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Krishnamurthy A, Lee AS, Bayin NS, Stephen DN, Nasef O, Lao Z, Joyner AL. Engrailed transcription factors direct excitatory cerebellar neuron diversity and survival. Development 2024; 151:dev202502. [PMID: 38912572 DOI: 10.1242/dev.202502] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 06/17/2024] [Indexed: 06/25/2024]
Abstract
The neurons of the three cerebellar nuclei (CN) are the primary output neurons of the cerebellum. The excitatory neurons (e) of the medial (m) CN (eCNm) were recently divided into molecularly defined subdomains in the adult; however, how they are established during development is not known. We define molecular subdomains of the mouse embryonic eCNm using single-cell RNA-sequencing and spatial expression analysis, showing that they evolve during embryogenesis to prefigure the adult. Furthermore, eCNm are transcriptionally divergent from cells in the other nuclei by embryonic day 14.5. We previously showed that loss of the homeobox genes En1 and En2 leads to loss of approximately half of the embryonic eCNm. We demonstrate that mutation of En1/2 in the embryonic eCNm results in death of specific posterior eCNm molecular subdomains and downregulation of TBR2 (EOMES) in an anterior embryonic subdomain, as well as reduced synaptic gene expression. We further reveal a similar function for EN1/2 in mediating TBR2 expression, neuron differentiation and survival in the other excitatory neurons (granule and unipolar brush cells). Thus, our work defines embryonic eCNm molecular diversity and reveals conserved roles for EN1/2 in the cerebellar excitatory neuron lineage.
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Affiliation(s)
- Anjana Krishnamurthy
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
- Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
| | - Andrew S Lee
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
- Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
| | - N Sumru Bayin
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Daniel N Stephen
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Olivia Nasef
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Zhimin Lao
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
| | - Alexandra L Joyner
- Developmental Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, NY 10021, USA
- Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
- Biochemistry, Cell and Molecular Biology Program, Weill Cornell Graduate School of Medical Sciences, New York, NY 10065, USA
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Krishnamurthy A, Lee AS, Bayin NS, Stephen DN, Nasef O, Lao Z, Joyner AL. Engrailed transcription factors direct excitatory cerebellar neuron diversity and survival. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.30.569445. [PMID: 38077070 PMCID: PMC10705369 DOI: 10.1101/2023.11.30.569445] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/09/2024]
Abstract
The excitatory neurons of the three cerebellar nuclei (eCN) form the primary output for the cerebellar circuit. The medial eCN (eCNm) were recently divided into molecularly defined subdomains in the adult, however how they are established during development is not known. We define molecular subdomains of the eCNm using scRNA-seq and spatial expression analysis and show they evolve during embryogenesis to resemble the adult. Furthermore, the eCNm is transcriptionally divergent from the rest of the eCN by E14.5. We previously showed that loss of the homeobox genes En1 and En2 leads to death of a subset of embryonic eCNm. We demonstrate that mutation of En1/2 in embryonic eCNm results in cell death of specific posterior eCNm molecular subdomains and loss of TBR2 (EOMES) expression in an anterior subdomain, as well as reduced synaptic gene expression. We further reveal a similar function for EN1/2 in mediating TBR2 expression, neuron differentiation and survival in the two other cerebellar excitatory neuron types. Thus, our work defines embryonic eCNm molecular diversity and reveals conserved roles for EN1/2 in the cerebellar excitatory neuron lineage.
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Ramirez M, Robert R, Yeung J, Wu J, Abdalla-Wyse A, Goldowitz D. Identification and characterization of transcribed enhancers during cerebellar development through enhancer RNA analysis. BMC Genomics 2023; 24:351. [PMID: 37365500 DOI: 10.1186/s12864-023-09368-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Accepted: 05/08/2023] [Indexed: 06/28/2023] Open
Abstract
BACKGROUND The development of the brain requires precise coordination of molecular processes across many cell-types. Underpinning these events are gene expression programs which require intricate regulation by non-coding regulatory sequences known as enhancers. In the context of the developing brain, transcribed enhancers (TEs) regulate temporally-specific expression of genes critical for cell identity and differentiation. Transcription of non-coding RNAs at active enhancer sequences, known as enhancer RNAs (eRNAs), is tightly associated with enhancer activity and has been correlated with target gene expression. TEs have been characterized in a multitude of developing tissues, however their regulatory role has yet to be described in the context of embryonic and early postnatal brain development. In this study, eRNA transcription was analyzed to identify TEs active during cerebellar development, as a proxy for the developing brain. Cap Analysis of Gene Expression followed by sequencing (CAGE-seq) was conducted at 12 stages throughout embryonic and early postnatal cerebellar development. RESULTS Temporal analysis of eRNA transcription identified clusters of TEs that peak in activity during either embryonic or postnatal times, highlighting their importance for temporally specific developmental events. Functional analysis of putative target genes identified molecular mechanisms under TE regulation revealing that TEs regulate genes involved in biological processes specific to neurons. We validate enhancer activity using in situ hybridization of eRNA expression from TEs predicted to regulate Nfib, a gene critical for cerebellar granule cell differentiation. CONCLUSIONS The results of this analysis provide a valuable dataset for the identification of cerebellar enhancers and provide insight into the molecular mechanisms critical for brain development under TE regulation. This dataset is shared with the community through an online resource ( https://goldowitzlab.shinyapps.io/trans-enh-app/ ).
