing and Health Sciences, Monash University, Melbourne, Australia
| | - Ishwar S. Parhar
- Brain Research Institute, Jeffrey Cheah School of Medicine and Health Science, Monash University Malaysia, Bandar Sunway, Malaysia
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53
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Ediger BN, Lim HW, Juliana C, Groff DN, Williams LT, Dominguez G, Liu JH, Taylor BL, Walp ER, Kameswaran V, Yang J, Liu C, Hunter CS, Kaestner KH, Naji A, Li C, Sander M, Stein R, Sussel L, Won KJ, May CL, Stoffers DA. LIM domain-binding 1 maintains the terminally differentiated state of pancreatic β cells. J Clin Invest 2016; 127:215-229. [PMID: 27941246 DOI: 10.1172/jci88016] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Accepted: 10/13/2016] [Indexed: 12/11/2022] Open
Abstract
The recognition of β cell dedifferentiation in type 2 diabetes raises the translational relevance of mechanisms that direct and maintain β cell identity. LIM domain-binding protein 1 (LDB1) nucleates multimeric transcriptional complexes and establishes promoter-enhancer looping, thereby directing fate assignment and maturation of progenitor populations. Many terminally differentiated endocrine cell types, however, remain enriched for LDB1, but its role is unknown. Here, we have demonstrated a requirement for LDB1 in maintaining the terminally differentiated status of pancreatic β cells. Inducible ablation of LDB1 in mature β cells impaired insulin secretion and glucose homeostasis. Transcriptomic analysis of LDB1-depleted β cells revealed the collapse of the terminally differentiated gene program, indicated by a loss of β cell identity genes and induction of the endocrine progenitor factor neurogenin 3 (NEUROG3). Lineage tracing confirmed that LDB1-depleted, insulin-negative β cells express NEUROG3 but do not adopt alternate endocrine cell fates. In primary mouse islets, LDB1 and its LIM homeodomain-binding partner islet 1 (ISL1) were coenriched at chromatin sites occupied by pancreatic and duodenal homeobox 1 (PDX1), NK6 homeobox 1 (NKX6.1), forkhead box A2 (FOXA2), and NK2 homeobox 2 (NKX2.2) - factors that co-occupy active enhancers in 3D chromatin domains in human islets. Indeed, LDB1 was enriched at active enhancers in human islets. Thus, LDB1 maintains the terminally differentiated state of β cells and is a component of active enhancers in both murine and human islets.
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Rogdaki M, Jauhar S, McCutcheon R, Howes O. Treatment-Resistant Schizophrenia in a Patient With 17q12 Duplication. Biol Psychiatry 2016; 80:e19-e20. [PMID: 26582588 DOI: 10.1016/j.biopsych.2015.10.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/26/2015] [Revised: 09/30/2015] [Accepted: 10/01/2015] [Indexed: 11/26/2022]
Affiliation(s)
- Maria Rogdaki
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College.
| | - Sameer Jauhar
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College
| | - Robert McCutcheon
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College
| | - Oliver Howes
- Department of Psychosis Studies, Institute of Psychiatry, Psychology and Neuroscience, King's College; Psychiatric Imaging, MRC Clinical Sciences Centre, Hammersmith Hospital, London, United Kingdom
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55
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Olig2 regulates Purkinje cell generation in the early developing mouse cerebellum. Sci Rep 2016; 6:30711. [PMID: 27469598 PMCID: PMC4965836 DOI: 10.1038/srep30711] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Accepted: 07/07/2016] [Indexed: 02/06/2023] Open
Abstract
The oligodendrocyte transcription factor Olig2 plays a crucial role in the neurogenesis of both spinal cord and brain. In the cerebellum, deletion of both Olig2 and Olig1 results in impaired genesis of Purkinje cells (PCs) and Pax2+ interneurons. Here, we perform an independent study to show that Olig2 protein is transiently expressed in the cerebellar ventricular zone (VZ) during a period when PCs are specified. Further analyses demonstrate that Olig2 is expressed in both cerebellar VZ progenitors and early-born neurons. In addition, unlike in the ganglionic eminence of the embryonic forebrain where Olig2 is mostly expressed in proliferating progenitors, Olig2+ cells in the cerebellar VZ are in the process of leaving the cell cycle and differentiating into postmitotic neurons. Functionally, deletion of Olig2 alone results in a preferential reduction of PCs in the cerebellum, which is likely mediated by decreased neuronal generation from their cerebellar VZ progenitors. Furthermore, our long-term lineage tracing experiments show that cerebellar Olig gene-expressing progenitors produce PCs but rarely Pax2+ interneurons in the developing cerebellum, which opposes the “temporal identity transition” model of the cerebellar VZ progenitors stating that majority of Pax2+ interneuron progenitors are transitioned from Olig2+ PC progenitors.
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González-Peñas J, Amigo J, Santomé L, Sobrino B, Brenlla J, Agra S, Paz E, Páramo M, Carracedo Á, Arrojo M, Costas J. Targeted resequencing of regulatory regions at schizophrenia risk loci: Role of rare functional variants at chromatin repressive states. Schizophr Res 2016; 174:10-16. [PMID: 27066855 DOI: 10.1016/j.schres.2016.03.029] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 03/24/2016] [Indexed: 12/30/2022]
Abstract
There is mounting evidence that regulatory variation plays an important role in genetic risk for schizophrenia. Here, we specifically search for regulatory variants at risk by sequencing promoter regions of twenty-three genes implied in schizophrenia by copy number variant or genome-wide association studies. After strict quality control, a total of 55,206bp per sample were analyzed in 526 schizophrenia cases and 516 controls from Galicia, NW Spain, using the Applied Biosystems SOLiD System. Variants were filtered based on frequency from public databases, chromatin states from the RoadMap Epigenomics Consortium at tissues relevant for schizophrenia, such as fetal brain, mid-frontal lobe, and angular gyrus, and prediction of functionality from RegulomeDB. The proportion of rare variants at polycomb repressive chromatin state at relevant tissues was higher in cases than in controls. The proportion of rare variants with predicted regulatory role was significantly higher in cases than in controls (P=0.0028, OR=1.93, 95% C.I.=1.23-3.04). Combination of information from both sources led to the identification of an excess of carriers of rare variants with predicted regulatory role located at polycomb repressive chromatin state at relevant tissues in cases versus controls (P=0.0016, OR=19.34, 95% C.I.=2.45-2495.26). The variants are located at two genes affected by the 17q12 copy number variant, LHX1 and HNF1B. These data strongly suggest that a specific epigenetic mechanism, chromatin remodeling by histone modification during early development, may be impaired in a subset of schizophrenia patients, in agreement with previous data.
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Affiliation(s)
- Javier González-Peñas
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Jorge Amigo
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain; Fundación Pública Galega de Medicina Xenómica, Complexo Hospitalario Universitario de Santiago (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Luis Santomé
- Fundación Pública Galega de Medicina Xenómica, Complexo Hospitalario Universitario de Santiago (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Beatriz Sobrino
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain; Fundación Pública Galega de Medicina Xenómica, Complexo Hospitalario Universitario de Santiago (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Julio Brenlla
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Servizo de Psiquiatría, Complexo Hospitalario Universitario de Santiago de Compostela, Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Santiago Agra
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Servizo de Psiquiatría, Complexo Hospitalario Universitario de Santiago de Compostela, Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Eduardo Paz
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Servizo de Psiquiatría, Complexo Hospitalario Universitario de Santiago de Compostela, Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Mario Páramo
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Servizo de Psiquiatría, Complexo Hospitalario Universitario de Santiago de Compostela, Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Ángel Carracedo
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Grupo de Medicina Xenómica, Universidade de Santiago de Compostela (USC), Santiago de Compostela, Spain; Fundación Pública Galega de Medicina Xenómica, Complexo Hospitalario Universitario de Santiago (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Manuel Arrojo
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain; Servizo de Psiquiatría, Complexo Hospitalario Universitario de Santiago de Compostela, Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain
| | - Javier Costas
- Instituto de Investigación Sanitaria (IDIS) de Santiago de Compostela, Complexo Hospitalario Universitario de Santiago de Compostela (CHUS), Servizo Galego de Saúde (SERGAS), Santiago de Compostela, Spain.
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57
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Kim S, Zhao Y, Lee JM, Kim WR, Gorivodsky M, Westphal H, Geum D. Ldb1 Is Essential for the Development of Isthmic Organizer and Midbrain Dopaminergic Neurons. Stem Cells Dev 2016; 25:986-94. [PMID: 27171818 DOI: 10.1089/scd.2015.0307] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
LIM domain-binding protein 1 (Ldb1) is a nuclear cofactor that interacts with LIM homeodomain proteins to form multiprotein complexes that are important for transcription regulation. Ldb1 has been shown to play essential roles in various processes during mouse embryogenesis. To determine the role of Ldb1 in mid- and hindbrain development, we have generated a conditional mutant with a specific deletion of the Ldb1 in the Engrailed-1-expressing region of the developing mid- and hindbrain. Our study showed that the deletion impaired the expression of signaling molecules, such as fibroblast growth factor 8 (FGF8) and Wnt1, in the isthmic organizer and the expression of Shh in the ventral midbrain. The midbrain and the cerebellum were severely reduced in size, and the midbrain dopaminergic (mDA) neurons were missing in the mutant. These defects are identical to the phenotype that has been observed previously in mice with a deletion of the LIM homeodomain gene Lmx1b. Our results thus provide genetic evidence supporting that Ldb1 and Lmx1b function cooperatively to regulate mid- and hindbrain development. In addition, we found that mouse embryonic stem cells lacking Ldb1 failed to generate several types of differentiated neurons, including the mDA neurons, serotonergic neurons, cholinergic neurons, and olfactory bulb neurons, indicating an essential cell-autonomous role for Ldb1 in the development of these neurons.
