Regeneration of Dental Pulp After Pulpotomy by Transplantation of CD31^-/CD146^- Side Population Cells from a Canine Tooth

Abstract

Aim: To achieve complete regeneration of dental pulp in vivo by stem/progenitor cells obtained from a fraction of side population (SP) cells from canine pulp. Materials & methods: A subfraction of SP cells, CD31^-/CD146^- SP cells, were isolated by flow cytometry from canine dental pulp. The efficiency of this subfraction of SP cells was evaluated in an experimental model of pulp injury in the dog. Results: The fractionated SP cells formed extensive networks of tube-like structures in vitro. Transplantation of the SP cells into an in vivo model of amputated pulp resulted in complete regeneration of pulp tissue with capillaries and neuronal cells within 14 days. Gene-expression studies demonstrated the expression of pro-angiogenic factors, implying trophic action on endothelial cells. Conclusions: This investigation demonstrates the potential utility of fractionated SP cells as a source of cells for total pulp regeneration complete with angiogenesis and vasculogenesis.

KEYWORDS::

• amputated pulp
• CD31
• dental pulp stem cells
• dentinogenesis
• pulp regeneration
• side population cells

Financial & competing interests disclosure

This work was supported by grants from the Collaborative Development of Innovative Seeds, Potentiality verification stage from Japan Science and Technology Agency, a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan, #17390509 (M Nakashima), #19659499 (M Nakashima) and #19791418 (K Iohara), the Mitsubishi Pharma Research Foundation (M Nakashima), the Japan Health Foundation (M Nakashima) and Aichigakuin University High-Tech Research Center “Project for Private Universities: matching fund subsidy from MEXT (Ministry of Education, Culture, Sports, Science and Technology). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed.

No writing assistance was utilized in the production of this manuscript.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. All animal experiments were conducted using the strict guidelines of the Animal Protocol Committe, both in the National Center for Geriatrics and Gerontology and Aichigakuin University.

Additional information

Funding

This work was supported by grants from the Collaborative Development of Innovative Seeds, Potentiality verification stage from Japan Science and Technology Agency, a Grant-in-Aid for Scientific Research from the Ministry of Education, Science, Sports and Culture, Japan, #17390509 (M Nakashima), #19659499 (M Nakashima) and #19791418 (K Iohara), the Mitsubishi Pharma Research Foundation (M Nakashima), the Japan Health Foundation (M Nakashima) and Aichigakuin University High-Tech Research Center “Project for Private Universities: matching fund subsidy from MEXT (Ministry of Education, Culture, Sports, Science and Technology). The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.