研究者詳細 - 秋山　謙太郎

Stem cells in dentistry - Part II: Clinical applications 査読

Hiroshi Egusa, Wataru Sonoyama, Masahiro Nishimura, Ikiru Atsuta, Kentaro Akiyama

JOURNAL OF PROSTHODONTIC RESEARCH 56 ( 4 ) 229 - 248 2012年10月

記述言語：英語出版者・発行元：ELSEVIER IRELAND LTD

New technologies that facilitate solid alveolar ridge augmentation are receiving considerable attention in the field of prosthodontics because of the growing requirement for esthetic and functional reconstruction by dental implant treatments. Recently, several studies have demonstrated potential advantages for stem-cell-based therapies in regenerative treatments. Mesenchymal stem/stromal cells (MSCs) are now an excellent candidate for tissue replacement therapies, and tissue engineering approaches and chair-side cellular grafting approaches using autologous MSCs represent the clinical state of the art for stem-cell-based alveolar bone regeneration. Basic studies have revealed that crosstalk between implanted donor cells and recipient immune cells plays a key role in determining clinical success that may involve the recently observed immunomodulatory properties of MSCs. Part II of this review first overviews progress in regenerative dentistry to consider the implications of the stem cell technology in dentistry and then highlights cutting-edge stem-cell-based alveolar bone regenerative therapies. Factors that affect stem-cell-based bone regeneration as related to the local immune response are then discussed. Additionally, pre-clinical stem cell studies for the regeneration of teeth and other oral organs as well as possible applications of MSC-based immunotherapy in dentistry are outlined. Finally, the marketing of stem cell technology in dental stem cell banks with a view toward future regenerative therapies is introduced. (C) 2012 Japan Prosthodontic Society. Published by Elsevier Ireland. All rights reserved.

DOI： 10.1016/j.jpor.2012.10.001

Stem cells in dentistry - Part I: Stem cell sources 査読

Hiroshi Egusa, Wataru Sonoyama, Masahiro Nishimura, Ikiru Atsuta, Kentaro Akiyama

JOURNAL OF PROSTHODONTIC RESEARCH 56 ( 3 ) 151 - 165 2012年7月

記述言語：英語出版者・発行元：ELSEVIER IRELAND LTD

Stem cells can self-renew and produce different cell types, thus providing new strategies to regenerate missing tissues and treat diseases. In the field of dentistry, adult mesenchymal stem/stromal cells (MSCs) have been identified in several oral and maxillofacial tissues, which suggests that the oral tissues are a rich source of stem cells, and oral stem and mucosal cells are expected to provide an ideal source for genetically reprogrammed cells such as induced pluripotent stem (iPS) cells. Furthermore, oral tissues are expected to be not only a source but also a therapeutic target for stem cells, as stem cell and tissue engineering therapies in dentistry continue to attract increasing clinical interest. Part I of this review outlines various types of intra-and extra-oral tissue-derived stem cells with regard to clinical availability and applications in dentistry. Additionally, appropriate sources of stem cells for regenerative dentistry are discussed with regard to differentiation capacity, accessibility and possible immunomodulatory properties. (C) 2012 Japan Prosthodontic Society. Published by Elsevier Ireland. All rights reserved.

DOI： 10.1016/j.jpor.2012.06.001

間葉系幹細胞治療におけるFas/Fas Ligandを介したT細胞アポトーシス誘導

秋山謙太郎, 窪木拓男, シー・ソンタオ

日本骨代謝学会学術集会プログラム抄録集 30回 246 - 246 2012年7月

Mesenchymal-Stem-Cell-Induced Immunoregulation Involves FAS-Ligand-/FAS-Mediated T Cell Apoptosis 査読

Kentaro Akiyama, Chider Chen, DanDan Wang, Xingtian Xu, Cunye Qu, Takayoshi Yamaza, Tao Cai, WanJun Chen, Lingyun Sun, Songtao Shi

CELL STEM CELL 10 ( 5 ) 544 - 555 2012年5月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：CELL PRESS

