Sonic hedgehog Regulates Proliferation and Inhibits Differentiation of CNS Precursor Cells

Activation of the Sonic hedgehog (Shh) signal transduction pathway is essential for normal pattern formation and cellular differentiation in the developing CNS. However, it is also thought to be etiological in primitive neuroectodermal tumors. We adaptedGAL4/UAS methodology to ectopically express full-lengthShh in the dorsal neural tube of transgenic mouse embryos commencing at 10 d postcoitum (dpc), beyond the period of primary dorsal–ventral pattern formation and floorplate induction. Expression of Shh was maintained until birth, permitting us to investigate effects of ongoing exposure to Shh on CNS precursors in vivo. Proliferative rates of spinal cord precursors were twice that of wild-type littermates at 12.5 dpc. In contrast, at late fetal stages (18.5 dpc), cells that were Shh-responsive but postmitotic were present in persistent structures reminiscent of the ventricular zone germinal matrix. This tissue remained blocked in an undifferentiated state. These results indicate that cellular competence restricts the proliferative response to Shhin vivo and provide evidence that proliferation and differentiation can be regulated separately in precursor cells of the spinal cord. Thus, Hedgehog signaling may contribute to CNS tumorigenesis by directly enhancing proliferation and preventing neural differentiation in selected precursor cells.

[1]  Andrew P. McMahon,et al.  Engrailed-1 as a target of the Wnt-1 signalling pathway in vertebrate midbrain development , 1996, Nature.

[2]  P. Beachy,et al.  Cyclopia and defective axial patterning in mice lacking Sonic hedgehog gene function , 1996, Nature.

[3]  W. Richardson,et al.  A singularity of PDGF alpha-receptor expression in the dorsoventral axis of the neural tube may define the origin of the oligodendrocyte lineage. , 1993, Development.

[4]  R. Krumlauf,et al.  Evidence for a mitogenic effect of Wnt-1 in the developing mammalian central nervous system. , 1994, Development.

[5]  R. Shigemoto,et al.  Two mammalian helix-loop-helix factors structurally related to Drosophila hairy and Enhancer of split. , 1992, Genes & development.

[6]  T. Jessell,et al.  Floor plate and motor neuron induction by different concentrations of the amino-terminal cleavage product of sonic hedgehog autoproteolysis , 1995, Cell.

[7]  D. Ovchinnikov,et al.  Limb and kidney defects in Lmx1b mutant mice suggest an involvement of LMX1B in human nail patella syndrome , 1998, Nature Genetics.

[8]  N. Dahmane,et al.  Activation of the transcription factor Gli1 and the Sonic hedgehog signalling pathway in skin tumours , 1997, Nature.

[9]  N. L. Le Douarin,et al.  Sonic Hedgehog induces proliferation of committed skeletal muscle cells in the chick limb. , 1998, Development.

[10]  M. Scott,et al.  Antagonizing cAMP-dependent protein kinase A in the dorsal CNS activates a conserved Sonic hedgehog signaling pathway. , 1996, Development.

[11]  P. Ingham,et al.  hedgehog is required for the proliferation and specification of ovarian somatic cells prior to egg chamber formation in Drosophila. , 1996, Development.

[12]  N. Perrimon,et al.  Targeted gene expression as a means of altering cell fates and generating dominant phenotypes. , 1993, Development.

[13]  R. Miller,et al.  Sonic hedgehog signaling is required during the appearance of spinal cord oligodendrocyte precursors. , 1999, Development.

[14]  Eugene V Koonin,et al.  Hedgehog Patterning Activity: Role of a Lipophilic Modification Mediated by the Carboxy-Terminal Autoprocessing Domain , 1996, Cell.

[15]  E. Turner,et al.  Inhibitory effects of ventral signals on the development of Brn-3.0-expressing neurons in the dorsal spinal cord. , 1997, Developmental biology.

[16]  M. Scott,et al.  Altered neural cell fates and medulloblastoma in mouse patched mutants. , 1997, Science.

[17]  T. Jessell,et al.  A Role for the Roof Plate and Its Resident TGFβ-Related Proteins in Neuronal Patterning in the Dorsal Spinal Cord , 1997, Cell.

[18]  David J. Anderson,et al.  Mash1 and neurogenin1 Expression Patterns Define Complementary Domains of Neuroepithelium in the Developing CNS and Are Correlated with Regions Expressing Notch Ligands , 1997, The Journal of Neuroscience.

[19]  V. Wallace,et al.  Expression of Sonic hedgehog and its putative role as a precursor cell mitogen in the developing mouse retina. , 1997, Development.

