Original Paper

Histochemistry and Cell Biology

, Volume 134, Issue 3, pp 227-241

First online:

Mapping of BrdU label-retaining dental pulp cells in growing teeth and their regenerative capacity after injuries

  • Yuko IshikawaAffiliated withDivision of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental SciencesDivision of Oral Science for Health Promotion, Department of Oral Health and Welfare, Niigata University Graduate School of Medical and Dental Sciences
  • , Hiroko Ida-YonemochiAffiliated withDivision of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences
  • , Hironobu SuzukiAffiliated withDivision of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences
  • , Kuniko Nakakura-OhshimaAffiliated withPediatric Dentistry, Niigata University Medical and Dental Hospital
  • , Han-Sung JungAffiliated withDivision of Anatomy and Developmental Biology, Department of Oral Biology, Research Center for Orofacial Hard Tissue Regeneration, Oral Science Research Center, College of Dentistry, Brain Korea 21 Project for Medical Science, Yonsei University
  • , Masaki J. HondaAffiliated withDepartment of Anatomy, Nihon University School of Dentistry
  • , Yumiko IshiiAffiliated withFACS Core Laboratory, Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo
  • , Nobukazu WatanabeAffiliated withLaboratory of Diagnostic Medicine, Center for Stem Cell Biology and Regenerative Medicine, The Institute of Medical Science, The University of Tokyo
  • , Hayato OhshimaAffiliated withDivision of Anatomy and Cell Biology of the Hard Tissue, Department of Tissue Regeneration and Reconstruction, Niigata University Graduate School of Medical and Dental Sciences Email author 

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access

Abstract

Recent studies have demonstrated that human dental pulp contains adult stem cells. A pulse of the thymidine analog BrdU given to young animals at the optimal time could clarify where slow-cycling long-term label-retaining cells (LRCs), putative adult stem cells, reside in the pulp tissue. This study focuses on the mapping of LRCs in growing teeth and their regenerative capacity after tooth injuries. Two to seven peritoneal injections of BrdU into pregnant Wistar rats revealed slow-cycling long-term dense LRCs in the mature tissues of born animals. Numerous dense LRCs were postnatally decreased in number and reached a plateau at 4 weeks after birth when they mainly resided in the center of the dental pulp, associating with blood vessels. Mature dental pulp cells were stained with Hoechst 33342 and sorted into (<0.76%) side population cells using FACS, which included dense LRCs. Some dense LRCs co-expressed mesenchymal stem cell markers such as STRO-1 or CD146. Tooth injuries caused degeneration of the odontoblast layer, and newly differentiated odontoblast-like cells contained LRCs. Thus, dense LRCs in mature pulp tissues were supposed to be dental pulp stem cells possessing regenerative capacity for forming newly differentiated odontoblast-like cells. The present study proposes the new hypothesis that both granular and dense LRCs are equipped in the dental pulp and that the dense LRCs with proliferative capacity play crucial roles in the pulpal healing process following exogenous stimuli in cooperation with the granular LRCs.

Keywords

Dental cavity preparation Tooth replantation Cell proliferation Cell differentiation Rats (Wistar)