1
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Ott CM, Torres R, Kuan TS, Kuan A, Buchanan J, Elabbady L, Seshamani S, Bodor AL, Collman F, Bock DD, Lee WC, da Costa NM, Lippincott-Schwartz J. Ultrastructural differences impact cilia shape and external exposure across cell classes in the visual cortex. Curr Biol 2024; 34:2418-2433.e4. [PMID: 38749425 PMCID: PMC11217952 DOI: 10.1016/j.cub.2024.04.043] [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: 11/06/2023] [Revised: 03/27/2024] [Accepted: 04/22/2024] [Indexed: 06/06/2024]
Abstract
A primary cilium is a membrane-bound extension from the cell surface that contains receptors for perceiving and transmitting signals that modulate cell state and activity. Primary cilia in the brain are less accessible than cilia on cultured cells or epithelial tissues because in the brain they protrude into a deep, dense network of glial and neuronal processes. Here, we investigated cilia frequency, internal structure, shape, and position in large, high-resolution transmission electron microscopy volumes of mouse primary visual cortex. Cilia extended from the cell bodies of nearly all excitatory and inhibitory neurons, astrocytes, and oligodendrocyte precursor cells (OPCs) but were absent from oligodendrocytes and microglia. Ultrastructural comparisons revealed that the base of the cilium and the microtubule organization differed between neurons and glia. Investigating cilia-proximal features revealed that many cilia were directly adjacent to synapses, suggesting that cilia are poised to encounter locally released signaling molecules. Our analysis indicated that synapse proximity is likely due to random encounters in the neuropil, with no evidence that cilia modulate synapse activity as would be expected in tetrapartite synapses. The observed cell class differences in proximity to synapses were largely due to differences in external cilia length. Many key structural features that differed between neuronal and glial cilia influenced both cilium placement and shape and, thus, exposure to processes and synapses outside the cilium. Together, the ultrastructure both within and around neuronal and glial cilia suggest differences in cilia formation and function across cell types in the brain.
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Affiliation(s)
- Carolyn M Ott
- Janelia Research Campus, Howard Hughes Medical Institute, Ashburn, VA 20147, USA.
| | - Russel Torres
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Tung-Sheng Kuan
- Department of Physics, University at Albany, State University of New York, Albany, NY 12222, USA
| | - Aaron Kuan
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
| | - JoAnn Buchanan
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | - Leila Elabbady
- Allen Institute for Brain Science, Seattle, WA 98109, USA; University of Washington, Seattle, WA 98195, USA
| | | | - Agnes L Bodor
- Allen Institute for Brain Science, Seattle, WA 98109, USA
| | | | - Davi D Bock
- Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Wei Chung Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115, USA
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2
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Tingey M, Ruba A, Jiang Z, Yang W. Deciphering vesicle-assisted transport mechanisms in cytoplasm to cilium trafficking. Front Cell Neurosci 2024; 18:1379976. [PMID: 38860265 PMCID: PMC11163138 DOI: 10.3389/fncel.2024.1379976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2024] [Accepted: 05/13/2024] [Indexed: 06/12/2024] Open
Abstract
The cilium, a pivotal organelle crucial for cell signaling and proper cell function, relies on meticulous macromolecular transport from the cytoplasm for its formation and maintenance. While the intraflagellar transport (IFT) pathway has traditionally been the focus of extensive study concerning ciliogenesis and ciliary maintenance, recent research highlights a complementary and alternative mechanism-vesicle-assisted transport (VAT) in cytoplasm to cilium trafficking. Despite its potential significance, the VAT pathway remains largely uncharacterized. This review explores recent studies providing evidence for the dynamics of vesicle-related diffusion and transport within the live primary cilium, employing high-speed super-resolution light microscopy. Additionally, we analyze the spatial distribution of vesicles in the cilium, mainly relying on electron microscopy data. By scrutinizing the VAT pathways that facilitate cargo transport into the cilium, with a specific emphasis on recent advancements and imaging data, our objective is to synthesize a comprehensive model of ciliary transport through the integration of IFT-VAT mechanisms.
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Affiliation(s)
| | | | | | - Weidong Yang
- Department of Biology, Temple University, Philadelphia, PA, United States
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3
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Jurisch-Yaksi N, Wachten D, Gopalakrishnan J. The neuronal cilium - a highly diverse and dynamic organelle involved in sensory detection and neuromodulation. Trends Neurosci 2024; 47:383-394. [PMID: 38580512 DOI: 10.1016/j.tins.2024.03.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/04/2024] [Accepted: 03/14/2024] [Indexed: 04/07/2024]
Abstract
Cilia are fascinating organelles that act as cellular antennae, sensing the cellular environment. Cilia gained significant attention in the late 1990s after their dysfunction was linked to genetic diseases known as ciliopathies. Since then, several breakthrough discoveries have uncovered the mechanisms underlying cilia biogenesis and function. Like most cells in the animal kingdom, neurons also harbor cilia, which are enriched in neuromodulatory receptors. Yet, how neuronal cilia modulate neuronal physiology and animal behavior remains poorly understood. By comparing ciliary biology between the sensory and central nervous systems (CNS), we provide new perspectives on the functions of cilia in brain physiology.
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Affiliation(s)
- Nathalie Jurisch-Yaksi
- Department of Clinical and Molecular Medicine (IKOM), Faculty of Medicine and Health Science, Norwegian University of Science and Technology, Erling Skalgssons gate 1, 7491 Trondheim, Norway.
| | - Dagmar Wachten
- Department of Biophysical Imaging, Institute of Innate Immunity, Medical Faculty, University of Bonn, Venusberg-Campus 1, 53127 Bonn, Germany
| | - Jay Gopalakrishnan
- Institute of Human Genetics, University Hospital, Heinrich-Heine-Universität, 40225 Düsseldorf, Germany; Institute for Human Genetics, Universitätsklinikum Jena, Friedrich-Schiller-Universität Jena, 07740 Jena, Germany
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4
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Wu JY, Cho SJ, Descant K, Li PH, Shapson-Coe A, Januszewski M, Berger DR, Meyer C, Casingal C, Huda A, Liu J, Ghashghaei T, Brenman M, Jiang M, Scarborough J, Pope A, Jain V, Stein JL, Guo J, Yasuda R, Lichtman JW, Anton ES. Mapping of neuronal and glial primary cilia contactome and connectome in the human cerebral cortex. Neuron 2024; 112:41-55.e3. [PMID: 37898123 PMCID: PMC10841524 DOI: 10.1016/j.neuron.2023.09.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 07/25/2023] [Accepted: 09/22/2023] [Indexed: 10/30/2023]
Abstract
Primary cilia act as antenna receivers of environmental signals and enable effective neuronal or glial responses. Disruption of their function is associated with circuit disorders. To understand the signals these cilia receive, we comprehensively mapped cilia's contacts within the human cortical connectome using serial-section EM reconstruction of a 1 mm3 cortical volume, spanning the entire cortical thickness. We mapped the "contactome" of cilia emerging from neurons and astrocytes in every cortical layer. Depending on the layer and cell type, cilia make distinct patterns of contact. Primary cilia display cell-type- and layer-specific variations in size, shape, and microtubule axoneme core, which may affect their signaling competencies. Neuronal cilia are intrinsic components of a subset of cortical synapses and thus a part of the connectome. This diversity in the structure, contactome, and connectome of primary cilia endows each neuron or glial cell with a unique barcode of access to the surrounding neural circuitry.
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Affiliation(s)
- Jun Yao Wu
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Su-Ji Cho
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Katherine Descant
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Peter H Li
- Google Research, Mountain View, CA 94043, USA
| | - Alexander Shapson-Coe
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | | | - Daniel R Berger
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA
| | - Cailyn Meyer
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Cristine Casingal
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Ariba Huda
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Jiaqi Liu
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Tina Ghashghaei
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Mikayla Brenman
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Michelle Jiang
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Joseph Scarborough
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Art Pope
- Google Research, Mountain View, CA 94043, USA
| | - Viren Jain
- Google Research, Mountain View, CA 94043, USA
| | - Jason L Stein
- UNC Neuroscience Center and the Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA
| | - Jiami Guo
- Department of Cell Biology and Anatomy, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| | - Ryohei Yasuda
- Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA.
| | - Jeff W Lichtman
- Department of Molecular and Cellular Biology, Harvard University, Cambridge, MA 02138, USA.
| | - E S Anton
- UNC Neuroscience Center and the Department of Cell Biology and Physiology, University of North Carolina School of Medicine, Chapel Hill, NC 27599, USA.
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5
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Ott CM, Torres R, Kuan TS, Kuan A, Buchanan J, Elabbady L, Seshamani S, Bodor AL, Collman F, Bock DD, Lee WC, da Costa NM, Lippincott-Schwartz J. Nanometer-scale views of visual cortex reveal anatomical features of primary cilia poised to detect synaptic spillover. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.31.564838. [PMID: 37961618 PMCID: PMC10635062 DOI: 10.1101/2023.10.31.564838] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/15/2023]
Abstract
A primary cilium is a thin membrane-bound extension off a cell surface that contains receptors for perceiving and transmitting signals that modulate cell state and activity. While many cell types have a primary cilium, little is known about primary cilia in the brain, where they are less accessible than cilia on cultured cells or epithelial tissues and protrude from cell bodies into a deep, dense network of glial and neuronal processes. Here, we investigated cilia frequency, internal structure, shape, and position in large, high-resolution transmission electron microscopy volumes of mouse primary visual cortex. Cilia extended from the cell bodies of nearly all excitatory and inhibitory neurons, astrocytes, and oligodendrocyte precursor cells (OPCs), but were absent from oligodendrocytes and microglia. Structural comparisons revealed that the membrane structure at the base of the cilium and the microtubule organization differed between neurons and glia. OPC cilia were distinct in that they were the shortest and contained pervasive internal vesicles only occasionally observed in neuron and astrocyte cilia. Investigating cilia-proximal features revealed that many cilia were directly adjacent to synapses, suggesting cilia are well poised to encounter locally released signaling molecules. Cilia proximity to synapses was random, not enriched, in the synapse-rich neuropil. The internal anatomy, including microtubule changes and centriole location, defined key structural features including cilium placement and shape. Together, the anatomical insights both within and around neuron and glia cilia provide new insights into cilia formation and function across cell types in the brain.
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Affiliation(s)
- Carolyn M. Ott
- Janelia Research Campus, Howard Hughes Medical Institute
| | | | | | - Aaron Kuan
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
- Current address Department of Neuroscience, Yale School of Medicine, New Haven, CT, USA
| | | | - Leila Elabbady
- Allen Institute for Brain Science
- University of Washington, Seattle, WA, USA
| | | | | | | | - Davi D. Bock
- Larner College of Medicine, University of Vermont, Burlington, VT, USA
| | - Wei Chung Lee
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
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6
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Impact of 5-HT 6 Receptor Subcellular Localization on Its Signaling and Its Pathophysiological Roles. Cells 2023; 12:cells12030426. [PMID: 36766768 PMCID: PMC9913600 DOI: 10.3390/cells12030426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 01/20/2023] [Accepted: 01/24/2023] [Indexed: 02/03/2023] Open
Abstract
The serotonin (5-HT)6 receptor still raises particular interest given its unique spatio-temporal pattern of expression among the serotonin receptor subtypes. It is the only serotonin receptor specifically expressed in the central nervous system, where it is detected very early in embryonic life and modulates key neurodevelopmental processes, from neuronal migration to brain circuit refinement. Its predominant localization in the primary cilium of neurons and astrocytes is also unique among the serotonin receptor subtypes. Consistent with the high expression levels of the 5-HT6 receptor in brain regions involved in the control of cognitive processes, it is now well-established that the pharmacological inhibition of the receptor induces pro-cognitive effects in several paradigms of cognitive impairment in rodents, including models of neurodevelopmental psychiatric disorders and neurodegenerative diseases. The 5-HT6 receptor can engage several signaling pathways in addition to the canonical Gs signaling, but there is still uncertainty surrounding the signaling pathways that underly its modulation of cognition, as well as how the receptor's coupling is dependent on its cellular compartmentation. Here, we describe recent findings showing how the proper subcellular localization of the receptor is achieved, how this peculiar localization determines signaling pathways engaged by the receptor, and their pathophysiological influence.
