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Hwang SH, White KA, Somatilaka BN, Wang B, Mukhopadhyay S. Context-dependent ciliary regulation of hedgehog pathway repression in tissue morphogenesis. PLoS Genet 2023; 19:e1011028. [PMID: 37943875 PMCID: PMC10662714 DOI: 10.1371/journal.pgen.1011028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 11/21/2023] [Accepted: 10/24/2023] [Indexed: 11/12/2023] Open
Abstract
A fundamental problem in tissue morphogenesis is identifying how subcellular signaling regulates mesoscale organization of tissues. The primary cilium is a paradigmatic organelle for compartmentalized subcellular signaling. How signaling emanating from cilia orchestrates tissue organization-especially, the role of cilia-generated effectors in mediating diverse morpho-phenotypic outcomes-is not well understood. In the hedgehog pathway, bifunctional GLI transcription factors generate both GLI-activators (GLI-A) and GLI-repressors (GLI-R). The formation of GLI-A/GLI-R requires cilia. However, how these counterregulatory effectors coordinate cilia-regulated morphogenetic pathways is unclear. Here we determined GLI-A/GLI-R requirements in phenotypes arising from lack of hedgehog pathway repression (derepression) during mouse neural tube and skeletal development. We studied hedgehog pathway repression by the GPCR GPR161, and the ankyrin repeat protein ANKMY2 that direct cAMP/protein kinase-A signaling by cilia in GLI-R generation. We performed genetic epistasis between Gpr161 or Ankmy2 mutants, and Gli2/Gli3 knockouts, Gli3R knock-in and knockout of Smoothened, the hedgehog pathway transducer. We also tested the role of cilia-generated signaling using a Gpr161 ciliary localization knock-in mutant that is cAMP signaling competent. We found that the cilia-dependent derepression phenotypes arose in three modes: lack of GLI-R only, excess GLI-A formation only, or dual regulation of either lack of GLI-R or excess GLI-A formation. These modes were mostly independent of Smoothened. The cAMP signaling-competent non-ciliary Gpr161 knock-in recapitulated Gpr161 loss-of-function tissue phenotypes solely from lack of GLI-R only. Our results show complex tissue-specific GLI-effector requirements in morphogenesis and point to tissue-specific GLI-R thresholds generated by cilia in hedgehog pathway repression. Broadly, our study sets up a conceptual framework for rationalization of different modes of signaling generated by the primary cilium in mediating morphogenesis in diverse tissues.
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Affiliation(s)
- Sun-Hee Hwang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Kevin Andrew White
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Bandarigoda Nipunika Somatilaka
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Present address, Department of Dermatology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Baolin Wang
- Department of Genetic Medicine, Weill Medical College of Cornell University, New York, New York, United States of America
| | - Saikat Mukhopadhyay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
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Wang YB, Song NN, Zhang L, Ma P, Chen JY, Huang Y, Hu L, Mao B, Ding YQ. Rnf220 is Implicated in the Dorsoventral Patterning of the Hindbrain Neural Tube in Mice. Front Cell Dev Biol 2022; 10:831365. [PMID: 35399523 PMCID: PMC8988044 DOI: 10.3389/fcell.2022.831365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2021] [Accepted: 02/08/2022] [Indexed: 11/24/2022] Open
Abstract
Rnf220 is reported to regulate the patterning of the ventral spinal neural tube in mice. The brainstem has divergent connections with peripheral and central targets and contains unique internal neuronal groups, but the role of Rnf220 in the early development of the hindbrain has not been explored. In this study, Nestin-Cre-mediated conditional knockout (Rnf220Nestin CKO) mice were used to examine if Rnf220 is involved in the early morphogenesis of the hindbrain. Rnf220 showed restricted expression in the ventral half of ventricular zone (VZ) of the hindbrain at embryonic day (E) 10.5, and as development progressed, Rnf220-expressing cells were also present in the mantle zone outside the VZ at E12.5. In Rnf220Nestin CKO embryos, alterations of progenitor domains in the ventral VZ were observed at E10.5. There were significant reductions of the p1 and p2 domains shown by expression of Dbx1, Olig2, and Nkx6.1, accompanied by a ventral expansion of the Dbx1+ p0 domain and a dorsal expansion of the Nkx2.2+ p3 domain. Different from the case in the spinal cord, the Olig2+ pMN (progenitors of somatic motor neuron) domain shifted and expanded dorsally. Notably, the total range of the ventral VZ and the extent of the dorsal tube were unchanged. In addition, the post-mitotic cells derived from their corresponding progenitor domain, including oligodendrocyte precursor cells (OPCs) and serotonergic neurons (5-HTNs), were also changed in the same trend as the progenitor domains do in the CKO embryos at E12.5. In summary, our data suggest similar functions of Rnf220 in the hindbrain dorsoventral (DV) patterning as in the spinal cord with different effects on the pMN domain. Our work also reveals novel roles of Rnf220 in the development of 5-HTNs and OPCs.
