mTORC1 signaling and primary cilia are required for brain ventricle morphogenesis

ABSTRACT Radial glial cells (RCGs) are self-renewing progenitor cells that give rise to neurons and glia during embryonic development. Throughout neurogenesis, these cells contact the cerebral ventricles and bear a primary cilium. Although the role of the primary cilium in embryonic patterning has been studied, its role in brain ventricular morphogenesis is poorly characterized. Using conditional mutants, we show that the primary cilia of radial glia determine the size of the surface of their ventricular apical domain through regulation of the mTORC1 pathway. In cilium-less mutants, the orientation of the mitotic spindle in radial glia is also significantly perturbed and associated with an increased number of basal progenitors. The enlarged apical domain of RGCs leads to dilatation of the brain ventricles during late embryonic stages (ventriculomegaly), which initiates hydrocephalus during postnatal stages. These phenotypes can all be significantly rescued by treatment with the mTORC1 inhibitor rapamycin. These results suggest that primary cilia regulate ventricle morphogenesis by acting as a brake on the mTORC1 pathway. This opens new avenues for the diagnosis and treatment of hydrocephalus. Highlighted article: Primary cilia regulate ventricle morphogenesis in mice by modulating the mTORC1 pathway, highlighting a new role for mTOR signalling during brain development.

[1]  Anne E Carpenter,et al.  CellProfiler: free, versatile software for automated biological image analysis. , 2007, BioTechniques.

[2]  S. Shi,et al.  Asymmetric centrosome inheritance maintains neural progenitors in the , 2009 .

[3]  R. McCarley,et al.  A review of MRI findings in schizophrenia , 2001, Schizophrenia Research.

[4]  L. Luo,et al.  A global double‐fluorescent Cre reporter mouse , 2007, Genesis.

[5]  T. Weissman,et al.  Neurogenic radial glial cells in reptile, rodent and human: from mitosis to migration. , 2003, Cerebral cortex.

[6]  S. Mcconnell,et al.  Primary cilia and Gli3 activity regulate cerebral cortical size , 2012, Developmental neurobiology.

[7]  Frank Jülicher,et al.  Cell Flow Reorients the Axis of Planar Polarity in the Wing Epithelium of Drosophila , 2010, Cell.

[8]  L. Goldstein,et al.  Situs inversus and embryonic ciliary morphogenesis defects in mouse mutants lacking the KIF3A subunit of kinesin-II. , 1999, Proceedings of the National Academy of Sciences of the United States of America.

[9]  V. Sheffield,et al.  Abnormal development of NG2+PDGFRα+ neural progenitor cells leads to neonatal hydrocephalus in a ciliopathy mouse model , 2012, Nature Medicine.

[10]  Joseph G. Gleeson,et al.  Transgenic Mouse Line with Green-fluorescent Protein-labeled Centrin 2 allows Visualization of the Centrosome in Living Cells , 2004, Transgenic Research.

[11]  Martin Catala,et al.  The role of primary cilia in corpus callosum formation is mediated by production of the Gli3 repressor. , 2015, Human molecular genetics.

[12]  B. Durand,et al.  The Ciliogenic Transcription Factor RFX3 Regulates Early Midline Distribution of Guidepost Neurons Required for Corpus Callosum Development , 2012, PLoS genetics.

[13]  Jose Manuel García-Verdugo,et al.  Cilia Organize Ependymal Planar Polarity , 2010, The Journal of Neuroscience.

[14]  A. Álvarez-Buylla,et al.  Primary cilia are required in a unique subpopulation of neural progenitors , 2014, Proceedings of the National Academy of Sciences.

[15]  Wieland B Huttner,et al.  Neurogenesis during development of the vertebrate central nervous system , 2014, EMBO reports.

[16]  K. Anderson,et al.  Cilia and developmental signaling. , 2007, Annual review of cell and developmental biology.

[17]  S. Shi,et al.  Asymmetric centrosome inheritance maintains neural progenitors in neocortex , 2009, Nature.

[18]  P. Pandolfi,et al.  Polycystin-1 Regulates Extracellular Signal-Regulated Kinase-Dependent Phosphorylation of Tuberin To Control Cell Size through mTOR and Its Downstream Effectors S6K and 4EBP1 , 2009, Molecular and Cellular Biology.

[19]  J. Reiter,et al.  Kif3a interacts with Dynactin subunit p150Glued to organize centriole subdistal appendages , 2013, The EMBO journal.

[20]  M. Ogawa,et al.  Survey of the morphogenetic dynamics of the ventricular surface of the developing mouse neocortex , 2007, Developmental dynamics : an official publication of the American Association of Anatomists.

[21]  O. Marín,et al.  Tangential Neuronal Migration Controls Axon Guidance: A Role for Neuregulin-1 in Thalamocortical Axon Navigation , 2006, Cell.

[22]  N. Osumi,et al.  Ninein is essential for the maintenance of the cortical progenitor character by anchoring the centrosome to microtubules , 2013, Biology Open.

[23]  L. A. Lowery,et al.  Totally tubular: the mystery behind function and origin of the brain ventricular system , 2009, BioEssays : news and reviews in molecular, cellular and developmental biology.

[24]  Joseph G. Gleeson,et al.  Primary Cilia in the Developing and Mature Brain , 2014, Neuron.