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Affiliation(s)
- Miguel Ramirez
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada
| | - Remi Robert
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada
| | - Joanna Yeung
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada
| | - Joshua Wu
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada
| | - Ayasha Abdalla-Wyse
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada
| | - Daniel Goldowitz
- Centre for Molecular Medicine and Therapeutics, BC Children's Hospital Research Institute, 950 W 28th Ave, V6H 3V5, Vancouver, BC, Canada.
- University of British Columbia, V6T 1Z4, Vancouver, BC, Canada.
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Puls R, von Haefen C, Bührer C, Endesfelder S. Protective Effect of Dexmedetomidine against Hyperoxia-Damaged Cerebellar Neurodevelopment in the Juvenile Rat. Antioxidants (Basel) 2023; 12:antiox12040980. [PMID: 37107355 PMCID: PMC10136028 DOI: 10.3390/antiox12040980] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 04/18/2023] [Accepted: 04/20/2023] [Indexed: 04/29/2023] Open
Abstract
Impaired cerebellar development of premature infants and the associated impairment of cerebellar functions in cognitive development could be crucial factors for neurodevelopmental disorders. Anesthetic- and hyperoxia-induced neurotoxicity of the immature brain can lead to learning and behavioral disorders. Dexmedetomidine (DEX), which is associated with neuroprotective properties, is increasingly being studied for off-label use in the NICU. For this purpose, six-day-old Wistar rats (P6) were exposed to hyperoxia (80% O2) or normoxia (21% O2) for 24 h after DEX (5 µg/kg, i.p.) or vehicle (0.9% NaCl) application. An initial detection in the immature rat cerebellum was performed after the termination of hyperoxia at P7 and then after recovery in room air at P9, P11, and P14. Hyperoxia reduced the proportion of Calb1+-Purkinje cells and affected the dendrite length at P7 and/or P9/P11. Proliferating Pax6+-granule progenitors remained reduced after hyperoxia and until P14. The expression of neurotrophins and neuronal transcription factors/markers of proliferation, migration, and survival were also reduced by oxidative stress in different manners. DEX demonstrated protective effects on hyperoxia-injured Purkinje cells, and DEX without hyperoxia modulated neuronal transcription in the short term without any effects at the cellular level. DEX protects hyperoxia-damaged Purkinje cells and appears to differentially affect cerebellar granular cell neurogenesis following oxidative stress.
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Affiliation(s)
- Robert Puls
- Department of Neonatology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Clarissa von Haefen
- Department of Anesthesiology and Intensive Care Medicine, Charité-Universitätsmedizin Berlin, 13353 Berlin, Germany
| | - Christoph Bührer
- Department of Neonatology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
| | - Stefanie Endesfelder
- Department of Neonatology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany
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Ramirez M, Badayeva Y, Yeung J, Wu J, Abdalla-Wyse A, Yang E, Trost B, Scherer SW, Goldowitz D. Temporal analysis of enhancers during mouse cerebellar development reveals dynamic and novel regulatory functions. eLife 2022; 11:74207. [PMID: 35942939 PMCID: PMC9398453 DOI: 10.7554/elife.74207] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 08/05/2022] [Indexed: 11/13/2022] Open
Abstract
We have identified active enhancers in the mouse cerebellum at embryonic and postnatal stages which provides a view of novel enhancers active during cerebellar development. The majority of cerebellar enhancers have dynamic activity between embryonic and postnatal development. Cerebellar enhancers were enriched for neural transcription factor binding sites with temporally specific expression. Putative gene targets displayed spatially restricted expression patterns, indicating cell-type specific expression regulation. Functional analysis of target genes indicated that enhancers regulate processes spanning several developmental epochs such as specification, differentiation and maturation. We use these analyses to discover one novel regulator and one novel marker of cerebellar development: Bhlhe22 and Pax3, respectively. We identified an enrichment of de novo mutations and variants associated with autism spectrum disorder in cerebellar enhancers. Furthermore, by comparing our data with relevant brain development ENCODE histone profiles and cerebellar single-cell datasets we have been able to generalize and expand on the presented analyses, respectively. We have made the results of our analyses available online in the Developing Mouse Cerebellum Enhancer Atlas (https://goldowitzlab.shinyapps.io/developing_mouse_cerebellum_enhancer_atlas/), where our dataset can be efficiently queried, curated and exported by the scientific community to facilitate future research efforts. Our study provides a valuable resource for studying the dynamics of gene expression regulation by enhancers in the developing cerebellum and delivers a rich dataset of novel gene-enhancer associations providing a basis for future in-depth studies in the cerebellum.