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Affiliation(s)
- Yu-Bing Wang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, China
| | - Ning-Ning Song
- Department of Laboratory Animal Science, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Lei Zhang
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, China
| | - Pengcheng Ma
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
| | - Jia-Yin Chen
- Department of Laboratory Animal Science, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ying Huang
- Department of Laboratory Animal Science, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Ling Hu
- Department of Laboratory Animal Science, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
| | - Bingyu Mao
- State Key Laboratory of Genetic Resources and Evolution, Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, China
- *Correspondence: Bingyu Mao, ; Yu-Qiang Ding,
| | - Yu-Qiang Ding
- Key Laboratory of Arrhythmias, Ministry of Education, East Hospital, Department of Anatomy and Neurobiology, Tongji University School of Medicine, Shanghai, China
- Department of Laboratory Animal Science, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, MOE Frontiers Center for Brain Science, Institutes of Brain Science, Fudan University, Shanghai, China
- *Correspondence: Bingyu Mao, ; Yu-Qiang Ding,
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Ali S, Arif I, Iqbal A, Hussain I, Abrar M, Khan MR, Shubin N, Abbasi AA. Comparative genomic analysis of human GLI2 locus using slowly evolving fish revealed the ancestral gnathostome set of early developmental enhancers. Dev Dyn 2021; 250:669-683. [PMID: 33381902 PMCID: PMC9292287 DOI: 10.1002/dvdy.291] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 12/18/2020] [Accepted: 12/19/2020] [Indexed: 12/03/2022] Open
Abstract
Background The zinc finger‐containing transcription factor Gli2, is a key mediator of Hedgehog (Hh) signaling and participates in embryonic patterning of various organs including the central nervous system (CNS) and limbs. Abnormal expression of Gli2 can impede the transcription of Hh target genes through disruption of proper balance between Gli2 and Gli3 functions. Therefore, delineation of enhancers that are required for complementary roles of Glis would allow the interrogation of those pathogenic variants that cause gene dysregulation, and a corresponding abnormal phenotype. Previously, we reported tissue‐specific enhancers for Gli family including Gli2 through direct tetrapod‐teleost comparisons. Results Here, we employed the sequence alignments of slowly evolving spotted gar and elephant shark and have identified six novel conserved noncoding elements in human GLI2 containing locus. Zebrafish‐based transgenic assays revealed that combined action of these autonomous CNEs reflects many aspects of Gli2 specific endogenous transcriptional activity, including CNS and pectoral fins. Conclusion Taken together with our previous findings, this study suggests that Hh‐signaling controlled deployment of Gli2 activity in embryonic patterning arose in the common ancestor of gnathostomes. These GLI2 specific cis‐regulatory modules will help to identify DNA variants that probably reside outside of coding intervals and are associated with congenital anomalies. We performed a phylogenetic footprint analyses of human GLI2 containing locus by incorporating relatively slowly evolving gar and elephant shark genomes and have identified multiple novel conserved non‐coding elements (CNEs) that were not predicted by direct human‐teleostcomparisons. Comparative analyses suggest that majority of the GLI2 associated CNEs identified in the present data and reported previously arose in the common ancestor of gnathostomes but lost in teleosts, presumably because of fast teleost sequence evolution. Functional testing of GLI2 associated CNEs by employing zebrafish based transgenic reporter assays revealed their tissue specific cis‐regulatory potential that corresponds with the results based on whole‐mount in situ hybridization analysis of gli2 mRNA in zebrafish. The delineated set of GLI2 associated enhancers can be further interrogated to determine their role in canonical Hh signaling, gene dysregulation, and a corresponding congenital anomaly.
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Affiliation(s)
- Shahid Ali
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
| | - Irum Arif
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
| | - Ayesha Iqbal
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
| | - Irfan Hussain
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
| | - Muhammad Abrar
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
| | - Muhammad Ramzan Khan
- National Institute for Genomics and Advanced Biotechnology, National Agricultural Research Center, Islamabad, Pakistan
| | - Neil Shubin
- Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, Illinois, USA
| | - Amir Ali Abbasi
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i- Azam University, Islamabad, Pakistan
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Fiore L, Takata N, Acosta S, Ma W, Pandit T, Oxendine M, Oliver G. Optic vesicle morphogenesis requires primary cilia. Dev Biol 2020; 462:119-128. [PMID: 32169553 PMCID: PMC8167498 DOI: 10.1016/j.ydbio.2020.02.016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 12/25/2022]
Abstract
Arl13b is a gene known to regulate ciliogenesis. Functional alterations in this gene's activity have been associated with Joubert syndrome. We found that in Arl13 null mouse embryos the orientation of the optic cup is inverted, such that the lens is abnormally surrounded by an inverted optic cup whose retina pigmented epithelium is oddly facing the surface ectoderm. Loss of Arl13b leads to the disruption of optic vesicle's patterning and expansion of ventral fates. We show that this phenotype is consequence of miss-regulation of Sonic hedgehog (Shh) signaling and demonstrate that the Arl13b-/- eye phenotype can be rescued by deletion of Gli2, a downstream effector of the Shh pathway. This work identified an unexpected role of primary cilia during the morphogenetic movements required for the formation of the eye.
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Affiliation(s)
- Luciano Fiore
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Nozomu Takata
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Sandra Acosta
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA; Institute of Evolutive Biology, Pompeu Fabra University, Barcelona, Spain
| | - Wanshu Ma
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Tanushree Pandit
- Department of Genetics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Michael Oxendine
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA
| | - Guillermo Oliver
- Center for Vascular and Developmental Biology, Feinberg Cardiovascular and Renal Research Institute (FCVRRI), Northwestern University, Chicago, IL, USA.
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Martinez-Chavez E, Scheerer C, Wizenmann A, Blaess S. The zinc-finger transcription factor GLI3 is a regulator of precerebellar neuronal migration. Development 2018; 145:dev.166033. [PMID: 30470704 DOI: 10.1242/dev.166033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Accepted: 11/15/2018] [Indexed: 01/24/2023]
Abstract
Hindbrain precerebellar neurons arise from progenitor pools at the dorsal edge of the embryonic hindbrain: the caudal rhombic lip. These neurons follow distinct migratory routes to establish nuclei that provide climbing or mossy fiber inputs to the cerebellum. Gli3, a zinc-finger transcription factor in the Sonic hedgehog signaling pathway, is an important regulator of dorsal brain development. We demonstrate that in Gli3-null mutant mice, disrupted neuronal migratory streams lead to a disorganization of precerebellar nuclei. Precerebellar progenitors are properly established in Gli3-null embryos and, using conditional gene inactivation, we provide evidence that Gli3 does not play a cell-autonomous role in migrating precerebellar neurons. Thus, GLI3 likely regulates the development of other hindbrain structures, such as non-precerebellar nuclei or cranial ganglia and their respective projections, which may in turn influence precerebellar migration. Although the organization of non-precerebellar hindbrain nuclei appears to be largely unaffected in absence of Gli3, trigeminal ganglia and their central descending tracts are disrupted. We show that rostrally migrating precerebellar neurons are normally in close contact with these tracts, but are detached in Gli3-null embryos.
