Oligodendrocytes regulate formation of nodes of Ranvier via the recognition molecule OMgp.
The molecular mechanisms underlying the involvement of oligodendrocytes in formation of the nodes of Ranvier (NORs) remain poorly understood. Here we show that oligodendrocyte-myelin glycoprotein (OMgp) aggregates specifically at NORs. Nodal location of OMgp does not occur along demyelinated axons of either Shiverer or proteolipid protein (PLP) transgenic mice. Over-expression of OMgp in OLN-93 cells facilitates process outgrowth. In transgenic mice in which expression of OMgp is down-regulated, myelin thickness declines, and lateral oligodendrocyte loops at the node-paranode junction are less compacted and even join together with the opposite loops, which leads to shortened nodal gaps. Notably, each of these structural abnormalities plus modest down-regulation of expression of Na(+) channel alpha subunit result in reduced conduction velocity in the spinal cords of the mutant mice. Thus, OMgp that is derived from glia has distinct roles in regulating nodal formation and function during CNS myelination.
Nie
Du-Yu
DY
Institute of Molecular and Cell Biology, Singapore.
Ma
Quan-Hong
QH
Law
Janice W S
JW
Chia
Chern-Pang
CP
Dhingra
Narender K
NK
Shimoda
Yasushi
Y
Yang
Wu-Lin
WL
Gong
Neng
N
Chen
Qing-Wen
QW
Xu
Gang
G
Hu
Qi-Dong
QD
Chow
Pierce K H
PK
Ng
Yee-Kong
YK
Ling
Eng-Ang
EA
Watanabe
Kazutada
K
Xu
Tian-Le
TL
Habib
Amyn A
AA
Schachner
Melitta
M
Xiao
Zhi-Cheng
ZC