[25]  J. García-Verdugo,et al.  Mechanosensory Genes Pkd1 and Pkd2 Contribute to the Planar Polarization of Brain Ventricular Epithelium , 2015, The Journal of Neuroscience.

[26]  Andrew R. Harris,et al.  Emergence of homeostatic epithelial packing and stress dissipation through divisions oriented along the long cell axis , 2015, Proceedings of the National Academy of Sciences.

[27]  S. Wölfl,et al.  A Crucial Role for Primary Cilia in Cortical Morphogenesis , 2008, The Journal of Neuroscience.

[28]  E. Anton,et al.  Arl13b-regulated cilia activities are essential for polarized radial glial scaffold formation , 2013, Nature Neuroscience.

[29]  Shuo Lin,et al.  Inactivation of mTORC1 in the Developing Brain Causes Microcephaly and Affects Gliogenesis , 2013, The Journal of Neuroscience.

[30]  Maria K. Lehtinen,et al.  Neurogenesis at the brain-cerebrospinal fluid interface. , 2011, Annual review of cell and developmental biology.

[31]  F. Ruddle,et al.  Mouse homeobox gene Dbx: sequence, gene structure and expression pattern during mod-gestation , 1994, Mechanisms of Development.

[32]  J. García-Verdugo,et al.  Sustained activation of mTOR pathway in embryonic neural stem cells leads to development of tuberous sclerosis complex-associated lesions. , 2011, Cell stem cell.

[33]  Jason E. Waller,et al.  Division , 2018, Bad Arguments.

[34]  M. D. Del Bigio,et al.  Ependymal cells: biology and pathology , 2009, Acta Neuropathologica.

[35]  N. Katsanis,et al.  Nde1-mediated inhibition of ciliogenesis affects cell cycle re-entry , 2011, Nature Cell Biology.

[36]  H. T. Ghashghaei,et al.  A Nestin-cre transgenic mouse is insufficient for recombination in early embryonic neural progenitors , 2012, Biology Open.

[37]  N. Hirokawa,et al.  The KIF3 motor transports N-cadherin and organizes the developing neuroepithelium , 2005, Nature Cell Biology.

[38]  M. Bornens,et al.  Microtubule minus-end anchorage at centrosomal and non-centrosomal sites: the role of ninein. , 2000, Journal of cell science.

[39]  P. Codogno,et al.  Primary-cilium-dependent autophagy controls epithelial cell volume in response to fluid flow , 2016, Nature Cell Biology.

[40]  W. Jackson,et al.  Intraflagellar transport is essential for endochondral bone formation , 2007, Development.

[41]  D. Rigamonti,et al.  Genetics of human hydrocephalus , 2006, Journal of Neurology.

[42]  S. Mcconnell,et al.  Targeting of cre to the Foxg1 (BF-1) locus mediates loxP recombination in the telencephalon and other developing head structures. , 2000, Developmental biology.

[43]  C. Wodarczyk,et al.  A Novel Mouse Model Reveals that Polycystin-1 Deficiency in Ependyma and Choroid Plexus Results in Dysfunctional Cilia and Hydrocephalus , 2009, PloS one.

[44]  M. Gambello,et al.  Loss of Tsc2 in radial glia models the brain pathology of tuberous sclerosis complex in the mouse , 2009, Human molecular genetics.

[45]  Erich A. Nigg,et al.  The centrosome cycle: Centriole biogenesis, duplication and inherent asymmetries , 2011, Nature Cell Biology.

[46]  Maria K. Lehtinen,et al.  Progressive Differentiation and Instructive Capacities of Amniotic Fluid and Cerebrospinal Fluid Proteomes following Neural Tube Closure. , 2015, Developmental cell.

[47]  B. Yoder,et al.  Dysfunctional cilia lead to altered ependyma and choroid plexus function, and result in the formation of hydrocephalus , 2005, Development.

[48]  O. Kretz,et al.  Disruption of the glucocorticoid receptor gene in the nervous system results in reduced anxiety , 1999, Nature Genetics.

[49]  B. Delaval,et al.  The cilia protein IFT88 is required for spindle orientation in mitosis , 2011, Nature Cell Biology.

[50]  W. Huttner,et al.  Asymmetric Inheritance of Centrosome-Associated Primary Cilium Membrane Directs Ciliogenesis after Cell Division , 2013, Cell.

[51]  Sylvie Schneider-Maunoury,et al.  Primary cilia control telencephalic patterning and morphogenesis via Gli3 proteolytic processing , 2011, Development.

[52]  N. Heintz,et al.  To beat or not to beat: roles of cilia in development and disease. , 2003, Human molecular genetics.

[53]  Maria K. Lehtinen,et al.  The Cerebrospinal Fluid Provides a Proliferative Niche for Neural Progenitor Cells , 2011, Neuron.

[54]  J. García-Verdugo,et al.  Adult Ependymal Cells Are Postmitotic and Are Derived from Radial Glial Cells during Embryogenesis , 2005, The Journal of Neuroscience.

[55]  R. Galli,et al.  mTOR signaling in neural stem cells: from basic biology to disease , 2012, Cellular and Molecular Life Sciences.

[56]  Gerd Walz,et al.  Primary cilia regulate mTORC1 activity and cell size through Lkb1 , 2010, Nature Cell Biology.