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Affiliation(s)
- Erick Martinez-Chavez
- Institute of Reconstructive Neurobiology, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Claudia Scheerer
- Institute of Reconstructive Neurobiology, University of Bonn Medical Center, 53127 Bonn, Germany
| | - Andrea Wizenmann
- Institute of Clinical Anatomy and Cell Analysis, Department of Anatomy, University of Tübingen, 72074 Tübingen, Germany
| | - Sandra Blaess
- Institute of Reconstructive Neurobiology, University of Bonn Medical Center, 53127 Bonn, Germany
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6
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Sabol M, Trnski D, Musani V, Ozretić P, Levanat S. Role of GLI Transcription Factors in Pathogenesis and Their Potential as New Therapeutic Targets. Int J Mol Sci 2018; 19:E2562. [PMID: 30158435 PMCID: PMC6163343 DOI: 10.3390/ijms19092562] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Revised: 08/17/2018] [Accepted: 08/25/2018] [Indexed: 02/05/2023] Open
Abstract
GLI transcription factors have important roles in intracellular signaling cascade, acting as the main mediators of the HH-GLI signaling pathway. This is one of the major developmental pathways, regulated both canonically and non-canonically. Deregulation of the pathway during development leads to a number of developmental malformations, depending on the deregulated pathway component. The HH-GLI pathway is mostly inactive in the adult organism but retains its function in stem cells. Aberrant activation in adult cells leads to carcinogenesis through overactivation of several tightly regulated cellular processes such as proliferation, angiogenesis, EMT. Targeting GLI transcription factors has recently become a major focus of potential therapeutic protocols.
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Affiliation(s)
- Maja Sabol
- Laboratory for Hereditary Cancer, Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Diana Trnski
- Laboratory for Hereditary Cancer, Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Vesna Musani
- Laboratory for Hereditary Cancer, Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Petar Ozretić
- Laboratory for Hereditary Cancer, Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
| | - Sonja Levanat
- Laboratory for Hereditary Cancer, Division of Molecular Medicine, Ruđer Bošković Institute, Bijenička cesta 54, 10000 Zagreb, Croatia.
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7
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Zhang L, Mubarak T, Chen Y, Lee T, Pollock A, Sun T. Counter-Balance Between Gli3 and miR-7 Is Required for Proper Morphogenesis and Size Control of the Mouse Brain. Front Cell Neurosci 2018; 12:259. [PMID: 30210296 PMCID: PMC6121149 DOI: 10.3389/fncel.2018.00259] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Accepted: 07/30/2018] [Indexed: 12/25/2022] Open
Abstract
Brain morphogenesis requires precise regulation of multiple genes to control specification of distinct neural progenitors (NPs) and neuronal production. Dysregulation of these genes results in severe brain malformation such as macrocephaly and microcephaly. Despite studies of the effect of individual pathogenic genes, the counter-balance between multiple factors in controlling brain size remains unclear. Here we show that cortical deletion of Gli3 results in enlarged brain and folding structures in the cortical midline at the postnatal stage, which is mainly caused by the increased percentage of intermediate progenitors (IPs) and newborn neurons. In addition, dysregulation of neuronal migration also contributes to the folding defects in the cortical midline region. Knockdown of microRNA (miRNA) miR-7 can rescue abnormal brain morphology in Gli3 knockout mice by recovering progenitor specification, neuronal production and migration through a counter-balance of the Gli3 activity. Moreover, miR-7 likely exerts its function through silencing target gene Pax6. Our results indicate that proper brain morphogenesis is an outcome of interactive regulations of multiple molecules such as Gli3 and miR-7. Because miRNAs are easy to synthesize and deliver, miR-7 could be a potential therapeutic means to macrocephaly caused by Gli3-deficiency.
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Affiliation(s)
- Longbin Zhang
- Center for Precision Medicine, School of Medicine and School of Biomedical Sciences, Huaqiao University, Xiamen, China
| | - Taufif Mubarak
- Department of Cell and Developmental Biology, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Yase Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, China
| | - Trevor Lee
- Department of Cell and Developmental Biology, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Andrew Pollock
- Department of Cell and Developmental Biology, Weill Cornell Medicine, Cornell University, New York, NY, United States
| | - Tao Sun
- Center for Precision Medicine, School of Medicine and School of Biomedical Sciences, Huaqiao University, Xiamen, China
- Department of Cell and Developmental Biology, Weill Cornell Medicine, Cornell University, New York, NY, United States
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Puelles L, Tvrdik P, Martínez-de-la-torre M. The Postmigratory Alar Topography of Visceral Cranial Nerve Efferents Challenges the Classical Model of Hindbrain Columns. Anat Rec (Hoboken) 2018; 302:485-504. [DOI: 10.1002/ar.23830] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 12/07/2017] [Accepted: 12/08/2017] [Indexed: 12/21/2022]
Affiliation(s)
- Luis Puelles
- Department of Human Anatomy and Psychobiology and IMIB-Arrixaca Institute, School of Medicine; University of Murcia; Murcia 30071 Spain
| | - Petr Tvrdik
- Department of Neurosurgery-Physiology; University of Utah; Salt Lake City, Utah 84112
| | - Margaret Martínez-de-la-torre
- Department of Human Anatomy and Psychobiology and IMIB-Arrixaca Institute, School of Medicine; University of Murcia; Murcia 30071 Spain
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Di Bonito M, Studer M. Cellular and Molecular Underpinnings of Neuronal Assembly in the Central Auditory System during Mouse Development. Front Neural Circuits 2017; 11:18. [PMID: 28469562 PMCID: PMC5395578 DOI: 10.3389/fncir.2017.00018] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Accepted: 03/01/2017] [Indexed: 11/13/2022] Open
Abstract
During development, the organization of the auditory system into distinct functional subcircuits depends on the spatially and temporally ordered sequence of neuronal specification, differentiation, migration and connectivity. Regional patterning along the antero-posterior axis and neuronal subtype specification along the dorso-ventral axis intersect to determine proper neuronal fate and assembly of rhombomere-specific auditory subcircuits. By taking advantage of the increasing number of transgenic mouse lines, recent studies have expanded the knowledge of developmental mechanisms involved in the formation and refinement of the auditory system. Here, we summarize several findings dealing with the molecular and cellular mechanisms that underlie the assembly of central auditory subcircuits during mouse development, focusing primarily on the rhombomeric and dorso-ventral origin of auditory nuclei and their associated molecular genetic pathways.
