[Primary culture and identification of mouse odontoblast-like cells].

PURPOSE: To culture primary mouse odontoblast and to provide a base for study on inducing ES cells to odontoblast. METHODS: Lower incisor germs were removed from 1-week-old mouse. The dental papillae were isolated in microscope, and the dental papillae cells were dispersed using 0.25% collagenase and 0.25% trypsin. The cell clones, which had similar morphology to odontoblasts, were selected for further culturing. The primary cultured cells were identified by light and electron microscopes and mRNA expression of mouse dentin sialophoprotein. RESULTS: The cultured cells had the same morphology and ultrastructure. They were rich in Golgi's complex, ribosome and rough endoplasmic reticulum. These cells expressed DSPP at mRNA levels. CONCLUSION: The cultured cells were mouse odontoblast-like cells. The method could be used for the study of odontal cells in vitro.

[Induction of mouse embryonic stem cells forming odontoblast-like cells by co-culture with pulp fibroblast].

PURPOSE: To investigate the methods of induction of mouse embryonic stem cells to differentiate into odontoblast-like cells by co-culture with pulp fibroblast. METHODS: By suspension culture, embryonic stem cells were induced to form embryoid bodies. Then the cells from embryoid bodies were co-cultured with pulp fibroblast in Transwell system for differentiation toward odontoblast-like cells. RESULTS: By RT-PCR analysis, embryoid body cells gave rise to the cell population expressing DSPP, a specific odontoblast cell marker, after 10 days of co-culture with pulp fibroblast and the expression of DSPP was enhanced after 15 days of co-culture. On the other hand, the expression of DSPP was not detected in the isolately cultured embryoid body cells. CONCLUSIONS: Embryonic stem cells can be induced into odontoblast-like cells by co-culture with pulp fibroblast. Supported by Science and Technology Development Fund of Shanghai Municipality (Grant No. 03ZR14027).