Journal of Dental Research, Vol 73, 1509-1514, Copyright © 1994 by International & American Associations for Dental Research Online Journals
Transforming growth factor-beta-1 reduces alkaline phosphatase mRNA and activity and stimulates cell proliferation in cultures of human pulp cells
M. Shirakawa, H. Shiba, K. Nakanishi, T. Ogawa, H. Okamoto, K. Nakashima, M. Noshiro and Y. Kato
Department of Endodontology and Periodontology, Hiroshima University School of Dentistry, Japan.
Transforming growth factor-beta-1 (TGF-beta-1) is a potent modulator of
proliferation and differentiation in various tissues, and may be involved
in the control of dental development and repair. This study was carried out
to investigate the effects of TGF-beta-1 on alkaline phosphatase (ALPase)
activity and mRNA level, and on DNA content in cultures of human pulp
cells. Four lines of pulp cells (P1-P4), isolated from the upper wisdom
teeth of four patients, were maintained separately in monolayer cultures in
the presence of 10% fetal bovine serum. TGF-beta-1, at 0.1 ng/mL, increased
ALPase activity and DNA content in P1 cultures, but not in P2-P4 cultures.
In all cultures, TGF-beta-1, at 5 ng/mL, decreased ALPase activity to a
very low level, and increased DNA content. Northern analysis showed that
human pulp cells synthesized a single species of 2.6-kb
liver/bone/kidney-type ALPase, and that TGF-beta-1, at 5 ng/mL, decreased
the level of the ALPase mRNA. These results suggest that TGF-beta-1 is a
mitogen for human pulp cells, and that it regulates the activity of the
universal-type ALPase at the pre-translational level.
