Journal of Dental Research, Vol 80, 881-886, Copyright © 2001 by International & American Associations for Dental Research Online Journals
Mitogenic effects of neutrophins on a periodontal ligament cell line
Y. Tsuboi, T. Nakanishi, T. Takano-Yamamoto, M. Miyamoto, T. Yamashiro and M. Takigawa
Department of Orthodontics, Okayama University Dental School, Japan.
Nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and
neurotrophin-3 (NT-3) are three representative neurotrophins responsible
for the differentiation and survival of neurons, and their high-affinity
receptors are tropomyosin-receptor-kinase (TRK)A, TRKB, and TRKC,
respectively. In this study, we investigated the expression of
neurotrophins in a mouse periodontal ligament cell line (MPL), by reverse
transcription-polymerase chain-reaction (RT-PCR) and enzyme-linked
immunoabsorbent assay (ELISA). We also studied the expression of TRK
receptors on MPL by immunostaining and the effects of neurotrophins on the
proliferation of MPL, with a hypothesis of autocrine mechanism of
neurotrophins. Each neurotrophin and TRK receptor was expressed, and
neurotrophins enhanced the proliferation of MPL. These findings suggest
that the MPL has functional neurotrophin receptors involved in an autocrine
function of neurotrophins. The expression level of neurotrophins and TRKs
showed the reverse pattern, and we propose an auto-regulatory mechanism of
ligands and receptors in accordance with the level of synthesized
neurotrophins.