[20]  M. Rao,et al.  Spinal Cord Neuronal Precursors Generate Multiple Neuronal Phenotypes in Culture , 1998, The Journal of Neuroscience.

[21]  K. Kinzler,et al.  The zinc finger protein GLI transforms primary cells in cooperation with adenovirus E1A , 1991, Molecular and cellular biology.

[22]  Johan Ericson,et al.  Two Critical Periods of Sonic Hedgehog Signaling Required for the Specification of Motor Neuron Identity , 1996, Cell.

[23]  R. Oppenheim,et al.  Programmed cell death during the earliest stages of spinal cord development in the chick embryo: A possible means of early phenotypic selection , 1994, The Journal of comparative neurology.

[24]  Yaolin Wang,et al.  Ligand-inducible and liver-specific target gene expression in transgenic mice , 1997, Nature Biotechnology.

[25]  P. Leder,et al.  Binary system for regulating transgene expression in mice: targeting int-2 gene expression with yeast GAL4/UAS control elements. , 1991, Proceedings of the National Academy of Sciences of the United States of America.

[26]  A. McMahon,et al.  Requirement of 19K form of Sonic hedgehog for induction of distinct ventral cell types in CNS explants , 1995, Nature.

[27]  T. Lints,et al.  Cooperation of BMP7 and SHH in the Induction of Forebrain Ventral Midline Cells by Prechordal Mesoderm , 1997, Cell.

[28]  P. Ingham,et al.  Transducing Hedgehog: the story so far , 1998, The EMBO journal.

[29]  J. Rubenstein,et al.  Homeobox gene Nkx2.2 and specification of neuronal identity by graded Sonic hedgehog signalling , 1999, Nature.

[30]  N. Copeland,et al.  Limb alterations in brachypodism mice due to mutations in a new member of the TGFβ-superfamily , 1994, Nature.

[31]  R. Balling,et al.  The role of Pax-1 in axial skeleton development. , 1994, Development.

[32]  A. McMahon,et al.  Cis-acting regulatory sequences governing Wnt-1 expression in the developing mouse CNS. , 1994, Development.

[33]  P. Ingham,et al.  Role of the Drosophila patched gene in positional signalling , 1991, Nature.

[34]  K. Moriyoshi,et al.  Persistent expression of helix‐loop‐helix factor HES‐1 prevents mammalian neural differentiation in the central nervous system. , 1994, The EMBO journal.

[35]  W. Richardson,et al.  Pax6 Influences the Time and Site of Origin of Glial Precursors in the Ventral Neural Tube , 1998, Molecular and Cellular Neuroscience.

[36]  B. Hogan,et al.  Differential expression of multiple fork head related genes during gastrulation and axial pattern formation in the mouse embryo. , 1993, Development.

[37]  W. Richardson,et al.  Determination of neuroepithelial cell fate: induction of the oligodendrocyte lineage by ventral midline cells and sonic hedgehog. , 1996, Developmental biology.

[38]  A. Joyner,et al.  Expression of three mouse homologs of the Drosophila segment polarity gene cubitus interruptus, Gli, Gli-2, and Gli-3, in ectoderm- and mesoderm-derived tissues suggests multiple roles during postimplantation development. , 1994, Developmental biology.

[39]  Andrew P. McMahon,et al.  Sonic hedgehog, a member of a family of putative signaling molecules, is implicated in the regulation of CNS polarity , 1993, Cell.

[40]  A. Gurney,et al.  Control of Cell Pattern in the Neural Tube by the Zinc Finger Transcription Factor and Oncogene Gli-1 , 1997, Neuron.

[41]  R. Kageyama,et al.  Targeted disruption of mammalian hairy and Enhancer of split homolog-1 (HES-1) leads to up-regulation of neural helix-loop-helix factors, premature neurogenesis, and severe neural tube defects. , 1995, Genes & development.

[42]  T. Jessell,et al.  Induction of floor plate differentiation by contact-dependent, homeogenetic signals. , 1993, Development.

[43]  A. McMahon,et al.  Distribution of Sonic hedgehog peptides in the developing chick and mouse embryo. , 1995, Development.

[44]  M. Scott,et al.  Basal cell carcinomas in mice overexpressing sonic hedgehog. , 1997, Science.

[45]  M. Scott,et al.  Control of Neuronal Precursor Proliferation in the Cerebellum by Sonic Hedgehog , 1999, Neuron.