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Anwar S, Minhas R, Ali S, Lambert N, Kawakami Y, Elgar G, Azam SS, Abbasi AA. Identification and functional characterization of novel transcriptional enhancers involved in regulating human GLI3 expression during early development. Dev Growth Differ 2015; 57:570-80. [PMID: 26464005 PMCID: PMC4609622 DOI: 10.1111/dgd.12239] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Revised: 08/06/2015] [Accepted: 08/25/2015] [Indexed: 12/13/2022]
Abstract
The zinc-finger transcription factor GLI3 acts as a primary transducer of Sonic hedgehog (Shh) signaling in a context-dependent combinatorial fashion. GLI3 participates in the patterning and growth of many organs, including the central nervous system (CNS) and limbs. Previously, we reported a subset of human intronic cis-regulators controlling many known aspects of endogenous Gli3 expression in mouse and zebrafish. Here we demonstrate in a transgenic zebrafish assay the potential of two novel tetrapod-teleost conserved non-coding elements (CNEs) docking within GLI3 intronic intervals (intron 3 and 4) to induce reporter gene expression at known sites of endogenous Gli3 transcription in embryonic domains such as the central nervous system (CNS) and limbs. Interestingly, the cell culture based assays reveal harmony with the context dependent dual nature of intra-GLI3 conserved elements. Furthermore, a transgenic zebrafish assay of previously reported limb-specific GLI3 transcriptional enhancers (previously tested in mice and chicken limb buds) induced reporter gene expression in zebrafish blood precursor cells and notochord instead of fin. These results demonstrate that the appendage-specific activity of a subset of GLI3-associated enhancers might be a tetrapod innovation. Taken together with our recent data, these results suggest that during the course of vertebrate evolution Gli3 expression control acquired a complex cis-regulatory landscape for spatiotemporal patterning of CNS and limbs. Comparative data from fish and mice suggest that the functional aspects of a subset of these cis-regulators have diverged significantly between these two lineages.
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Affiliation(s)
- Saneela Anwar
- National Center for Bioinformatics, Computational Biology Lab, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Rashid Minhas
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Shahid Ali
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Nicholas Lambert
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Yasuhiko Kawakami
- Department of Genetics, Cell Biology and Development, University of Minnesota, Minneapolis, Minnesota, 55455, USA
| | - Greg Elgar
- The Francis Crick Institute, Mill Hill Laboratory, The Ridgeway, London, NW7 1AA, UK
| | - Syed Sikandar Azam
- National Center for Bioinformatics, Computational Biology Lab, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
| | - Amir Ali Abbasi
- National Center for Bioinformatics, Program of Comparative and Evolutionary Genomics, Faculty of Biological Sciences, Quaid-i-Azam University, Islamabad, 45320, Pakistan
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11
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Arnhold IJP, França MM, Carvalho LR, Mendonca BB, Jorge AAL. Role of GLI2 in hypopituitarism phenotype. J Mol Endocrinol 2015; 54:R141-50. [PMID: 25878059 DOI: 10.1530/jme-15-0009] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/01/2015] [Indexed: 02/01/2023]
Abstract
GLI2 is a zinc-finger transcription factor involved in the Sonic Hedgehog pathway. Gli2 mutant mice have hypoplastic anterior and absent posterior pituitary glands. We reviewed the literature for patients with hypopituitarism and alterations in GLI2. Twenty-five patients (16 families) had heterozygous truncating mutations, and the phenotype frequently included GH deficiency, a small anterior pituitary lobe and an ectopic/undescended posterior pituitary lobe on magnetic resonance imaging and postaxial polydactyly. The inheritance pattern was autosomal dominant with incomplete penetrance and variable expressivity. The mutation was frequently inherited from an asymptomatic parent. Eleven patients had heterozygous non-synonymous GLI2 variants that were classified as variants of unknown significance, because they were either absent from or had a frequency lower than 0.001 in the databases. In these patients, the posterior pituitary was also ectopic, but none had polydactyly. A third group of variants found in patients with hypopituitarism were considered benign because their frequency was ≥ 0.001 in the databases. GLI2 is a large and polymorphic gene, and sequencing may identify variants whose interpretation may be difficult. Incomplete penetrance implies in the participation of other genetic and/or environmental factors. An interaction between Gli2 mutations and prenatal ethanol exposure has been demonstrated in mice dysmorphology. In conclusion, a relatively high frequency of GLI2 mutations and variants were identified in patients with congenital GH deficiency without other brain defects, and most of these patients presented with combined pituitary hormone deficiency and an ectopic posterior pituitary lobe. Future studies may clarify the relative role and frequency of GLI2 alterations in the aetiology of hypopituitarism.