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7
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Dupuy V, Prieur M, Pizzoccaro A, Margarido C, Valjent E, Bockaert J, Bouschet T, Marin P, Chaumont-Dubel S. Spatiotemporal dynamics of 5-HT 6 receptor ciliary localization during mouse brain development. Neurobiol Dis 2023; 176:105949. [PMID: 36496200 DOI: 10.1016/j.nbd.2022.105949] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Revised: 11/25/2022] [Accepted: 12/05/2022] [Indexed: 12/12/2022] Open
Abstract
The serotonin 5-HT6 receptor (5-HT6R) is a promising target to improve cognitive symptoms of psychiatric diseases of neurodevelopmental origin, such as autism spectrum disorders and schizophrenia. However, its expression and localization at different stages of brain development remain largely unknown, due to the lack of specific antibodies to detect endogenous 5-HT6R. Here, we used transgenic mice expressing a GFP-tagged 5-HT6R under the control of its endogenous promoter (Knock-in) as well as embryonic stem cells expressing the GFP-tagged receptor to extensively characterize its expression at cellular and subcellular levels during development. We show that the receptor is already expressed at E13.5 in the cortex, the striatum, the ventricular zone, and to a lesser extent the subventricular zone. In adulthood, it is preferentially found in projection neurons of the hippocampus and cerebral cortex, in striatal medium-sized spiny neurons, as well as in a large proportion of astrocytes, while it is expressed in a minor population of interneurons. Whereas the receptor is almost exclusively detected in the primary cilia of neurons at embryonic and adult stages and in differentiated stem cells, it is located in the somatodendritic compartment of neurons from some brain regions at the neonatal stage and in the soma of undifferentiated stem cells. Finally, knocking-out the receptor induces a shortening of the primary cilium, suggesting that it plays a role in its function. This study provides the first global picture of 5-HT6R expression pattern in the mouse brain at different developmental stages. It reveals dynamic changes in receptor localization in neurons at the neonatal stage, which might underlie its key role in neuronal differentiation and psychiatric disorders of neurodevelopmental origin.
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Affiliation(s)
- Vincent Dupuy
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Matthieu Prieur
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Anne Pizzoccaro
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Clara Margarido
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Emmanuel Valjent
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Joël Bockaert
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Tristan Bouschet
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Philippe Marin
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
| | - Séverine Chaumont-Dubel
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France.
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8
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Kobayashi Y, Saito Y. Evaluation of ciliary-GPCR dynamics using a validated organotypic brain slice culture method. Methods Cell Biol 2023; 175:69-83. [PMID: 36967146 DOI: 10.1016/bs.mcb.2022.09.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The primary cilium is a structural organelle present in most mammalian cells. Primary cilia are enriched with a unique protein repertoire distinct from that of the cytosol and the plasma membrane. Such a highly organized microenvironment creates effective machinery for translating extracellular cues into intracellular signals. G protein-coupled receptors (GPCRs) are key receptors in sensing environmental stimuli transmitted via a second messenger into a cellular response. Recent data has demonstrated that a limited number of non-olfactory GPCRs, including melanin-concentrating hormone receptor 1 (MCHR1), are preferentially localized to ciliary membranes of several mammalian cell types, including neuronal cells. Evidence was accumulated to support the functional importance of ciliary-GPCR signaling accompanying ciliary structural changes using cilia-specific cell and molecular biology techniques. Thus, cilia are now considered to function as a unique sensory platform for the integration of GPCR signaling and various cytoplasmic domains. Dissociated neurons expressing ciliary-GPCRs can be a useful tool for examining ciliary dynamics. However, losing preexisting neuronal connectivity may alter neuronal ciliary morphology, such as abnormal elongation. Brain slices prepared under ex vitro conditions are a powerful approach that maintains the cytoarchitecture, enabling researchers to have accurate control over experimental conditions and to study individual cells from subregions of the brain. Here, we present a detailed description of our novel modified method for organotypic culture of rat brain slice and a validated immunostaining protocol to characterize ciliary-GPCR dynamics in coupling with neuropeptides or aminergic activation.
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Affiliation(s)
- Yuki Kobayashi
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Yumiko Saito
- Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan.
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9
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Ono K, Gotoh H, Nomura T, Morita T, Baba O, Matsumoto M, Saitoh S, Ohno N. Ultrastructural characteristics of oligodendrocyte precursor cells in the early postnatal mouse optic nerve observed by serial block-face scanning electron microscopy. PLoS One 2022; 17:e0278118. [PMID: 36454994 PMCID: PMC9714907 DOI: 10.1371/journal.pone.0278118] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 11/10/2022] [Indexed: 12/05/2022] Open
Abstract
Oligodendrocyte precursor cells (OPC) arise from restricted regions of the central nervous system (CNS) and differentiate into myelin-forming cells after migration, but their ultrastructural characteristics have not been fully elucidated. This study examined the three-dimensional ultrastructure of OPCs in comparison with other glial cells in the early postnatal optic nerve by serial block-face scanning electron microscopy. We examined 70 putative OPCs (pOPC) that were distinct from other glial cells according to established morphological criteria. The pOPCs were unipolar in shape with relatively few processes, and their Golgi apparatus were localized in the perinuclear region with a single cisterna. Astrocytes abundant in the optic nerve were distinct from pOPCs and had a greater number of processes and more complicated Golgi apparatus morphology. All pOPCs and astrocytes contained a pair of centrioles (basal bodies). Among them, 45% of pOPCs extended a short cilium, and 20% of pOPCs had centrioles accompanied by vesicles, whereas all astrocytes with basal bodies had cilia with invaginated ciliary pockets. These results suggest that the fine structures of pOPCs during the developing and immature stages may account for their distinct behavior. Additionally, the vesicular transport of the centrioles, along with a short cilium length, suggests active ciliogenesis in pOPCs.
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Affiliation(s)
- Katsuhiko Ono
- Developmental Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
- * E-mail:
| | - Hitoshi Gotoh
- Developmental Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tadashi Nomura
- Developmental Neurobiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, Kyoto, Japan
| | - Tsuyoshi Morita
- Oral & Maxillofacial Anatomy, Graduate School of Oral Science, Tokushima University, Tokushima, Japan
| | - Otto Baba
- Oral & Maxillofacial Anatomy, Graduate School of Oral Science, Tokushima University, Tokushima, Japan
| | - Mami Matsumoto
- Section of Electron Microscopy, Supportive for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan
- Developmental & Regenerative Neurobiology, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Japan
| | - Sei Saitoh
- Section of Electron Microscopy, Supportive for Brain Research, National Institute for Physiological Sciences, Okazaki, Japan
- Department of Anatomy II and Cell Biology, Fujita Health University, School of Medicine, Toyoake, Japan
| | - Nobuhiko Ohno
- Division of Histology and Cell Biology, Department of Anatomy, Jichi Medical University School of Medicine, Tochigi, Japan
- Division of Ultrastructural Research, National Institute for Physiological Sciences, Okazaki, Japan
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10
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Stoufflet J, Caillé I. The Primary Cilium and Neuronal Migration. Cells 2022; 11:3384. [PMID: 36359777 PMCID: PMC9658458 DOI: 10.3390/cells11213384] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 10/19/2022] [Accepted: 10/20/2022] [Indexed: 09/29/2023] Open
Abstract
The primary cilium (PC) is a microtubule-based tiny sensory organelle emanating from the centrosome and protruding from the surface of most eukaryotic cells, including neurons. The extremely severe phenotypes of ciliopathies have suggested their paramount importance for multiple developmental events, including brain formation. Neuronal migration is an essential step of neural development, with all neurons traveling from their site of birth to their site of integration. Neurons perform a unique type of cellular migration called cyclic saltatory migration, where their soma periodically jumps along with the stereotyped movement of their centrosome. We will review here how the role of the PC on cell motility was first described in non-neuronal cells as a guide pointing to the direction of migration. We will see then how these findings are extended to neuronal migration. In neurons, the PC appears to regulate the rhythm of cyclic saltatory neuronal migration in multiple systems. Finally, we will review recent findings starting to elucidate how extracellular cues sensed by the PC could be intracellularly transduced to regulate the machinery of neuronal migration. The PC of migrating neurons was unexpectedly discovered to display a rhythmic extracellular emergence during each cycle of migration, with this transient exposure to the external environment associated with periodic transduction of cyclic adenosine monophosphate (cAMP) signaling at the centrosome. The PC in migrating neurons thus uniquely appears as a beat maker, regulating the tempo of cyclic saltatory migration.
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Affiliation(s)
- Julie Stoufflet
- Laboratory of Molecular Regulation of Neurogenesis, GIGA-Stem Cells and GIGA-Neurosciences, Interdisciplinary Cluster for Applied Genoproteomics (GIGA-R), University of Liège, CHU Sart Tilman, 4000 Liège, Belgium
| | - Isabelle Caillé
- Inserm U1130, Institut de Biologie Paris Seine (IBPS), Neuroscience Paris Seine (NPS), Sorbonne University, CNRS UMR8246, 75005 Paris, France
- University of Paris Cité, 75020 Paris, France
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11
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A serotonergic axon-cilium synapse drives nuclear signaling to alter chromatin accessibility. Cell 2022; 185:3390-3407.e18. [PMID: 36055200 PMCID: PMC9789380 DOI: 10.1016/j.cell.2022.07.026] [Citation(s) in RCA: 58] [Impact Index Per Article: 29.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Revised: 05/16/2022] [Accepted: 07/25/2022] [Indexed: 12/27/2022]
Abstract
Chemical synapses between axons and dendrites mediate neuronal intercellular communication. Here, we describe a synapse between axons and primary cilia: the axo-ciliary synapse. Using enhanced focused ion beam-scanning electron microscopy on samples with optimally preserved ultrastructure, we discovered synapses between brainstem serotonergic axons and the primary cilia of hippocampal CA1 pyramidal neurons. Functionally, these cilia are enriched in a ciliary-restricted serotonin receptor, the 5-hydroxytryptamine receptor 6 (5-HTR6). Using a cilia-targeted serotonin sensor, we show that opto- and chemogenetic stimulation of serotonergic axons releases serotonin onto cilia. Ciliary 5-HTR6 stimulation activates a non-canonical Gαq/11-RhoA pathway, which modulates nuclear actin and increases histone acetylation and chromatin accessibility. Ablation of this pathway reduces chromatin accessibility in CA1 pyramidal neurons. As a signaling apparatus with proximity to the nucleus, axo-ciliary synapses short circuit neurotransmission to alter the postsynaptic neuron's epigenetic state.
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12
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Tereshko L, Turrigiano GG, Sengupta P. Primary cilia in the postnatal brain: Subcellular compartments for organizing neuromodulatory signaling. Curr Opin Neurobiol 2022; 74:102533. [PMID: 35405626 PMCID: PMC9167775 DOI: 10.1016/j.conb.2022.102533] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2022] [Revised: 02/22/2022] [Accepted: 03/06/2022] [Indexed: 11/03/2022]
Abstract
Primary cilia have well characterized roles in early brain development, relaying signals critical for neurogenesis and brain formation during embryonic stages. Less understood are the contributions of cilia-mediated signaling to postnatal brain function. Several cilia-localized receptors that bind neuropeptides and neurotransmitters endogenous to the brain have been identified in adult neurons, but the functional significance of signaling through these cilia-localized receptors is largely unexplored. Ciliopathic disorders in humans often manifest with neurodevelopmental abnormalities and cognitive deficits. Intriguingly, recent research has also linked several neuropsychiatric disorders and neurodegenerative diseases to ciliary dysfunction. This review summarizes recent evidence suggesting that cilia signaling may dynamically regulate postnatal neuronal physiology and connectivity, and highlights possible links among cilia, neuronal circuitry, neuron survival, and neurological disorders.