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Affiliation(s)
- Soojin Kim
- 1 Department of Biomedical Sciences, Korea University Medical School , Seoul, South Korea
| | - Yangu Zhao
- 2 Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health , Bethesda, Maryland
| | - Ja-Myong Lee
- 1 Department of Biomedical Sciences, Korea University Medical School , Seoul, South Korea
| | - Woon Ryoung Kim
- 1 Department of Biomedical Sciences, Korea University Medical School , Seoul, South Korea
| | - Marat Gorivodsky
- 2 Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health , Bethesda, Maryland
| | - Heiner Westphal
- 2 Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health , Bethesda, Maryland
| | - Dongho Geum
- 1 Department of Biomedical Sciences, Korea University Medical School , Seoul, South Korea
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58
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Bertini V, Orsini A, Bonuccelli A, Cambi F, Del Pistoia M, Vannozzi I, Toschi B, Saggese G, Simi P, Valetto A. 17q12 microduplications: a challenge for clinicians. Am J Med Genet A 2016; 167A:674-6. [PMID: 25691423 DOI: 10.1002/ajmg.a.36905] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2014] [Accepted: 11/14/2014] [Indexed: 11/10/2022]
Abstract
In the recent years, some cases of 17q12 deletions and duplications have been reported, but the clinical impact of these imbalances is still to be fully elucidated. In particular, 17q12 duplications elude syndrome classification, since they are associated with a wide phenotypic spectrum, ranging from very mild to quite severe phenotypes. Here, two unrelated patients with the same 1.2 Mb microduplication of 17q12 are reported. Comparing these patients' phenotype with those previously published, it emerges that the more patients reported, the more difficult is finding common characteristics, even in presence of exactly the same genetic anomaly. The role of the genes duplicated in this region and the impact of this chromosomal imbalance are discussed.
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Affiliation(s)
- V Bertini
- Cytogenetics and Molecular Genetics Unit, Children Department, AOUP, Pisa, Italy
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59
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Feng X, Juan AH, Wang HA, Ko KD, Zare H, Sartorelli V. Polycomb Ezh2 controls the fate of GABAergic neurons in the embryonic cerebellum. Development 2016; 143:1971-80. [PMID: 27068104 DOI: 10.1242/dev.132902] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2015] [Accepted: 04/06/2016] [Indexed: 12/31/2022]
Abstract
Although the genetic interactions between signaling pathways and transcription factors have been largely decoded, much remains to be learned about the epigenetic regulation of cerebellar development. Here, we report that cerebellar deletion of Ezh2, the methyltransferase subunit of the PRC2 complex, results in reduced H3K27me3 and profound transcriptional dysregulation, including that of a set of transcription factors directly involved in cerebellar neuronal cell-type specification and differentiation. Such transcriptional changes lead to increased GABAergic interneurons and decreased Purkinje cells. Transcriptional changes also inhibit the proliferation of granule precursor cells derived from the rhombic lip. The loss of both cell types ultimately results in cerebellar hypoplasia. These findings indicate Ezh2/PRC2 plays crucial roles in regulating neurogenesis from both cerebellar germinal zones.
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Affiliation(s)
- Xuesong Feng
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
| | - Aster H Juan
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
| | - Hongjun A Wang
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
| | - Kyung Dae Ko
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
| | - Hossein Zare
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
| | - Vittorio Sartorelli
- Laboratory of Muscle Stem Cells and Gene Regulation, National Institute of Arthritis, Musculoskeletal and Skin Diseases (NIAMS), National Institutes of Health, 50 South Drive, Bethesda, MD 20892, USA
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60
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Carter MG, Smagghe BJ, Stewart AK, Rapley JA, Lynch E, Bernier KJ, Keating KW, Hatziioannou VM, Hartman EJ, Bamdad CC. A Primitive Growth Factor, NME7AB , Is Sufficient to Induce Stable Naïve State Human Pluripotency; Reprogramming in This Novel Growth Factor Confers Superior Differentiation. Stem Cells 2016; 34:847-59. [PMID: 26749426 DOI: 10.1002/stem.2261] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Revised: 11/10/2015] [Accepted: 11/26/2015] [Indexed: 12/28/2022]
Abstract
Scientists have generated human stem cells that in some respects mimic mouse naïve cells, but their dependence on the addition of several extrinsic agents, and their propensity to develop abnormal karyotype calls into question their resemblance to a naturally occurring "naïve" state in humans. Here, we report that a recombinant, truncated human NME7, referred to as NME7AB here, induces a stable naïve-like state in human embryonic stem cells and induced pluripotent stem cells without the use of inhibitors, transgenes, leukemia inhibitory factor (LIF), fibroblast growth factor 2 (FGF2), feeder cells, or their conditioned media. Evidence of a naïve state includes reactivation of the second X chromosome in female source cells, increased expression of naïve markers and decreased expression of primed state markers, ability to be clonally expanded and increased differentiation potential. RNA-seq analysis shows vast differences between the parent FGF2 grown, primed state cells, and NME7AB converted cells, but similarities to altered gene expression patterns reported by others generating naïve-like stem cells via the use of biochemical inhibitors. Experiments presented here, in combination with our previous work, suggest a mechanistic model of how human stem cells regulate self-replication: an early naïve state driven by NME7, which cannot itself limit self-replication and a later naïve state regulated by NME1, which limits self-replication when its multimerization state shifts from the active dimer to the inactive hexamer.
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Affiliation(s)
- M G Carter
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - B J Smagghe
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - A K Stewart
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - J A Rapley
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - E Lynch
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - K J Bernier
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | - K W Keating
- Minerva Biotechnologies, Waltham, Massachusetts, USA
| | | | - E J Hartman
- Minerva Biotechnologies, Waltham, Massachusetts, USA
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61
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Barber M, Pierani A. Tangential migration of glutamatergic neurons and cortical patterning during development: Lessons from Cajal-Retzius cells. Dev Neurobiol 2015; 76:847-81. [PMID: 26581033 DOI: 10.1002/dneu.22363] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 12/14/2022]
Abstract
Tangential migration is a mode of cell movement, which in the developing cerebral cortex, is defined by displacement parallel to the ventricular surface and orthogonal to the radial glial fibers. This mode of long-range migration is a strategy by which distinct neuronal classes generated from spatially and molecularly distinct origins can integrate to form appropriate neural circuits within the cortical plate. While it was previously believed that only GABAergic cortical interneurons migrate tangentially from their origins in the subpallial ganglionic eminences to integrate in the cortical plate, it is now known that transient populations of glutamatergic neurons also adopt this mode of migration. These include Cajal-Retzius cells (CRs), subplate neurons (SPs), and cortical plate transient neurons (CPTs), which have crucial roles in orchestrating the radial and tangential development of the embryonic cerebral cortex in a noncell-autonomous manner. While CRs have been extensively studied, it is only in the last decade that the molecular mechanisms governing their tangential migration have begun to be elucidated. To date, the mechanisms of SPs and CPTs tangential migration remain unknown. We therefore review the known signaling pathways, which regulate parameters of CRs migration including their motility, contact-redistribution and adhesion to the pial surface, and discuss this in the context of how CR migration may regulate their signaling activity in a spatial and temporal manner. © 2015 Wiley Periodicals, Inc. Develop Neurobiol 76: 847-881, 2016.
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Affiliation(s)
- Melissa Barber
- Institut Jacques-Monod, CNRS, Université Paris Diderot, Sorbonne Cité, Paris, France.,Department of Cell and Developmental Biology, University College London, WC1E 6BT, United Kingdom
| | - Alessandra Pierani
- Institut Jacques-Monod, CNRS, Université Paris Diderot, Sorbonne Cité, Paris, France
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62
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Miquelajáuregui A, Sandoval-Schaefer T, Martínez-Armenta M, Pérez-Martínez L, Cárabez A, Zhao Y, Heide M, Alvarez-Bolado G, Varela-Echavarría A. LIM homeobox protein 5 (Lhx5) is essential for mamillary body development. Front Neuroanat 2015; 9:136. [PMID: 26578897 PMCID: PMC4621302 DOI: 10.3389/fnana.2015.00136] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2015] [Accepted: 10/12/2015] [Indexed: 02/01/2023] Open
Abstract
The mamillary body (MM) is a group of hypothalamic nuclei related to memory and spatial navigation that interconnects hippocampal, thalamic, and tegmental regions. Here we demonstrate that Lhx5, a LIM-HD domain transcription factor expressed early in the developing posterior hypothalamus, is required for the generation of the MM and its derived tracts. The MM markers Foxb1, Sim2, and Lhx1 are absent in Lhx5 knock-out mice from early embryonic stages, suggesting abnormal specification of this region. This was supported by the absence of Nkx2.1 and expansion of Shh in the prospective mamillary area. Interestingly, we also found an ectopic domain expressing Lhx2 and Lhx9 along the anterio-posterior hypothalamic axis. Our results suggest that Lhx5 controls early aspects of hypothalamic development by regulating gene expression and cellular specification in the prospective MM.