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Affiliation(s)
- Ivo J P Arnhold
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Marcela M França
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Luciani R Carvalho
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Berenice B Mendonca
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
| | - Alexander A L Jorge
- Divisão de EndocrinologiaUnidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Hospital das Clinicas da FMUSP, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, Avenida Eneas de Carvalho Aguiar, 155, Prédio dos Ambulatórios, 8° andar, Bloco 3, CEP 05403-900 Sao Paulo, BrazilUnidade de Endocrinologia GeneticaLaboratorio de Endocrinologia Celular e Molecular LIM/25, Disciplina de Endocrinologia da Faculdade de Medicina da Universidade de Sao Paulo, 01246-903 Sao Paulo, Brazil
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12
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Minhas R, Pauls S, Ali S, Doglio L, Khan MR, Elgar G, Abbasi AA. Cis-regulatory control of human GLI2 expression in the developing neural tube and limb bud. Dev Dyn 2015; 244:681-92. [DOI: 10.1002/dvdy.24266] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 01/29/2015] [Accepted: 02/16/2015] [Indexed: 11/08/2022] Open
Affiliation(s)
- Rashid Minhas
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
| | - Stefan Pauls
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Shahid Ali
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
| | - Laura Doglio
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Muhammad Ramzan Khan
- National Institute for Genomics and Advanced Biotechnology; National Agricultural Research Center; Park Road Islamabad Pakistan
| | - Greg Elgar
- Division of Systems Biology; MRC National Institute for Medical Research; The Ridgeway, Mill Hill London NW7 1AA United Kingdom
| | - Amir Ali Abbasi
- National Center for Bioinformatics; Program of Comparative and Evolutionary Genomics; Faculty of Biological Sciences; Quaid-i-Azam University; Islamabad 45320 Pakistan
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13
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Haddad-Tóvolli R, Paul FA, Zhang Y, Zhou X, Theil T, Puelles L, Blaess S, Alvarez-Bolado G. Differential requirements for Gli2 and Gli3 in the regional specification of the mouse hypothalamus. Front Neuroanat 2015; 9:34. [PMID: 25859185 PMCID: PMC4373379 DOI: 10.3389/fnana.2015.00034] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2015] [Accepted: 03/09/2015] [Indexed: 11/13/2022] Open
Abstract
Secreted protein Sonic hedgehog (Shh) ventralizes the neural tube by modulating the crucial balance between activating and repressing functions (GliA, GliR) of transcription factors Gli2 and Gli3. This balance—the Shh-Gli code—is species- and context-dependent and has been elucidated for the mouse spinal cord. The hypothalamus, a forebrain region regulating vital functions like homeostasis and hormone secretion, shows dynamic and intricate Shh expression as well as complex regional differentiation. Here we asked if particular combinations of Gli2 and Gli3 and of GliA and GliR functions contribute to the variety of hypothalamic regions, i.e., we wanted to approach the question of a possible hypothalamic version of the Shh-Gli code. Based on mouse mutant analysis, we show that: (1) hypothalamic regional heterogeneity is based in part on differentially stringent requirements for Gli2 or Gli3; (2) another source of diversity are differential requirements for Shh of neural vs. non-neural origin; (3) the medial progenitor domain known to depend on Gli2 for its development generates several essential hypothalamic nuclei plus the pituitary and median eminence; (4) the suppression of Gli3R by neural and non-neural Shh is essential for hypothalamic specification. Finally, we have mapped our results on a recent model which considers the hypothalamus as a transverse region with alar and basal portions. Our data confirm the model and are explained by it.
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Affiliation(s)
- Roberta Haddad-Tóvolli
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Fabian A Paul
- Laboratory of Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn Bonn, Germany
| | - Yuanfeng Zhang
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Xunlei Zhou
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
| | - Thomas Theil
- Centre for Integrative Physiology, University of Edinburgh Edinburgh, UK
| | - Luis Puelles
- Department of Morphology, Instituto Murciano de Investigación Biosanitaria, School of Medicine, University of Murcia Murcia, Spain ; Facultad de Medicina, University of Murcia Murcia, Spain
| | - Sandra Blaess
- Laboratory of Neurodevelopmental Genetics, Institute of Reconstructive Neurobiology, Life and Brain Center, University of Bonn Bonn, Germany
| | - Gonzalo Alvarez-Bolado
- Department of Medical Cell Biology and Neuroanatomy, University of Heidelberg Heidelberg, Germany
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14
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Investigation of genetic factors underlying typical orofacial clefts: mutational screening and copy number variation. J Hum Genet 2014; 60:17-25. [PMID: 25391604 DOI: 10.1038/jhg.2014.96] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Revised: 10/01/2014] [Accepted: 10/10/2014] [Indexed: 12/13/2022]
Abstract
Typical orofacial clefts (OFCs) comprise cleft lip, cleft palate and cleft lip and palate. The complex etiology has been postulated to involve chromosome rearrangements, gene mutations and environmental factors. A group of genes including IRF6, FOXE1, GLI2, MSX2, SKI, SATB2, MSX1 and FGF has been implicated in the etiology of OFCs. Recently, the role of the copy number variations (CNVs) has been studied in genetic defects and diseases. CNVs act by modifying gene expression, disrupting gene sequence or altering gene dosage. The aims of this study were to screen the above-mentioned genes and to investigate CNVs in patients with OFCs. The sample was composed of 23 unrelated individuals who were grouped according to phenotype (associated with other anomalies or isolated) and familial recurrence. New sequence variants in GLI2, MSX1 and FGF8 were detected in patients, but not in their parents, as well as in 200 control chromosomes, indicating that these were rare variants. CNV screening identified new genes that can influence OFC pathogenesis, particularly highlighting TCEB3 and KIF7, that could be further analyzed. The findings of the present study suggest that the mechanism underlying CNV associated with sequence variants may play a role in the etiology of OFC.
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15
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Bear KA, Solomon BD, Antonini S, Arnhold IJP, França MM, Gerkes EH, Grange DK, Hadley DW, Jääskeläinen J, Paulo SS, Rump P, Stratakis CA, Thompson EM, Willis M, Winder TL, Jorge AAL, Roessler E, Muenke M. Pathogenic mutations in GLI2 cause a specific phenotype that is distinct from holoprosencephaly. J Med Genet 2014; 51:413-8. [PMID: 24744436 DOI: 10.1136/jmedgenet-2013-102249] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
BACKGROUND Mutations in GLI2 have been associated with holoprosencephaly (HPE), a neuroanatomic anomaly resulting from incomplete cleavage of the developing forebrain, and an HPE-like phenotype involving pituitary anomalies and polydactyly. OBJECTIVE To characterise the genotypic and phenotypic findings in individuals with GLI2 variants and clarify clinical findings in individuals with loss-of-function mutations. METHODS Through the National Institutes of Health and collaborating centres, ∼400 individuals with HPE spectrum disorders, endocrine disorders or craniofacial anomalies were screened for GLI2 mutations. Results were combined with all published cases. We compared the clinical and molecular features of individuals with truncating mutations to individuals with variants of unknown significance (defined as not resulting in protein truncation, reported in normal controls and/or deemed unlikely to be pathogenic by functional prediction software). RESULTS 112 individuals with variants in GLI2 were identified, with 43 having truncating mutations. Individuals with truncating mutations were more likely to have both pituitary anomalies and polydactyly versus those with variants of unknown significance (p<0.0001 by Fisher's exact test); only 1 of 43 had frank HPE. These individuals were more likely to have recognised penetrance (polydactyly or pituitary anomalies or both) than those without truncating mutations (p=0.0036 by Fisher's exact test). A common facial phenotype was seen in individuals (with midface hypoplasia, cleft lip/palate and hypotelorism) with truncating mutations. CONCLUSIONS Individuals with truncating mutations in GLI2 typically present with pituitary anomalies, polydactyly and subtle facial features rather than HPE. This will be helpful in screening populations for GLI2 mutations and for counselling affected patients. TRIAL REGISTRATION 98-HG-0249/04-HG-0093.