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Affiliation(s)
- Lauren Tereshko
- Department of Biology, Brandeis University, Waltham, MA 02454,Current address: Biogen, Cambridge, MA 02142
| | - Gina G. Turrigiano
- Department of Biology, Brandeis University, Waltham, MA 02454,Corresponding authors: ;
| | - Piali Sengupta
- Department of Biology, Brandeis University, Waltham, MA 02454, USA.
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13
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Shi P, Tian J, Ulm BS, Mallinger JC, Khoshbouei H, Deleyrolle LP, Sarkisian MR. Tumor Treating Fields Suppression of Ciliogenesis Enhances Temozolomide Toxicity. Front Oncol 2022; 12:837589. [PMID: 35359402 PMCID: PMC8962950 DOI: 10.3389/fonc.2022.837589] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Accepted: 02/03/2022] [Indexed: 12/19/2022] Open
Abstract
Tumor Treating Fields (TTFields) are low-intensity, alternating intermediate-frequency (200 kHz) electrical fields that extend survival of glioblastoma patients receiving maintenance temozolomide (TMZ) chemotherapy. How TTFields exert efficacy on cancer over normal cells or interact with TMZ is unclear. Primary cilia are microtubule-based organelles triggered by extracellular ligands, mechanical and electrical field stimulation and are capable of promoting cancer growth and TMZ chemoresistance. We found in both low- and high-grade patient glioma cell lines that TTFields ablated cilia within 24 h. Halting TTFields treatment led to recovered frequencies of elongated cilia. Cilia on normal primary astrocytes, neurons, and multiciliated/ependymal cells were less affected by TTFields. The TTFields-mediated loss of glioma cilia was partially rescued by chloroquine pretreatment, suggesting the effect is in part due to autophagy activation. We also observed death of ciliated cells during TTFields by live imaging. Notably, TMZ and TTFields have opposing effects on glioma ciliogenesis. TMZ-induced stimulation of ciliogenesis in both adherent cells and gliomaspheres was blocked by TTFields. Surprisingly, the inhibitory effects of TTFields and TMZ on tumor cell recurrence are linked to the relative timing of TMZ exposure to TTFields and ARL13B+ cilia. Finally, TTFields disrupted cilia in patient tumors treated ex vivo. Our findings suggest that the efficacy of TTFields may depend on the degree of tumor ciliogenesis and relative timing of TMZ treatment.
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Affiliation(s)
- Ping Shi
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Jia Tian
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Brittany S. Ulm
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Julianne C. Mallinger
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Habibeh Khoshbouei
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Loic P. Deleyrolle
- Department of Neurosurgery, University of Florida College of Medicine, Gainesville, FL, United States
- Preston A. Wells Jr. Center for Brain Tumor Therapy, University of Florida College of Medicine, Gainesville, FL, United States
| | - Matthew R. Sarkisian
- Department of Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
- Preston A. Wells Jr. Center for Brain Tumor Therapy, University of Florida College of Medicine, Gainesville, FL, United States
- *Correspondence: Matthew R. Sarkisian,
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14
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Akhshi T, Shannon R, Trimble WS. The complex web of canonical and non-canonical Hedgehog signaling. Bioessays 2022; 44:e2100183. [PMID: 35001404 DOI: 10.1002/bies.202100183] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 12/21/2021] [Accepted: 12/30/2021] [Indexed: 12/11/2022]
Abstract
Hedgehog (Hh) signaling is a widely studied signaling pathway because of its critical roles during development and in cell homeostasis. Vertebrate canonical and non-canonical Hh signaling are typically assumed to be distinct and occur in different cellular compartments. While research has primarily focused on the canonical form of Hh signaling and its dependency on primary cilia - microtubule-based signaling hubs - an extensive list of crucial functions mediated by non-canonical Hh signaling has emerged. Moreover, amounting evidence indicates that canonical and non-canonical modes of Hh signaling are interlinked, and that they can overlap spatially, and in many cases interact functionally. Here, we discuss some of the many cellular effects of non-canonical signaling and discuss new evidence indicating inter-relationships with canonical signaling. We discuss how Smoothened (Smo), a key component of the Hh pathway, might coordinate such diverse downstream effects. Collectively, pursuit of questions such as those proposed here will aid in elucidating the full extent of Smo function in development and advance its use as a target for cancer therapeutics.
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Affiliation(s)
- Tara Akhshi
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - Rachel Shannon
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
| | - William S Trimble
- Program in Cell Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Department of Biochemistry, University of Toronto, Toronto, Ontario, Canada
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15
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Khan SS, Sobu Y, Dhekne HS, Tonelli F, Berndsen K, Alessi DR, Pfeffer SR. Pathogenic LRRK2 control of primary cilia and Hedgehog signaling in neurons and astrocytes of mouse brain. eLife 2021; 10:67900. [PMID: 34658337 PMCID: PMC8550758 DOI: 10.7554/elife.67900] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 10/17/2021] [Indexed: 12/11/2022] Open
Abstract
Activating LRRK2 mutations cause Parkinson’s disease, and pathogenic LRRK2 kinase interferes with ciliogenesis. Previously, we showed that cholinergic interneurons of the dorsal striatum lose their cilia in R1441C LRRK2 mutant mice (Dhekne et al., 2018). Here, we show that cilia loss is seen as early as 10 weeks of age in these mice and also in two other mouse strains carrying the most common human G2019S LRRK2 mutation. Loss of the PPM1H phosphatase that is specific for LRRK2-phosphorylated Rab GTPases yields the same cilia loss phenotype seen in mice expressing pathogenic LRRK2 kinase, strongly supporting a connection between Rab GTPase phosphorylation and cilia loss. Moreover, astrocytes throughout the striatum show a ciliation defect in all LRRK2 and PPM1H mutant models examined. Hedgehog signaling requires cilia, and loss of cilia in LRRK2 mutant rodents correlates with dysregulation of Hedgehog signaling as monitored by in situ hybridization of Gli1 and Gdnf transcripts. Dopaminergic neurons of the substantia nigra secrete a Hedgehog signal that is sensed in the striatum to trigger neuroprotection; our data support a model in which LRRK2 and PPM1H mutant mice show altered responses to critical Hedgehog signals in the nigrostriatal pathway.
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Affiliation(s)
- Shahzad S Khan
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States
| | - Yuriko Sobu
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States
| | - Herschel S Dhekne
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States
| | - Francesca Tonelli
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States.,MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Kerryn Berndsen
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States.,MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Dario R Alessi
- Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States.,MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee, United Kingdom
| | - Suzanne R Pfeffer
- Department of Biochemistry, Stanford University School of Medicine, Stanford, United States.,Aligning Science Across Parkinson's (ASAP) Collaborative Research Network, Chevy Chase, United States
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16
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Loo CKC, Pearen MA, Ramm GA. The Role of Sonic Hedgehog in Human Holoprosencephaly and Short-Rib Polydactyly Syndromes. Int J Mol Sci 2021; 22:ijms22189854. [PMID: 34576017 PMCID: PMC8468456 DOI: 10.3390/ijms22189854] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/03/2021] [Accepted: 09/09/2021] [Indexed: 12/18/2022] Open
Abstract
The Hedgehog (HH) signalling pathway is one of the major pathways controlling cell differentiation and proliferation during human development. This pathway is complex, with HH function influenced by inhibitors, promotors, interactions with other signalling pathways, and non-genetic and cellular factors. Many aspects of this pathway are not yet clarified. The main features of Sonic Hedgehog (SHH) signalling are discussed in relation to its function in human development. The possible role of SHH will be considered using examples of holoprosencephaly and short-rib polydactyly (SRP) syndromes. In these syndromes, there is wide variability in phenotype even with the same genetic mutation, so that other factors must influence the outcome. SHH mutations were the first identified genetic causes of holoprosencephaly, but many other genes and environmental factors can cause malformations in the holoprosencephaly spectrum. Many patients with SRP have genetic defects affecting primary cilia, structures found on most mammalian cells which are thought to be necessary for canonical HH signal transduction. Although SHH signalling is affected in both these genetic conditions, there is little overlap in phenotype. Possible explanations will be canvassed, using data from published human and animal studies. Implications for the understanding of SHH signalling in humans will be discussed.
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Affiliation(s)
- Christine K. C. Loo
- South Eastern Area Laboratory Services, Department of Anatomical Pathology, NSW Health Pathology, Prince of Wales Hospital, Sydney, NSW 2031, Australia
- Correspondence: ; Tel.: +61-2-93829015
| | - Michael A. Pearen
- Hepatic Fibrosis Group, Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (M.A.P.); (G.A.R.)
| | - Grant A. Ramm
- Hepatic Fibrosis Group, Department of Cell and Molecular Biology, QIMR Berghofer Medical Research Institute, Brisbane, QLD 4006, Australia; (M.A.P.); (G.A.R.)
- Faculty of Medicine, The University of Queensland, Brisbane, QLD 4006, Australia
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17
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Mustafa R, Rawas C, Mannal N, Kreiner G, Spittau B, Kamińska K, Yilmaz R, Pötschke C, Kirsch J, Liss B, Tucker KL, Parlato R. Targeted Ablation of Primary Cilia in Differentiated Dopaminergic Neurons Reduces Striatal Dopamine and Responsiveness to Metabolic Stress. Antioxidants (Basel) 2021; 10:antiox10081284. [PMID: 34439532 PMCID: PMC8389284 DOI: 10.3390/antiox10081284] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/01/2021] [Accepted: 08/09/2021] [Indexed: 12/17/2022] Open
Abstract
Primary cilia (PC) are microtubule-based protrusions of the cell membrane transducing molecular signals during brain development. Here, we report that PC are required for maintenance of Substantia nigra (SN) dopaminergic (DA) neurons highly vulnerable in Parkinson's disease (PD). Targeted blockage of ciliogenesis in differentiated DA neurons impaired striato-nigral integrity in adult mice. The relative number of SN DA neurons displaying a typical auto-inhibition of spontaneous activity in response to dopamine was elevated under control metabolic conditions, but not under metabolic stress. Strikingly, in the absence of PC, the remaining SN DA neurons were less vulnerable to the PD neurotoxin 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridin (MPTP). Our data indicate conserved PC-dependent neuroadaptive responses to DA lesions in the striatum. Moreover, PC control the integrity and dopamine response of a subtype of SN DA neurons. These results reinforce the critical role of PC as sensors of metabolic stress in PD and other disorders of the dopamine system.
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Affiliation(s)
- Rasem Mustafa
- Institute of Anatomy and Cell Biology, Heidelberg Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany; (R.M.); (J.K.); (K.L.T.)
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
| | - Chahinaz Rawas
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
| | - Nadja Mannal
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
| | - Grzegorz Kreiner
- Department of Brain Biochemistry, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland;
| | - Björn Spittau
- Institute of Anatomy and Cell Biology, Department of Molecular Embryology, Faculty of Medicine, University of Freiburg, 79104 Freiburg, Germany;
- Anatomy and Cell Biology, Medical School OWL, Bielefeld University, 33615 Bielefeld, Germany
| | - Katarzyna Kamińska
- Department of Pharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Smetna 12, 31-343 Kraków, Poland;
- Jagiellonian Center for Experimental Therapeutics, Jagiellonian University, Bobrzynskiego 14, 30-348 Kraków, Poland
| | - Rüstem Yilmaz
- Mannheim Center for Translational Neuroscience, Division of Neurodegenerative Disorders, Department of Neurology, Mannheim Medical Faculty, University of Heidelberg, 68167 Mannheim, Germany;
| | - Christina Pötschke
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
| | - Joachim Kirsch
- Institute of Anatomy and Cell Biology, Heidelberg Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany; (R.M.); (J.K.); (K.L.T.)
| | - Birgit Liss
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
- Linacre College and New College, University of Oxford, Oxford OX1 2JD, UK
| | - Kerry L. Tucker
- Institute of Anatomy and Cell Biology, Heidelberg Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany; (R.M.); (J.K.); (K.L.T.)
- Department of Biomedical Sciences, College of Osteopathic Medicine, Biddeford, ME 04005, USA
- Center for Excellence in the Neurosciences, University of New England, Biddeford, ME 04005, USA
| | - Rosanna Parlato
- Institute of Anatomy and Cell Biology, Heidelberg Medical Faculty, University of Heidelberg, 69120 Heidelberg, Germany; (R.M.); (J.K.); (K.L.T.)
