Modulation of Early but Not Later Stages of Programmed Cell Death in Embryonic Avian Spinal Cord by Sonic Hedgehog
| Autor: | Shunsaku Homma, Ronald W. Oppenheim, Hiroyuki Yaginuma, Elisa Martí, Andrew P. McMahon, Siwei Wang, David Prevette |
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| Rok vydání: | 1999 |
| Předmět: |
Programmed cell death
animal structures Apoptosis Cell Count Chick Embryo Cellular and Molecular Neuroscience Interneurons Ganglia Spinal Notochord medicine Animals Hedgehog Proteins RNA Messenger Sonic hedgehog Molecular Biology Cells Cultured Floor plate Embryonic Induction Motor Neurons Ganglia Sympathetic biology Neural tube Gene Expression Regulation Developmental Proteins Embryo Cell Biology Spinal cord Embryonic stem cell medicine.anatomical_structure Spinal Cord nervous system embryonic structures Trans-Activators biology.protein Neuroscience |
| Zdroj: | Molecular and Cellular Neuroscience. 13:348-361 |
| ISSN: | 1044-7431 |
| DOI: | 10.1006/mcne.1999.0755 |
| Popis: | Sonic hedgehog (Shh) is a secreted glycoprotein expressed by the notochord and floor plate that is involved in the induction and specification of ventral phenotypes in the vertebrate neural tube. Recently, Shh has also been shown to promote the survival of cultured rat embryo ventral brain and spinal cord cells. We have examined whether Shh can promote the survival of chick embryo neurons in vivo or in vitro. In the chick, Shh is expressed in notochord, floor plate, and ventral neural tube/spinal cord at several stages at which programmed cell death (PCD) occurs. However, the administration of exogenous Shh to embryos in vivo or to motoneuron cultures at these stages failed to promote the survival of several different neuronal populations, including spinal motoneurons, spinal interneurons, sympathetic preganglionic neurons, sensory neurons, and neuronal precursor cells. Rather, at the earliest stage of PCD examined here (embryonic day 3) Shh selectively induced the death of ventral neuronal precursors and floor-plate cells, resulting in a net loss of cells in the neural tube. Altered concentrations of Shh induce aberrant phenotypes that are removed by PCD. Accordingly, normal PCD in the early neural tube may play a role in dorsal-ventral patterning. |
| Databáze: | OpenAIRE |
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