Peripheral myelin maintenance is a dynamic process requiring constant Krox20 expression.

Abstract

Onset of myelination in Schwann cells is governed by several transcription factors, including Krox20/Egr2, and mutations affecting Krox20 result in various human hereditary peripheral neuropathies, including congenital hypomyelinating neuropathy (CHN) and Charcot-Marie-Tooth disease (CMT). Similar molecular information is not available on the process of myelin maintenance. We have generated conditional Krox20 mutations in the mouse that allowed us to develop models for CHN and CMT. In the latter case, specific inactivation of Krox20 in adult Schwann cells results in severe demyelination, involving rapid Schwann cell dedifferentiation and increased proliferation, followed by an attempt to remyelinate and a block at the promyelinating stage. These data establish that Krox20 is not only required for the onset of myelination but that it is also crucial for the maintenance of the myelinating state. Furthermore, myelin maintenance appears as a very dynamic process in which Krox20 may constitute a molecular switch between Schwann cell myelination and demyelination programs.

• Authors: Laurence Decker, Carole Desmarquet-Trin-Dinh, Emmanuel Taillebourg, Julien Ghislain, Jean-Michel Vallat, Patrick Charnay
• Journal: The Journal of neuroscience : the official journal of the Society for Neuroscience (J Neurosci) Vol. 26 Issue 38 Pg. 9771-9 (Sep 20 2006) ISSN: 1529-2401 [Electronic] United States
• PMID: 16988048 (Publication Type: Comparative Study, Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Early Growth Response Protein 2

Topics

• Alleles
• Animals
• Cell Proliferation
• Early Growth Response Protein 2 (biosynthesis, genetics)
• Gene Expression Regulation (physiology)
• Mice
• Mice, Transgenic
• Mutation
• Myelin Sheath (genetics, metabolism, ultrastructure)
• Peripheral Nerves (metabolism, ultrastructure)