- Institute of Applied Physiology, Ulm Medical Faculty, University of Ulm, 89081 Ulm, Germany; (C.R.); (N.M.); (C.P.); (B.L.)
- Mannheim Center for Translational Neuroscience, Division of Neurodegenerative Disorders, Department of Neurology, Mannheim Medical Faculty, University of Heidelberg, 68167 Mannheim, Germany;
- Correspondence: ; Tel.: +49-621-3835-611
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18
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Akhshi T, Trimble WS. A non-canonical Hedgehog pathway initiates ciliogenesis and autophagy. J Cell Biol 2021; 220:211568. [PMID: 33258871 PMCID: PMC7714386 DOI: 10.1083/jcb.202004179] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 08/19/2020] [Accepted: 10/14/2020] [Indexed: 12/17/2022] Open
Abstract
Primary cilia function as critical signaling hubs whose absence leads to severe disorders collectively known as ciliopathies; our knowledge of ciliogenesis remains limited. We show that Smo induces ciliogenesis through two distinct yet essential noncanonical Hh pathways in several cell types, including neurons. Surprisingly, ligand activation of Smo induces autophagy via an LKB1-AMPK axis to remove the satellite pool of OFD1. This is required, but not sufficient, for ciliogenesis. Additionally, Smo activates the Gαi-LGN-NuMA-dynein axis, causing accumulation of a portion of OFD1 at centrioles in early ciliogenesis. Both pathways are critical for redistribution of BBS4 from satellites to centrioles, which is also mediated by OFD1 centriolar translocation. Notably, different Smo agonists, which activate Smo distinctly, activate one or the other of these pathways; only in combination they recapitulate the activity of Hh ligand. These studies provide new insight into physiological stimuli (Hh) that activate autophagy and promote ciliogenesis and introduce a novel role for the Gαi-LGN-NuMA-dynein complex in this process.
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Affiliation(s)
- Tara Akhshi
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
| | - William S Trimble
- Cell Biology Program, Hospital for Sick Children, Toronto, Canada.,Department of Biochemistry, University of Toronto, Toronto, Canada
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19
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Tereshko L, Gao Y, Cary BA, Turrigiano GG, Sengupta P. Ciliary neuropeptidergic signaling dynamically regulates excitatory synapses in postnatal neocortical pyramidal neurons. eLife 2021; 10:e65427. [PMID: 33650969 PMCID: PMC7952091 DOI: 10.7554/elife.65427] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/01/2021] [Indexed: 02/06/2023] Open
Abstract
Primary cilia are compartmentalized sensory organelles present on the majority of neurons in the mammalian brain throughout adulthood. Recent evidence suggests that cilia regulate multiple aspects of neuronal development, including the maintenance of neuronal connectivity. However, whether ciliary signals can dynamically modulate postnatal circuit excitability is unknown. Here we show that acute cell-autonomous knockdown of ciliary signaling rapidly strengthens glutamatergic inputs onto cultured rat neocortical pyramidal neurons and increases spontaneous firing. This increased excitability occurs without changes to passive neuronal properties or intrinsic excitability. Further, the neuropeptide receptor somatostatin receptor 3 (SSTR3) is localized nearly exclusively to excitatory neuron cilia both in vivo and in culture, and pharmacological manipulation of SSTR3 signaling bidirectionally modulates excitatory synaptic inputs onto these neurons. Our results indicate that ciliary neuropeptidergic signaling dynamically modulates excitatory synapses and suggest that defects in this regulation may underlie a subset of behavioral and cognitive disorders associated with ciliopathies.
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Affiliation(s)
- Lauren Tereshko
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Ya Gao
- Department of Biology, Brandeis UniversityWalthamUnited States
| | - Brian A Cary
- Department of Biology, Brandeis UniversityWalthamUnited States
| | | | - Piali Sengupta
- Department of Biology, Brandeis UniversityWalthamUnited States
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20
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Liu S, Trupiano MX, Simon J, Guo J, Anton ES. The essential role of primary cilia in cerebral cortical development and disorders. Curr Top Dev Biol 2021; 142:99-146. [PMID: 33706927 DOI: 10.1016/bs.ctdb.2020.11.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Primary cilium, first described in the 19th century in different cell types and organisms by Alexander Ecker, Albert Kolliker, Aleksandr Kowalevsky, Paul Langerhans, and Karl Zimmermann (Ecker, 1844; Kolliker, 1854; Kowalevsky, 1867; Langerhans, 1876; Zimmermann, 1898), play an essential modulatory role in diverse aspects of nervous system development and function. The primary cilium, sometimes referred to as the cell's 'antennae', can receive wide ranging inputs from cellular milieu, including morphogens, growth factors, neuromodulators, and neurotransmitters. Its unique structural and functional organization bequeaths it the capacity to hyper-concentrate signaling machinery in a restricted cellular domain approximately one-thousandth the volume of cell soma. Thus enabling it to act as a signaling hub that integrates diverse developmental and homestatic information from cellular milieu to regulate the development and function of neural cells. Dysfunction of primary cilia contributes to the pathophysiology of several brain malformations, intellectual disabilities, epilepsy, and psychiatric disorders. This review focuses on the most essential contributions of primary cilia to cerebral cortical development and function, in the context of neurodevelopmental disorders and malformations. It highlights the recent progress made in identifying the mechanisms underlying primary cilia's role in cortical progenitors, neurons and glia, in health and disease. A future challenge will be to translate these insights and advances into effective clinical treatments for ciliopathies.
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Affiliation(s)
- Siling Liu
- UNC Neuroscience Center and the Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Mia X Trupiano
- UNC Neuroscience Center and the Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Jeremy Simon
- UNC Neuroscience Center and the Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Jiami Guo
- Hotchkiss Brain Institute, Alberta Children's Hospital Research Institute, and the Department of Cell Biology and Anatomy, University of Calgary, Calgary, AB, Canada
| | - E S Anton
- UNC Neuroscience Center and the Department of Cell and Molecular Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, United States.
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21
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Cullen CL, O'Rourke M, Beasley SJ, Auderset L, Zhen Y, Pepper RE, Gasperini R, Young KM. Kif3a deletion prevents primary cilia assembly on oligodendrocyte progenitor cells, reduces oligodendrogenesis and impairs fine motor function. Glia 2020; 69:1184-1203. [PMID: 33368703 PMCID: PMC7986221 DOI: 10.1002/glia.23957] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2020] [Revised: 11/06/2020] [Accepted: 12/10/2020] [Indexed: 12/17/2022]
Abstract
Primary cilia are small microtubule‐based organelles capable of transducing signals from growth factor receptors embedded in the cilia membrane. Developmentally, oligodendrocyte progenitor cells (OPCs) express genes associated with primary cilia assembly, disassembly, and signaling, however, the importance of primary cilia for adult myelination has not been explored. We show that OPCs are ciliated in vitro and in vivo, and that they disassemble their primary cilia as they progress through the cell cycle. OPC primary cilia are also disassembled as OPCs differentiate into oligodendrocytes. When kinesin family member 3a (Kif3a), a gene critical for primary cilium assembly, was conditionally deleted from adult OPCs in vivo (Pdgfrα‐CreER™:: Kif3afl/fl transgenic mice), OPCs failed to assemble primary cilia. Kif3a‐deletion was also associated with reduced OPC proliferation and oligodendrogenesis in the corpus callosum and motor cortex and a progressive impairment of fine motor coordination.
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Affiliation(s)
- Carlie L Cullen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Megan O'Rourke
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Shannon J Beasley
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Loic Auderset
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Yilan Zhen
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Renee E Pepper
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Robert Gasperini
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia.,School of Medicine, University of Tasmania, Hobart, Australia
| | - Kaylene M Young
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
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22
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Primary cilia safeguard cortical neurons in neonatal mouse forebrain from environmental stress-induced dendritic degeneration. Proc Natl Acad Sci U S A 2020; 118:2012482118. [PMID: 33443207 DOI: 10.1073/pnas.2012482118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
The developing brain is under the risk of exposure to a multitude of environmental stressors. While perinatal exposure to excessive levels of environmental stress is responsible for a wide spectrum of neurological and psychiatric conditions, the developing brain is equipped with intrinsic cell protection, the mechanisms of which remain unknown. Here we show, using neonatal mouse as a model system, that primary cilia, hair-like protrusions from the neuronal cell body, play an essential role in protecting immature neurons from the negative impacts of exposure to environmental stress. More specifically, we found that primary cilia prevent the degeneration of dendritic arbors upon exposure to alcohol and ketamine, two major cell stressors, by activating cilia-localized insulin-like growth factor 1 receptor and downstream Akt signaling. We also found that activation of this pathway inhibits Caspase-3 activation and caspase-mediated cleavage/fragmentation of cytoskeletal proteins in stress-exposed neurons. These results indicate that primary cilia play an integral role in mitigating adverse impacts of environmental stressors such as drugs on perinatal brain development.
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23
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Morozov YM, Mackie K, Rakic P. Cannabinoid Type 1 Receptor is Undetectable in Rodent and Primate Cerebral Neural Stem Cells but Participates in Radial Neuronal Migration. Int J Mol Sci 2020; 21:ijms21228657. [PMID: 33212822 PMCID: PMC7696736 DOI: 10.3390/ijms21228657] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 11/13/2020] [Accepted: 11/15/2020] [Indexed: 12/14/2022] Open
Abstract
Cannabinoid type 1 receptor (CB1R) is expressed and participates in several aspects of cerebral cortex embryonic development as demonstrated with whole-transcriptome mRNA sequencing and other contemporary methods. However, the cellular location of CB1R, which helps to specify molecular mechanisms, remains to be documented. Using three-dimensional (3D) electron microscopic reconstruction, we examined CB1R immunolabeling in proliferating neural stem cells (NSCs) and migrating neurons in the embryonic mouse (Mus musculus) and rhesus macaque (Macaca mulatta) cerebral cortex. We found that the mitotic and postmitotic ventricular and subventricular zone (VZ and SVZ) cells are immunonegative in both species while radially migrating neurons in the intermediate zone (IZ) and cortical plate (CP) contain CB1R-positive intracellular vesicles. CB1R immunolabeling was more numerous and more extensive in monkeys compared to mice. In CB1R-knock out mice, projection neurons in the IZ show migration abnormalities such as an increased number of lateral processes. Thus, in radially migrating neurons CB1R provides a molecular substrate for the regulation of cell movement. Undetectable level of CB1R in VZ/SVZ cells indicates that previously suggested direct CB1R-transmitted regulation of cellular proliferation and fate determination demands rigorous re-examination. More abundant CB1R expression in monkey compared to mouse suggests that therapeutic or recreational cannabis use may be more distressing for immature primate neurons than inferred from experiments with rodents.
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Affiliation(s)
- Yury M. Morozov
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale School of Medicine, Yale University, New Haven, CT 6510, USA
- Correspondence: (Y.M.M.); (P.R.)
| | - Ken Mackie
- Gill Center for Biomolecular Science, Indiana University, Bloomington, IN 47405-2204, USA;
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN 47405-2204, USA
| | - Pasko Rakic
- Department of Neuroscience, Kavli Institute for Neuroscience, Yale School of Medicine, Yale University, New Haven, CT 6510, USA
- Correspondence: (Y.M.M.); (P.R.)