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Affiliation(s)
- Miguel Ramirez
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
| | - Yuliya Badayeva
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
| | - Joanna Yeung
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
| | - Joshua Wu
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
| | - Ayasha Abdalla-Wyse
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
| | - Erin Yang
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
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- Department of Molecular Genetics, Hospital for Sick Children, Toronto, Canada
| | - Brett Trost
- The Centre for Applied Genomics, Hospital for Sick Children, Toronto, Canada
| | - Stephen W Scherer
- Department of Molecular Genetics, Hospital for Sick Children, Toronto, Canada
| | - Daniel Goldowitz
- Centre for Molecular Medicine and Therapeutics, British Columbia Children's Hospital, Vancouver, Canada
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6
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The Conflicting Role of Caffeine Supplementation on Hyperoxia-Induced Injury on the Cerebellar Granular Cell Neurogenesis of Newborn Rats. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:5769784. [PMID: 35693697 PMCID: PMC9175096 DOI: 10.1155/2022/5769784] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Revised: 03/04/2022] [Accepted: 04/28/2022] [Indexed: 11/28/2022]
Abstract
Preterm birth disrupts cerebellar development, which may be mediated by systemic oxidative stress that damages neuronal developmental stages. Impaired cerebellar neurogenesis affects several downstream targets important for cognition, emotion, and speech. In this study, we demonstrate that oxidative stress induced with high oxygen (80%) for three or five postnatal days (P3/P5) could significantly damage neurogenesis and proliferative capacity of granular cell precursor and Purkinje cells in rat pups. Reversal of cellular neuronal damage after recovery to room air (P15) was augmented by treatment with caffeine. However, downstream transcripts important for migration and differentiation of postmitotic granular cells were irreversibly reduced by hyperoxia, without rescue by caffeine. Protective effects of caffeine in the cerebellum were limited to neuronal survival but failed to restore important transcript signatures.
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Multi-scale Chimerism: An experimental window on the algorithms of anatomical control. Cells Dev 2022; 169:203764. [PMID: 34974205 DOI: 10.1016/j.cdev.2021.203764] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2021] [Revised: 12/12/2021] [Accepted: 12/24/2021] [Indexed: 12/22/2022]
Abstract
Despite the immense progress in genetics and cell biology, major knowledge gaps remain with respect to prediction and control of the global morphologies that will result from the cooperation of cells with known genomes. The understanding of cooperativity, competition, and synergy across diverse biological scales has been obscured by a focus on standard model systems that exhibit invariant species-specific anatomies. Morphogenesis of chimeric biological material is an especially instructive window on the control of biological growth and form because it emphasizes the need for prediction without reliance on familiar, standard outcomes. Here, we review an important and fascinating body of data from experiments utilizing DNA transfer, cell transplantation, organ grafting, and parabiosis. We suggest that these are all instances (at different levels of organization) of one general phenomenon: chimerism. Multi-scale chimeras are a powerful conceptual and experimental tool with which to probe the mapping between properties of components and large-scale anatomy: the laws of morphogenesis. The existing data and future advances in this field will impact not only the understanding of cooperation and the evolution of body forms, but also the design of strategies for system-level outcomes in regenerative medicine and swarm robotics.
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8
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Zosen D, Austdal LPE, Bjørnstad S, Lumor JS, Paulsen RE. Antiepileptic drugs lamotrigine and valproate differentially affect neuronal maturation in the developing chick embryo, yet with PAX6 as a potential common mediator. Neurotoxicol Teratol 2022; 90:107057. [DOI: 10.1016/j.ntt.2021.107057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Revised: 12/14/2021] [Accepted: 12/14/2021] [Indexed: 10/19/2022]
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Hawkes R. Cerebellar Patterning Defects in Mutant Mice. Front Neurosci 2021; 15:787425. [PMID: 34955734 PMCID: PMC8692567 DOI: 10.3389/fnins.2021.787425] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 11/01/2021] [Indexed: 11/25/2022] Open
Abstract
The cerebellar cortex is highly compartmentalized and serves as a remarkable model for pattern formation throughout the brain. In brief, the adult cerebellar cortex is subdivided into five anteroposterior units—transverse zones—and subsequently, each zone is divided into ∼20 parasagittal stripes. Zone-and-stripe pattern formation involves the interplay of two parallel developmental pathways—one for inhibitory neurons, the second for excitatory. In the inhibitory pathway, progenitor cells of the 4th ventricle generate the Purkinje cells and inhibitory interneurons. In the excitatory pathway, progenitor cells in the upper rhombic lip give rise to the external granular layer, and subsequently to the granular layer of the adult. Both the excitatory and inhibitory developmental pathways are spatially patterned and the interactions of the two generate the complex topography of the adult. This review briefly describes the cellular and molecular mechanisms that underly zone-and-stripe development with a particular focus on mutations known to interfere with normal cerebellar development and the light they cast on the mechanisms of pattern formation.
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Affiliation(s)
- Richard Hawkes
- Department of Cell Biology, Cumming School of Medicine, Anatomy and Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
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10
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Consalez GG, Goldowitz D, Casoni F, Hawkes R. Origins, Development, and Compartmentation of the Granule Cells of the Cerebellum. Front Neural Circuits 2021; 14:611841. [PMID: 33519389 PMCID: PMC7843939 DOI: 10.3389/fncir.2020.611841] [Citation(s) in RCA: 79] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 12/17/2020] [Indexed: 12/21/2022] Open
Abstract
Granule cells (GCs) are the most numerous cell type in the cerebellum and indeed, in the brain: at least 99% of all cerebellar neurons are granule cells. In this review article, we first consider the formation of the upper rhombic lip, from which all granule cell precursors arise, and the way by which the upper rhombic lip generates the external granular layer, a secondary germinal epithelium that serves to amplify the upper rhombic lip precursors. Next, we review the mechanisms by which postmitotic granule cells are generated in the external granular layer and migrate radially to settle in the granular layer. In addition, we review the evidence that far from being a homogeneous population, granule cells come in multiple phenotypes with distinct topographical distributions and consider ways in which the heterogeneity of granule cells might arise during development.
