Expression analysis of the N-Myc downstream-regulated gene 1 indicates that myelinating Schwann cells are the primary disease target in hereditary motor and sensory neuropathy-Lom.
Mutations in the gene encoding N-myc downstream-regulated gene-1 (NDRG1) lead to truncations of the encoded protein and are associated with an autosomal recessive demyelinating neuropathy--hereditary motor and sensory neuropathy-Lom. NDRG1 protein is highly expressed in peripheral nerve and is localized in the cytoplasm of myelinating Schwann cells, including the paranodes and Schmidt-Lanterman incisures. In contrast, sensory and motor neurons as well as their axons lack NDRG1. NDRG1 mRNA levels in developing and injured adult sciatic nerves parallel those of myelin-related genes, indicating that the expression of NDRG1 in myelinating Schwann cells is regulated by axonal interactions. Oligodendrocytes also express NDRG1, and the subtle CNS deficits of affected patients may result from a lack of NDRG1 in these cells. Our data predict that the loss of NDRG1 leads to a Schwann cell autonomous phenotype resulting in demyelination, with secondary axonal loss.
Department of Biology, Institute of Cell Biology, Swiss Federal Institute of Technology, ETH-Hönggerberg, CH-8093 Zürich, Switzerland.
Philipp
P
Berger
Erich E
EE
Sirkowski
Steven S
SS
Scherer
Ueli
U
Suter
D000818:Animals; D001369:Axons; D019556:COS Cells; D018797:Cell Cycle Proteins; D002478:Cells, Cultured; D002522:Chlorocebus aethiops; D015417:Hereditary Sensory and Motor Neuropathy / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D047908:Intracellular Signaling Peptides and Proteins; D051379:Mice; D009186:Myelin Sheath; D009687:Nuclear Proteins / Q000378:metabolism*; D009836:Oligodendroglia / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D012583:Schwann Cells / Q000378:metabolism*; D000099259:N-myc Downstream-Regulated Gene 1 Protein
D018797:Cell Cycle Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; D000099259:N-myc Downstream-Regulated Gene 1 Protein