Systemic infusion of bone marrow mesenchymal stem cells (BMMSCs) yields therapeutic benefit for a variety of autoimmune diseases, but the underlying mechanisms are poorly understood. Here we show that in mice systemic infusion of BMMSCs induced transient T cell apoptosis via the FAS ligand (FASL)dependent FAS pathway and could ameliorate disease phenotypes in fibrillin-1 mutated systemic sclerosis (SS) and dextran-sulfate-sodium-induced experimental colitis. FASL(-/-) BMMSCs did not induce T cell apoptosis in recipients, and could not ameliorate SS and colitis. Mechanistic analysis revealed that FAS-regulated monocyte chemotactic protein 1 (MCP-1) secretion by BMMSCs recruited T cells for FASL-mediated apoptosis. The apoptotic T cells subsequently triggered macrophages to produce high levels of TGF beta, which in turn led to the upregulation of Ca4(+)CD25(+)Foxp3(+) regulatory T cells and, ultimately, immune tolerance. These data therefore demonstrate a previously unrecognized mechanism underlying BMMSC-based immunotherapy involving coupling via FAS/FASL to induce T cell apoptosis.

DOI： 10.1016/j.stem.2012.03.007

Double Allogenic Mesenchymal Stem Cells Transplantations Could Not Enhance Therapeutic Effect Compared with Single Transplantation in Systemic Lupus Erythematosus 査読

Dandan Wang, Kentaro Akiyama, Huayong Zhang, Takayoshi Yamaza, Xia Li, Xuebing Feng, Hong Wang, Bingzhu Hua, Bujun Liu, Huji Xu, Wanjun Chen, Songtao Shi, Lingyun Sun

CLINICAL & DEVELOPMENTAL IMMUNOLOGY 2012 273291 2012年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：HINDAWI PUBLISHING CORPORATION

The clinical trial of allogenic mesenchymal stem cells (MSCs) transplantation for refractory SLE patients has shown significant safety and efficacy profiles. However, the optimum frequency of the MSCs transplantation (MSCT) is unknown. This study was undertaken to observe whether double transplantations of MSCs is superior to single transplantation. Fifty-eight refractory SLE patients were enrolled in this study, in which 30 were randomly given single MSCT, and the other 28 were given double MSCT. Patients were followed up for rates of survival, disease remission, and relapse, as well as transplantation-related adverse events. SLE disease activity index (SLEDAI) and serologic features were evaluated. Our results showed that no remarkable differences between single and double allogenic MSCT were found in terms of disease remission and relapse, amelioration of disease activity, and serum indexes in an SLE clinical trial with more than one year followup. This study demonstrated that single MSCs transplantation at the dose of one million MSCs per kilogram of body weight was sufficient to induce disease remission for refractory SLE patients.

DOI： 10.1155/2012/273291

Lineage differentiation of mesenchymal stem cells from dental pulp, apical papilla, and periodontal ligament. 査読

Akiyama K, Chen C, Gronthos S, Shi S

Methods in molecular biology (Clifton, N.J.) 887 111 - 121 2012年

Mesenchymal stem cell-based tissue regeneration is governed by recipient T lymphocytes via IFN-γ and TNF-α. 査読

Liu Y, Wang L, Kikuiri T, Akiyama K, Chen C, Xu X, Yang R, Chen W, Wang S, Shi S

Nature medicine 17 ( 12 ) 1594 - U106 2011年12月

Signaling by FGFR2b controls the regenerative capacity of adult mouse incisors 査読

Sara Parsa, Koh-ichi Kuremoto, Kerstin Seidel, Reza Tabatabai, BreAnne MacKenzie, Takayoshi Yamaza, Kentaro Akiyama, Jonathan Branch, Chester J. Koh, Denise Al Alam, Ophir D. Klein, Saverio Bellusci

DEVELOPMENT 137 ( 22 ) 3743 - 3752 2010年11月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：COMPANY OF BIOLOGISTS LTD