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Affiliation(s)
- G Giacomo Consalez
- Division of Neuroscience, San Raffaele Scientific Institute, San Raffaele University, Milan, Italy
| | - Daniel Goldowitz
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, University of British Columbia, Vancouver, BC, Canada
| | - Filippo Casoni
- Division of Neuroscience, San Raffaele Scientific Institute, San Raffaele University, Milan, Italy
| | - Richard Hawkes
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, AB, Canada
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Discovery of Transcription Factors Novel to Mouse Cerebellar Granule Cell Development Through Laser-Capture Microdissection. THE CEREBELLUM 2019; 17:308-325. [PMID: 29307116 DOI: 10.1007/s12311-017-0912-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Laser-capture microdissection was used to isolate external germinal layer tissue from three developmental periods of mouse cerebellar development: embryonic days 13, 15, and 18. The cerebellar granule cell-enriched mRNA library was generated with next-generation sequencing using the Helicos technology. Our objective was to discover transcriptional regulators that could be important for the development of cerebellar granule cells-the most numerous neuron in the central nervous system. Through differential expression analysis, we have identified 82 differentially expressed transcription factors (TFs) from a total of 1311 differentially expressed genes. In addition, with TF-binding sequence analysis, we have identified 46 TF candidates that could be key regulators responsible for the variation in the granule cell transcriptome between developmental stages. Altogether, we identified 125 potential TFs (82 from differential expression analysis, 46 from motif analysis with 3 overlaps in the two sets). From this gene set, 37 TFs are considered novel due to the lack of previous knowledge about their roles in cerebellar development. The results from transcriptome-wide analyses were validated with existing online databases, qRT-PCR, and in situ hybridization. This study provides an initial insight into the TFs of cerebellar granule cells that might be important for development and provide valuable information for further functional studies on these transcriptional regulators.
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Meis1 Coordinates Cerebellar Granule Cell Development by Regulating Pax6 Transcription, BMP Signaling and Atoh1 Degradation. J Neurosci 2018; 38:1277-1294. [PMID: 29317485 DOI: 10.1523/jneurosci.1545-17.2017] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2017] [Revised: 12/12/2017] [Accepted: 12/19/2017] [Indexed: 11/21/2022] Open
Abstract
Cerebellar granule cell precursors (GCPs) and granule cells (GCs) represent good models to study neuronal development. Here, we report that the transcription factor myeloid ectopic viral integration site 1 homolog (Meis1) plays pivotal roles in the regulation of mouse GC development. We found that Meis1 is expressed in GC lineage cells and astrocytes in the cerebellum during development. Targeted disruption of the Meis1 gene specifically in the GC lineage resulted in smaller cerebella with disorganized lobules. Knock-down/knock-out (KO) experiments for Meis1 and in vitro assays showed that Meis1 binds to an upstream sequence of Pax6 to enhance its transcription in GCPs/GCs and also suggested that the Meis1-Pax6 cascade regulates morphology of GCPs/GCs during development. In the conditional KO (cKO) cerebella, many Atoh1-positive GCPs were observed ectopically in the inner external granule layer (EGL) and a similar phenomenon was observed in cultured cerebellar slices treated with a bone morphogenic protein (BMP) inhibitor. Furthermore, expression of Smad proteins and Smad phosphorylation were severely reduced in the cKO cerebella and Meis1-knock-down GCPs cerebella. Reduction of phosphorylated Smad was also observed in cerebellar slices electroporated with a Pax6 knock-down vector. Because it is known that BMP signaling induces Atoh1 degradation in GCPs, these findings suggest that the Meis1-Pax6 pathway increases the expression of Smad proteins to upregulate BMP signaling, leading to degradation of Atoh1 in the inner EGL, which contributes to differentiation from GCPs to GCs. Therefore, this work reveals crucial functions of Meis1 in GC development and gives insights into the general understanding of the molecular machinery underlying neural differentiation from neural progenitors.SIGNIFICANCE STATEMENT We report that myeloid ectopic viral integration site 1 homolog (Meis1) plays pivotal roles in the regulation of mouse granule cell (GC) development. Here, we show Meis1 is expressed in GC precursors (GCPs) and GCs during development. Our knock-down and conditional knock-out (cKO) experiments and in vitro assays revealed that Meis1 is required for proper cerebellar structure formation and for Pax6 transcription in GCPs and GCs. The Meis1-Pax6 cascade regulates the morphology of GCs. In the cKO cerebella, Smad proteins and bone morphogenic protein (BMP) signaling are severely reduced and Atoh1-expressing GCPs are ectopically detected in the inner external granule layer. These findings suggest that Meis1 regulates degradation of Atoh1 via BMP signaling, contributing to GC differentiation in the inner EGL, and should provide understanding into GC development.
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Abstract
With the growing recognition of the extent and prevalence of human cerebellar disorders, an understanding of developmental programs that build the mature cerebellum is necessary. In this chapter we present an overview of the basic epochs and key molecular regulators of the developmental programs of cerebellar development. These include early patterning of the cerebellar territory, the genesis of cerebellar cells from multiple spatially distinct germinal zones, and the extensive migration and coordinated cellular rearrangements that result in the formation of the exquisitely foliated and laminated mature cerebellum. This knowledge base is founded on extensive analysis of animal models, particularly mice, due in large part to the ease of genetic manipulation of this important model organism. Since cerebellar structure and function are largely conserved across species, mouse cerebellar development is highly relevant to humans and has led to important insights into the developmental pathogenesis of human cerebellar disorders. Human fetal cerebellar development remains largely undescribed; however, several human-specific developmental features are known which are relevant to human disease and underline the importance of ongoing human fetal research.