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24
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Ramos C, Roberts JB, Jasso KR, Ten Eyck TW, Everett T, Pozo P, Setlow B, McIntyre JC. Neuron-specific cilia loss differentially alters locomotor responses to amphetamine in mice. J Neurosci Res 2020; 99:827-842. [PMID: 33175436 DOI: 10.1002/jnr.24755] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 10/07/2020] [Accepted: 10/25/2020] [Indexed: 12/20/2022]
Abstract
The neural mechanisms that underlie responses to drugs of abuse are complex, and impacted by a number of neuromodulatory peptides. Within the past 10 years it has been discovered that several of the receptors for neuromodulators are enriched in the primary cilia of neurons. Primary cilia are microtubule-based organelles that project from the surface of nearly all mammalian cells, including neurons. Despite what we know about cilia, our understanding of how cilia regulate neuronal function and behavior is still limited. The primary objective of this study was to investigate the contributions of primary cilia on specific neuronal populations to behavioral responses to amphetamine. To test the consequences of cilia loss on amphetamine-induced locomotor activity we selectively ablated cilia from dopaminergic or GAD2-GABAergic neurons in mice. Cilia loss had no effect on baseline locomotion in either mouse strain. In mice lacking cilia on dopaminergic neurons, locomotor activity compared to wild- type mice was reduced in both sexes in response to acute administration of 3.0 mg/kg amphetamine. In contrast, changes in the locomotor response to amphetamine in mice lacking cilia on GAD2-GABAergic neurons were primarily driven by reductions in locomotor activity in males. Following repeated amphetamine administration (1.0 mg kg-1 day-1 over 5 days), mice lacking cilia on GAD2-GABAergic neurons exhibited enhanced sensitization of the locomotor stimulant response to the drug, whereas mice lacking cilia on dopaminergic neurons did not differ from wild-type controls. These results indicate that cilia play neuron-specific roles in both acute and neuroplastic responses to psychostimulant drugs of abuse.
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Affiliation(s)
- Carlos Ramos
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Jonté B Roberts
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Kalene R Jasso
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Tyler W Ten Eyck
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Thomas Everett
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Patricia Pozo
- Department of Neuroscience, University of Florida, Gainesville, FL, USA
| | - Barry Setlow
- Department of Psychiatry, University of Florida, Gainesville, FL, USA.,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
| | - Jeremy C McIntyre
- Department of Neuroscience, University of Florida, Gainesville, FL, USA.,Center for Addiction Research and Education, University of Florida, Gainesville, FL, USA
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25
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Lauter G, Coschiera A, Yoshihara M, Sugiaman-Trapman D, Ezer S, Sethurathinam S, Katayama S, Kere J, Swoboda P. Differentiation of ciliated human midbrain-derived LUHMES neurons. J Cell Sci 2020; 133:jcs249789. [PMID: 33115758 DOI: 10.1242/jcs.249789] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2020] [Accepted: 10/05/2020] [Indexed: 12/15/2022] Open
Abstract
Many human cell types are ciliated, including neural progenitors and differentiated neurons. Ciliopathies are characterized by defective cilia and comprise various disease states, including brain phenotypes, where the underlying biological pathways are largely unknown. Our understanding of neuronal cilia is rudimentary, and an easy-to-maintain, ciliated human neuronal cell model is absent. The Lund human mesencephalic (LUHMES) cell line is a ciliated neuronal cell line derived from human fetal mesencephalon. LUHMES cells can easily be maintained and differentiated into mature, functional neurons within one week. They have a single primary cilium as proliferating progenitor cells and as postmitotic, differentiating neurons. These developmental stages are completely separable within one day of culture condition change. The sonic hedgehog (SHH) signaling pathway is active in differentiating LUHMES neurons. RNA-sequencing timecourse analyses reveal molecular pathways and gene-regulatory networks critical for ciliogenesis and axon outgrowth at the interface between progenitor cell proliferation, polarization and neuronal differentiation. Gene expression dynamics of cultured LUHMES neurons faithfully mimic the corresponding in vivo dynamics of human fetal midbrain. In LUHMES cells, neuronal cilia biology can be investigated from proliferation through differentiation to mature neurons.
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Affiliation(s)
- Gilbert Lauter
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
| | - Andrea Coschiera
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
| | - Masahito Yoshihara
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
| | | | - Sini Ezer
- University of Helsinki, Research Program of Molecular Neurology and Folkhälsan Institute of Genetics, FI-00290 Helsinki, Finland
| | - Shalini Sethurathinam
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
| | - Shintaro Katayama
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
- University of Helsinki, Stem Cells and Metabolism Research Program and Folkhälsan Research Center, FI-00290 Helsinki, Finland
| | - Juha Kere
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
- University of Helsinki, Research Program of Molecular Neurology and Folkhälsan Institute of Genetics, FI-00290 Helsinki, Finland
| | - Peter Swoboda
- Karolinska Institute, Department of Biosciences and Nutrition, SE-141 83 Huddinge, Sweden
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26
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Lee KH. Involvement of Wnt signaling in primary cilia assembly and disassembly. FEBS J 2020; 287:5027-5038. [PMID: 33015954 DOI: 10.1111/febs.15579] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/21/2020] [Accepted: 09/29/2020] [Indexed: 11/28/2022]
Abstract
The primary cilium is a nonmotile microtubule-based structure, which functions as an antenna-like cellular sensing organelle. The primary cilium is assembled from the basal body, a mother centriole-based structure, during interphase or a quiescent cell stage, and rapidly disassembles before entering mitosis in a dynamic cycle. Defects in this ciliogenesis dynamics are associated with human diseases such as ciliopathy and cancer, but the molecular mechanisms of the ciliogenesis dynamics are still largely unknown. To date, various cellular signaling pathways associated with primary cilia have been proposed, but the main signaling pathways regulating primary cilia assembly/disassembly remain enigmatic. This review describes recent findings in Wnt-induced primary cilia assembly/disassembly and potential future directions for the study of the cellular signaling related to the primary ciliogenesis dynamics.
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Affiliation(s)
- Kyung Ho Lee
- Anticancer Agent Research Center, Korea Research Institute of Bioscience and Biotechnology (KRIBB), Ochang, Korea
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27
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Alvarado JA, Dhande OS, Prosseda PP, Kowal TJ, Ning K, Jabbehdari S, Hu Y, Sun Y. Developmental distribution of primary cilia in the retinofugal visual pathway. J Comp Neurol 2020; 529:1442-1455. [PMID: 32939774 DOI: 10.1002/cne.25029] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2020] [Revised: 07/21/2020] [Accepted: 08/17/2020] [Indexed: 12/21/2022]
Abstract
The mammalian visual system is composed of circuitry connecting sensory input from the retina to the processing core of the visual cortex. The two main retinorecipient brain targets, the superior colliculus (SC) and dorsal lateral geniculate nucleus (dLGN), bridge retinal input and visual output. The primary cilium is a conserved organelle increasingly viewed as a critical sensor for the regulation of developmental and homeostatic pathways in most mammalian cell types. Moreover, cilia have been described as crucial for neurogenesis, neuronal maturation, and survival in the cortex and retina. However, cilia in the visual relay center remain to be fully described. In this study, we characterized the ciliation profile of the SC and dLGN and found that the overall number of ciliated cells declined during development. Interestingly, shorter ciliated cells in both regions were identified as neurons, whose numbers remained stable over time, suggesting that cilia retention is a critical feature for optimal neuronal function in SC and dLGN. Our study suggests that primary cilia are important for neuronal maturation and function in cells of the SC and dLGN.
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Affiliation(s)
- Jorge A Alvarado
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Onkar S Dhande
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Philipp P Prosseda
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Tia J Kowal
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Ke Ning
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
| | - Sayena Jabbehdari
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, Chicago, Illinois, USA
| | - Yang Hu
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, California, USA
| | - Yang Sun
- Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA.,Wu Tsai Neurosciences Institute, Stanford University School of Medicine, Stanford, California, USA.,Palo Alto Veterans Administration, Palo Alto, California, USA
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28
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Primary Cilia Signaling Promotes Axonal Tract Development and Is Disrupted in Joubert Syndrome-Related Disorders Models. Dev Cell 2020; 51:759-774.e5. [PMID: 31846650 DOI: 10.1016/j.devcel.2019.11.005] [Citation(s) in RCA: 53] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 08/08/2019] [Accepted: 11/10/2019] [Indexed: 12/18/2022]
Abstract
Appropriate axonal growth and connectivity are essential for functional wiring of the brain. Joubert syndrome-related disorders (JSRD), a group of ciliopathies in which mutations disrupt primary cilia function, are characterized by axonal tract malformations. However, little is known about how cilia-driven signaling regulates axonal growth and connectivity. We demonstrate that the deletion of related JSRD genes, Arl13b and Inpp5e, in projection neurons leads to de-fasciculated and misoriented axonal tracts. Arl13b deletion disrupts the function of its downstream effector, Inpp5e, and deregulates ciliary-PI3K/AKT signaling. Chemogenetic activation of ciliary GPCR signaling and cilia-specific optogenetic modulation of downstream second messenger cascades (PI3K, AKT, and AC3) commonly regulated by ciliary signaling receptors induce rapid changes in axonal dynamics. Further, Arl13b deletion leads to changes in transcriptional landscape associated with dysregulated PI3K/AKT signaling. These data suggest that ciliary signaling acts to modulate axonal connectivity and that impaired primary cilia signaling underlies axonal tract defects in JSRD.
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29
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Bieder A, Yoshihara M, Katayama S, Krjutškov K, Falk A, Kere J, Tapia-Páez I. Dyslexia Candidate Gene and Ciliary Gene Expression Dynamics During Human Neuronal Differentiation. Mol Neurobiol 2020; 57:2944-2958. [PMID: 32445086 PMCID: PMC7320047 DOI: 10.1007/s12035-020-01905-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2019] [Accepted: 03/19/2020] [Indexed: 11/30/2022]
Abstract
Developmental dyslexia (DD) is a neurodevelopmental condition with complex genetic mechanisms. A number of candidate genes have been identified, some of which are linked to neuronal development and migration and to ciliary functions. However, expression and regulation of these genes in human brain development and neuronal differentiation remain uncharted. Here, we used human long-term self-renewing neuroepithelial stem (lt-NES, here termed NES) cells derived from human induced pluripotent stem cells to study neuronal differentiation in vitro. We characterized gene expression changes during differentiation by using RNA sequencing and validated dynamics for selected genes by qRT-PCR. Interestingly, we found that genes related to cilia were significantly enriched among upregulated genes during differentiation, including genes linked to ciliopathies with neurodevelopmental phenotypes. We confirmed the presence of primary cilia throughout neuronal differentiation. Focusing on dyslexia candidate genes, 33 out of 50 DD candidate genes were detected in NES cells by RNA sequencing, and seven candidate genes were upregulated during differentiation to neurons, including DYX1C1 (DNAAF4), a highly replicated DD candidate gene. Our results suggest a role of ciliary genes in differentiating neuronal cells and show that NES cells provide a relevant human neuronal model to study ciliary and DD candidate genes.
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Affiliation(s)
- Andrea Bieder
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden.
| | - Masahito Yoshihara
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden
| | - Shintaro Katayama
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden
| | - Kaarel Krjutškov
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden.,Competence Centre on Health Technologies, Tartu, Estonia.,Research Program of Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki, Finland.,Folkhälsan Institute of Genetics, Helsinki, Finland
| | - Anna Falk
- Department of Neuroscience, Karolinska Institutet, Stockholm, Sweden
| | - Juha Kere
- Department of Biosciences and Nutrition, Karolinska Institutet, Hälsovägen 9, 141 57, Huddinge, Sweden. .,Research Program of Molecular Neurology, Research Programs Unit, University of Helsinki, Helsinki, Finland. .,Folkhälsan Institute of Genetics, Helsinki, Finland. .,School of Basic and Medical Biosciences, King's College London, London, UK.