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Affiliation(s)
- Kelly A Bear
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA Department of Pediatrics, Tripler Army Medical Center, Honolulu, Hawaii, USA
| | - Benjamin D Solomon
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA Division of Medical Genomics, Inova Translational Medicine Institute, Inova Health System, Falls Church, Virginia, USA Department of Pediatrics, Inova Children's Hospital, Inova Health System, Falls Church, Virginia, USA
| | - Sonir Antonini
- Department of Pediatrics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Sao Paulo, Brazil
| | - Ivo J P Arnhold
- Unidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Disciplina de Endocrinologia, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Marcela M França
- Unidade de Endocrinologia do Desenvolvimento, Laboratorio de Hormonios e Genetica Molecular LIM/42, Disciplina de Endocrinologia, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Erica H Gerkes
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | | | - Donald W Hadley
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Jarmo Jääskeläinen
- Department of Pediatrics, University of Eastern Finland and Kuopio University Hospital, Kuopio, Finland
| | - Sabrina S Paulo
- Department of Pediatrics, School of Medicine of Ribeirao Preto, University of Sao Paulo, Sao Paulo, Brazil
| | - Patrick Rump
- Department of Genetics, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
| | - Constantine A Stratakis
- Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, Maryland, USA
| | - Elizabeth M Thompson
- SA Pathology, South Australian Clinical Genetics Service, Women's and Children's Hospital, Adelaide, South Australia, Australia Department of Paediatrics, University of Adelaide, Adelaide, South Australia, Australia
| | - Mary Willis
- Department of Pediatrics, Clinical Genetics, Naval Medical Center, San Diego, California, USA
| | | | - Alexander A L Jorge
- Unidade de Endocrinologia Genética, LIM/25, Disciplina de Endocrinologia, Hospital das Clinicas da Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
| | - Erich Roessler
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
| | - Maximilian Muenke
- Medical Genetics Branch, National Human Genome Research Institute, National Institutes of Health, Bethesda, Maryland, USA
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16
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Achim K, Salminen M, Partanen J. Mechanisms regulating GABAergic neuron development. Cell Mol Life Sci 2014; 71:1395-415. [PMID: 24196748 PMCID: PMC11113277 DOI: 10.1007/s00018-013-1501-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/10/2013] [Accepted: 10/14/2013] [Indexed: 12/17/2022]
Abstract
Neurons using gamma-aminobutyric acid (GABA) as their neurotransmitter are the main inhibitory neurons in the mature central nervous system (CNS) and show great variation in their form and function. GABAergic neurons are produced in all of the main domains of the CNS, where they develop from discrete regions of the neuroepithelium. Here, we review the gene expression and regulatory mechanisms controlling the main steps of GABAergic neuron development: early patterning of the proliferative neuroepithelium, production of postmitotic neural precursors, establishment of their identity and migration. By comparing the molecular regulation of these events across CNS, we broadly identify three regions utilizing distinct molecular toolkits for GABAergic fate determination: telencephalon-anterior diencephalon (DLX2 type), posterior diencephalon-midbrain (GATA2 type) and hindbrain-spinal cord (PTF1A and TAL1 types). Similarities and differences in the molecular regulatory mechanisms reveal the core determinants of a GABAergic neuron as well as provide insights into generation of the vast diversity of these neurons.
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Affiliation(s)
- Kaia Achim
- EMBL Heidelberg, Meyerhofstr. 1, 69117 Heidelberg, Germany
| | - Marjo Salminen
- Department of Veterinary Biosciences, University of Helsinki, Agnes Sjobergin katu 2, PO Box 66, 00014 Helsinki, Finland
| | - Juha Partanen
- Department of Biosciences, University of Helsinki, Viikinkaari 5, PO Box 56, 00014 Helsinki, Finland
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17
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Di Bonito M, Glover JC, Studer M. Hox genes and region-specific sensorimotor circuit formation in the hindbrain and spinal cord. Dev Dyn 2013; 242:1348-68. [PMID: 23996673 DOI: 10.1002/dvdy.24055] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2013] [Revised: 08/29/2013] [Accepted: 08/29/2013] [Indexed: 01/17/2023] Open
Abstract
Homeobox (Hox) genes were originally discovered in the fruit fly Drosophila, where they function through a conserved homeodomain as transcriptional regulators to control embryonic morphogenesis. In vertebrates, 39 Hox genes have been identified and like their Drosophila counterparts they are organized within chromosomal clusters. Hox genes interact with various cofactors, such as the TALE homeodomain proteins, in recognition of consensus sequences within regulatory elements of their target genes. In vertebrates, Hox genes display spatially restricted patterns of expression within the developing hindbrain and spinal cord, and are considered crucial determinants of segmental identity and cell specification along the anterioposterior and dorsoventral axes of the embryo. Here, we review their later roles in the assembly of neuronal circuitry, in stereotypic neuronal migration, axon pathfinding, and topographic connectivity. Importantly, we will put some emphasis on how their early-segmented expression patterns can influence the formation of complex vital hindbrain and spinal cord circuitries.