Rodent incisors regenerate throughout the lifetime of the animal owing to the presence of epithelial and mesenchymal stem cells in the proximal region of the tooth. Enamel, the hardest component of the tooth, is continuously deposited by stem cell-derived ameloblasts exclusively on the labial, or outer, surface of the tooth. The epithelial stem cells that are the ameloblast progenitors reside in structures called cervical loops at the base of the incisors. Previous studies have suggested that FGF10, acting mainly through fibroblast growth factor receptor 2b (FGFR2b), is crucial for development of the epithelial stem cell population in mouse incisors. To explore the role of FGFR2b signaling during development and adult life, we used an rtTA transactivator/tetracycline promoter approach that allows inducible and reversible attenuation of FGFR2b signaling. Downregulation of FGFR2b signaling during embryonic stages led to abnormal development of the labial cervical loop and of the inner enamel epithelial layer. In addition, postnatal attenuation of signaling resulted in impaired incisor growth, characterized by failure of enamel formation and degradation of the incisors. At a cellular level, these changes were accompanied by decreased proliferation of the transit-amplifying cells that are progenitors of the ameloblasts. Upon release of the signaling blockade, the incisors resumed growth and reformed an enamel layer, demonstrating that survival of the stem cells was not compromised by transient postnatal attenuation of FGFR2b signaling. Taken together, our results demonstrate that FGFR2b signaling regulates both the establishment of the incisor stem cell niches in the embryo and the regenerative capacity of incisors in the adult.

DOI： 10.1242/dev.051672

Cell-Based Immunotherapy With Mesenchymal Stem Cells Cures Bisphosphonate-Related Osteonecrosis of the Jaw-like Disease in Mice 査読

Takashi Kikuiri, Insoo Kim, Takyoshi Yamaza, Kentaro Akiyama, Qunzhou Zhang, Yunsheng Li, Chider Chen, WanJun Chen, Songlin Wang, Anh D. Le, Songtao Shi

JOURNAL OF BONE AND MINERAL RESEARCH 25 ( 7 ) 1668 - 1679 2010年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY

Patients on high-dose bisphosphonate and immunosuppressive therapy have an increased risk of bisphosphonate-related osteonecrosis of the jaw (BRONJ); despite the disease severity, its pathophysiology remains unknown, and appropriate therapy is not established. Here we have developed a mouse model of BRONJ-like disease that recapitulates major clinical and radiographic manifestations of the human disease, including characteristic features of an open alveolar socket, exposed necrotic bone or sequestra, increased inflammatory infiltrates, osseous sclerosis, and radiopaque alveolar bone. We show that administration of zoledronate, a potent aminobisphosphonate, and dexamethasone, an immunosuppressant drug, causes BRONJ-like disease in mice in part by suppressing the adaptive regulatory T cells, Tregs, and activating the inflammatory T-helper-producing interleukin 17 cells, Th17. Most interestingly, we demonstrate that systemic infusion with mesenchymal stem cells (MSCs) prevents and cures BRONJ-like disease possibly via induction of peripheral tolerance, shown as an inhibition of Th17 and increase in Treg cells. The suppressed Tregs/Th17 ratio in zoledronate- and dexamethasone-treated mice is restored in mice undergoing salvage therapy with Tregs. These findings provide evidence of an immunity-based mechanism of BRONJ-like disease and support the rationale for in vivo immunomodulatory therapy using Tregs or MSCs to treat BRONJ. (C) 2010 American Society for Bone and Mineral Research.

DOI： 10.1002/jbmr.37

Immunomodulatory properties of stem cells from human exfoliated deciduous teeth 査読

Takayoshi Yamaza, Akiyama Kentaro, Chider Chen, Yi Liu, Yufang Shi, Stan Gronthos, Songlin Wang, Songtao Shi

STEM CELL RESEARCH & THERAPY 1 ( 1 ) 5 2010年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：BIOMED CENTRAL LTD