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30
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Dynamic Changes in Ultrastructure of the Primary Cilium in Migrating Neuroblasts in the Postnatal Brain. J Neurosci 2019; 39:9967-9988. [PMID: 31685650 DOI: 10.1523/jneurosci.1503-19.2019] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 10/08/2019] [Accepted: 10/24/2019] [Indexed: 11/21/2022] Open
Abstract
New neurons, referred to as neuroblasts, are continuously generated in the ventricular-subventricular zone of the brain throughout an animal's life. These neuroblasts are characterized by their unique potential for proliferation, formation of chain-like cell aggregates, and long-distance and high-speed migration through the rostral migratory stream (RMS) toward the olfactory bulb (OB), where they decelerate and differentiate into mature interneurons. The dynamic changes of ultrastructural features in postnatal-born neuroblasts during migration are not yet fully understood. Here we report the presence of a primary cilium, and its ultrastructural morphology and spatiotemporal dynamics, in migrating neuroblasts in the postnatal RMS and OB. The primary cilium was observed in migrating neuroblasts in the postnatal RMS and OB in male and female mice and zebrafish, and a male rhesus monkey. Inhibition of intraflagellar transport molecules in migrating neuroblasts impaired their ciliogenesis and rostral migration toward the OB. Serial section transmission electron microscopy revealed that each migrating neuroblast possesses either a pair of centrioles or a basal body with an immature or mature primary cilium. Using immunohistochemistry, live imaging, and serial block-face scanning electron microscopy, we demonstrate that the localization and orientation of the primary cilium are altered depending on the mitotic state, saltatory migration, and deceleration of neuroblasts. Together, our results highlight a close mutual relationship between spatiotemporal regulation of the primary cilium and efficient chain migration of neuroblasts in the postnatal brain.SIGNIFICANCE STATEMENT Immature neurons (neuroblasts) generated in the postnatal brain have a mitotic potential and migrate in chain-like cell aggregates toward the olfactory bulb. Here we report that migrating neuroblasts possess a tiny cellular protrusion called a primary cilium. Immunohistochemical studies with zebrafish, mouse, and monkey brains suggest that the presence of the primary cilium in migrating neuroblasts is evolutionarily conserved. Ciliogenesis in migrating neuroblasts in the rostral migratory stream is suppressed during mitosis and promoted after cell cycle exit. Moreover, live imaging and 3D electron microscopy revealed that ciliary localization and orientation change during saltatory movement of neuroblasts. Our results reveal highly organized dynamics in maturation and positioning of the primary cilium during neuroblast migration that underlie saltatory movement of postnatal-born neuroblasts.
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31
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Cilia function is associated with axon initial segment morphology. Biochem Biophys Res Commun 2019; 516:15-21. [DOI: 10.1016/j.bbrc.2019.05.172] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 05/29/2019] [Indexed: 12/25/2022]
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32
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Miki D, Kobayashi Y, Okada T, Miyamoto T, Takei N, Sekino Y, Koganezawa N, Shirao T, Saito Y. Characterization of Functional Primary Cilia in Human Induced Pluripotent Stem Cell-Derived Neurons. Neurochem Res 2019; 44:1736-1744. [PMID: 31037609 DOI: 10.1007/s11064-019-02806-4] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2018] [Revised: 04/15/2019] [Accepted: 04/15/2019] [Indexed: 12/11/2022]
Abstract
Recent advances in human induced pluripotent stem cells (hiPSCs) offer new possibilities for biomedical research and clinical applications. Neurons differentiated from hiPSCs may be promising tools to develop novel treatment methods for various neurological diseases. However, the detailed process underlying functional maturation of hiPSC-derived neurons remains poorly understood. Here, we analyze the developmental architecture of hiPSC-derived cortical neurons, iCell GlutaNeurons, focusing on the primary cilium, a single sensory organelle that protrudes from the surface of most growth-arrested vertebrate cells. To characterize the neuronal cilia, cells were cultured for various periods and evaluated immunohistochemically by co-staining with antibodies against ciliary markers Arl13b and MAP2. Primary cilia were detected in neurons within days, and their prevalence and length increased with increasing days in culture. Treatment with the mood stabilizer lithium led to primary cilia length elongation, while treatment with the orexigenic neuropeptide melanin-concentrating hormone caused cilia length shortening in iCell GlutaNeurons. The present findings suggest that iCell GlutaNeurons develop neuronal primary cilia together with the signaling machinery for regulation of cilia length. Our approach to the primary cilium as a cellular antenna can be useful for both assessment of neuronal maturation and validation of pharmaceutical agents in hiPSC-derived neurons.
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Affiliation(s)
- Daisuke Miki
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521, Japan
| | - Yuki Kobayashi
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521, Japan
| | - Tomoya Okada
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521, Japan
| | - Tatuso Miyamoto
- Department of Genetics and Cell Biology, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima, 734-8553, Japan
| | - Nobuyuki Takei
- Department of Molecular Neurobiology, Brain Research Institute, Niigata University, Niigata, 951-8585, Japan
| | - Yuko Sekino
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, 113-0033, Japan
| | - Noriko Koganezawa
- Department of Neurobiology and Behavior, Graduate School of Medicine, Gunma University, Maebashi, 371-8511, Japan
| | - Tomoaki Shirao
- Department of Neurobiology and Behavior, Graduate School of Medicine, Gunma University, Maebashi, 371-8511, Japan
| | - Yumiko Saito
- Graduate School of Integrated Arts and Sciences, Hiroshima University, 1-7-1 Kagamiyama, Higashi-Hiroshima, Hiroshima, 739-8521, Japan.
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33
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King CR, A A Quadros AR, Chazeau A, Saarloos I, van der Graaf AJ, Verhage M, Toonen RF. Fbxo41 Promotes Disassembly of Neuronal Primary Cilia. Sci Rep 2019; 9:8179. [PMID: 31160656 PMCID: PMC6546786 DOI: 10.1038/s41598-019-44589-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/20/2019] [Indexed: 01/02/2023] Open
Abstract
Neuronal primary cilia are signaling organelles with crucial roles in brain development and disease. Cilia structure is decisive for their signaling capacities but the mechanisms regulating it are poorly understood. We identify Fbxo41 as a novel Skp1/Cullin1/F-box (SCF) E3-ligase complex subunit that targets to neuronal centrioles where its accumulation promotes disassembly of primary cilia, and affects sonic hedgehog signaling, a canonical ciliary pathway. Fbxo41 targeting to centrioles requires its Coiled-coil and F-box domains. Levels of Fbxo41 at the centrioles inversely correlate with neuronal cilia length, and mutations that disrupt Fbxo41 targeting or assembly into SCF-complexes also disturb its function in cilia disassembly and signaling. Fbxo41 dependent cilia disassembly in mitotic and post-mitotic cells requires rearrangements of the actin-cytoskeleton, but requires Aurora A kinase activation only in mitotic cells, highlighting important mechanistical differences controlling cilia size between mitotic and post-mitotic cells. Phorbol esters induce recruitment of overexpressed Fbxo41 to centrioles and cilia disassembly in neurons, but disassembly can also occur in absence of Fbxo41. We propose that Fbxo41 targeting to centrosomes regulates neuronal cilia structure and signaling capacity in addition to Fbxo41-independent pathways controlling cilia size.
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Affiliation(s)
- Cillian R King
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Ana R A A Quadros
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Anaël Chazeau
- Cell Biology, Faculty of Science, Utrecht University, 3584 CH, Utrecht, The Netherlands
| | - Ingrid Saarloos
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.,Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Anne Jolien van der Graaf
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Matthijs Verhage
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.,Department of Clinical Genetics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands
| | - Ruud F Toonen
- Department of Functional Genomics, Center for Neurogenomics and Cognitive Research, VU University Amsterdam and VU Medical Center, 1081 HV, Amsterdam, The Netherlands.
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34
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Park SM, Jang HJ, Lee JH. Roles of Primary Cilia in the Developing Brain. Front Cell Neurosci 2019; 13:218. [PMID: 31139054 PMCID: PMC6527876 DOI: 10.3389/fncel.2019.00218] [Citation(s) in RCA: 66] [Impact Index Per Article: 13.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2019] [Accepted: 04/30/2019] [Indexed: 01/07/2023] Open
Abstract
Essential to development, primary cilia are microtubule-based cellular organelles that protrude from the surface of cells. Acting as cellular antenna, primary cilia play central roles in transducing or regulating several signaling pathways, including Sonic hedgehog (Shh) and Wnt signaling. Defects in primary cilia contribute to a group of syndromic disorders known as “ciliopathies” and can adversely affect development of the brain and other essential organs, including the kidneys, eyes, and liver. The molecular mechanisms of how defective primary cilia contribute to neurological defects, however, remain poorly understood. In this mini review, we summarize recent advances in understanding of the interactions between primary cilia and signaling pathways essential to cellular homeostasis and brain development.
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Affiliation(s)
- Sang Min Park
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Hee Jin Jang
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
| | - Jeong Ho Lee
- Biomedical Science and Engineering Interdisciplinary Program, Korea Advanced Institute of Science and Technology, Daejeon, South Korea.,Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, South Korea
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35
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Pruski M, Lang B. Primary Cilia-An Underexplored Topic in Major Mental Illness. Front Psychiatry 2019; 10:104. [PMID: 30886591 PMCID: PMC6409319 DOI: 10.3389/fpsyt.2019.00104] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Accepted: 02/12/2019] [Indexed: 12/20/2022] Open
Abstract
Though much progress has been made in recent years towards understanding the function and physiology of primary cilia, they remain a somewhat elusive organelle. Some studies have explored the role of primary cilia in the developing nervous system, and their dysfunction has been linked with several neurosensory deficits. Yet, very little has been written on their potential role in psychiatric disorders. This article provides an overview of some of the functions of primary cilia in signalling pathways, and demonstrates that they are a worthy candidate in psychiatric research. The links between primary cilia and major mental illness have been demonstrated to exist at several levels, spanning genetics, signalling pathways, and pharmacology as well as cell division and migration. The primary focus of this review is on the sensory role of the primary cilium and the neurodevelopmental hypothesis of psychiatric disease. As such, the primary cilium is demonstrated to be a key link between the cellular environment and cell behaviour, and hence of key importance in the considerations of the nature and nurture debate in psychiatric research.
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Affiliation(s)
- Michal Pruski
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China
- Critical Care Laboratory, Critical Care Directorate, Manchester Royal Infirmary, Manchester University NHS Foundation Trust, Manchester, United Kingdom
- School of Healthcare Science, Faculty of Science and Engineering, Manchester Metropolitan University, Manchester, United Kingdom
| | - Bing Lang
- Department of Psychiatry, The Second Xiangya Hospital, Central South University, Changsha, China
- School of Medicine, Medical Sciences and Nutrition, Institute of Medical Sciences, University of Aberdeen, Aberdeen, United Kingdom
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36
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Chang M, Suzuki N, Kawai HD. Laminar specific gene expression reveals differences in postnatal laminar maturation in mouse auditory, visual, and somatosensory cortex. J Comp Neurol 2018; 526:2257-2284. [DOI: 10.1002/cne.24481] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2018] [Revised: 05/03/2018] [Accepted: 05/21/2018] [Indexed: 01/01/2023]
Affiliation(s)
- Minzi Chang
- Department of Bioinformatics; Graduate School of Engineering; Hachioji Tokyo 192-8577 Japan
| | - Nobuko Suzuki
- Department of Bioinformatics; Graduate School of Engineering; Hachioji Tokyo 192-8577 Japan
| | - Hideki Derek Kawai
- Department of Bioinformatics; Graduate School of Engineering; Hachioji Tokyo 192-8577 Japan
- Department of Science and Engineering for Sustainable Innovation; Faculty of Science and Engineering; Hachioji Tokyo 192-8577 Japan
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Vorobyeva AG, Saunders AJ. Amyloid-β interrupts canonical Sonic hedgehog signaling by distorting primary cilia structure. Cilia 2018; 7:5. [PMID: 30140428 PMCID: PMC6098584 DOI: 10.1186/s13630-018-0059-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 08/08/2018] [Indexed: 12/13/2022] Open
Abstract
Background Primary cilia are small non-motile microtubule and cell membrane protrusions expressed on most vertebrate cells, including cortical and hippocampal neurons. These small organelles serve as sensory structures sampling the extracellular environment and reprogramming the transcriptional machinery in response to environmental change. Primary cilia are decorated with a variety of receptor proteins and are necessary for specific signaling cascades such as the Sonic hedgehog (Shh) pathway. Disrupting cilia structure or function results in a spectrum of diseases collectively referred to as ciliopathies. Common to human ciliopathies is cognitive impairment, a symptom also observed in Alzheimer's disease (AD). One hallmark of AD is accumulation of senile plaques composed of neurotoxic Amyloid-β (Aβ) peptide. The Aβ peptide is generated by the proteolytic cleavage of the amyloid precursor protein (APP). We set out to determine if Aβ affects primary cilia structure and the Shh signaling cascade. Methods We utilized in vitro cell-based assays in combination with fluorescent confocal microscopy to address our study goals. Shh signaling and cilia structure was studied using two different cell lines, mouse NIH3T3 and human HeLa cells. To investigate how Aβ levels affect Shh signaling and cilia structure in these cells, we utilized naturally secreted Aβ as well as synthetic Aβ. Effects on Shh signaling were assessed by luciferase activity while cilia structure was analyzed by fluorescent microscopy. Results Here, we report that APP localizes to primary cilia and Aβ treatment results in distorted primary cilia structure. In addition, we demonstrate that Aβ treatment interrupts canonical Shh signal transduction. Conclusions Overall, our study illustrates that Aβ can alter primary cilia structure suggesting that elevated Aβ levels, like those observed in AD patients, could have similar effects on neuronal primary cilia in the brain. Additionally, our study suggests that Aβ impairs the Shh signaling pathway. Together our findings shed light on two novel targets for future AD therapeutics.
