Involvement of GDNF and its receptors in the maturation of the periodontal Ruffini endings.
Our recent study revealed an intense immunoreaction for GDNF and its receptors in the Ruffini endings, primary mechanoreceptors in the periodontal ligament, of young rats. However, no information is available for the expression of GDNF and its receptors during their development. The present study aimed to reveal postnatal changes in the immuno-expression of GDNF, GFRalpha1 and RET in the periodontal Ruffini endings of the rat incisors by double immunofluorescent staining. At postnatal day 3 (PO 3d), no structure with GDNF-, GFRalpha1-, or RET-immunoreaction existed in the periodontal ligament. The PGP 9.5-positive nerve fibers without GDNF- and RET-immunoreaction displayed a dendritic fashion at PO 1w, with a GFRalpha1-reaction found around these nerves. At PO 2w, GDNF-positive terminal Schwann cells occurred near the thick and dendritic axons, a part of which showed a RET-reaction, with no reactive cells near the thin nerves. The terminal Schwann cells became positive for GFRalpha1, but lacked RET-immunoreaction. At PO 3w, when the formation of the periodontal Ruffini endings had proceeded, GDNF-positive terminal Schwann cells began to increase in number. This stage-specific immuno-expression pattern suggests that GDNF is a key molecule for the maturation and maintenance of the periodontal Ruffini endings.
Igarashi
Yasushi
Y
Division of Oral Anatomy, Niigata University Graduate School of Medical and Dental Sciences, 2-5274 Gakkocho-dori, Niigata 951-8514, Japan.
Aita
Megumi
M
Suzuki
Akiko
A
Nandasena
Tharanga
T
Kawano
Yoshiro
Y
Nozawa-Inoue
Kayoko
K
Maeda
Takeyasu
T
D000367:Age Factors; D000818:Animals; D000831:Animals, Newborn; D004268:DNA-Binding Proteins / Q000378:metabolism; D005455:Fluorescent Antibody Technique / Q000379:methods; D018507:Gene Expression Regulation, Developmental / Q000502:physiology*; D051100:Glial Cell Line-Derived Neurotrophic Factor / Q000378:metabolism*; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors / Q000378:metabolism*; D008465:Mechanoreceptors / Q000254:growth & development* / Q000378:metabolism*; D009687:Nuclear Proteins / Q000378:metabolism; D010513:Periodontal Ligament / Q000166:cytology / Q000254:growth & development / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D043222:Ubiquitin Thiolesterase / Q000378:metabolism; D000070584:Tripartite Motif Proteins
D004268:DNA-Binding Proteins; D051100:Glial Cell Line-Derived Neurotrophic Factor; D051097:Glial Cell Line-Derived Neurotrophic Factor Receptors; D009687:Nuclear Proteins; D043222:Ubiquitin Thiolesterase; C489295:Trim27 protein, rat; D000070584:Tripartite Motif Proteins; C489034:UCHL1 protein, rat