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Affiliation(s)
- Parthiv Haldipur
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, United States
| | - Derek Dang
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, United States
| | - Kathleen J Millen
- Seattle Children's Research Institute, Center for Integrative Brain Research, Seattle, WA, United States; Department of Pediatrics, Genetics Division, University of Washington, Seattle, WA, United States.
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A Novel and Multivalent Role of Pax6 in Cerebellar Development. J Neurosci 2017; 36:9057-69. [PMID: 27581449 DOI: 10.1523/jneurosci.4385-15.2016] [Citation(s) in RCA: 36] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 07/12/2016] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Pax6 is a prominent gene in brain development. The deletion of Pax6 results in devastated development of eye, olfactory bulb, and cortex. However, it has been reported that the Pax6-null Sey cerebellum only has minor defects involving granule cells despite Pax6 being expressed throughout cerebellar development. The present work has uncovered a requirement of Pax6 in the development of all rhombic lip (RL) lineages. A significant downregulation of Tbr1 and Tbr2 expression is found in the Sey cerebellum, these are cell-specific markers of cerebellar nuclear (CN) neurons and unipolar brush cells (UBCs), respectively. The examination of Tbr1 and Lmx1a immunolabeling and Nissl staining confirmed the loss of CN neurons from the Sey cerebellum. CN neuron progenitors are produced in the mutant but there is an enhanced death of these neurons as shown by increased presence of caspase-3-positive cells. These data indicate that Pax6 regulates the survival of CN neuron progenitors. Furthermore, the analysis of experimental mouse chimeras suggests a cell-extrinsic role of Pax6 in CN neuron survival. For UBCs, using Tbr2 immunolabeling, these cells are significantly reduced in the Sey cerebellum. The loss of UBCs in the mutant is due partly to cell death in the RL and also to the reduced production of progenitors from the RL. These results demonstrate a critical role for Pax6 in regulating the generation and survival of UBCs. This and previous work from our laboratory demonstrate a seminal role of Pax6 in the development of all cerebellar glutamatergic neurons. SIGNIFICANCE STATEMENT Pax6 is a key molecule in development. Pax6 is best known as the master control gene in eye development with mutations causing aniridia in humans. Pax6 also plays important developmental roles in the cortex and olfactory bulb. During cerebellar development, Pax6 is robustly expressed in the germinal zone of all glutamatergic neurons [cerebellar nuclear (CN) neurons, granule cells, and unipolar brush cells (UBCs)]. Past work has not found abnormalities in the CN and UBC populations. Our study reveals that the Pax6-null mutation dramatically affects these cells and identifies Pax6 as a key regulator of cell survival in CN neurons and of cell production in UBCs. The present study shows how Pax6 is key to the development of glutamatergic cells in the cerebellum.
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Austdal LPE, Bjørnstad S, Mathisen GH, Aden PK, Mikkola I, Paulsen RE, Rakkestad KE. Glucocorticoid Effects on Cerebellar Development in a Chicken Embryo Model: Exploring Changes in PAX6 and Metalloproteinase-9 After Exposure to Dexamethasone. J Neuroendocrinol 2016; 28. [PMID: 27791298 DOI: 10.1111/jne.12438] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Revised: 10/25/2016] [Accepted: 10/25/2016] [Indexed: 12/22/2022]
Abstract
The developing cerebellum is vulnerable to effects of glucocorticoids and cerebellar dysfunction is associated with neurodevelopmental disorders (e.g. autism). Transcription factor PAX6 and matrix metalloproteinase-9 (MMP-9) are critical for normal cerebellar development and are highly expressed in migrating neurones. Alterations in MMP-9 and PAX6 are associated with altered cerebellar development. In the present study, we characterised the growth rate and development of the cortical layers, and further investigated how the levels of PAX6 and MMP-9, as well as glucocorticoid receptor (GR) and proliferating cell nuclear antigen (PCNA), change in the cerebellum during the foetal period [embryonic day (E)12-21] in chicken, which corresponds to the human perinatal period. Dexamethasone (DEX) was administered in ovo at E13 and E16, aiming to investigate how prenatal exposure to glucocorticoids interferes with normal development. DEX reduced foetal and cerebellar weight at E17 in a dose-dependent manner linked to a reduced level of PCNA and, over time, down-regulation of GR. We report that promoter activity of PAX6 and MMP-9 increased as a result of GR-stimulation in vitro. Prenatal DEX increased the protein level of PAX6 in a transient manner. PAX6 is reduced in mature granule neurones, and this occurred earlier in embryos exposed to DEX than in non-exposed controls. DEX exposure also led to a slow-onset down-regulation of MMP-9. Taken together, these findings indicate that excess prenatal glucocorticoid stimulation disturbs normal development of the cerebellum through mechanisms associated with reduced proliferation and accelerated maturation where PAX6 and MMP-9 play important roles.
