Award type：Award from Japanese society, conference, symposium, etc. 

Language：English   Publisher：Stem Cells and Development  

The periodontal ligament (PDL) is a fibrous connective tissue that connects the cementum of the root to the alveolar bone. PDL stem cells (PDLSCs) contained in the PDL can differentiate into cementoblasts, osteoblasts, and PDL fibroblasts, with essential roles in periodontal tissue regeneration. Therefore, PDLSCs are expected to be useful in periodontal tissue regeneration therapy. In a previous study, we differentiated induced pluripotent stem cells (iPSCs) into PDLSC-like cells (iPDLSCs), which expressed PDL-related markers and mesenchymal stem cell (MSC) markers; they also exhibited high proliferation and multipotency. However, the iPSCs used in this differentiation method were cultured on mouse embryonic fibroblasts; thus, they constituted on-feeder iPSCs (OF-iPSCs). Considering the risk of contamination with feeder cell-derived components, iPDLSCs differentiated from OF-iPSCs (ie, OF-iPDLSCs) are unsuitable for clinical applications. In this study, we aimed to obtain PDLSC-like cells from feeder-free iPSCs (FF-iPSCs) using OF-iPDLSC differentiation method. First, we differentiated FF-iPSCs into neural crest cell-like cells (FF-iNCCs) and confirmed that FF-iNCCs expressed NCC markers (eg, Nestin and p75NTR). Then, we cultured FF-iNCCs on human primary PDL cell-derived extracellular matrix for 2 weeks; the resulting cells were named FF-iPDLSCs. FF-iPDLSCs exhibited higher expression of PDL-related and MSC markers compared with OF-iPDLSCs. FF-iPDLSCs also demonstrated proliferation and multipotency in vitro. Finally, we analyzed the ability of FF-iPDLSCs to form periodontal tissue in vivo upon subcutaneous transplantation with β-tricalcium phosphate scaffolds into dorsal tissues of immunodeficient mice. Eight weeks after transplantation, FF-iPDLSCs had formed osteocalcin-positive bone/cementum-like tissues and collagen 1-positive PDL-like fibers. These results suggested that we successfully obtained PDLSC-like cells from FF-iPSCs. Our findings will contribute to the development of novel periodontal regeneration therapies.

DOI： 10.1089/scd.2024.0122

Web of Science

Scopus

PubMed

Language：English   Publisher：Biomolecules  

Deep caries and severe periodontitis cause bone resorption in periodontal tissue, and severe bone resorption leads to tooth loss. Periodontal ligament stem cells (PDLSCs) are important for the healing of defective periodontal tissue. It is increasingly understood that healing of periodontal tissue is mediated through the secretion of trophic factors, particularly exosomes. This study investigated the effects of exosomes from human PDLSCs (HPDLSCs-Exo) on human osteoblast-like cells in vitro and on the healing of rat calvarial bone defects in vivo. HPDLSCs-Exo were isolated and characterized by their particle shape, size (133 ± 6.4 nm), and expression of surface markers (CD9, CD63, and CD81). In vitro results showed that HPDLSCs-Exo promoted the migration, mineralization, and expression of bone-related genes such as alkaline phosphatase (ALP), bone morphogenetic protein 2 (BMP2), osteocalcin (OCN), and osteopontin (OPN) in human osteoblast-like cells. Furthermore, in vivo results showed that more newly formed bone was observed in the HPDLSCs-Exo-treated group than in the non-treated group at the defect sites in rats. These results indicated that HPDLSCs-Exo could promote osteogenesis in vitro and in vivo, and this suggests that HPDLSCs-Exo may be an attractive treatment tool for bone healing in defective periodontal tissue.