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Affiliation(s)
- Amaya Miquelajáuregui
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
| | - Teresa Sandoval-Schaefer
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
| | - Miriam Martínez-Armenta
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México Cuernavaca, Mexico
| | - Leonor Pérez-Martínez
- Laboratorio de Neuroinmunobiología, Departamento de Medicina Molecular y Bioprocesos, Instituto de Biotecnología, Universidad Nacional Autónoma de México Cuernavaca, Mexico
| | - Alfonso Cárabez
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
| | - Yangu Zhao
- Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health Bethesda, MD, USA
| | - Michael Heide
- Institute of Anatomy and Cell Biology, University of Heidelberg Heidelberg, Germany
| | | | - Alfredo Varela-Echavarría
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México Querétaro, Mexico
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Sun L, Chen F, Peng G. Conserved Noncoding Sequences Regulate lhx5 Expression in the Zebrafish Forebrain. PLoS One 2015; 10:e0132525. [PMID: 26147098 PMCID: PMC4492605 DOI: 10.1371/journal.pone.0132525] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2015] [Accepted: 06/15/2015] [Indexed: 01/23/2023] Open
Abstract
The LIM homeobox family protein Lhx5 plays important roles in forebrain development in the vertebrates. The lhx5 gene exhibits complex temporal and spatial expression patterns during early development but its transcriptional regulation mechanisms are not well understood. Here, we have used transgenesis in zebrafish in order to define regulatory elements that drive lhx5 expression in the forebrain. Through comparative genomic analysis we identified 10 non-coding sequences conserved in five teleost species. We next examined the enhancer activities of these conserved non-coding sequences with Tol2 transposon mediated transgenesis. We found a proximately located enhancer gave rise to robust reporter EGFP expression in the forebrain regions. In addition, we identified an enhancer located at approximately 50 kb upstream of lhx5 coding region that is responsible for reporter gene expression in the hypothalamus. We also identify an enhancer located approximately 40 kb upstream of the lhx5 coding region that is required for expression in the prethalamus (ventral thalamus). Together our results suggest discrete enhancer elements control lhx5 expression in different regions of the forebrain.
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Affiliation(s)
- Liu Sun
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Fengjiao Chen
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Gang Peng
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
- * E-mail:
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64
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Bedont JL, Blackshaw S. Constructing the suprachiasmatic nucleus: a watchmaker's perspective on the central clockworks. Front Syst Neurosci 2015; 9:74. [PMID: 26005407 PMCID: PMC4424844 DOI: 10.3389/fnsys.2015.00074] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2014] [Accepted: 04/23/2015] [Indexed: 11/13/2022] Open
Abstract
The circadian system constrains an organism's palette of behaviors to portions of the solar day appropriate to its ecological niche. The central light-entrained clock in the suprachiasmatic nucleus (SCN) of the mammalian circadian system has evolved a complex network of interdependent signaling mechanisms linking multiple distinct oscillators to serve this crucial function. However, studies of the mechanisms controlling SCN development have greatly lagged behind our understanding of its physiological functions. We review advances in the understanding of adult SCN function, what has been described about SCN development to date, and the potential of both current and future studies of SCN development to yield important insights into master clock function, dysfunction, and evolution.
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Affiliation(s)
- Joseph L Bedont
- Department of Neuroscience, Johns Hopkins University School of Medicine Baltimore, MD, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Ophthalmology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Physiology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Department of Neurology, Johns Hopkins University School of Medicine Baltimore, MD, USA ; Center for High-Throughput Biology, Johns Hopkins University School of Medicine Baltimore, MD, USA
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65
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Vong KI, Leung CKY, Behringer RR, Kwan KM. Sox9 is critical for suppression of neurogenesis but not initiation of gliogenesis in the cerebellum. Mol Brain 2015; 8:25. [PMID: 25888505 PMCID: PMC4406026 DOI: 10.1186/s13041-015-0115-0] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2014] [Accepted: 03/27/2015] [Indexed: 01/20/2023] Open
Abstract
Background The high mobility group (HMG) family transcription factor Sox9 is critical for induction and maintenance of neural stem cell pool in the central nervous system (CNS). In the spinal cord and retina, Sox9 is also the master regulator that defines glial fate choice by mediating the neurogenic-to-gliogenic fate switch. On the other hand, the genetic repertoire governing the maintenance and fate decision of neural progenitor pool in the cerebellum has remained elusive. Results By employing the Cre/loxP strategy, we specifically inactivated Sox9 in the mouse cerebellum. Unexpectedly, the self-renewal capacity and multipotency of neural progenitors at the cerebellar ventricular zone (VZ) were not perturbed upon Sox9 ablation. Instead, the mutants exhibited an increased number of VZ-derived neurons including Purkinje cells and GABAergic interneurons. Simultaneously, we observed continuous neurogenesis from Sox9-null VZ at late gestation, when normally neurogenesis ceases to occur and gives way for gliogenesis. Surprisingly, glial cell specification was not affected upon Sox9 ablation. Conclusion Our findings suggest Sox9 may mediate the neurogenic-to-gliogenic fate switch in mouse cerebellum by modulating the termination of neurogenesis, and therefore indicate a functional discrepancy of Sox9 between the development of cerebellum and other major neural tissues.
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Affiliation(s)
- Keng Ioi Vong
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, P.R. China.
| | | | - Richard R Behringer
- Department of Genetics, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA.
| | - Kin Ming Kwan
- School of Life Sciences, The Chinese University of Hong Kong, Hong Kong, P.R. China. .,RGC-AoE Centre for Organelle Biogenesis and Function, The Chinese University of Hong Kong, Hong Kong, P.R. China. .,Partner State Key Laboratory of Agrobiotechnology (CUHK), The Chinese University of Hong Kong, Hong Kong, P.R. China.
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66
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Tong KK, Ma TC, Kwan KM. BMP/Smad signaling and embryonic cerebellum development: Stem cell specification and heterogeneity of anterior rhombic lip. Dev Growth Differ 2015; 57:121-34. [DOI: 10.1111/dgd.12198] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2014] [Revised: 12/15/2014] [Accepted: 01/05/2015] [Indexed: 01/16/2023]
Affiliation(s)
- Ka Kui Tong
- School of Life Sciences; The Chinese University of Hong Kong; Hong Kong China
| | - Tsz Ching Ma
- School of Life Sciences; The Chinese University of Hong Kong; Hong Kong China
| | - Kin Ming Kwan
- School of Life Sciences; The Chinese University of Hong Kong; Hong Kong China
- RGC-AoE Centre for Organelle Biogenesis and Function; The Chinese University of Hong Kong; Hong Kong China
- Partner State Key Laboratory of Agrobiotechnology (CUHK); The Chinese University of Hong Kong; Hong Kong China
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67
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Okamura-Oho Y, Shimokawa K, Nishimura M, Takemoto S, Sato A, Furuichi T, Yokota H. Broad integration of expression maps and co-expression networks compassing novel gene functions in the brain. Sci Rep 2014; 4:6969. [PMID: 25382412 PMCID: PMC4225549 DOI: 10.1038/srep06969] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 10/07/2014] [Indexed: 12/12/2022] Open
Abstract
Using a recently invented technique for gene expression mapping in the whole-anatomy context, termed transcriptome tomography, we have generated a dataset of 36,000 maps of overall gene expression in the adult-mouse brain. Here, using an informatics approach, we identified a broad co-expression network that follows an inverse power law and is rich in functional interaction and gene-ontology terms. Our framework for the integrated analysis of expression maps and graphs of co-expression networks revealed that groups of combinatorially expressed genes, which regulate cell differentiation during development, were present in the adult brain and each of these groups was associated with a discrete cell types. These groups included non-coding genes of unknown function. We found that these genes specifically linked developmentally conserved groups in the network. A previously unrecognized robust expression pattern covering the whole brain was related to the molecular anatomy of key biological processes occurring in particular areas.
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Affiliation(s)
- Yuko Okamura-Oho
- Brain Research Network (BReNt), 2-2-41 Sakurayama, Zushi-shi, Kanagawa, 249-0005, Japan
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Kazuro Shimokawa
- Department of Health Record Informatics, Tohoku Medical Megabank Organization, Tohoku University, 2-1 Seiryo-chou Aoba-ku Sendai-shi Miyagi, 980-8573, Japan
| | - Masaomi Nishimura
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Satoko Takemoto
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
| | - Akira Sato
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, 278-8510, Japan
| | - Teiichi Furuichi
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda-shi, Chiba, 278-8510, Japan
| | - Hideo Yokota
- Image Processing Research Team, Extreme Photonics Research Group, RIKEN Center for Advanced Photonics, 2-1 Hirosawa Wako-shi Saitama, 351-0198, Japan
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68
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Plautz CZ, Zirkle BE, Deshotel MJ, Grainger RM. Early stages of induction of anterior head ectodermal properties in Xenopus embryos are mediated by transcriptional cofactor ldb1. Dev Dyn 2014; 243:1606-18. [PMID: 25258326 DOI: 10.1002/dvdy.24193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 09/02/2014] [Accepted: 09/22/2014] [Indexed: 01/06/2023] Open
Abstract
BACKGROUND Specific molecules involved in early inductive signaling from anterior neural tissue to the placodal ectoderm to establish a lens-forming bias, as well as their regulatory factors, remain largely unknown. In this study, we sought to identify and characterize these molecules. RESULTS Using an expression cloning strategy to isolate genes with lens-inducing activity, we identified the transcriptional cofactor ldb1. This, together with evidence for its nuclear dependence, suggests its role as a regulatory factor, not a direct signaling molecule. We propose that ldb1 mediates induction of early lens genes in our functional assay by transcriptional activation of lens-inducing signals. Gain-of-function assays demonstrate that the inductive activity of the anterior neural plate on head ectodermal structures can be augmented by ldb1. Loss-of-function assays show that knockdown of ldb1 leads to decreased expression of early lens and retinal markers and subsequently to defects in eye development. CONCLUSIONS The functional cloning, expression pattern, overexpression, and knockdown data show that an ldb1-regulated mechanism acts as an early signal for Xenopus lens induction.
