In vivo administration of dental epithelial stem cells at the apical end of the mouse incisor.

Giovanna Orsini,Angelo Putignano,Despoina Natsiou,Lucia Jimenez-Rojo,Thimios A Mitsiadis

doi:10.3389/fphys.2015.00112

Giovanna Orsini, Angelo Putignano + Show 3 more

Open Access

https://doi.org/10.3389/fphys.2015.00112

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Abstract

Cell-based tissue regeneration is an attractive approach that complements traditional surgical techniques for replacement of injured and lost tissues. The continuously growing rodent incisor provides an excellent model system for investigating cellular and molecular mechanisms that underlie tooth renewal and regeneration. An active population of dental epithelial progenitor/stem cells located at the posterior part of the incisor, commonly called cervical loop area, ensures the continuous supply of cells that are responsible for the secretion of enamel matrix. To explore the potential of these epithelial cells in therapeutic approaches dealing with enamel defects, we have developed a new method for their in vivo administration in the posterior part of the incisor. Here, we provide the step-by-step protocol for the isolation of dental epithelial stem cells and their delivery at targeted areas of the jaw. This simple and yet powerful protocol, consisting in drilling a hole in the mandibular bone, in close proximity to the cervical loop area of the incisor, followed up by injection of stem cells, is feasible, reliable, and effective. This in vivo approach opens new horizons and possibilities for cellular therapies involving pathological and injured dental tissues.

Highlights

The continuously erupting rodent incisor represents a suitable model system for studying cell proliferation, migration, differentiation, and mineral matrix deposition during development, homeostasis and regeneration of organs
In vivo and in vitro cell tracing studies have shown that the cervical loops, which are located at the posterior part of the incisor, are niches for dental epithelial stem cells (DESCs) (Harada et al, 1999; Mitsiadis et al, 2007; Mitsiadis and Graf, 2009; Li et al, 2012)
To investigate the potential of DESCs in dental tissue regeneration and repair, we have applied an experimental model consisting of drilling a “window” in the alveolar bone of the mouse mandible, which overlies the apical part of the incisor

Summary

Introduction

The continuously erupting rodent incisor represents a suitable model system for studying cell proliferation, migration, differentiation, and mineral matrix deposition during development, homeostasis and regeneration of organs. Loss of dental hard tissues in rodents caused by the frequent chewing and gnawing is balanced by constant cell divisions at the apical end of the incisor, allowing de novo enamel and dentin matrix formation by newly differentiated cells. To investigate the potential of DESCs in dental tissue regeneration and repair, we have applied an experimental model consisting of drilling a “window” in the alveolar bone of the mouse mandible, which overlies the apical part of the incisor. The creation of this bone window allows the injection of the DESCs at precise areas of the jaw, without affecting the overall physiology and masticatory attitudes of the animal. We demonstrate that this technique is successful and can be efficiently used to in vivo administer DESCs that could eventually be used for the repair of damaged or pathological dental tissues

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