DOI： 10.3390/biom14111455

Web of Science

Scopus

PubMed

Language：English   Publisher：Cell Biochemistry and Function  

We aimed to evaluate the materials based on 4-methacryloxyethyl trimellitate anhydride/methyl methacrylate tri-n-butylborane (Super-bond [SB]) and nano hydroxyapatite (naHAp) for the repair of perforation at pulp chamber floor (PPF) in vitro and in vivo models. SB and naHAp were mixed in the mass ratio of 10% or 30% to produce naHAp/SB. Human periodontal ligament stem cells (HPDLSCs) were cultured on resin discs of SB or naHAp/SB to analyze the effects of naHAp/SB on cell adhesion, proliferation, and cementoblastic differentiation. A rat PPF model was treated with SB or naHAp/SB to examine the effects of naHAp/SB on the healing of defected cementum and periodontal ligament (PDL) at the site of PPF. HPDLSCs were spindle-shaped and adhered to all resin discs. Changing the resin from SB to naHAp/SB did not significantly alter cell proliferation. Both 10% and 30% naHAp/SB were more effective than SB in promoting cementoblastic differentiation of HPDLSCs. In the rat PPF model, 30% naHAp/SB was more effective than SB in promoting the formation Sharpey's fiber-like structures with expression of the PDL-related marker and cementum-like structures with expression of cementum-related markers. In conclusion, 30% naHAp/SB can be the new restorative material for PPF because it exhibited the abilities of adhering to dentin and healing of defected periodontal tissue.

DOI： 10.1002/cbf.4058

Web of Science

Scopus

PubMed

Language：English   Publisher：Stem Cells and Development  

Periodontal tissue regeneration is important for preserving teeth. Periodontal ligament stem cells (PDLSCs) are useful in periodontal tissue regeneration; however, tooth extraction is required to obtain these cells. Therefore, we focused on induced pluripotent stem (iPS) cells and established a method to obtain PDLSC-like cells from iPS cells. Specifically, we first differentiated iPS cells into neural crest-like cells (iNCs). Next, we obtained PDLSC-like cells (iPDLSCs) by culturing iNCs on extracellular matrix (ECM) derived from human primary periodontal ligament cells (HPDLCs). This differentiation method suggested that ECM derived from HPDLCs is important for iPDLSC differentiation. Thus, we aimed to identify the PDLSC-inducing factor present in HPDLC-derived ECM in this study. We first performed comprehensive analyses of HPDLC genes and identified fibrillin-2 (FBN2), an ECM-related factor. Furthermore, to clarify the effect of FBN2 on iPDLSC differentiation, we cultured iNCs using ECM derived from HPDLCs with FBN2 knocked down. As a result, expression of PDL-related markers was reduced in iNCs cultured on ECM derived from HPDLCs transfected with FBN2 siRNA (iNC-siFBN2) compared with iPDLSCs. Furthermore, the expression of CD105 (a mesenchymal stem cell marker), proliferation ability, and multipotency of iNC-siFBN2 were lower compared with iPDLSCs. Next, we cultured iNCs on FBN2 recombinant protein; however, expression of PDL-related markers did not increase compared with iPDLSC. The present results suggest the critical involvement of FBN2 in inducing iPDLSCs from iNCs when in fact it does not promote iPDLSC differantiation. Therefore, we need to elucidate the entire HPDLC-ECMs, responsible for iPDLSCs induction.

DOI： 10.1089/scd.2024.0013

Web of Science

Scopus

PubMed

Language：English   Publisher：Scientific Reports  

Conventional direct pulp-capping materials induce pulp cells to secrete various biomolecules in pulp tissues that promote reparative dentin formation through induction of odontoblastic differentiation of dental pulp stem cells (DPSCs). However, these biomolecules sometimes induce bone-like dentin with poor sealing properties. Therefore, exploration of biomolecules that allow tight sealing by tubular reparative dentin is required. We recently reported that dopamine (DA) is involved in dentinogenesis. Hence, we investigated the effect of DA on odontoblastic differentiation of DPSCs and reparative dentin formation. Both tyrosine hydroxylase (TH), a DA synthetase, and DA were expressed in odontoblast-like cells in vivo. In vitro, their expression was increased during odontoblastic differentiation of DPSCs. Furthermore, TH-overexpressing DPSCs had promoted odontoblastic differentiation and DA production. Moreover, DA stimulation promoted their differentiation and induced tubular reparative dentin. These results suggest that DA produced by TH is involved in odontoblastic differentiation of DPSCs and has an inductive capacity for reparative dentin formation similar to primary dentin. This study may lead to the development of therapy to preserve vital pulp tissues.

DOI： 10.1038/s41598-023-32126-1

Web of Science

Scopus

PubMed

Event date： 2025.6

Language：Japanese   Presentation type：Symposium, workshop panel (nominated)  

Venue：愛媛県民文化会館  

Event date： 2024.5

Language：Japanese  

Country：Japan  

Event date： 2023.8

Language：English  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan  

Event date： 2023.6

Language：Japanese  

Country：Japan