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Affiliation(s)
- Carol Zygar Plautz
- Shepherd University, Department of Biology, Shepherdstown, West Virginia
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69
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Bedont JL, LeGates TA, Slat EA, Byerly MS, Wang H, Hu J, Rupp AC, Qian J, Wong GW, Herzog ED, Hattar S, Blackshaw S. Lhx1 controls terminal differentiation and circadian function of the suprachiasmatic nucleus. Cell Rep 2014; 7:609-22. [PMID: 24767996 PMCID: PMC4254772 DOI: 10.1016/j.celrep.2014.03.060] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Revised: 02/23/2014] [Accepted: 03/21/2014] [Indexed: 12/27/2022] Open
Abstract
Vertebrate circadian rhythms are organized by the hypothalamic suprachiasmatic nucleus (SCN). Despite its physiological importance, SCN development is poorly understood. Here, we show that Lim homeodomain transcription factor 1 (Lhx1) is essential for terminal differentiation and function of the SCN. Deletion of Lhx1 in the developing SCN results in loss of SCN-enriched neuropeptides involved in synchronization and coupling to downstream oscillators, among other aspects of circadian function. Intact, albeit damped, clock gene expression rhythms persist in Lhx1-deficient SCN; however, circadian activity rhythms are highly disorganized and susceptible to surprising changes in period, phase, and consolidation following neuropeptide infusion. Our results identify a factor required for SCN terminal differentiation. In addition, our in vivo study of combinatorial SCN neuropeptide disruption uncovered synergies among SCN-enriched neuropeptides in regulating normal circadian function. These animals provide a platform for studying the central oscillator's role in physiology and cognition.
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Affiliation(s)
- Joseph L Bedont
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Tara A LeGates
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Emily A Slat
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Mardi S Byerly
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Hong Wang
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Jianfei Hu
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Alan C Rupp
- Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Jiang Qian
- Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - G William Wong
- Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Center for Metabolism and Obesity Research, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA
| | - Erik D Herzog
- Department of Biology, Washington University, St. Louis, MO 63130, USA
| | - Samer Hattar
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Biology, Johns Hopkins University, Baltimore, MD 21218, USA
| | - Seth Blackshaw
- Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Physiology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Center for High-Throughput Biology, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA; Institute for Cell Engineering, Johns Hopkins University School of Medicine, Baltimore, MD 21287, USA.
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Makarev E, Gorivodsky M. Islet1 and its co-factor Ldb1 are expressed in quiescent cells of mouse intestinal epithelium. PLoS One 2014; 9:e95256. [PMID: 24755910 PMCID: PMC3995853 DOI: 10.1371/journal.pone.0095256] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2013] [Accepted: 03/26/2014] [Indexed: 01/06/2023] Open
Abstract
Islet1 belongs to Lim homeobox (Lhx) gene family which encodes transcription factors that have been conserved in evolution. They form complexes with other transcriptional regulators, among them obligatory co-factors encoded by Ldb genes. Isl1 (Islet1), Lhx and Ldb1 genes play a crucial role in organ patterning, cell fate determination and cell differentiation in both embryonic and adult tissues. In this study we analyzed expression pattern of Isl1 and its co-factor Ldb1 in small intestine. We also studied the biological role of Ldb1 in gut endoderm. Quantitative PCR analysis revealed a relatively high level of expression of Lhx1, Isl1, Isl2, Lmx1a, Ldb1 and Ldb2 mRNAs in the gut tissue as compared to the level of less abundant detectable Lmx1b mRNA. Immunohistochemical studies demonstrated a unique pattern of Ldb1 and Islet1 proteins in the crypt compartment. Ldb1 is produced at a low level in majority of crypt cells; but, its abundant expression was demonstrated for some single cells. Islet1 is also expressed in single cells of the crypt. Double staining experiments with Ldb1 and Isl1 antibodies showed that both genes are co-expressed in certain cells of the crypt. Further analysis revealed the Ldb1-expressing cells in the gut are both of endodermal and mesodermal origin. Proliferation studies using antibodies to phospho-histone H3 and Ki-67 antigens, as well as long-term BrdU labeling, showed that cells prominently expressing Ldb1/Islet1 are quiescent but do not belong to any known terminally differentiated cell lineages. They may represent a group of stem-like cells in the crypt. Further experiments by cell lineage tracing should be performed to better characterize this cell population. Functional studies of mice with Ldb1 gene ablated in gut endoderm revealed no specific role of Ldb1 in that tissue.
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Affiliation(s)
- Evgeny Makarev
- Section on Mammalian Molecular Genetics, Laboratory of Mammalian Genes and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America
| | - Marat Gorivodsky
- Section on Mammalian Molecular Genetics, Laboratory of Mammalian Genes and Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, Bethesda, Maryland, United States of America
- * E-mail:
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71
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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: 37] [Impact Index Per Article: 3.7] [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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Nakatani T, Minaki Y, Kumai M, Nitta C, Ono Y. The c-Ski family member and transcriptional regulator Corl2/Skor2 promotes early differentiation of cerebellar Purkinje cells. Dev Biol 2014; 388:68-80. [DOI: 10.1016/j.ydbio.2014.01.016] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 01/16/2014] [Accepted: 01/22/2014] [Indexed: 10/25/2022]
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73
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Huang CC, Orvis GD, Kwan KM, Behringer RR. Lhx1 is required in Müllerian duct epithelium for uterine development. Dev Biol 2014; 389:124-36. [PMID: 24560999 DOI: 10.1016/j.ydbio.2014.01.025] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Accepted: 01/29/2014] [Indexed: 02/08/2023]
Abstract
The female reproductive tract organs of mammals, including the oviducts, uterus, cervix and upper vagina, are derived from the Müllerian ducts, a pair of epithelial tubes that form within the mesonephroi. The Müllerian ducts form in a rostral to caudal manner, guided by and dependent on the Wolffian ducts that have already formed. Experimental embryological studies indicate that caudal elongation of the Müllerian duct towards the urogenital sinus occurs in part by proliferation at the ductal tip. The molecular mechanisms that regulate the elongation of the Müllerian duct are currently unclear. Lhx1 encodes a LIM-homeodomain transcription factor that is essential for male and female reproductive tract development. Lhx1 is expressed in both the Wolffian and Müllerian ducts. Wolffian duct-specific knockout of Lhx1 results in degeneration of the Wolffian duct and consequently the non-cell-autonomous loss of the Müllerian duct. To determine the role of Lhx1 specifically in the Müllerian duct epithelium, we performed a Müllerian duct-specific knockout study using Wnt7a-Cre mice. Loss of Lhx1 in the Müllerian duct epithelium led to a block in Müllerian duct elongation and uterine hypoplasia characterized by loss of the entire endometrium (luminal and glandular epithelium and stroma) and inner circular but not the outer longitudinal muscle layer. Time-lapse imaging and molecular analyses indicate that Lhx1 acts cell autonomously to maintain ductal progenitor cells for Müllerian duct elongation. These studies identify LHX1 as the first transcription factor that is essential in the Müllerian duct epithelial progenitor cells for female reproductive tract development. Furthermore, these genetic studies demonstrate the requirement of epithelial-mesenchymal interactions for uterine tissue compartment differentiation.
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Affiliation(s)
- Cheng-Chiu Huang
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Grant D Orvis
- Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA
| | - Kin Ming Kwan
- Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA; School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong, PR China
| | - Richard R Behringer
- Program in Developmental Biology, Baylor College of Medicine, Houston, TX 77030, USA; Department of Genetics, University of Texas M.D. Anderson Cancer Center, Houston, TX 77030, USA.
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74
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Neural crest-specific deletion of Ldb1 leads to cleft secondary palate with impaired palatal shelf elevation. BMC DEVELOPMENTAL BIOLOGY 2014; 14:3. [PMID: 24433583 PMCID: PMC3899388 DOI: 10.1186/1471-213x-14-3] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Accepted: 01/08/2014] [Indexed: 11/10/2022]
Abstract
Background LIM domain binding protein 1 (LDB1) is a transcriptional co-factor, which interacts with multiple transcription factors and other proteins containing LIM domains. Complete inactivation of Ldb1 in mice resulted in early embryonic lethality with severe patterning defects during gastrulation. Tissue-specific deletions using a conditional knockout allele revealed additional roles of Ldb1 in the development of the central nervous system, hematopoietic system, and limbs. The goal of the current study was to determine the importance of Ldb1 function during craniofacial development in mouse embryos. Results We generated tissue-specific Ldb1 mutants using Wnt1-Cre, which causes deletion of a floxed allele in the neural crest; neural crest-derived cells contribute to most of the mesenchyme of the developing face. All examined Wnt1-Cre;Ldb1fl/- mutants suffered from cleft secondary palate. Therefore, we performed a series of experiments to investigate how Ldb1 regulated palate development. First, we examined the expression of Ldb1 during normal development, and found that Ldb1 was expressed broadly in the palatal mesenchyme during early stages of palate development. Second, we compared the morphology of the developing palate in control and Ldb1 mutant embryos using sections. We found that the mutant palatal shelves had abnormally blunt appearance, and failed to elevate above the tongue at the posterior domain. An in vitro head culture experiment indicated that the elevation defect was not due to interference by the tongue. Finally, in the Ldb1 mutant palatal shelves, cell proliferation was abnormal in the anterior, and the expression of Wnt5a, Pax9 and Osr2, which regulate palatal shelf elevation, was also altered. Conclusions The function of Ldb1 in the neural crest-derived palatal mesenchyme is essential for normal morphogenesis of the secondary palate.