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Affiliation(s)
- Maria Di Bonito
- University of Nice-Sophia Antipolis, F-06108, Nice, France; INSERM, iBV, UMR 1091, F-06108, Nice, France
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18
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Abstract
Hedgehog (Hh) proteins regulate the development of a wide range of metazoan embryonic and adult structures, and disruption of Hh signaling pathways results in various human diseases. Here, we provide a comprehensive review of the signaling pathways regulated by Hh, consolidating data from a diverse array of organisms in a variety of scientific disciplines. Similar to the elucidation of many other signaling pathways, our knowledge of Hh signaling developed in a sequential manner centered on its earliest discoveries. Thus, our knowledge of Hh signaling has for the most part focused on elucidating the mechanism by which Hh regulates the Gli family of transcription factors, the so-called "canonical" Hh signaling pathway. However, in the past few years, numerous studies have shown that Hh proteins can also signal through Gli-independent mechanisms collectively referred to as "noncanonical" signaling pathways. Noncanonical Hh signaling is itself subdivided into two distinct signaling modules: (i) those not requiring Smoothened (Smo) and (ii) those downstream of Smo that do not require Gli transcription factors. Thus, Hh signaling is now proposed to occur through a variety of distinct context-dependent signaling modules that have the ability to crosstalk with one another to form an interacting, dynamic Hh signaling network.
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Affiliation(s)
- David J Robbins
- Molecular Oncology Program, Department of Surgery, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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19
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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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20
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Abstract
Gli zinc-finger proteins are transcription factors involved in the intracellular signal transduction controlled by the Hedgehog family of secreted molecules. They are frequently mutated in human congenital malformations, and their abnormal regulation leads to tumorigenesis. Genetic studies in several model systems indicate that their activity is tightly regulated by Hedgehog signaling through various posttranslational modifications, including phosphorylation, ubiquitin-mediated degradation, and proteolytic processing, as well as through nucleocytoplasmic shuttling. In vertebrate cells, primary cilia are required for the sensing of Hedgehog pathway activity and involved in the processing and activation of Gli proteins. Two evolutionarily conserved Hedgehog pathway components, Suppressor of fused and Kif7, are core intracellular regulators of mammalian Gli proteins. Recent studies revealed that Gli proteins are also regulated transcriptionally and posttranslationally through noncanonical mechanisms independent of Hedgehog signaling. In this review, we describe the regulation of Gli proteins during development and discuss possible mechanisms for their abnormal activation during tumorigenesis.
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Affiliation(s)
- Chi-Chung Hui
- Program in Developmental and Stem Cell Biology, Hospital for Sick Children, Toronto, Ontario M5G 1X8, Canada.
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21
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Wang CKL, Tsugane MH, Scranton V, Kosher RA, Pierro LJ, Upholt WB, Dealy CN. Pleiotropic patterning response to activation of Shh signaling in the limb apical ectodermal ridge. Dev Dyn 2011; 240:1289-302. [PMID: 21465622 DOI: 10.1002/dvdy.22628] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/05/2011] [Indexed: 11/07/2022] Open
Abstract
Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the zone of polarizing activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or apical ectodermal ridge (AER), but recent studies suggest a role for AER-Shh signaling in limb patterning. Here, we have examined the effects of activation of Shh signaling in the AER. We find that targeted expression of Shh in the AER activates constitutive Shh signaling throughout the AER and subjacent limb mesoderm, and causes a range of limb patterning defects with progressive severity from mild polydactyly, to polysyndactyly with proximal defects, to severe oligodactyly with phocomelia and partial limb ventralization. Our studies emphasize the importance of control of the timing, level and location of Shh pathway signaling for limb anterior-posterior, proximal-distal, and dorsal-ventral patterning.
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Affiliation(s)
- Chi-Kuang Leo Wang
- Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, Connecticut, USA
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22
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Bertolacini CDP, Ribeiro-Bicudo LA, Petrin A, Richieri-Costa A, Murray JC. Clinical findings in patients with GLI2 mutations--phenotypic variability. Clin Genet 2011; 81:70-5. [PMID: 21204792 DOI: 10.1111/j.1399-0004.2010.01606.x] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Mutations in the human GLI2 gene were first reported in association with defective anterior pituitary formation, panhypopituitarism, and forebrain anomalies represented by typical holoprosencephaly (HPE) and holoprosencephaly-like (HPE-L) phenotypes and postaxial polydactyly. Subsequently, anophthalmia plus orbital anomalies, heminasal aplasia, branchial arch anomalies and polydactyly have also been incorporated into the general phenotype. Here we described six Brazilian patients with phenotypic manifestations that range from isolated cleft lip/palate with polydactyly, branchial arch anomalies to semi-lobar holoprosencephaly. Novel sequence variants were found in the GLI2 gene in patients with marked involvement of the temporomandibular joint (TMJ), a new clinical finding observed with mutations of this gene. Clinical, molecular and genetic aspects are discussed.
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Affiliation(s)
- C D P Bertolacini
- Hospital of Rehabilitation of Craniofacial Anomalies, USP, Bauru, SP, Brazil
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23
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Berrios-Otero CA, Wadghiri YZ, Nieman BJ, Joyner AL, Turnbull DH. Three-dimensional micro-MRI analysis of cerebral artery development in mouse embryos. Magn Reson Med 2010; 62:1431-9. [PMID: 19859945 DOI: 10.1002/mrm.22113] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Vascular system development involves a complex, three-dimensional branching process that is critical for normal embryogenesis. In the brain, the arterial systems appear to develop in a stereotyped fashion, but no detailed quantitative analyses of the mouse embryonic cerebral arteries have been described. In this study, a gadolinium-based contrast perfusion method was developed to selectively enhance the cerebral arteries in fixed mouse embryos. Three-dimensional magnetic resonance micro-imaging (micro-MRI) data were acquired simultaneously from multiple embryos staged between 10 and 17 days of gestation, and a variety of image analysis methods was used to extract and analyze the cerebral arterial patterns. The results show that the primary arterial branches in the mouse brain are very similar between individuals, with the patterns established early and growth occurring by extension of the segments, while maintaining the underlying vascular geometry. To investigate the utility of this method for mutant mouse phenotype analysis, contrast-enhanced micro-MRI data were acquired from Gli2(-/-) mutant embryos and their wild-type littermates, showing several previously unreported vascular phenotypes in Gli2(-/-) embryos, including the complete absence of the basilar artery. These results demonstrate that contrast-enhanced micro-MRI provides a powerful tool for analyzing vascular phenotypes in a variety of genetically engineered mice.