Introduction: Stem cells from human exfoliated deciduous teeth (SHED) have been identified as a population of postnatal stem cells capable of differentiating into osteogenic and odontogenic cells, adipogenic cells, and neural cells. Herein we have characterized mesenchymal stem cell properties of SHED in comparison to human bone marrow mesenchymal stem cells (BMMSCs).
Methods: We used in vitro stem cell analysis approaches, including flow cytometry, inductive differentiation, telomerase activity, and Western blot analysis to assess multipotent differentiation of SHED and in vivo implantation to assess tissue regeneration of SHED. In addition, we utilized systemic SHED transplantation to treat systemic lupus erythematosus (SLE)-like MRL/lpr mice.
Results: We found that SHED are capable of differentiating into osteogenic and adipogenic cells, expressing mesenchymal surface molecules (STRO-1, CD146, SSEA4, CD73, CD105, and CD166), and activating multiple signaling pathways, including TGF beta, ERK, Akt, Wnt, and PDGF. Recently, BMMSCs were shown to possess an immunomodulatory function that leads to successful therapies for immune diseases. We examined the immunomodulatory properties of SHED in comparison to BMMSCs and found that SHED had significant effects on inhibiting T helper 17 (Th17) cells in vitro. Moreover, we found that SHED transplantation is capable of effectively reversing SLE-associated disorders in MRL/lpr mice. At the cellular level, SHED transplantation elevated the ratio of regulatory T cells (Tregs) via Th17 cells.
Conclusions: These data suggest that SHED are an accessible and feasible mesenchymal stem cell source for treating immune disorders like SLE.

DOI： 10.1186/scrt5

Simvastatin Induces the Odontogenic Differentiation of Human Dental Pulp Stem Cells In Vitro and In Vivo 査読

Yosuke Okamoto, Wataru Sonoyama, Mitsuaki Ono, Kentaro Akiyama, Takuo Fujisawa, Masamitstu Oshima, Yohei Tsuchimoto, Yoshizo Matsuka, Tatsuji Yasuda, Songtao Shi, Takuo Kuboki

JOURNAL OF ENDODONTICS 35 ( 3 ) 367 - 372 2009年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ELSEVIER SCIENCE INC

Statin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, is known to promote bone formation. However, it is not clear whether statin affects the differentiation of pulp cells. This study used a cell proliferation assay, cell cycle analysis, quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and in vivo transplantation to examine the effects of simvastatin on human dental pulp stem cells (DPSCs) in vitro and in vivo. Simvastatin at 1 mu mol/L was able to significantly suppress the proliferation of DPSCs without inducing apoptosis. Quantitative RT-PCR revealed both osteocalcin and dentin sialophosphoprotein to be significantly up-regulated when DPSCs were cultured with simvastatin in comparison to bone morphogenetic protein-2 treatment. The in vivo transplantation data showed that simvastatin treatment promoted mineralized tissue formation. Taken together, these results suggest that statin might be an ideal active ingredient to accelerate the differentiation of DPSCs. (J Endod 2009;35:367-372)

DOI： 10.1016/j.joen.2008.11.024

Mesenchymal stem cell-mediated ectopic hematopoiesis alleviates aging-related phenotype in immunocompromised mice 査読

Takayoshi Yamaza, Yasuo Miura, Kentaro Akiyama, Yanming Bi, Wataru Sonoyama, Stan Gronthos, WanJun Chen, Anh Le, Songtao Shi

BLOOD 113 ( 11 ) 2595 - 2604 2009年3月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：AMER SOC HEMATOLOGY

Subcutaneous transplants of bone marrow mesenchymal stem cells (BMMSCs) are capable of generating ectopic bone and organizing functional hematopoietic marrow elements in animal models. Here we report that immunocompromised mice received subcutaneous BMMSC transplants using hydroxyapatite tricalcium phosphate as a carrier suppressed age-related degeneration in multiple organs and benefited an increase in life span extension compared with control littermates. The newly organized ectopic bone/marrow system restores active hematopoiesis via the erythropoietin receptor/signal transducer and activator of transcription 5 (Stat5) pathway. Furthermore, the BMMSC recipient mice showed elevated level of Klotho and suppression of insulin-like growth factor I signaling, which may be the mechanism contributing to the alleviation of aging-like phenotypes and prolongation of life in the treated mice. This work reveals that erythropoietin receptor/Stat5 pathway contributes to BMMSC-organized ectopic hematopoiesis, which may offer a treatment paradigm of reversing age-related degeneration of multiple organs in adult immunocompromised mice. (Blood.2009;113:2595-2604)

