Related Experiment Video
Updated: Jul 11, 2026

Evaluation of Keratinocyte Proliferation on Two- and Three-dimensional Type I Collagen Substrates
Published on: April 22, 2019
Semaphorin 4D inhibits collagen synthesis of rat pulp-derived cells
Makoto Abe1, Shinobu Inagaki, Tatsuo Furuyama
1Department of Oral Anatomy and Developmental Biology, Osaka University Graduate School of Dentistry, Osaka 565-0871, Japan. m-abe@dent.osaka-u.ac.jp
Objective:
Semaphorins are a group of secreted and membrane-associated molecules that play important roles in axon navigation. Several semaphorin family molecules are expressed in the pharyngeal arches and tooth germs. We analysed the expression of membrane-associated Semaphorin 4D (Sema4D) in tooth germs, and examined its potential role in regulating the differentiation of rat incisor pulp-derived cells in vitro.
Design:
mRNA expression was examined by in situ hybridisation. The effects of Sema4D on rat pulp-derived cells were examined by adenovirus-mediated overexpression in vitro.
Results:
Both epithelial and mesenchymal cells of tooth germs expressed Sema4D at the early bell stage. Later, the odontoblasts predominantly expressed Sema4D, while the epithelial expression greatly decreased. The overexpression of Sema4D in rat incisor pulp-derived cells strongly inhibited mineralisation. This inhibition was preceded by a reduction of collagen fibre production at the level of mRNA synthesis.
Conclusions:
These results indicate that Sema4D is expressed in both epithelial and mesenchymal cells of the tooth germs. Sema4D represses collagen synthesis of pulp-derived cells, indicating it might negatively regulate odontoblast differentiation.