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Di Giovannantonio LG, Di Salvio M, Omodei D, Prakash N, Wurst W, Pierani A, Acampora D, Simeone A. Otx2 cell-autonomously determines dorsal mesencephalon versus cerebellum fate independently of isthmic organizing activity. Development 2013; 141:377-88. [PMID: 24335253 DOI: 10.1242/dev.102954] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
During embryonic development, the rostral neuroectoderm is regionalized into broad areas that are subsequently subdivided into progenitor compartments with specialized identity and fate. These events are controlled by signals emitted by organizing centers and interpreted by target progenitors, which activate superimposing waves of intrinsic factors restricting their identity and fate. The transcription factor Otx2 plays a crucial role in mesencephalic development by positioning the midbrain-hindbrain boundary (MHB) and its organizing activity. Here, we investigated whether Otx2 is cell-autonomously required to control identity and fate of dorsal mesencephalic progenitors. With this aim, we have inactivated Otx2 in the Pax7(+) dorsal mesencephalic domain, previously named m1, without affecting MHB integrity. We found that the Pax7(+) m1 domain can be further subdivided into a dorsal Zic1(+) m1a and a ventral Zic1(-) m1b sub-domain. Loss of Otx2 in the m1a (Pax7(+) Zic1(+)) sub-domain impairs the identity and fate of progenitors, which undergo a full switch into a coordinated cerebellum differentiation program. By contrast, in the m1b sub-domain (Pax7(+) Zic1(-)) Otx2 is prevalently required for post-mitotic transition of mesencephalic GABAergic precursors. Moreover, genetic cell fate, BrdU cell labeling and Otx2 conditional inactivation experiments indicate that in Otx2 mutants all ectopic cerebellar cell types, including external granule cell layer (EGL) precursors, originate from the m1a progenitor sub-domain and that reprogramming of mesencephalic precursors into EGL or cerebellar GABAergic progenitors depends on temporal sensitivity to Otx2 ablation. Together, these findings indicate that Otx2 intrinsically controls different aspects of dorsal mesencephalic neurogenesis. In this context, Otx2 is cell-autonomously required in the m1a sub-domain to suppress cerebellar fate and promote mesencephalic differentiation independently of the MHB organizing activity.
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Affiliation(s)
- Luca G Di Giovannantonio
- Institute of Genetics and Biophysics "Adriano Buzzati-Traverso", CNR, Via P. Castellino 111, 80131 Naples, Italy
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Serrano-Saiz E, Poole RJ, Felton T, Zhang F, De La Cruz ED, Hobert O. Modular control of glutamatergic neuronal identity in C. elegans by distinct homeodomain proteins. Cell 2013; 155:659-73. [PMID: 24243022 DOI: 10.1016/j.cell.2013.09.052] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2013] [Revised: 08/14/2013] [Accepted: 09/23/2013] [Indexed: 10/26/2022]
Abstract
The choice of using one of many possible neurotransmitter systems is a critical step in defining the identity of an individual neuron type. We show here that the key defining feature of glutamatergic neurons, the vesicular glutamate transporter EAT-4/VGLUT, is expressed in 38 of the 118 anatomically defined neuron classes of the C. elegans nervous system. We show that distinct cis-regulatory modules drive expression of eat-4/VGLUT in distinct glutamatergic neuron classes. We identify 13 different transcription factors, 11 of them homeodomain proteins, that act in distinct combinations in 25 different glutamatergic neuron classes to initiate and maintain eat-4/VGLUT expression. We show that the adoption of a glutamatergic phenotype is linked to the adoption of other terminal identity features of a neuron, including cotransmitter phenotypes. Examination of mouse orthologs of these homeodomain proteins resulted in the identification of mouse LHX1 as a regulator of glutamatergic neurons in the brainstem.
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Affiliation(s)
- Esther Serrano-Saiz
- Department of Biochemistry and Molecular Biophysics, HHMI, Columbia University Medical Center, New York, NY 10032, USA.
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77
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Zhao Y, Flandin P, Vogt D, Blood A, Hermesz E, Westphal H, Rubenstein JLR. Ldb1 is essential for development of Nkx2.1 lineage derived GABAergic and cholinergic neurons in the telencephalon. Dev Biol 2013; 385:94-106. [PMID: 24157949 DOI: 10.1016/j.ydbio.2013.10.010] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2013] [Revised: 10/08/2013] [Accepted: 10/09/2013] [Indexed: 11/30/2022]
Abstract
The progenitor zones of the embryonic mouse ventral telencephalon give rise to GABAergic and cholinergic neurons. We have shown previously that two LIM-homeodomain (LIM-HD) transcription factors, Lhx6 and Lhx8, that are downstream of Nkx2.1, are critical for the development of telencephalic GABAergic and cholinergic neurons. Here we investigate the role of Ldb1, a nuclear protein that binds directly to all LIM-HD factors, in the development of these ventral telencephalon derived neurons. We show that Ldb1 is expressed in the Nkx2.1 cell lineage during embryonic development and in mature neurons. Conditional deletion of Ldb1 causes defects in the expression of a series of genes in the ventral telencephalon and severe impairment in the tangential migration of cortical interneurons from the ventral telencephalon. Similar to the phenotypes observed in Lhx6 or Lhx8 mutant mice, the Ldb1 conditional mutants show a reduction in the number of both GABAergic and cholinergic neurons in the telencephalon. Furthermore, our analysis reveals defects in the development of the parvalbumin-positive neurons in the globus pallidus and striatum of the Ldb1 mutants. These results provide evidence that Ldb1 plays an essential role as a transcription co-regulator of Lhx6 and Lhx8 in the control of mammalian telencephalon development.
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Affiliation(s)
- Yangu Zhao
- Program on Genomics of Differentiation, Eunice Kennedy Shriver National Institute of Child Health and Human Development, NIH, Bethesda, MD 20892, USA.
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78
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Currie KW, Pearson BJ. Transcription factors lhx1/5-1 and pitx are required for the maintenance and regeneration of serotonergic neurons in planarians. Development 2013; 140:3577-88. [PMID: 23903188 DOI: 10.1242/dev.098590] [Citation(s) in RCA: 100] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
In contrast to most adult organisms, freshwater planarians can regenerate any injured body part, including their entire nervous system. This allows for the analysis of genes required for both the maintenance and regeneration of specific neural subtypes. In addition, the loss of specific neural subtypes may uncover previously unknown behavioral roles for that neural population in the context of the adult animal. Here we show that two homeodomain transcription factor homologs, Smed-lhx1/5-1 and Smed-pitx, are required for the maintenance and regeneration of serotonergic neurons in planarians. When either lhx1/5-1 or pitx was knocked down by RNA interference, the expression of multiple canonical markers for serotonergic neurons was lost. Surprisingly, the loss of serotonergic function uncovered a role for these neurons in the coordination of motile cilia on the ventral epidermis of planarians that are required for their nonmuscular gliding locomotion. Finally, we show that in addition to its requirement in serotonergic neurons, Smed-pitx is required for proper midline patterning during regeneration, when it is required for the expression of the midline-organizing molecules Smed-slit in the anterior and Smed-wnt1 in the posterior.
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Affiliation(s)
- Ko W Currie
- Hospital for Sick Children, Program in Developmental and Stem Cell Biology, Toronto, ON, Canada
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79
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Common partner Smad-independent canonical bone morphogenetic protein signaling in the specification process of the anterior rhombic lip during cerebellum development. Mol Cell Biol 2013; 33:1925-37. [PMID: 23459943 DOI: 10.1128/mcb.01143-12] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Bone morphogenetic protein (BMP) signaling is critical for cerebellum development. However, the details of receptor regulated-Smad (R-Smad) and common partner Smad (Co-Smad, or Smad4) involvement are unclear. Here, we report that cerebellum-specific double conditional inactivation of Smad1 and Smad5 (Smad1/5) results in cerebellar hypoplasia, reduced granule cell numbers, and disorganized Purkinje neuron migration during embryonic development. However, single conditional inactivation of either Smad1 or Smad5 did not result in cerebellar abnormalities. Surprisingly, conditional inactivation of Smad4, which is considered to be the central mediator of canonical BMP-Smad signaling, resulted only in very mild cerebellar defects. Conditional inactivation of Smad1/5 led to developmental defects in the anterior rhombic lip (ARL), as shown by reduced cell proliferation and loss of Pax6 and Atoh1 expression. These defects subsequently caused the loss of the nuclear transitory zone and a region of the deep cerebellar nuclei. The normal maturation of the remaining granule cell precursors in the external granular layer (EGL) suggests Smad1/5 signaling is required for the specification process in ARL but not for the subsequent EGL development. Our results demonstrate functional redundancy for Smad1 and Smad5 but functional discrepancy between Smad1/5 and Smad4 during cerebellum development.
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80
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Hunter CS, Dixit S, Cohen T, Ediger B, Wilcox C, Ferreira M, Westphal H, Stein R, May CL. Islet α-, β-, and δ-cell development is controlled by the Ldb1 coregulator, acting primarily with the islet-1 transcription factor. Diabetes 2013; 62. [PMID: 23193182 PMCID: PMC3581213 DOI: 10.2337/db12-0952] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ldb1 and Ldb2 are coregulators that mediate Lin11-Isl1-Mec3 (LIM)-homeodomain (HD) and LIM-only transcription factor-driven gene regulation. Although both Ldb1 and Ldb2 mRNA were produced in the developing and adult pancreas, immunohistochemical analysis illustrated a broad Ldb1 protein expression pattern during early pancreatogenesis, which subsequently became enriched in islet and ductal cells perinatally. The islet-enriched pattern of Ldb1 was similar to pan-endocrine cell-expressed Islet-1 (Isl1), which was demonstrated in this study to be the primary LIM-HD transcription factor in developing and adult islet cells. Endocrine cell-specific removal of Ldb1 during mouse development resulted in a severe reduction of hormone⁺ cell numbers (i.e., α, β, and δ) and overt postnatal hyperglycemia, reminiscent of the phenotype described for the Isl1 conditional mutant. In contrast, neither endocrine cell development nor function was affected in the pancreas of Ldb2(-/-) mice. Gene expression and chromatin immunoprecipitation (ChIP) analyses demonstrated that many important Isl1-activated genes were coregulated by Ldb1, including MafA, Arx, insulin, and Glp1r. However, some genes (i.e., Hb9 and Glut2) only appeared to be impacted by Ldb1 during development. These findings establish Ldb1 as a critical transcriptional coregulator during islet α-, β-, and δ-cell development through Isl1-dependent and potentially Isl1-independent control.
