GDNF expression in terminal schwann cells associated with the periodontal ruffini endings of the rat incisors during nerve regeneration.
The terminal Schwann cells (TSCs) which play crucial roles in regeneration of the periodontal Ruffini endings (RE) exhibit immunoreaction for glial cell line-derived neurotrophic factor (GDNF). However, no information is available regarding the role of GDNF in the periodontal RE during nerve regeneration. This study was undertaken to examine the changes in GDNF expression in the rat periodontal RE following transection of the inferior alveolar nerve (IAN) using immunohistochemistry for GDNF and S-100 protein, a marker for the TSCs. We additionally investigated the changes in expression of GDNF in the trigeminal ganglion (TG) at protein and mRNA levels. A transection to IAN induced a disappearance of the TSCs from the alveolus-related part (ARP), followed by a migration of spindle-shaped cells with S-100 but without GDNF immunoreactions into the tooth-related part (TRP) by postoperative (PO) week 2. At PO week 2, GDNF immunoreacted cellular elements increased in number in the ARP although the spindle-shaped cells without GDNF reaction remained in the TRP. After PO week 4, many GDNF-positive TSCs appeared in the ARP though the spindle-shaped cells vanished from the TRP. A real time RT-PCR analysis demonstrated the highest elevation of GDNF mRNA in the TG at PO week 2. These findings suggested the involvement of this molecule in the maturation and maintenance of the periodontal RE during regeneration. Taken together with our previous and current studies, it appears that the regeneration of the periodontal RE is controlled by multiple neurotrophins in a stage-specific manner.
Ohishi
Megumi
M
Division of Oral Anatomy, Department of Oral Biological Science, Niigata University Graduate School of Medical and Dental Sciences, Chuo-ku, Niigata, Japan.
Harada
Fumiko
F
Rahman
Farhana
F
Saito
Isao
I
Kawano
Yoshiro
Y
Nozawa-Inoue
Kayoko
K
Maeda
Takeyasu
T
D000818:Animals; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000096:biosynthesis* / Q000235:genetics; D007150:Immunohistochemistry; D007180:Incisor / Q000294:innervation*; D008340:Mandibular Nerve / Q000502:physiology; D008465:Mechanoreceptors / Q000502:physiology*; D009416:Nerve Regeneration; D010513:Periodontal Ligament / Q000294:innervation; D010519:Periodontium / Q000294:innervation*; D012333:RNA, Messenger / Q000235:genetics; D051381:Rats; D020133:Reverse Transcriptase Polymerase Chain Reaction; D009418:S100 Proteins / Q000235:genetics / Q000378:metabolism; D012583:Schwann Cells / Q000378:metabolism*; D012668:Trigeminal Ganglion / Q000737:chemistry
D051100:Glial Cell Line-Derived Neurotrophic Factor; D012333:RNA, Messenger; D009418:S100 Proteins