DOI： 10.1182/blood-2008-10-182246

Simvastatin induces the odontogenic differentiation of human dental pulp stem cells in vitro and in vivo. 査読

Yosuke Okamoto, Wataru Sonoyama, Mitsuaki Ono, Kentaro Akiyama, Takuo Fujisawa, Masamitsu Oshima, Yohei Tsuchimoto, Yoshizo Matsuka, Tatsuji Yasuda, Songtao Shi, Takuo Kuboki

Journal of Endodontics Vol.35 ( No.3 ) 367 - 372 2009年3月

記述言語：英語掲載種別：研究論文（学術雑誌）

Statin, 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitor, is known to promote bone formation. However, it is not clear whether statin affects the differentiation of pulp cells. This study used a cell proliferation assay, cell cycle analysis, quantitative reverse transcriptase polymerase chain reaction (RT-PCR) and in vivo transplantation to examine the effects of simvastatin on human dental pulp stem cells (DPSCs) in vitro and in vivo. Simvastatin at 1 mumol/L was able to significantly suppress the proliferation of DPSCs without inducing apoptosis. Quantitative RT-PCR revealed both osteocalcin and dentin sialophosphoprotein to be significantly up-regulated when DPSCs were cultured with simvastatin in comparison to bone morphogenetic protein-2 treatment. The in vivo transplantation data showed that simvastatin treatment promoted mineralized tissue formation. Taken together, these results suggest that statin might be an ideal active ingredient to accelerate the differentiation of DPSCs.

DOI： 10.1016/j.joen.2008.11.024

Mesenchymal Stem Cell Transplantation Reverses Multiorgan Dysfunction in Systemic Lupus Erythematosus Mice and Humans 査読

Lingyun Sun, Kentaro Akiyama, Huayong Zhang, Takayoshi Yamaza, Yayi Hou, Shengnan Zhao, Ting Xu, Anh Le, Songtao Shi

STEM CELLS 27 ( 6 ) 1421 - 1432 2009年

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：ALPHAMED PRESS

Systemic lupus erythematosus (SLE) is a multisystem autoimmune disease that, despite the advances in immunosuppressive medical therapies, remains potentially fatal in some patients, especially in treatment-refractory patients. Here, we reported that impairment of bone marrow mesenchymal stem cells (BMMSCs) and their associated osteoblastic niche deficiency contribute in part to the pathogenesis of SLE-like disease in MRL/lpr mice. Interestingly, allogenic BMMSC transplantation (MSCT) is capable of reconstructing the bone marrow osteoblastic niche and more effectively reverses multiorgan dysfunction when compared with medical immunosuppression with cyclophosphamide (CTX). At the cellular level, MSCT, not CTX treatment, was capable to induce osteoblastic niche reconstruction, possibly contributing to the recovery of regulatory T-cells and reestablishment of the immune homeostasis. On the basis of the promising clinical outcomes in SLE mice, we treated four CTX/glucocorticoid treatment-refractory SLE patients using allogenic MSCT and showed a stable 12-18 months disease remission in all treated patients. The patients benefited an amelioration of disease activity, improvement in serologic markers and renal function. These early evidences suggest that allogenic MSCT may be a feasible and safe salvage therapy in refractory SLE patients. STEM CELLS 2009;27:1421-1432

DOI： 10.1002/stem.68

Is aspirin treatment an appropriate intervention to osteoporosis? 査読国際誌

Shi S, Yamaza T, Akiyama K

Future rheumatology 3 ( 6 ) 499 - 502 2008年12月

Pharmacologic Stem Cell Based Intervention as a New Approach to Osteoporosis Treatment in Rodents 査読