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Affiliation(s)
- L P E Austdal
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - S Bjørnstad
- Department of Pathology, Oslo University Hospital - Ullevål, Oslo, Norway
| | - G H Mathisen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - P K Aden
- Department of Neurosciences for Children, Oslo University Hospital, University of Oslo, Oslo, Norway
| | - I Mikkola
- Department of Pharmacy, Faculty of Health Sciences, UiT - The Arctic University of Norway, Tromsø, Norway
| | - R E Paulsen
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
| | - K E Rakkestad
- Department of Pharmaceutical Biosciences, School of Pharmacy, University of Oslo, Oslo, Norway
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16
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Hiraoka K, Sumiyoshi A, Nonaka H, Kikkawa T, Kawashima R, Osumi N. Regional Volume Decreases in the Brain of Pax6 Heterozygous Mutant Rats: MRI Deformation-Based Morphometry. PLoS One 2016; 11:e0158153. [PMID: 27355350 PMCID: PMC4927189 DOI: 10.1371/journal.pone.0158153] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Accepted: 06/10/2016] [Indexed: 11/18/2022] Open
Abstract
Pax6 is a transcription factor that pleiotropically regulates various developmental processes in the central nervous system. In a previous study, we revealed that Pax6 heterozygous mutant (rSey2/+) adult rats exhibit abnormalities in social interaction. However, the brain malformations underlying the behavioral abnormality are unknown. To elucidate the brain malformations in rSey2/+ rats, we morphometrically analyzed brains of rSey2/+ and wild type rats using small-animal magnetic resonance imaging (MRI). Sixty 10-week-old rats underwent brain MRI (29 rSey2/+ rats and 31 wild type rats). SPM8 software was used for image preprocessing and statistical image analysis. Normalized maps of the Jacobian determinant, a parameter for the expansion and/or contraction of brain regions, were obtained for each rat. rSey2/+ rats showed significant volume decreases in various brain regions including the neocortex, corpus callosum, olfactory structures, hippocampal formation, diencephalon, and midbrain compared to wild type rats. Among brain regions, the anterior commissure showed significant interaction between genotype and sex, indicating the effect of genotype difference on the anterior commissure volume was more robust in females than in males. The rSey2/+ rats exhibited decreased volume in various gray and white matter regions of the brain, which may contribute to manifestation of abnormal social behaviors.
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Affiliation(s)
- Kotaro Hiraoka
- Division of Cyclotron Nuclear Medicine, Cyclotron and Radioisotope Center, Tohoku University, Sendai, Japan
- * E-mail:
| | - Akira Sumiyoshi
- Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Hiroi Nonaka
- Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Takako Kikkawa
- Department of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Sendai, Japan
| | - Ryuta Kawashima
- Department of Functional Brain Imaging, Institute of Development, Aging and Cancer, Tohoku University, Sendai, Japan
| | - Noriko Osumi
- Department of Developmental Neuroscience, Center for Translational and Advanced Animal Research, Tohoku University Graduate School of Medicine, Sendai, Japan
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Breuss M, Morandell J, Nimpf S, Gstrein T, Lauwers M, Hochstoeger T, Braun A, Chan K, Sánchez Guajardo ER, Zhang L, Suplata M, Heinze KG, Elsayad K, Keays DA. The Expression of Tubb2b Undergoes a Developmental Transition in Murine Cortical Neurons. J Comp Neurol 2015; 523:2161-86. [PMID: 26105993 DOI: 10.1002/cne.23836] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 06/17/2015] [Accepted: 06/18/2015] [Indexed: 01/20/2023]
Abstract
The development of the mammalian brain requires the generation, migration, and differentiation of neurons, cellular processes that are dependent on a dynamic microtubule cytoskeleton. Mutations in tubulin genes, which encode for the structural subunits of microtubules, cause detrimental neurological disorders known as the tubulinopathies. The disease spectra associated with different tubulin genes are overlapping but distinct, an observation believed to reflect functional specification of this multigene family. Perturbation of the β-tubulin TUBB2B is known to cause polymicrogyria, pachygyria, microcephaly, and axon guidance defects. Here we provide a detailed analysis of the expression pattern of its murine homolog Tubb2b. The generation and characterization of BAC-transgenic eGFP reporter mouse lines has revealed that it is highly expressed in progenitors and postmitotic neurons during cortical development. This contrasts with the 8-week-old cortex, in which Tubb2b expression is restricted to macroglia, and expression is almost completely absent in mature neurons. This developmental transition in neurons is mirrored in the adult hippocampus and the cerebellum but is not a universal feature of Tubb2b; its expression persists in a population of postmitotic neurons in the 8-week-old retina. We propose that the dynamic spatial and temporal expression of Tubb2b reflects specific functional requirements of the microtubule cytoskeleton.
