Odontoblast expression of semaphorin 7A during innervation of human dentin

• Published in: Matrix biology Vol. 24; no. 3; pp. 232 - 238
• Main Authors: Maurin, Jean-Christophe, Delorme, Guillaume, Machuca-Gayet, Irma, Couble, Marie-Lise, Magloire, Henry, Jurdic, Pierre, Bleicher, Françoise
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 01.05.2005
• Subjects: Adolescent; Animals; Animals, Newborn - metabolism; Antigens, CD - genetics; Antigens, CD - metabolism; Axonal growth; Cells, Cultured; Cercopithecus aethiops; Coculture Techniques; COS Cells - metabolism; Dental Pulp - cytology; Dental Pulp - innervation; Dentin - innervation; Embryo, Mammalian - metabolism; GPI-Linked Proteins; Human tooth pulp; Humans; Integrin beta1 - metabolism; Nerve Fibers - metabolism; Nerve Fibers - physiology; Nerve Fibers - ultrastructure; Nervous System - growth & development; Nervous System - metabolism; Nervous System - ultrastructure; Neurites - physiology; Odontoblasts; Odontoblasts - metabolism; Rats; Rats, Sprague-Dawley; Semaphorin 7A; Semaphorins - genetics; Semaphorins - metabolism; Tissue Distribution; Transfection; Trigeminal ganglion; Trigeminal Ganglion - cytology; Trigeminal Ganglion - physiology; β1-integrin; Human tooth pulp; β1-integrin; Semaphorin 7A; Axonal growth; Odontoblasts; Trigeminal ganglion
• ISSN: 0945-053X; 1569-1802
• DOI: 10.1016/j.matbio.2005.03.005

Semaphorin 7A (SEMA 7A) is a membrane-anchored member of the semaphorin family of guidance proteins, previously identified in the immune system. Expressed in central and peripheral nervous system during embryonic and post-natal stages, it can mediate neuronal functions by promoting axonal growth. We show here that SEMA 7A is expressed in human odontoblasts in vivo and in vitro and that its expression is correlated with the establishment of dentin–pulp complex terminal innervation . Co-cultures of trigeminal ganglion (TG) with COS cells overexpressing SEMA 7A demonstrate that SEMA 7A can promote the growth of trigeminal nerve fibers. Finally, by RT-PCR and immunochemistry, we show that β1-integrin, a SEMA 7A putative receptor, is expressed in pulpal nerve fibers but we failed to detect a co-localization between nerves and odontoblasts through these molecules. On the basis of these data, we suggest that SEMA 7A might be a molecule involved in the terminal innervation of the dentin–pulp complex.