Takayoshi Yamaza, Yasuo Miura, Yanming Bi, Yongzhong Liu, Kentaro Akiyama, Wataru Sonoyama, Voymesh Patel, Silvio Gutkind, Marian Young, Stan Gronthos, Anh Le, Cun-Yu Wang, WanJun Chen, Songtao Shi

PLOS ONE 3 ( 7 ) e2615 2008年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：PUBLIC LIBRARY SCIENCE

Background: Osteoporosis is the most prevalent skeletal disorder, characterized by a low bone mineral density (BMD) and bone structural deterioration, leading to bone fragility fractures. Accelerated bone resorption by osteoclasts has been established as a principal mechanism in osteoporosis. However, recent experimental evidences suggest that inappropriate apoptosis of osteoblasts/osteocytes accounts for, at least in part, the imbalance in bone remodeling as occurs in osteoporosis. The aim of this study is to examine whether aspirin, which has been reported as an effective drug improving bone mineral density in human epidemiology studies, regulates the balance between bone resorption and bone formation at stem cell levels.
Methods and Findings: We found that T cell-mediated bone marrow mesenchymal stem cell (BMMSC) impairment plays a crucial role in ovariectomized-induced osteoporosis. Ex vivo mechanistic studies revealed that T cell-mediated BMMSC impairment was mainly attributed to the apoptosis of BMMSCs via the Fas/Fas ligand pathway. To explore potential of using pharmacologic stem cell based intervention as an approach for osteoporosis treatment, we selected ovariectomy (OVX)-induced ostoeporosis mouse model to examine feasibility and mechanism of aspirin-mediated therapy for osteoporosis. We found that aspirin can inhibit T cell activation and Fas ligand induced BMMSC apoptosis in vitro. Further, we revealed that aspirin increases osteogenesis of BMMSCs by aiming at telomerase activity and inhibits osteoclast activity in OVX mice, leading to ameliorating bone density.
Conclusion: Our findings have revealed a novel osteoporosis mechanism in which activated T cells induce BMMSC apoptosis via Fas/Fas ligand pathway and suggested that pharmacologic stem cell based intervention by aspirin may be a new alternative in osteoporosis treatment including activated osteoblasts and inhibited osteoclasts.

DOI： 10.1371/journal.pone.0002615

SHED repair critical-size calvarial defects in mice 査読

B. M. Seo, W. Sonoyama, T. Yamaza, C. Coppe, T. Kikuiri, K. Akiyama, J. S. Lee, S. Shi

ORAL DISEASES 14 ( 5 ) 428 - 434 2008年7月

記述言語：英語掲載種別：研究論文（学術雑誌）出版者・発行元：WILEY-BLACKWELL

OBJECTIVE: Stem cells from human exfoliated deciduous teeth (SHED) are a population of highly proliferative postnatal stem cells capable of differentiating into odontoblasts, adipocytes, neural cells, and osteo-inductive cells. To examine whether SHED-mediated bone regeneration can be utilized for therapeutic purposes, we used SHED to repair critical-size calvarial defects in immunocompromised mice.
MATERIALS AND METHODS: We generated calvarial defects and transplanted SHED with hydroxyapatite/tricalcium phosphate as a carrier into the defect areas.
RESULTS: SHED were able to repair the defects with substantial bone formation. Interestingly, SHED-mediated osteogenesis failed to recruit hematopoietic marrow elements that are commonly seen in bone marrow mesenchymal stem cell-generated bone. Furthermore, SHED were found to co-express mesenchymal stem cell marker, CC9/MUC18/CD146, with an array of growth factor receptors such as transforming growth factor beta receptor I and II, fibroblast growth factor receptor I and III, and vascular endothelial growth factor receptor I, implying their comprehensive differentiation potential.
CONCLUSIONS: Our data indicate that SHED, derived from neural crest cells, may select unique mechanisms to exert osteogenesis. SHED might be a suitable resource for orofacial bone regeneration.

DOI： 10.1111/j.1601-0825.2007.01396.x