Reduction of oligodendrocyte myelin glycoprotein expression following facial nerve transection.
Oligodendrocyte myelin glycoprotein (OMgp) has been thought to be expressed in the oligodendrocytes and inhibit the regeneration of the nerves by binding to the Nogo receptor expressed in neurons in the central nervous system (CNS). However, OMgp is expressed in the CNS in the neurons as well as oligodendrocytes. In order to help understanding the physiological role of neuronal OMgp, we examined the change of OMgp expression in the facial nucleus after the facial nerve transection. Real-time RT-PCR and Western blot analysis showed a down-regulation of OMgp expression in the facial nucleus 5-7 (mRNA) or 5-14 (protein) days after transection. Thereafter, expression of OMgp returned to the control level at 28 days after axotomy. Subsequent analysis using in situ hybridization histochemistry and immunohistochemistry established that the decrease of OMgp expression was attributable to the expression in facial motoneurons, but not in oligodendrocytes. These findings suggest a possibility that the change of neuronal OMgp expression might be involved in reconnection of neural circuit between axotomized facial neuron and upper motor neuron after transection.
Koyama
Yoshihisa
Y
Department of Anatomy and Neuroscience, Graduate School of Medicine, Osaka University, Suita, Osaka, Japan; The 21st Century COE program, Japan. koyama@anat2.med.osaka-u.ac.jp
Fujiwara
Toshihiro
T
Kubo
Tateki
T
Tomita
Koichi
K
Yano
Kenji
K
Hosokawa
Ko
K
Tohyama
Masaya
M
D000818:Animals; D015153:Blotting, Western; D003712:Dendrites / Q000378:metabolism / Q000473:pathology; D020220:Facial Nerve Injuries / Q000378:metabolism* / Q000473:pathology*; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D008856:Microscopy, Fluorescence; D009046:Motor Neurons / Q000378:metabolism / Q000473:pathology; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein / Q000096:biosynthesis*; D063308:Myelin-Oligodendrocyte Glycoprotein; D009416:Nerve Regeneration / Q000502:physiology; D019581:Neuropil / Q000378:metabolism / Q000473:pathology; D009836:Oligodendroglia / Q000378:metabolism* / Q000473:pathology*; D012313:RNA / Q000096:biosynthesis / Q000235:genetics; D051381:Rats; D017207:Rats, Sprague-Dawley; D020133:Reverse Transcriptase Polymerase Chain Reaction
C571328:Mog protein, rat; D009185:Myelin Proteins; D018992:Myelin-Associated Glycoprotein; D063308:Myelin-Oligodendrocyte Glycoprotein; D012313:RNA