Kunimichi Niibe

Mesenchymal stem cells (MSCs) exhibit self-renewal, multi-lineage differentiation potential and immunomodulatory properties, and are promising candidates for cellular therapy of various tissues. Despite the effective function of MSCs, the gradual loss of stem cell characteristics that occurs with repeated passages may significantly limit their therapeutic potential. A novel 3D shaking method was previously established to generate MSC spheroids in growth medium (GM-spheroids) and successfully mai

Mesenchymal stromal/stem cells (MSCs), which generally expand into adherent monolayers, readily lose their proliferative and multilineage potential following repeated passages. Floating culture systems can be used to generate MSC spheroids, which are expected to overcome limitations associated with conventional adherent cultures while facilitating scaffold-free cell transplantation. However, the phenotypic characteristics of spheroids after long-term culture are unknown. In addition, regenerativ

Effective regenerative treatments for periodontal tissue defects have recently been demonstrated using mesenchymal stromal/stem cells (MSCs). Furthermore, current bioengineering techniques have enabled <i>de novo</i> fabrication of tooth-perio dental units in mice. These cutting-edge technologies are expected to address unmet needs within regenerative dentistry. However, to achieve efficient and stable treatment outcomes, preparation of an appropriate stem cell source is essential. Many research

Microenvironmental factors, including substrate stiffness, regulate stem cell behavior and differentiation. However, the effects of substrate stiffness on the behavior of induced pluripotent stem cell (iPSC)- derived embryoid bodies (EB) remain unclear. To investigate the effects of mechanical cues on iPSC-EB differentiation, a 3D hydrogel-sandwich culture (HGSC) system is developed that controls the microenvironment surrounding iPSC-EBs using a stiffness-tunable polyacrylamide hydrogel assembly

The expression of receptor activator of Nuclear Factor Kappa Beta (RANK) and its ligand (RANKL), as well as osteoprotegrin (OPG), in the alveolar bone (AB), may improve bone remodeling during orthodontic tooth movement (OTM). It is hypothesized that hypoxia-preconditioned gingival mesenchymal stem cells (GMSC) may be more effective than normoxia-preconditioned GMSC in this regard. This study aims to investigate the expression of RANK, RANKL, and OPG in the compression and tension sides of AB aft

Induced pluripotent stem cells (iPSCs) offer an unlimited source for cartilage regeneration as they can generate a wide spectrum of cell types. Here, we established a tetracycline (tet) controlled <i>bone morphogenetic protein-4</i> (<i>BMP-4</i>) expressing iPSC (iPSC-<i>Tet/BMP-4</i>) line in which transcriptional activation of <i>BMP-4</i> was associated with enhanced chondrogenesis. Moreover, we developed an efficient and simple approach for directly guiding iPSC-<i>Tet/BMP-4</i> differentia

Mesenchymal stem cells (MSCs) are defined as cells that undergo sustained in vitro growth and are able of giving rise to multiple mesenchymal lineages. Although MSCs are already used in regenerative medicine, little is known about their in vivo behavior and developmental derivation. MSCs are a heterogeneous subset of stromal stem cells isolated from many adult tissues. Previous studies have reported that MSCs can differentiate into both mesodermal and neural lineages through a phenomenon referre

Amelogenin comprises ~90% of enamel proteins; however, the involvement of <i>Amelx</i> transcriptional activation in regulating ameloblast differentiation from induced pluripotent stem cells (iPSCs) remains unknown. In this study, we generated doxycycline-inducible <i>Amelx</i>-expressing mouse iPSCs (Amelx-iPSCs). We then established a three-stage ameloblast induction strategy from Amelx-iPSCs, including induction of surface ectoderm (stage 1), dental epithelial cells (DECs; stage 2), and amelo

The transcriptional regulation of induced pluripotent stem cells (iPSCs) holds promise for their directed differentiation into ameloblasts, which are usually lost after tooth eruption. Ameloblast differentiation is regulated by multiple signaling molecules, including bone morphogenetic proteins (BMPs). Epiprofin (Epfn), a transcription factor, is expressed in the dental epithelium, and epithelial Epfn overexpression results in ectopic ameloblast differentiation and enamel formation in mouse inci

Studies on human and animal models have demonstrated a complex molecular regulatory network between the dental mesenchyme and epithelium governing tooth development. However, epigenetic regulation of tooth development is largely unexplored. This study aimed to elucidate the relationship between epigenetic modifiers and dental root development using mice deficient in histone deacetylase 3 (Hdac3) under the control of the osterix promoter (Osx-Cre/Hdac3fl/fl or Hdac3-CKOosx). We observed tooth roo

近年，歯学領域では顎骨や歯周組織，歯の再生医療を目的とした幹細胞研究が盛んに行われている．また，補綴歯科領域における幹細胞研究は再生医療にとどまらず，疾患モデルの構築や創薬研究へと発展しつつある．安定した再生医療の確立には，用いる幹細胞の発生学的な由来を考慮し，本来たどってきた発生過程を模倣した組織再生をいかに導くかが鍵と考えられている．特に歯はユニークで複雑な発生過程をたどるため，選択した細胞によってその過程を再現する方法は異なってくる．本稿では，組織再生に重要な要素の一つである「細胞」に焦点を当て，補綴歯科領域に応用可能と期待されるさまざまな幹細胞を紹介する．

症例の概要：患者は59歳男性．義歯の不安定，咀嚼困難・審美不良を主訴に紹介受診した．全顎的な咬耗による咬合高径の低下，それに起因する上下顎部分床義歯の不安定と下顎前歯の審美障害を認めた．咬合挙上後，上顎の部分床義歯を固定性補綴装置に置き換えることでアンテリアガイダンスを強固にし，生理的咬合を安定させることで，全顎的な改善を図った．