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Wheway G, Nazlamova L, Hancock JT. Signaling through the Primary Cilium. Front Cell Dev Biol 2018; 6:8. [PMID: 29473038 PMCID: PMC5809511 DOI: 10.3389/fcell.2018.00008] [Citation(s) in RCA: 296] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Accepted: 01/23/2018] [Indexed: 12/13/2022] Open
Abstract
The presence of single, non-motile “primary” cilia on the surface of epithelial cells has been well described since the 1960s. However, for decades these organelles were believed to be vestigial, with no remaining function, having lost their motility. It wasn't until 2003, with the discovery that proteins responsible for transport along the primary cilium are essential for hedgehog signaling in mice, that the fundamental importance of primary cilia in signal transduction was realized. Little more than a decade later, it is now clear that the vast majority of signaling pathways in vertebrates function through the primary cilium. This has led to the adoption of the term “the cells's antenna” as a description for the primary cilium. Primary cilia are particularly important during development, playing fundamental roles in embryonic patterning and organogenesis, with a suite of inherited developmental disorders known as the “ciliopathies” resulting from mutations in genes encoding cilia proteins. This review summarizes our current understanding of the role of these fascinating organelles in a wide range of signaling pathways.
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Affiliation(s)
- Gabrielle Wheway
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| | - Liliya Nazlamova
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
| | - John T Hancock
- Department of Applied Science, Faculty of Health and Applied Sciences, Centre for Research in Biosciences, University of the West of England, Bristol, United Kingdom
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Wang Y, Ji T, Nelson AD, Glanowska K, Murphy GG, Jenkins PM, Parent JM. Critical roles of αII spectrin in brain development and epileptic encephalopathy. J Clin Invest 2018; 128:760-773. [PMID: 29337302 DOI: 10.1172/jci95743] [Citation(s) in RCA: 40] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 11/28/2017] [Indexed: 12/26/2022] Open
Abstract
The nonerythrocytic α-spectrin-1 (SPTAN1) gene encodes the cytoskeletal protein αII spectrin. Mutations in SPTAN1 cause early infantile epileptic encephalopathy type 5 (EIEE5); however, the role of αII spectrin in neurodevelopment and EIEE5 pathogenesis is unknown. Prior work suggests that αII spectrin is absent in the axon initial segment (AIS) and contributes to a diffusion barrier in the distal axon. Here, we have shown that αII spectrin is expressed ubiquitously in rodent and human somatodendritic and axonal domains. CRISPR-mediated deletion of Sptan1 in embryonic rat forebrain by in utero electroporation caused altered dendritic and axonal development, loss of the AIS, and decreased inhibitory innervation. Overexpression of human EIEE5 mutant SPTAN1 in embryonic rat forebrain and mouse hippocampal neurons led to similar developmental defects that were also observed in EIEE5 patient-derived neurons. Additionally, patient-derived neurons displayed aggregation of spectrin complexes. Taken together, these findings implicate αII spectrin in critical aspects of dendritic and axonal development and synaptogenesis, and support a dominant-negative mechanism of SPTAN1 mutations in EIEE5.
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Affiliation(s)
| | | | | | | | - Geoffrey G Murphy
- Molecular and Behavioral Neuroscience Institute.,Department of Molecular and Integrative Physiology, and
| | - Paul M Jenkins
- Department of Pharmacology.,Department of Psychiatry, University of Michigan, Ann Arbor, Michigan, USA
| | - Jack M Parent
- Department of Neurology.,Ann Arbor VA Healthcare System, Ann Arbor, Michigan, USA
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40
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Agirman G, Broix L, Nguyen L. Cerebral cortex development: an outside‐in perspective. FEBS Lett 2017; 591:3978-3992. [DOI: 10.1002/1873-3468.12924] [Citation(s) in RCA: 50] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 11/17/2017] [Accepted: 11/28/2017] [Indexed: 12/18/2022]
Affiliation(s)
- Gulistan Agirman
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
| | - Loïc Broix
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
| | - Laurent Nguyen
- GIGA‐Neurosciences Interdisciplinary Cluster for Applied Genoproteomics (GIGA‐R) Liège Belgium
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41
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Phencyclidine-induced dysregulation of primary cilia in the rodent brain. Brain Res 2017; 1674:62-69. [PMID: 28842124 DOI: 10.1016/j.brainres.2017.08.022] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2016] [Revised: 08/17/2017] [Accepted: 08/18/2017] [Indexed: 11/22/2022]
Abstract
Significant roles of the primary cilia in the central nervous system have been reported in neural generation and cognitive functions. However, little is known about the possible pathological changes in brain primary cilia in neuropsychiatric disorders. To obtain an insight into the relationship between cilial dysregulation and schizophrenia, we presently investigated the effects of psychotomimetics, phencyclidine, MK-801 (dizocilpine), and methamphetamine, on morphological and molecular indices in the rodent brain. Using an immunohistochemical technique, we found that a subcutaneous injection of phencyclidine, an NMDA type glutamate receptor (NMDAR) antagonist, caused a reduction in the long axis length of a primary cilium in the CA1 region of the hippocampus without affecting that in the dentate gyrus and medial prefrontal cortex of rats and mice. The region-selective modulation of primary cilia was mimicked by another NMDAR antagonist, MK-801, but not by the indirect dopamine agonist methamphetamine. Furthermore, systemic administration of phencyclidine, but not methamphetamine, down-regulated mRNA expression of primary cilium morphology-related genes, including kif3a, 5-HTR6, RPGRIP1L, and TMEM67, and of genes composing the cilial Wnt/β-catenin signaling pathway, β-catenin, syn2 and Bcl-2, in the hippocampus, but not in the cerebral cortex of rats. These findings suggest that NMDAR hypofunction-induced dysregulation of CA1 primary cilia could be involved in the pathophysiology of dopamine transmission-independent symptoms of schizophrenia.
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42
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Canterini S, Dragotto J, Dardis A, Zampieri S, De Stefano ME, Mangia F, Erickson RP, Fiorenza MT. Shortened primary cilium length and dysregulated Sonic hedgehog signaling in Niemann-Pick C1 disease. Hum Mol Genet 2017; 26:2277-2289. [DOI: 10.1093/hmg/ddx118] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Accepted: 03/25/2017] [Indexed: 11/13/2022] Open
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43
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Stuart KE, King AE, Fernandez-Martos CM, Dittmann J, Summers MJ, Vickers JC. Mid-life environmental enrichment increases synaptic density in CA1 in a mouse model of Aβ-associated pathology and positively influences synaptic and cognitive health in healthy ageing. J Comp Neurol 2017; 525:1797-1810. [DOI: 10.1002/cne.24156] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Kimberley E. Stuart
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Anna E. King
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Carmen M. Fernandez-Martos
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Justin Dittmann
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Mathew J. Summers
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
- School of Social Sciences; University of the Sunshine Coast; Sippy Downs Queensland Australia
| | - James C. Vickers
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
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44
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Brodsky M, Lesiak AJ, Croicu A, Cohenca N, Sullivan JM, Neumaier JF. 5-HT 6 receptor blockade regulates primary cilia morphology in striatal neurons. Brain Res 2017; 1660:10-19. [PMID: 28087224 DOI: 10.1016/j.brainres.2017.01.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 01/06/2017] [Accepted: 01/09/2017] [Indexed: 12/12/2022]
Abstract
The 5-HT6 receptor has been implicated in a variety of cognitive processes including habitual behaviors, learning, and memory. It is found almost exclusively in the brain, is expressed abundantly in striatum, and localizes to neuronal primary cilia. Primary cilia are antenna-like, sensory organelles found on most neurons that receive both chemical and mechanical signals from other cells and the surrounding environment; however, the effect of 5-HT6 receptor function on cellular morphology has not been examined. We confirmed that 5-HT6 receptors were localized to primary cilia in wild-type (WT) but not 5-HT6 knockout (5-HT6KO) in both native mouse brain tissue and primary cultured striatal neurons then used primary neurons cultured from WT or 5-HT6KO mice to study the function of these receptors. Selective 5-HT6 antagonists reduced cilia length in neurons cultured from wild-type mice in a concentration and time-dependent manner without altering dendrites, but had no effect on cilia length in 5-HT6KO cultured neurons. Varying the expression levels of heterologously expressed 5-HT6 receptors affected the fidelity of ciliary localization in both WT and 5-HT6KO neurons; overexpression lead to increasing amounts of 5-HT6 localization outside of the cilia but did not alter cilia morphology. Introducing discrete mutations into the third cytoplasmic loop of the 5-HT6 receptor greatly reduced, but did not entirely eliminate, trafficking of the 5-HT6 receptor to primary cilia. These data suggest that blocking 5-HT6 receptor activity reduces the length of primary cilia and that mechanisms that regulate trafficking of 5-HT6 receptors to cilia are more complex than previously thought.
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Affiliation(s)
- Matthew Brodsky
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98104, USA; Department of Pharmacology, University of Washington, Seattle, WA 98104, USA; Graduate Program in Neuroscience, University of Washington, Seattle, WA 98104, USA
| | - Adam J Lesiak
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98104, USA; Department of Pharmacology, University of Washington, Seattle, WA 98104, USA
| | - Alex Croicu
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98104, USA; Department of Pharmacology, University of Washington, Seattle, WA 98104, USA
| | - Nathalie Cohenca
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98104, USA; Department of Pharmacology, University of Washington, Seattle, WA 98104, USA
| | - Jane M Sullivan
- Department of Physiology & Biophysics, University of Washington, Seattle, WA 98104, USA; Graduate Program in Neuroscience, University of Washington, Seattle, WA 98104, USA
| | - John F Neumaier
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, WA 98104, USA; Department of Pharmacology, University of Washington, Seattle, WA 98104, USA.
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45
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Orczyk JJ, Batka R, Gore A, Maio-Lexa M, Kulkarni A, Garraghty PE. Female rat transcriptome response to infraorbital nerve transection differs from that of males: RNA-seq. J Comp Neurol 2017; 525:140-150. [PMID: 27224679 DOI: 10.1002/cne.24045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/20/2016] [Accepted: 05/23/2016] [Indexed: 11/06/2022]
Abstract
The effects of infraorbital nerve (ION) transection on gene expression in the adult female rat barrel cortex were investigated using RNA sequencing. After a 24-hour survival duration, 28 genes were differentially regulated by ION transection. Differentially expressed genes suggest microglial activity, increased retrograde ciliary transport, and a decrease in inhibition. These changes may be functionally comparable to changes in the male barrel cortex, where changes in genes related to morphology, neuronal activity, and neuronal excitability were observed. However, the patterns in changes in gene expression are vastly different between male and female rats. The results strongly caution against the practice of generalizing data from one sex to both sexes. This cautionary note has potentially profound implications for a range of research lines, including substance abuse and stress, both research domains in which subjects have been predominantly males. Future research needs to employ sex as a classification variable, as sex differences can generally be expected. Future research is also needed to confirm that changes in gene expression observed with RNA-seq correlate with changes in protein expression. J. Comp. Neurol. 525:140-150, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- John J Orczyk
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Richard Batka
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Ashleigh Gore
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Michelena Maio-Lexa
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Akhil Kulkarni
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA
| | - Preston E Garraghty
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, Indiana, USA.,Program in Neuroscience, Indiana University, Bloomington, Indiana, USA
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46
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Lepanto P, Badano JL, Zolessi FR. Neuron's little helper: The role of primary cilia in neurogenesis. NEUROGENESIS 2016; 3:e1253363. [PMID: 28090545 DOI: 10.1080/23262133.2016.1253363] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/01/2016] [Revised: 09/09/2016] [Accepted: 10/20/2016] [Indexed: 01/27/2023]
Abstract
The generation of new neurons involves a great variety of cell-extrinsic and cell-intrinsic signals. The primary cilium, long regarded as an "evolutionary vestige," has emerged as an essential signaling hub in many cells, including neural progenitors and differentiating neurons. Most progenitors harbor an apically-localized primary cilium, which is assembled and disassembled following the cell cycle, while the presence, position and length of this organelle appears to be even more variable in differentiating neurons. One of the main extracellular cues acting through the cilium is Sonic Hedgehog, which modulates spatial patterning, the progression of the cell cycle and the timing of neurogenesis. Other extracellular signals appear to bind to cilia-localized receptors and affect processes such as dendritogenesis. All the observed dynamics, as well as the many signaling pathways depending on cilia, indicate this organelle as an important structure involved in neurogenesis.