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Affiliation(s)
- Chad S. Hunter
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville Tennessee
| | - Shilpy Dixit
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville Tennessee
| | - Tsadok Cohen
- Section on Mammalian Molecular Genetics, Program in Genomics of Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Benjamin Ediger
- Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Crystal Wilcox
- Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Mark Ferreira
- Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
| | - Heiner Westphal
- Section on Mammalian Molecular Genetics, Program in Genomics of Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland
| | - Roland Stein
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical Center, Nashville Tennessee
- Corresponding authors: Roland Stein, , and Catherine Lee May,
| | - Catherine Lee May
- Department of Pathology and Laboratory Medicine, Children’s Hospital of Philadelphia and University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania
- Corresponding authors: Roland Stein, , and Catherine Lee May,
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81
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Winchell CJ, Jacobs DK. Expression of the Lhx genes apterous and lim1 in an errant polychaete: implications for bilaterian appendage evolution, neural development, and muscle diversification. EvoDevo 2013; 4:4. [PMID: 23369627 PMCID: PMC3579752 DOI: 10.1186/2041-9139-4-4] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Accepted: 12/03/2012] [Indexed: 11/10/2022] Open
Abstract
UNLABELLED BACKGROUND Arthropod and vertebrate appendages appear to have evolved via parallel co-option of a plesiomorphic gene regulatory network. Our previous work implies that annelids evolved unrelated appendage-forming mechanisms; we therefore found no support for homology of parapodia and arthropodia at the level of the whole appendage. We expand on that study here by asking whether expression of the LIM homeobox (Lhx) genes apterous and lim1 in the annelid Neanthes arenaceodentata supports homology of the dorsal branches as well as the proximodistal axes of parapodia and arthropodia. In addition, we explore whether the neural expression of apterous and lim1 in Neanthes supports the putative ancestral function of the Lhx gene family in regulating the differentiation and maintenance of neuronal subtypes. RESULTS Both genes exhibit continuous expression in specific portions of the developing central nervous system, from hatching to at least the 13-chaetiger stage. For example, nerve cord expression occurs in segmentally iterated patterns consisting of diffuse sets of many lim1-positive cells and comparatively fewer, clustered pairs of apterous-positive cells. Additionally, continuous apterous expression is observed in presumed neurosecretory ganglia of the posterior brain, while lim1 is continuously expressed in stomatogastric ganglia of the anterior brain. apterous is also expressed in the jaw sacs, dorsal parapodial muscles, and a presumed pair of cephalic sensory organs, whereas lim1 is expressed in multiple pharyngeal ganglia, the segmental peripheral nervous system, neuropodial chaetal sac muscles, and parapodial ligules. CONCLUSIONS The early and persistent nervous system expression of apterous and lim1 in Neanthes juveniles supports conservation of Lhx function in bilaterian neural differentiation and maintenance. Our results also suggest that diversification of parapodial muscle precursors involves a complementary LIM code similar to those generating distinct neuronal identities in fly and mouse nerve cords. Expression of apterous and lim1 in discrete components of developing parapodia is intriguing but does not map to comparable expression of these genes in developing arthropod appendages. Thus, annelid and arthropod appendage development apparently evolved, in part, via distinct co-option of the neuronal regulatory architecture. These divergent patterns of apterous and lim1 activity seemingly reflect de novo origins of parapodia and arthropodia, although we discuss alternative hypotheses.
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Affiliation(s)
- Christopher J Winchell
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E Young Drive South, Los Angeles, CA 90095-1606, USA
- Present address: Department of Molecular and Cell Biology, University of California, Berkeley, 515 LSA #3200, Berkeley, CA 94720-3200, USA
| | - David K Jacobs
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, 621 Charles E Young Drive South, Los Angeles, CA 90095-1606, USA
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82
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Bierhals T, Maddukuri SB, Kutsche K, Girisha KM. Expanding the phenotype associated with 17q12 duplication: Case report and review of the literature. Am J Med Genet A 2013; 161A:352-9. [DOI: 10.1002/ajmg.a.35730] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2012] [Accepted: 10/01/2012] [Indexed: 12/29/2022]
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83
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LMX1B is part of a transcriptional complex with PSPC1 and PSF. PLoS One 2013; 8:e53122. [PMID: 23308148 PMCID: PMC3537735 DOI: 10.1371/journal.pone.0053122] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2012] [Accepted: 11/22/2012] [Indexed: 11/19/2022] Open
Abstract
The LIM homeodomain transcription factor Lmx1b is essential for the development of the isthmic organizer and mesodiencephalic dopaminergic neurons. The uncoupling of Pitx3 and Th expression, in the Lmx1b null mutant, suggests that Lmx1b may act as a positional activator of the mdDA domain, eventually leading to properly differentiating mdDA neurons. In this study, we aimed to elucidate how Lmx1b functions mechanistically in this developmental process, by searching for molecular interactors of Lmx1b at the protein level. Initially, affinity-purification of LMX1B-HIS overexpressed protein in MN9D dopaminergic cells followed by mass-spectrometry analysis, resulted in the identification of PSPC1 protein as a possible binding partner of LMX1B. Subsequent immunoprecipitation experiments revealed an interaction between LMX1B and PSPC1 in a larger protein complex also containing PSF. This complex was observed in vitro and in vivo, and we hypothesize that, via PSF and PSPC1, LMX1B may be part of the previously identified Nurr1 transcriptional complex wherein interaction with the co-repressor PSF and the transcription factor Pitx3 is needed to drive expression of Nurr1 target genes in specifying the dopaminergic phenotype. Furthermore, we identified GRLF1, DHX9, MYO1C, HSP70 and TMPO as potential LMX1B interactors. DHX9 and GRLF1 are highly expressed in the developing mdDA neuronal field, and GRLF1 and MYO1C have both been linked to neurite outgrowth. The identification of these proteins suggests that Lmx1b may act directly in the transcriptional activation of Nurr1 target genes and be involved in other processes like neurite outgrowth as well.
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84
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Florio M, Leto K, Muzio L, Tinterri A, Badaloni A, Croci L, Zordan P, Barili V, Albieri I, Guillemot F, Rossi F, Consalez GG. Neurogenin 2 regulates progenitor cell-cycle progression and Purkinje cell dendritogenesis in cerebellar development. Development 2012; 139:2308-20. [PMID: 22669821 DOI: 10.1242/dev.075861] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
By serving as the sole output of the cerebellar cortex, integrating a myriad of afferent stimuli, Purkinje cells (PCs) constitute the principal neuron in cerebellar circuits. Several neurodegenerative cerebellar ataxias feature a selective cell-autonomous loss of PCs, warranting the development of regenerative strategies. To date, very little is known as to the regulatory cascades controlling PC development. During central nervous system development, the proneural gene neurogenin 2 (Neurog2) contributes to many distinct neuronal types by specifying their fate and/or dictating development of their morphological features. By analyzing a mouse knock-in line expressing Cre recombinase under the control of Neurog2 cis-acting sequences we show that, in the cerebellar primordium, Neurog2 is expressed by cycling progenitors cell-autonomously fated to become PCs, even when transplanted heterochronically. During cerebellar development, Neurog2 is expressed in G1 phase by progenitors poised to exit the cell cycle. We demonstrate that, in the absence of Neurog2, both cell-cycle progression and neuronal output are significantly affected, leading to an overall reduction of the mature cerebellar volume. Although PC fate identity is correctly specified, the maturation of their dendritic arbor is severely affected in the absence of Neurog2, as null PCs develop stunted and poorly branched dendrites, a defect evident from the early stages of dendritogenesis. Thus, Neurog2 represents a key regulator of PC development and maturation.
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Affiliation(s)
- Marta Florio
- Division of Neuroscience, San Raffaele Scientific Institute, 20132 Milan, Italy
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85
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GABAergic neuron specification in the spinal cord, the cerebellum, and the cochlear nucleus. Neural Plast 2012; 2012:921732. [PMID: 22830054 PMCID: PMC3395262 DOI: 10.1155/2012/921732] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2012] [Revised: 05/17/2012] [Accepted: 05/17/2012] [Indexed: 12/01/2022] Open
Abstract
In the nervous system, there are a wide variety of neuronal cell types that have morphologically, physiologically, and histochemically different characteristics. These various types of neurons can be classified into two groups: excitatory and inhibitory neurons. The elaborate balance of the activities of the two types is very important to elicit higher brain function, because its imbalance may cause neurological disorders, such as epilepsy and hyperalgesia. In the central nervous system, inhibitory neurons are mainly represented by GABAergic ones with some exceptions such as glycinergic. Although the machinery to specify GABAergic neurons was first studied in the telencephalon, identification of key molecules, such as pancreatic transcription factor 1a (Ptf1a), as well as recently developed genetic lineage-tracing methods led to the better understanding of GABAergic specification in other brain regions, such as the spinal cord, the cerebellum, and the cochlear nucleus.
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86
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Paul A, Cai Y, Atwal GS, Huang ZJ. Developmental Coordination of Gene Expression between Synaptic Partners During GABAergic Circuit Assembly in Cerebellar Cortex. Front Neural Circuits 2012; 6:37. [PMID: 22754500 PMCID: PMC3385560 DOI: 10.3389/fncir.2012.00037] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2012] [Accepted: 06/01/2012] [Indexed: 01/14/2023] Open
Abstract
The assembly of neural circuits involves multiple sequential steps such as the specification of cell-types, their migration to proper brain locations, morphological and physiological differentiation, and the formation and maturation of synaptic connections. This intricate and often prolonged process is guided by elaborate genetic mechanisms that regulate each step. Evidence from numerous systems suggests that each cell-type, once specified, is endowed with a genetic program that unfolds in response to, and is regulated by, extrinsic signals, including cell–cell and synaptic interactions. To a large extent, the execution of this intrinsic program is achieved by the expression of specific sets of genes that support distinct developmental processes. Therefore, a comprehensive analysis of the developmental progression of gene expression in synaptic partners of neurons may provide a basis for exploring the genetic mechanisms regulating circuit assembly. Here we examined the developmental gene expression profiles of well-defined cell-types in a stereotyped microcircuit of the cerebellar cortex. We found that the transcriptomes of Purkinje cell and stellate/basket cells are highly dynamic throughout postnatal development. We revealed “phasic expression” of transcription factors, ion channels, receptors, cell adhesion molecules, gap junction proteins, and identified distinct molecular pathways that might contribute to sequential steps of cerebellar inhibitory circuit formation. We further revealed a correlation between genomic clustering and developmental co-expression of hundreds of transcripts, suggesting the involvement of chromatin level gene regulation during circuit formation.