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Affiliation(s)
- Martin Breuss
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Jasmin Morandell
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Simon Nimpf
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Thomas Gstrein
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Mattias Lauwers
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Tobias Hochstoeger
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
| | - Andreas Braun
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria.,Centre for Genomic Regulation (CRG), 08003, Barcelona, Spain
| | - Kelvin Chan
- Medical Scientist Training Program, Stony Brook University Medical Center, Stony Brook, New York, 11794
| | | | - Lijuan Zhang
- Advanced Microscopy, Campus Science Support Facilities (CSF), Vienna, 1030, Austria
| | - Marek Suplata
- Rudolf Virchow Center, DFG-Research Center for Experimental Biomedicine of the University of Würzburg, Würzburg, 97080, Germany
| | - Katrin G Heinze
- Rudolf Virchow Center, DFG-Research Center for Experimental Biomedicine of the University of Würzburg, Würzburg, 97080, Germany
| | - Kareem Elsayad
- Advanced Microscopy, Campus Science Support Facilities (CSF), Vienna, 1030, Austria
| | - David A Keays
- IMP-Research Institute of Molecular Pathology, Vienna Biocenter (VBC), Vienna, 1030, Austria
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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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19
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Abstract
Math1 is the defining molecule of the cerebellar rhombic lip and Pax6 is downstream in the Math1 pathway. In the present study, we discover that Wntless (Wls) is a novel molecular marker of the cells in the interior face of the rhombic lip throughout normal mouse cerebellar development. Wls expression is found complementary to the expression of Math1 and Pax6, which are localized to the exterior face of the rhombic lip. To determine the interaction between these molecules, we examine the loss-of-Math1 or loss-of-Pax6 in the cerebellum, i.e., the Math1-null and Pax6-null (Sey) mutant cerebella. The presence of Wls-positive cells in the Math1-null rhombic lip indicates that Wls expression is independent of Math1. In the Sey mutant cerebellum, there is an expansion of Wls-expressing cells into regions that are normally colonized by Pax6-expressing cells. The ectopic expression of Wls in the Pax6-null cerebellum suggests a negative interaction between Wls-expressing cells and Pax6-positive cells. These findings suggest that the rhombic lip is dynamically patterned by the expression of Wls, Math1, and Pax6. We also examine five rhombic lip cell markers (Wls, Math1, Pax6, Lmx1a, and Tbr2) to identify four molecularly distinct compartments in the rhombic lip during cerebellar development. The existence of spatial compartmentation in the rhombic lip and the interplay between Wls, Math1, and Pax6 in the rhombic lip provides novel views of early cerebellar development.
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20
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Abstract
Math1 is the defining molecule of the cerebellar rhombic lip and Pax6 is downstream in the Math1 pathway. In the present study, we discover that Wntless (Wls) is a novel molecular marker of the cells in the interior face of the rhombic lip throughout normal mouse cerebellar development. Wls expression is found complementary to the expression of Math1 and Pax6, which are localized to the exterior face of the rhombic lip. To determine the interaction between these molecules, we examine the loss-of-Math1 or loss-of-Pax6 in the cerebellum, i.e., the Math1-null and Pax6-null (Sey) mutant cerebella. The presence of Wls-positive cells in the Math1-null rhombic lip indicates that Wls expression is independent of Math1. In the Sey mutant cerebellum, there is an expansion of Wls-expressing cells into regions that are normally colonized by Pax6-expressing cells. The ectopic expression of Wls in the Pax6-null cerebellum suggests a negative interaction between Wls-expressing cells and Pax6-positive cells. These findings suggest that the rhombic lip is dynamically patterned by the expression of Wls, Math1, and Pax6. We also examine five rhombic lip cell markers (Wls, Math1, Pax6, Lmx1a, and Tbr2) to identify four molecularly distinct compartments in the rhombic lip during cerebellar development. The existence of spatial compartmentation in the rhombic lip and the interplay between Wls, Math1, and Pax6 in the rhombic lip provides novel views of early cerebellar development.
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21
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Fauquier T, Chatonnet F, Picou F, Richard S, Fossat N, Aguilera N, Lamonerie T, Flamant F. Purkinje cells and Bergmann glia are primary targets of the TRα1 thyroid hormone receptor during mouse cerebellum postnatal development. Development 2014; 141:166-75. [PMID: 24346699 DOI: 10.1242/dev.103226] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Thyroid hormone is necessary for normal development of the central nervous system, as shown by the severe mental retardation syndrome affecting hypothyroid patients with low levels of active thyroid hormone. The postnatal defects observed in hypothyroid mouse cerebellum are recapitulated in mice heterozygous for a dominant-negative mutation of Thra, the gene encoding the ubiquitous TRα1 receptor. Using CRE/loxP-mediated conditional expression approach, we found that this mutation primarily alters the differentiation of Purkinje cells and Bergmann glia, two cerebellum-specific cell types. These primary defects indirectly affect cerebellum development in a global manner. Notably, the inward migration and terminal differentiation of granule cell precursors is impaired. Therefore, despite the broad distribution of its receptors, thyroid hormone targets few cell types that exert a predominant role in the network of cellular interactions that govern normal cerebellum maturation.
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Affiliation(s)
- Teddy Fauquier
- Université de Lyon, CNRS, INRA, Université Claude Bernard Lyon 1, École Normale Supérieure de Lyon, Institut de Génomique Fonctionnelle de Lyon, F-69364 Lyon, Cedex 07, France
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22
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Affiliation(s)
| | - Richard Hawkes
- Department of Cell Biology and Anatomy, Genes and Development Research Group and Hotchkiss Brain Institute, Faculty of Medicine, University of Calgary
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Consalez GG, Hawkes R. The compartmental restriction of cerebellar interneurons. Front Neural Circuits 2013; 6:123. [PMID: 23346049 PMCID: PMC3551280 DOI: 10.3389/fncir.2012.00123] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2012] [Accepted: 12/26/2012] [Indexed: 11/13/2022] Open
Abstract
The Purkinje cells (PC's) of the cerebellar cortex are subdivided into multiple different molecular phenotypes that form an elaborate array of parasagittal stripes. This array serves as a scaffold around which afferent topography is organized. The ways in which cerebellar interneurons may be restricted by this scaffolding are less well-understood. This review begins with a brief survey of cerebellar topography. Next, it reviews the development of stripes in the cerebellum with a particular emphasis on the embryological origins of cerebellar interneurons. These data serve as a foundation to discuss the hypothesis that cerebellar compartment boundaries also restrict cerebellar interneurons, both excitatory [granule cells, unipolar brush cells (UBCs)] and inhibitory (e.g., Golgi cells, basket cells). Finally, it is proposed that the same PC scaffold that restricts afferent terminal fields to stripes may also act to organize cerebellar interneurons.