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Affiliation(s)
- Paola Lepanto
- Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay; Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay
| | - Jose L Badano
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo , Montevideo, Uruguay
| | - Flavio R Zolessi
- Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Montevideo, Uruguay; Sección Biología Celular, Facultad de Ciencias, Universidad de la República, Montevideo, Uruguay
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47
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Ramos RL, Toia AR, Pasternack DM, Dotzler TP, Cuoco JA, Esposito AW, Le MM, Parker AK, Goodman JH, Sarkisian MR. Neuroanatomical characterization of the cellular and axonal architecture of subcortical band heterotopia in the BXD29-Tlr4 lps-2J/J mouse cortex. Neuroscience 2016; 337:48-65. [PMID: 27595889 DOI: 10.1016/j.neuroscience.2016.08.049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 08/24/2016] [Accepted: 08/28/2016] [Indexed: 10/21/2022]
Abstract
Subcortical band heterotopia (SBH) are malformations of the human cerebral cortex typically associated with epilepsy and cognitive delay/disability. Rodent models of SBH have demonstrated strong face validity as they are accompanied by both cognitive deficits and spontaneous seizures or reduced seizure threshold. BXD29-Tlr4lps-2J/J recombinant inbred mice display striking bilateral SBH, partial callosal agenesis, morphological changes in subcortical structures of the auditory pathway, and display sensory deficits in behavioral tests (Rosen et al., 2013; Truong et al., 2013, 2015). Surprisingly, these mice show no cognitive deficits and have a higher seizure threshold to chemi-convulsive treatment (Gabel et al., 2013) making them different than other rodent SBH models described previously. In the present report, we perform a detailed characterization of the cellular and axonal constituents of SBH in BXD29-Tlr4lps-2J/J mice and demonstrate that various types of interneurons and glia as well as cortical and subcortical projections are found in SBH. In addition, the length of neuronal cilia was reduced in SBH compared to neurons in the overlying and adjacent normotopic cortex. Finally, we describe additional and novel malformations of the hippocampus and neocortex present in BXD29-Tlr4lps-2J/J mice. Together, our findings in BXD29-Tlr4lps-2J/J mice are discussed in the context of the known neuroanatomy and phenotype of other SBH rodent models.
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Affiliation(s)
- Raddy L Ramos
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA.
| | - Alyssa R Toia
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Daniel M Pasternack
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Timothy P Dotzler
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Joshua A Cuoco
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Anthony W Esposito
- Department of Biomedical Sciences, New York Institute of Technology College of Osteopathic Medicine, Old Westbury, NY 11568, USA
| | - Megan M Le
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0244, USA
| | - Alexander K Parker
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0244, USA
| | - Jeffrey H Goodman
- Department of Developmental Neurobiology, NY State Institute for Basic Research in Developmental Disabilities, Staten Island, NY, USA; Department of Physiology & Pharmacology and Department of Neurology, SUNY Downstate Medical Center, Brooklyn, NY, USA
| | - Matthew R Sarkisian
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL 32610-0244, USA.
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48
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Guadiana SM, Parker AK, Filho GF, Sequeira A, Semple-Rowland S, Shaw G, Mandel RJ, Foster TC, Kumar A, Sarkisian MR. Type 3 Adenylyl Cyclase and Somatostatin Receptor 3 Expression Persists in Aged Rat Neocortical and Hippocampal Neuronal Cilia. Front Aging Neurosci 2016; 8:127. [PMID: 27303293 PMCID: PMC4885836 DOI: 10.3389/fnagi.2016.00127] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 05/17/2016] [Indexed: 01/09/2023] Open
Abstract
The primary cilia of forebrain neurons assemble around birth and become enriched with neuromodulatory receptors. Our understanding of the permanence of these structures and their associated signaling pathways in the aging brain is poor, but they are worthy of investigation because disruptions in neuronal cilia signaling have been implicated in changes in learning and memory, depression-like symptoms, and sleep anomalies. Here, we asked whether neurons in aged forebrain retain primary cilia and whether the staining characteristics of aged cilia for type 3 adenylyl cyclase (ACIII), somatostatin receptor 3 (SSTR3), and pericentrin resemble those of cilia in younger forebrain. To test this, we analyzed immunostained sections of forebrain tissues taken from young and aged male Fischer 344 (F344) and F344 × Brown Norway (F344 × BN) rats. Analyses of ACIII and SSTR3 in young and aged cortices of both strains of rats revealed that the staining patterns in the neocortex and hippocampus were comparable. Virtually every NeuN positive cell examined possessed an ACIII positive cilium. The lengths of ACIII positive cilia in neocortex were similar between young and aged for both strains, whereas in F344 × BN hippocampus, the cilia lengths increased with age in CA1 and CA3, but not in dentate gyrus (DG). Additionally, the percentages of ACIII positive cilia that were also SSTR3 positive did not differ between young and aged tissues in either strain. We also found that pericentrin, a protein that localizes to the basal bodies of neuronal cilia and functions in primary cilia assembly, persisted in aged cortical neurons of both rat strains. Collectively, our data show that neurons in aged rat forebrain possess primary cilia and that these cilia, like those present in younger brain, continue to localize ACIII, SSTR3, and pericentrin. Further studies will be required to determine if the function and signaling pathways regulated by cilia are similar in aged compared to young brain.
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Affiliation(s)
- Sarah M Guadiana
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Alexander K Parker
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Gileno F Filho
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Ashton Sequeira
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Susan Semple-Rowland
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Gerry Shaw
- Department of Neuroscience, McKnight Brain Institute, University of FloridaGainesville, FL, USA; EnCor Biotechnology Inc.Gainesville, FL, USA
| | - Ronald J Mandel
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Ashok Kumar
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Matthew R Sarkisian
- Department of Neuroscience, McKnight Brain Institute, University of Florida Gainesville, FL, USA
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49
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Neonatal seizures induced by pentylenetetrazol or kainic acid disrupt primary cilia growth on developing mouse cortical neurons. Exp Neurol 2016; 282:119-27. [PMID: 27181411 DOI: 10.1016/j.expneurol.2016.05.015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 04/19/2016] [Accepted: 05/11/2016] [Indexed: 11/23/2022]
Abstract
Neonatal or early-life seizures (ELS) are often associated with life-long neurophysiological, cognitive and behavioral deficits, but the underlying mechanisms contributing to these deficits remain poorly understood. Newborn, post-migratory cortical neurons sprout ciliary buds (procilia) that mature into primary cilia. Disruption of the growth or signaling capabilities of these cilia has been linked to atypical neurite outgrowth from neurons and abnormalities in neuronal circuitry. Here, we tested the hypothesis that generalized seizures induced by pentylenetetrazol (PTZ) or kainic acid (KA) during early postnatal development impair neuronal and/or glial ciliogenesis. Mice received PTZ (50 or 100mg/kg), KA (2mg/kg), or saline either once at birth (P0), or once daily from P0 to P4. Using immunohistochemistry and electron microscopy, the cilia of neurons and glia were examined at P7, P14, and P42. A total of 83 regions were analyzed, representing 13 unique neocortical and hippocampal regions. Neuronal cilia were identified by co-expression of NeuN and type 3 adenylyl cyclase (ACIII) or somatostatin receptor 3 (SSTR3), while glial cilia were identified by co-expression of GFAP, Arl13b, and gamma-tubulin. We found that PTZ exposure at either P0 or from P0 to P4 induced convulsive behavior, followed by acute and lasting effects on neuronal cilia lengths that varied depending on the cortical region, PTZ dose, injection frequency, and time post-PTZ. Both increases and decreases in neuronal cilia length were observed. No changes in the length of glial cilia were observed under any of the test conditions. Lastly, we found that a single KA seizure at P0 led to similar abnormalities in neuronal cilia lengths. Our results suggest that seizure(s) occurring during early stages of cortical development induce persistent and widespread changes in neuronal cilia length. Given the impact neuronal cilia have on neuronal differentiation, ELS-induced changes in ciliogenesis may contribute to long-term pathology and abnormal cortical function.
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50
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Lepanto P, Davison C, Casanova G, Badano JL, Zolessi FR. Characterization of primary cilia during the differentiation of retinal ganglion cells in the zebrafish. Neural Dev 2016; 11:10. [PMID: 27053191 PMCID: PMC4823885 DOI: 10.1186/s13064-016-0064-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 03/29/2016] [Indexed: 01/05/2023] Open
Abstract
Background Retinal ganglion cell (RGC) differentiation in vivo is a highly stereotyped process, likely resulting from the interaction of cell type-specific transcription factors and tissue-derived signaling factors. The primary cilium, as a signaling hub in the cell, may have a role during this process but its presence and localization during RGC generation, and its contribution to the process of cell differentiation, have not been previously assessed in vivo. Methods In this work we analyzed the distribution of primary cilia in vivo using laser scanning confocal microscopy, as well as their main ultrastructural features by transmission electron microscopy, in the early stages of retinal histogenesis in the zebrafish, around the time of RGC generation and initial differentiation. In addition, we knocked-down ift88 and elipsa, two genes with an essential role in cilia generation and maintenance, a treatment that caused a general reduction in organelle size. The effect on retinal development and RGC differentiation was assessed by confocal microscopy of transgenic or immunolabeled embryos. Results Our results show that retinal neuroepithelial cells have an apically-localized primary cilium usually protruding from the apical membrane. We also found a small proportion of sub-apical cilia, before and during the neurogenic period. This organelle was also present in an apical position in neuroblasts during apical process retraction and dendritogenesis, although between these stages cilia appeared highly dynamic regarding both presence and position. Disruption of cilia caused a decrease in the proliferation of retinal progenitors and a reduction of neural retina volume. In addition, retinal histogenesis was globally delayed albeit RGC layer formation was preferentially reduced with respect to the amacrine and photoreceptor cell layers. Conclusions These results indicate that primary cilia exhibit a highly dynamic behavior during early retinal differentiation, and that they are required for the proliferation and survival of retinal progenitors, as well as for neuronal generation, particularly of RGCs. Electronic supplementary material The online version of this article (doi:10.1186/s13064-016-0064-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Paola Lepanto
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11400, Uruguay
| | - Camila Davison
- Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11400, Uruguay.,Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, 11400, Uruguay
| | - Gabriela Casanova
- Unidad de Microscopía Electrónica, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, 11400, Uruguay
| | - Jose L Badano
- Human Molecular Genetics Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11400, Uruguay.
| | - Flavio R Zolessi
- Cell Biology of Neural Development Laboratory, Institut Pasteur de Montevideo, Mataojo 2020, Montevideo, 11400, Uruguay. .,Sección Biología Celular, Departamento de Biología Celular y Molecular, Facultad de Ciencias, Universidad de la República, Iguá 4225, Montevideo, 11400, Uruguay.
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