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Affiliation(s)
- Anirban Paul
- Cold Spring Harbor Laboratory, Neuroscience Cold Spring Harbor, New York, NY, USA
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87
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Dastjerdi FV, Consalez GG, Hawkes R. Pattern formation during development of the embryonic cerebellum. Front Neuroanat 2012; 6:10. [PMID: 22493569 PMCID: PMC3318227 DOI: 10.3389/fnana.2012.00010] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2011] [Accepted: 03/14/2012] [Indexed: 12/04/2022] Open
Abstract
The patterning of the embryonic cerebellum is vital to establish the elaborate zone and stripe architecture of the adult. This review considers early stages in cerebellar Purkinje cell patterning, from the organization of the ventricular zone to the development of Purkinje cell clusters—the precursors of the adult stripes.
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Affiliation(s)
- F V Dastjerdi
- Faculty of Medicine, Department of Cell Biology and Anatomy, Genes and Development Research Group, Hotchkiss Brain Institute, University of Calgary, Calgary AB, Canada
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88
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Brandt T, Desai K, Grodberg D, Mehta L, Cohen N, Tryfon A, Kolevzon A, Soorya L, Buxbaum JD, Edelmann L. Complex autism spectrum disorder in a patient with a 17q12 microduplication. Am J Med Genet A 2012; 158A:1170-7. [PMID: 22488896 DOI: 10.1002/ajmg.a.35267] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2011] [Accepted: 12/26/2011] [Indexed: 11/10/2022]
Abstract
Autism spectrum disorders (ASDs) are phenotypically complex developmental neuropsychiatric disorders affecting approximately 0.6% of the population. About 30-70% of affected children are also considered to have intellectual disability (ID). The underlying genetic causes of ASDs are diverse with a defined etiology in 16-20%. Array comparative genomic hybridization (aCGH) has proven useful in identifying sub-microscopic chromosome aberrations in a subset of patients, some of which have been shown to be recurrent. One such aberration is the 1.4 Mb microdeletion at chromosome 17q12, which has been reported to be associated with renal disease, growth restriction, diabetes, cognitive impairment, seizures, and in some cases an ASD. Patients with the reciprocal chromosome 17q12 microduplication typically have also been identified with ID and in some cases seizures and behavioral abnormalities. Here we report a patient with a de novo, 1.4 Mb microduplication diagnosed with significant ID involving complex deficits and autism. To our knowledge, this is the first report of a patient with the 17q12 microduplication and a complex ASD phenotype.
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Affiliation(s)
- Tracy Brandt
- Seaver Autism Center for Research and Treatment, Mount Sinai School of Medicine, New York, New York 100029, USA
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89
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Narkis G, Tzchori I, Cohen T, Holtz A, Wier E, Westphal H. Isl1 and Ldb co-regulators of transcription are essential early determinants of mouse limb development. Dev Dyn 2012; 241:787-91. [PMID: 22411555 PMCID: PMC3443392 DOI: 10.1002/dvdy.23761] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The developing limb has served as an excellent model for studying pattern formation and signal transduction in mammalians. Many of the crucial genes that regulate growth and patterning of the limb following limb bud formation are now well known. However, details regarding the control of limb initiation and early stages of outgrowth remain to be defined. This report is focused on genetic events that pave the way for the establishment of a hindlimb bud. RESULTS Fgf10 and Tbx are crucial for early phases of limb bud initiation. Here we show that in the absence of Isl1 or of Ldb1/2, there is no hindlimb bud development. Fgf10 expression in the bud mesenchyme is dependent on Isl1 and its Ldb co-regulators. CONCLUSIONS Thus, Isl1 and the Ldb co-regulators of transcription are essential early determinants of mouse limb development. Isl1/Ldb complexes regulate Fgf10 to orchestrate the earliest stages of hindlimb formation.
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Affiliation(s)
- Ginat Narkis
- Laboratory of Mammalian Genes and Development, Program in Genomics of Development, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland 20892, USA.
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90
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Abstract
In the nervous system, there are hundreds to thousands of neuronal cell types that have morphologically, physiologically, and histochemically different characteristics and this diversity may enable us to elicit higher brain function. A better understanding of the molecular machinery by which neuron subtype specification occurs is thus one of the most important issues in brain science. The dorsal hindbrain, including the cerebellum, is a good model system to study this issue because a variety of types of neurons are produced from this region. Recently developed genetic lineage-tracing methods in addition to gene-transfer technologies have clarified a fate map of neurons produced from the dorsal hindbrain and accelerated our understanding of the molecular machinery of neuronal subtype specification in the nervous system.
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Affiliation(s)
- Mikio Hoshino
- Department of Biochemistry and Cellular Biology, National Institute of Neuroscience, National Center of Neurology and Psychiatry (NCNP), 4-1-1 Ogawahigashi, Kodaira, Tokyo 187-8502, Japan.
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91
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Wilson SL, Kalinovsky A, Orvis GD, Joyner AL. Spatially restricted and developmentally dynamic expression of engrailed genes in multiple cerebellar cell types. THE CEREBELLUM 2012; 10:356-72. [PMID: 21431469 DOI: 10.1007/s12311-011-0254-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The cerebellum is a highly organized structure partitioned into lobules along the anterior-posterior (A-P) axis and into striped molecular domains along the medial-lateral (M-L) axis. The Engrailed (En) homeobox genes are required for patterning the morphological and molecular domains along both axes, as well as for the establishment of the normal afferent topography required to generate a fully functional cerebellum. As a means to understand how the En genes regulate multiple levels of cerebellum construction, we characterized En1 and En2 expression around birth and at postnatal day (P) 21 during the period when the cerebellum undergoes a remarkable transformation from a smooth ovoid structure to a highly foliated structure. We show that both En1 and En2 are expressed in many neuronal cell types in the cerebellum, and expression persists until at least P21. En1 and En2 expression, however, undergoes profound changes in their cellular and spatial distributions between embryonic stages and P21, and their expression domains become largely distinct. Comparison of the distribution of En-expressing Purkinje cells relative to early- and late-onset Purkinje cell M-L stripe proteins revealed that although En1- and En2-expressing Purkinje cell domains do not strictly align with those of ZEBRINII at P21, a clear pattern exists that is most evident at E17.5 by an inverse correlation between the level of En2 expression and PLCß4 and EPHA4.
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Affiliation(s)
- Sandra L Wilson
- Developmental Biology Program, Memorial Sloan-Kettering Cancer Center, New York, NY 10065, USA
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92
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Waite MR, Skaggs K, Kaviany P, Skidmore JM, Causeret F, Martin JF, Martin DM. Distinct populations of GABAergic neurons in mouse rhombomere 1 express but do not require the homeodomain transcription factor PITX2. Mol Cell Neurosci 2012; 49:32-43. [PMID: 21925604 PMCID: PMC3244529 DOI: 10.1016/j.mcn.2011.08.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2011] [Revised: 08/04/2011] [Accepted: 08/30/2011] [Indexed: 11/20/2022] Open
Abstract
Hindbrain rhombomere 1 (r1) is located caudal to the isthmus, a critical organizer region, and rostral to rhombomere 2 in the developing mouse brain. Dorsal r1 gives rise to the cerebellum, locus coeruleus, and several brainstem nuclei, whereas cells from ventral r1 contribute to the trochlear and trigeminal nuclei as well as serotonergic and GABAergic neurons of the dorsal raphe. Recent studies have identified several molecular events controlling dorsal r1 development. In contrast, very little is known about ventral r1 gene expression and the genetic mechanisms regulating its formation. Neurons with distinct neurotransmitter phenotypes have been identified in ventral r1 including GABAergic, serotonergic, and cholinergic neurons. Here we show that PITX2 marks a distinct population of GABAergic neurons in mouse embryonic ventral r1. This population appears to retain its GABAergic identity even in the absence of PITX2. We provide a comprehensive map of markers that places these PITX2-positive GABAergic neurons in a region of r1 that intersects and is potentially in communication with the dorsal raphe.
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Affiliation(s)
- Mindy R Waite
- Program in Cell and Molecular Biology, 2966 Taubman Medical Library, University of Michigan, Ann Arbor, MI 48109-0619, USA.
| | - Kaia Skaggs
- Department of Neurology, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA.
| | - Parisa Kaviany
- Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA.
| | - Jennifer M Skidmore
- Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA.
| | - Frédéric Causeret
- Institut Jacques Monod, Université Paris Diderot, CNRS UMR 7592, Sorbonne Paris Cité, Paris, France.
| | - James F Martin
- Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Cardiomyocyte Renewal Lab Texas Heart Institute, Houston Texas, 77030, USA.
| | - Donna M Martin
- Program in Cell and Molecular Biology, 2966 Taubman Medical Library, University of Michigan, Ann Arbor, MI 48109-0619, USA; Department of Pediatrics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA; Department of Human Genetics, 3520A MSRB I, University of Michigan, Ann Arbor, MI, 48019-5652, USA.