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Affiliation(s)
- G Giacomo Consalez
- Division of Neuroscience, San Raffaele Scientific Institute Milan, Italy
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24
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Fatemi SH, Aldinger KA, Ashwood P, Bauman ML, Blaha CD, Blatt GJ, Chauhan A, Chauhan V, Dager SR, Dickson PE, Estes AM, Goldowitz D, Heck DH, Kemper TL, King BH, Martin LA, Millen KJ, Mittleman G, Mosconi MW, Persico AM, Sweeney JA, Webb SJ, Welsh JP. Consensus paper: pathological role of the cerebellum in autism. CEREBELLUM (LONDON, ENGLAND) 2012; 11:777-807. [PMID: 22370873 PMCID: PMC3677555 DOI: 10.1007/s12311-012-0355-9] [Citation(s) in RCA: 456] [Impact Index Per Article: 38.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
There has been significant advancement in various aspects of scientific knowledge concerning the role of cerebellum in the etiopathogenesis of autism. In the current consensus paper, we will observe the diversity of opinions regarding the involvement of this important site in the pathology of autism. Recent emergent findings in literature related to cerebellar involvement in autism are discussed, including: cerebellar pathology, cerebellar imaging and symptom expression in autism, cerebellar genetics, cerebellar immune function, oxidative stress and mitochondrial dysfunction, GABAergic and glutamatergic systems, cholinergic, dopaminergic, serotonergic, and oxytocin-related changes in autism, motor control and cognitive deficits, cerebellar coordination of movements and cognition, gene-environment interactions, therapeutics in autism, and relevant animal models of autism. Points of consensus include presence of abnormal cerebellar anatomy, abnormal neurotransmitter systems, oxidative stress, cerebellar motor and cognitive deficits, and neuroinflammation in subjects with autism. Undefined areas or areas requiring further investigation include lack of treatment options for core symptoms of autism, vermal hypoplasia, and other vermal abnormalities as a consistent feature of autism, mechanisms underlying cerebellar contributions to cognition, and unknown mechanisms underlying neuroinflammation.
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Affiliation(s)
- S Hossein Fatemi
- University of Minnesota Medical School, 420 Delaware St. SE, Minneapolis, MN 55455, USA.
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25
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Ha TJ, Swanson DJ, Kirova R, Yeung J, Choi K, Tong Y, Chesler EJ, Goldowitz D. Genome-wide microarray comparison reveals downstream genes of Pax6 in the developing mouse cerebellum. Eur J Neurosci 2012; 36:2888-98. [PMID: 22817342 DOI: 10.1111/j.1460-9568.2012.08221.x] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The Pax6 transcription factor is expressed in cerebellar granule cells and when mutated, as in the Sey/Sey mouse, produces granule cells with disturbed survival and migration and with defects in neurite extension. The impact of Pax6 on other genes in the context of cerebellar development has not been identified. In this study, we performed transcriptome comparisons between wildtype and Pax6-null whole cerebellar tissue at embryonic day (E) 13.5, 15.5 and 18.5 using Affymetrix arrays (U74Av2). Statistical analyses identified 136 differentially regulated transcripts (FDR 0.05, 1.2-fold change cutoff) over time in Pax6-null cerebellar tissue. In parallel we examined the Math1-null granuloprival cerebellum and identified 228 down-regulated transcripts (FDR 0.05, 1.2-fold change cutoff). The intersection of these two microarray datasets produced a total of 21 differentially regulated transcripts. For a subset of the identified transcripts, we used qRT-PCR to validate the microarray data and demonstrated the expression in the rhombic lip lineage and differential expression in Pax6-null cerebellum with in situ hybridisation analysis. The candidate genes identified in this way represent direct or indirect Pax6-downstream genes involved in cerebellar development.
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Affiliation(s)
- Thomas J Ha
- Department of Medical Genetics, Centre for Molecular Medicine and Therapeutics, Child and Family Research Institute, University of British Columbia, 950 West 28th Avenue, Vancouver, BC, Canada
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26
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Pontén F, Schwenk JM, Asplund A, Edqvist PHD. The Human Protein Atlas as a proteomic resource for biomarker discovery. J Intern Med 2011; 270:428-46. [PMID: 21752111 DOI: 10.1111/j.1365-2796.2011.02427.x] [Citation(s) in RCA: 193] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The analysis of tissue-specific expression at both the gene and protein levels is vital for understanding human biology and disease. Antibody-based proteomics provides a strategy for the systematic generation of antibodies against all human proteins to combine with protein profiling in tissues and cells using tissue microarrays, immunohistochemistry and immunofluorescence. The Human Protein Atlas project was launched in 2003 with the aim of creating a map of protein expression patterns in normal cells, tissues and cancer. At present, 11,200 unique proteins corresponding to over 50% of all human protein-encoding genes have been analysed. All protein expression data, including underlying high-resolution images, are published on the free and publically available Human Protein Atlas portal (http://www.proteinatlas.org). This database provides an important source of information for numerous biomedical research projects, including biomarker discovery efforts. Moreover, the global analysis of how our genome is expressed at the protein level has provided basic knowledge on the ubiquitous expression of a large proportion of our proteins and revealed the paucity of cell- and tissue-type-specific proteins.
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Affiliation(s)
- F Pontén
- Department of Genetics and Pathology, Uppsala University, Uppsala, Sweden.
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