title: Sonic hedgehog signaling regulates mode of cell division of early cerebral cortex progenitors and increases astrogliogenesis.
abstract: The morphogen Sonic Hedgehog (SHH) plays a critical role in the development of different tissues. In the central nervous system, SHH is well known to contribute to the patterning of the spinal cord and separation of the brain hemispheres. In addition, it has recently been shown that SHH signaling also contributes to the patterning of the telencephalon and establishment of adult neurogenic niches. In this work, we investigated whether SHH signaling influences the behavior of neural progenitors isolated from the dorsal telencephalon, which generate excitatory neurons and macroglial cells in vitro. We observed that SHH increases proliferation of cortical progenitors and generation of astrocytes, whereas blocking SHH signaling with cyclopamine has opposite effects. In both cases, generation of neurons did not seem to be affected. However, cell survival was broadly affected by blockade of SHH signaling. SHH effects were related to three different cell phenomena: mode of cell division, cell cycle length and cell growth. Together, our data in vitro demonstrate that SHH signaling controls cell behaviors that are important for proliferation of cerebral cortex progenitors, as well as differentiation and survival of neurons and astroglial cells.
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte Natal, Brazil.
authors.forename: Geissy L L
authors.initials: GL
authors.lastname: Araújo
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte Natal, Brazil.
authors.forename: Jessica A M
authors.initials: JA
authors.lastname: Araújo
authors.affiliation: Department of Biosystems Science and Engineering, Cell Systems Dynamics, ETH Zurich Basel, Switzerland.
authors.forename: Timm
authors.initials: T
authors.lastname: Schroeder
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte Natal, Brazil.
authors.forename: Adriano B L
authors.initials: AB
authors.lastname: Tort
authors.affiliation: Brain Institute, Federal University of Rio Grande do Norte Natal, Brazil.
authors.forename: Marcos R
authors.initials: MR
authors.lastname: Costa
keywords: astrocytes; cell survival; cerebral cortex development; gliogenesis; mode of cell division; neurogenesis; progenitor cells; sonic hedgehog (SHH)