[46]  T. Möröy,et al.  Chromosomal localization and sequences of the murine Brn-3 family of developmental control genes. , 1994, Cytogenetics and cell genetics.

[47]  C. Tabin,et al.  Biochemical evidence that Patched is the Hedgehog receptor , 1996, Nature.

[48]  R. Krumlauf,et al.  Multiple spatially specific enhancers are required to reconstruct the pattern of Hox-2.6 gene expression. , 1991, Genes & development.

[49]  M. Scott,et al.  Conservation of the hedgehog/patched signaling pathway from flies to mice: induction of a mouse patched gene by Hedgehog. , 1996, Genes & development.

[50]  S. Ben‐Sasson,et al.  Identification of programmed cell death in situ via specific labeling of nuclear DNA fragmentation , 1992, The Journal of cell biology.

[51]  D. Duboule,et al.  Regional expression of the homeobox gene Nkx-2.2 in the developing mammalian forebrain , 1992, Neuron.

[52]  B. Hogan,et al.  Involvement of Sonic hedgehog (Shh) in mouse embryonic lung growth and morphogenesis. , 1997, Development.

[53]  Michael Dean,et al.  Mutations of the Human Homolog of Drosophila patched in the Nevoid Basal Cell Carcinoma Syndrome , 1996, Cell.

[54]  M. Goulding,et al.  Pax‐3, a novel murine DNA binding protein expressed during early neurogenesis. , 1991, The EMBO journal.

[55]  M. Scott,et al.  The tumour-suppressor gene patched encodes a candidate receptor for Sonic hedgehog , 1996, Nature.

[56]  T. Jessell,et al.  Diversity and Pattern in the Developing Spinal Cord , 1996, Science.

[57]  T. Jessell,et al.  Inductive signals and the assignment of cell fate in the spinal cord and hindbrain , 1998 .

[58]  T. Jessell,et al.  Pax6 Controls Progenitor Cell Identity and Neuronal Fate in Response to Graded Shh Signaling , 1997, Cell.

[59]  V. P. Collins,et al.  Somatic mutations in the human homologue of Drosophila patched in primitive neuroectodermal tumours , 1997, Oncogene.

[60]  J. Drukker,et al.  Effect of the notochord on proliferation and differentiation in the neural tube of the chick embryo. , 1989, Development.

[61]  T. Jessell,et al.  Floor plate and motor neuron induction by vhh-1, a vertebrate homolog of hedgehog expressed by the notochord , 1994, Cell.

[62]  O. Pourquié,et al.  Induction of oligodendrocyte progenitors in the trunk neural tube by ventralizing signals: effects of notochord and floor plate grafts, and of sonic hedgehog , 1996, Mechanisms of Development.

[63]  T. Jessell,et al.  Neuronal patterning by BMPs: a requirement for GDF7 in the generation of a discrete class of commissural interneurons in the mouse spinal cord. , 1998, Genes & development.

[64]  R. Myers,et al.  Human Homolog of patched, a Candidate Gene for the Basal Cell Nevus Syndrome , 1996, Science.

[65]  誠 浅島,et al.  Whole mount in situ hybridization , 1996 .

[66]  P. Gruss,et al.  Pax-6, a murine paired box gene, is expressed in the developing CNS. , 1991, Development.

[67]  C. Tabin,et al.  Recent advances in hedgehog signalling. , 1997, Trends in cell biology.

[68]  S. Kunes,et al.  Hedgehog, Transmitted along Retinal Axons, Triggers Neurogenesis in the Developing Visual Centers of the Drosophila Brain , 1996, Cell.

[69]  M. Tessier-Lavigne,et al.  Patterning of mammalian somites by surface ectoderm and notochord: Evidence for sclerotome induction by a hedgehog homolog , 1994, Cell.

[70]  C. James,et al.  Sporadic medulloblastomas contain PTCH mutations. , 1997, Cancer research.

[71]  C. Lance‐Jones,et al.  Motoneuron cell death in the developing lumbar spinal cord of the mouse. , 1982, Brain Research.

[72]  A. Monsoro-Burq,et al.  The developmental relationships of the neural tube and the notochord: short and long term effects of the notochord on the dorsal spinal cord , 1995, Mechanisms of Development.

[73]  B. Hogan,et al.  Colocalization of BMP 7 and BMP 2 RNAs suggests that these factors cooperatively mediate tissue interactions during murine development , 1995, Mechanisms of Development.

[74]  T. Jessell,et al.  Specification of Motor Neuron Identity by the MNR2 Homeodomain Protein , 1998, Cell.