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Affiliation(s)
- Cesar A Berrios-Otero
- Kimmel Center for Biology and Medicine at the Skirball Institute of Biomolecular Medicine, New York University School of Medicine, New York, New York 10016, USA
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24
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Stecca B, Ruiz i Altaba A. Context-dependent regulation of the GLI code in cancer by HEDGEHOG and non-HEDGEHOG signals. J Mol Cell Biol 2010; 2:84-95. [PMID: 20083481 DOI: 10.1093/jmcb/mjp052] [Citation(s) in RCA: 200] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
A surprisingly large and unrelated number of human tumors depend on sustained HEDGEHOG-GLI (HH-GLI) signaling for growth. This includes cancers of the skin, brain, colon, lungs, prostate, blood and pancreas among others. The basis of such commonality is not obvious. HH-GLI signaling has also been shown to be active in and required for cancer stem cell survival and expansion in different cancer types, and its activity is essential not only for tumor growth but also for recurrence and metastatic growth, two key medical problems. Here we review recent data on the role of HH-GLI signaling in cancer focusing on the role of the GLI code, the regulated combinatorial and cooperative function of repressive and activating forms of all Gli transcription factors, as a signaling nexus that integrates not only HH signals but also those of multiple tumor suppressors and oncogenes. Recent data support the view that the context-dependent regulation of the GLI code by oncogenes and tumor suppressors constitutes a basis for the widespread involvement of GLI1 in human cancers, representing a perversion of its normal role in the control of stem cell lineages during normal development and homeostasis.
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Affiliation(s)
- Barbara Stecca
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva CH-1211, Switzerland
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Amirthalingam GS, Howard S, Alvarez S, de Lera AR, Itasaki N. Regulation of Hoxb4 induction after neurulation by somite signal and neural competence. BMC DEVELOPMENTAL BIOLOGY 2009; 9:17. [PMID: 19243620 PMCID: PMC2667173 DOI: 10.1186/1471-213x-9-17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/30/2008] [Accepted: 02/25/2009] [Indexed: 11/10/2022]
Abstract
BACKGROUND While the body axis is largely patterned along the anterior-posterior (A-P) axis during gastrulation, the central nervous system (CNS) shows dynamic changes in the expression pattern of Hox genes during neurulation, suggesting that the CNS refines the A-P pattern continuously after neural tube formation. This study aims at clarifying the role of somites in up-regulating Hoxb4 expression to eventually establish its final pattern and how the neural tube develops a competence to respond to extrinsic signals. RESULTS We show that somites are required for the up-regulation of Hoxb4 in the neural tube at the level of somites 1 to 5, the anterior-most domain of expression. However, each somite immediately adjacent to the neural tube is not sufficient at each level; planar signaling is additionally required particularly at the anterior-most segments of the expression domain. We also show that the dorsal side of the neural tube has a greater susceptibility to expressing Hoxb4 than the ventral region, a feature associated with dorsalization of the neural tube by BMP signals. BMP4 is additionally able to up-regulate Hoxb4 ventrally, but the effect is restricted to the axial levels at which Hoxb4 is normally expressed, and only in the presence of retinoic acid (RA) or somites, suggesting a role for BMP in rendering the neural tube competent to express Hoxb4 in response to RA or somite signals. CONCLUSION In identifying the collaboration between somites and neural tube competence in the induction of Hoxb4, this study demonstrates interplay between A-P and dorsal-ventral (D-V) patterning systems, whereby a specific feature of D-V polarity may be a prerequisite for proper A-P patterning by Hox genes.
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Affiliation(s)
- Gayana S Amirthalingam
- Division of Developmental Neurobiology, MRC National Institute for Medical Research, The Ridgeway, London, NW7 1AA, UK.
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Farmer WT, Altick AL, Nural HF, Dugan JP, Kidd T, Charron F, Mastick GS. Pioneer longitudinal axons navigate using floor plate and Slit/Robo signals. Development 2008; 135:3643-53. [PMID: 18842816 PMCID: PMC2768610 DOI: 10.1242/dev.023325] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Longitudinal axons transmit all signals between the brain and spinal cord. Their axon tracts through the brain stem are established by a simple set of pioneer axons with precise trajectories parallel to the floor plate. To identify longitudinal guidance mechanisms in vivo, the overall role of floor plate tissue and the specific roles of Slit/Robo signals were tested. Ectopic induction or genetic deletion of the floor plate diverted longitudinal axons into abnormal trajectories. The expression patterns of the diffusible cues of the Slit family were altered in the floor plate experiments, suggesting their involvement in longitudinal guidance. Genetic tests of Slit1 and Slit2, and the Slit receptors Robo1 and Robo2 were carried out in mutant mice. Slit1;Slit2 double mutants had severe longitudinal errors, particularly for ventral axons, including midline crossing and wandering longitudinal trajectories. Robo1 and Robo2 were largely genetically redundant, and neither appeared to specify specific tract positions. However, combined Robo1 and Robo2 mutations strongly disrupted each pioneer tract. Thus, pioneer axons depend on long-range floor plate cues, with Slit/Robo signaling required for precise longitudinal trajectories.
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Affiliation(s)
- W. Todd Farmer
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Amy L. Altick
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | | | - James P. Dugan
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Thomas Kidd
- Department of Biology, University of Nevada, Reno, NV 89557, USA
| | - Frédéric Charron
- Molecular Biology of Neural Development, Institut de recherches cliniques de Montréal (IRCM), 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada
| | - Grant S. Mastick
- Department of Biology, University of Nevada, Reno, NV 89557, USA
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