RT Journal Article
SR Electronic
T1 CNS/PNS Boundary Transgression by Central Glia in the Absence of Schwann Cells or Krox20/Egr2 Function
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 5958
OP 5967
DO 10.1523/JNEUROSCI.0017-10.2010
VO 30
IS 17
A1 Fanny Coulpier
A1 Laurence Decker
A1 Benoît Funalot
A1 Jean-Michel Vallat
A1 Federico Garcia-Bragado
A1 Patrick Charnay
A1 Piotr Topilko
YR 2010
UL http://www.jneurosci.org/content/30/17/5958.abstract
AB CNS/PNS interfaces constitute cell boundaries, because they delimit territories with different neuronal and glial contents. Despite their potential interest in regenerative medicine, the mechanisms restricting oligodendrocytes and astrocytes to the CNS and Schwann cells to the PNS in mammals are not known. To investigate the involvement of peripheral glia and myelin in the maintenance of the CNS/PNS boundary, we have first made use of different mouse mutants. We show that depletion of Schwann cells and boundary cap cells or inactivation of Krox20/Egr2, a master regulatory gene for myelination in Schwann cells, results in transgression of the CNS/PNS boundary by astrocytes and oligodendrocytes and in myelination of nerve root axons by oligodendrocytes. In contrast, such migration does not occur with the TremblerJ mutation, which prevents PNS myelination without affecting Krox20 expression. Altogether, these data suggest that maintenance of the CNS/PNS boundary requires a Krox20 function separable from myelination control. Finally, we have analyzed a human patient affected by a congenital amyelinating neuropathy, associated with the absence of the KROX20 protein in Schwann cells. In this case, the nerve roots were also invaded by oligodendrocytes and astrocytes. This indicates that transgression of the CNS/PNS boundary by central glia can occur in pathological situations in humans and suggests that the underlying mechanisms are common with the mouse.