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93
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George AM, Love DR, Hayes I, Tsang B. Recurrent Transmission of a 17q12 Microdeletion and a Variable Clinical Spectrum. Mol Syndromol 2011; 2:72-75. [PMID: 22511894 DOI: 10.1159/000335344] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/18/2011] [Indexed: 12/16/2022] Open
Abstract
The relatively rare proximal microdeletion of 17q12 (including deletion of the HNF1B gene) is associated with the renal cysts and diabetes syndrome. Recent reports have suggested that there may also be an association between this microdeletion and learning difficulties/autism. This case report describes one of only a few reported families segregating the 17q12 microdeletion, but which highlights the nonpenetrance and variable expressivity of multiple features of this condition.
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Affiliation(s)
- A M George
- Diagnostic Genetics, LabPlus, Auckland, New Zealand
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94
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Uncovering genomic causes of co-morbidity in epilepsy: gene-driven phenotypic characterization of rare microdeletions. PLoS One 2011; 6:e23182. [PMID: 21858020 PMCID: PMC3157359 DOI: 10.1371/journal.pone.0023182] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Accepted: 07/07/2011] [Indexed: 12/13/2022] Open
Abstract
Background Patients with epilepsy often suffer from other important conditions. The existence of such co-morbidities is frequently not recognized and their relationship with epilepsy usually remains unexplained. Methodology/Principal Findings We describe three patients with common, sporadic, non-syndromic epilepsies in whom large genomic microdeletions were found during a study of genetic susceptibility to epilepsy. We performed detailed gene-driven clinical investigations in each patient. Disruption of the function of genes in the deleted regions can explain co-morbidities in these patients. Conclusions/Significance Co-morbidities in patients with epilepsy can be part of a genomic abnormality even in the absence of (known) congenital malformations or intellectual disabilities. Gene-driven phenotype examination can also reveal clinically significant unsuspected condition.
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95
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Li L, Jothi R, Cui K, Lee JY, Cohen T, Gorivodsky M, Tzchori I, Zhao Y, Hayes SM, Bresnick EH, Zhao K, Westphal H, Love PE. Nuclear adaptor Ldb1 regulates a transcriptional program essential for the maintenance of hematopoietic stem cells. Nat Immunol 2011; 12:129-36. [PMID: 21186366 PMCID: PMC3766981 DOI: 10.1038/ni.1978] [Citation(s) in RCA: 86] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2010] [Accepted: 12/01/2010] [Indexed: 01/15/2023]
Abstract
The nuclear adaptor Ldb1 functions as a core component of multiprotein transcription complexes that regulate differentiation in diverse cell types. In the hematopoietic lineage, Ldb1 forms a complex with the non-DNA-binding adaptor Lmo2 and the transcription factors E2A, Scl and GATA-1 (or GATA-2). Here we demonstrate a critical and continuous requirement for Ldb1 in the maintenance of both fetal and adult mouse hematopoietic stem cells (HSCs). Deletion of Ldb1 in hematopoietic progenitors resulted in the downregulation of many transcripts required for HSC maintenance. Genome-wide profiling by chromatin immunoprecipitation followed by sequencing (ChIP-Seq) identified Ldb1 complex-binding sites at highly conserved regions in the promoters of genes involved in HSC maintenance. Our results identify a central role for Ldb1 in regulating the transcriptional program responsible for the maintenance of HSCs.
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Affiliation(s)
- LiQi Li
- Section on Cellular & Developmental Biology, Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
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96
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Molecular pathways controlling development of thalamus and hypothalamus: from neural specification to circuit formation. J Neurosci 2010; 30:14925-30. [PMID: 21068293 DOI: 10.1523/jneurosci.4499-10.2010] [Citation(s) in RCA: 61] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The embryonic diencephalon gives rise to the vertebrate thalamus and hypothalamus, which play essential roles in sensory information processing and control of physiological homeostasis and behavior, respectively. In this review, we present new steps toward characterizing the molecular pathways that control development of these structures, based on findings in a variety of model organisms. We highlight advances in understanding how early regional patterning is orchestrated through the action of secreted signaling molecules such as Sonic hedgehog and fibroblast growth factors. We address the role of individual transcription factors in control of the regional identity and neural differentiation within the developing diencephalon, emphasizing the contribution of recent large-scale gene expression studies in providing an extensive catalog of candidate regulators of hypothalamic neural cell fate specification. Finally, we evaluate the molecular mechanisms involved in the experience-dependent development of both thalamo-cortical and hypothalamic neural circuitry.
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97
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Teufel A, Maass T, Strand S, Kanzler S, Galante T, Becker K, Strand D, Biesterfeld S, Westphal H, Galle PR. Liver-specific Ldb1 deletion results in enhanced liver cancer development. J Hepatol 2010; 53:1078-84. [PMID: 20828852 PMCID: PMC5903435 DOI: 10.1016/j.jhep.2010.05.027] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/22/2009] [Revised: 05/23/2010] [Accepted: 05/26/2010] [Indexed: 01/15/2023]
Abstract
BACKGROUND & AIMS LIM-domain-binding (Ldb) proteins have been demonstrated to be essential not only to key embryonic developmental processes but also to carcinogenesis. We have previously demonstrated Ldb1 to be of high biological and developmental relevance, as a targeted deletion of the Ldb1 gene in mice results in an embryonic lethal and pleiotropic phenotype. METHODS We have now established a liver-specific Ldb1 knock out to investigate the role of Ldb1 in carcinogenesis, in particular in hepatocellular carcinoma (HCC) development, in vivo. RESULTS These mice demonstrated a significantly enhanced growth of liver cancer by means of tumor size and number, advocating for an essential role of Ldb1 in HCC development. In addition, proliferation and resistance against apoptosis were increased. In order to identify the functional disturbances due to a lack of Ldb1, we performed a 15k mouse gene microarray expression analysis. We found the Myc oncogene to be regulated in the microarray analysis and were able to further confirm this regulation by demonstrating an over-expression of its downstream target Cyclin D1. Furthermore, we were able to demonstrate a down-regulation of the tumor suppressor p21. Finally, the liver stem cell marker EpCAM was also identified to be over expressed in Ldb1(-/-) knock out mice. CONCLUSIONS We have established a significant role of Ldb1 in cancer development. Furthermore, we provided evidence for a myc/cyclin D1, p21, and EpCAM-dependent signalling to be key downstream regulators of this novel concept in HCC development.
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Affiliation(s)
- Andreas Teufel
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany.
| | - Thorsten Maass
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
| | - Susanne Strand
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
| | - Stephan Kanzler
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
| | - Tiziana Galante
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
| | - Kevin Becker
- Gene Expression Unit, National Institute On Aging, National Institutes of Health, Bethesda, MD, USA
| | - Dennis Strand
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
| | | | - Heiner Westphal
- Laboratory of Mammalian Genes and Development, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA
| | - Peter R. Galle
- Department of Medicine I, Johannes Gutenberg University, Mainz, Germany
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98
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Abstract
Cajal-Retzius (C-R) cells play important roles in the lamination of the mammalian cortex via reelin secretion. The genetic mechanisms underlying the development of these neurons have just begun to be unraveled. Here, we show that two closely related LIM-homeobox genes Lhx1 and Lhx5 are expressed in reelin+ cells in various regions in the mouse telencephalon at or adjacent to sites where the C-R cells are generated, including the cortical hem, the mantle region of the septal/retrobulbar area, and the ventral pallium. Whereas Lhx5 is expressed in all of these reelin-expressing domains, Lhx1 is preferentially expressed in the septal area and in a continuous domain spanning from lateral olfactory region to caudomedial territories. Genetic ablation of Lhx5 results in decreased reelin+ and p73+ cells in the neocortical anlage, in the cortical hem, and in the septal, olfactory, and caudomedial telencephalic regions. The overall reduction in number of C-R cells in Lhx5 mutants is accompanied by formation of ectopic reelin+ cell clusters at the caudal telencephalon. Based on differential expression of molecular markers and by fluorescent cell tracing in cultured embryos, we located the origin of reelin+ ectopic cell clusters at the caudomedial telencephalic region. We also confirmed the existence of a normal migration stream of reelin+ cells from the caudomedial area to telencephalic olfactory territories in wild-type embryos. These results reveal a complex role for Lhx5 in regulating the development and normal distribution of C-R cells in the developing forebrain.
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99
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Rolando C, Gribaudo S, Yoshikawa K, Leto K, De Marchis S, Rossi F. Extracerebellar progenitors grafted to the neurogenic milieu of the postnatal rat cerebellum adapt to the host environment but fail to acquire cerebellar identities. Eur J Neurosci 2010; 31:1340-51. [DOI: 10.1111/j.1460-9568.2010.07167.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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100
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Lundell TG, Zhou Q, Doughty ML. Neurogenin1 expression in cell lineages of the cerebellar cortex in embryonic and postnatal mice. Dev Dyn 2010; 238:3310-25. [PMID: 19924827 DOI: 10.1002/dvdy.22165] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
The basic helix-loop-helix (bHLH) transcription factors Ptf1a and Math1 are necessary for the specification of gamma-aminobutyric acid-ergic and glutamatergic cell lineages in the cerebellum, respectively. Recent evidence suggests cascades of bHLH factor activities drive cell type specificity in Ptf1a(+ve) and Math1(+ve) lineages. In this manuscript, we reveal cell lineages in the cerebellar cortex but not deep cerebellar nuclei express the pro-neural bHLH factor Neurogenin1 (Ngn1). Ngn1 is expressed in ventricular zone progenitors and in newly generated neurons in the caudal cerebellar primordium. In later embryonic and postnatal developmental stages, Ngn1 is expressed in progenitors and in migrating interneurons in the prospective white matter. Transgenic fate-mapping reveals Ngn1 reporter-gene expression in Purkinje cells, multiple inhibitory interneuron cell types, and in unipolar brush cells of the cortex. The data suggest Ngn1 is a component of the bHLH factor code regulating cell type specification in the cerebellar cortex.
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Affiliation(s)
- T G Lundell
- Department of Anatomy, Physiology and Genetics, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814, USA
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