研究者詳細 - 秋山　謙太郎

Bone Regeneration Potential of Stem Cells Derived from Periodontal Ligament or Gingival Tissue Sources Encapsulated in RGD-Modified Alginate Scaffold 査読

Alireza Moshaverinia, Chider Chen, Xingtian Xu, Kentaro Akiyama, Sahar Ansari, Homayoun H. Zadeh, Songtao Shi

TISSUE ENGINEERING PART A 20 ( 3-4 ) 611 - 621 2014年2月

上顎洞底挙上術における大腸菌由来BMP-2/β-TCP複合体の有効性の検討

笈田育尚, 園山亘, 大野充昭, 新川重彦, 秋山謙太郎, 中島隆, 前川賢治, 窪木拓男

日本補綴歯科学会誌 6 ( 1 ) E5 - E5 2014年1月

Efficient bone formation in a swine socket lift model using Escherichia coli-derived recombinant human bone morphogenetic protein-2 adsorbed in β-tricalcium phosphate. 査読

Ono M, Sonoyama W, Yamamoto K, Oida Y, Akiyama K, Shinkawa S, Nakajima R, Pham HT, Hara ES, Kuboki T

Cells, tissues, organs 199 ( 4 ) 249 - 255 2014年

抜歯窩から採取した未分化間葉系幹細胞

Journal of Dental Research 93 ( 11 ) 1133 - 1140 2014年

Immunotherapy in Transplantation 査読

Kentaro Akiyama, Emilio Hara Satoshi, Takuo Kuboki

Stem Cell Biology and Tissue Engineering in Dental Sciences 831 2014年

Dental mesenchymal stem cells encapsulated in an alginate hydrogel co-delivery microencapsulation system for cartilage regeneration 査読

Alireza Moshaverinia, Xingtian Xu, Chider Chen, Kentaro Akiyama, Malcolm L. Snead, Songtao Shi

ACTA BIOMATERIALIA 9 ( 12 ) 9343 - 9350 2013年12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 SCI LTD

Dental-derived mesenchymal stem cells (MSCs) are promising candidates for cartilage regeneration, with a high capacity for chondrogenic differentiation. This property helps make dental MSCs an advantageous therapeutic option compared to current treatment modalities. The MSC delivery vehicle is the principal determinant for the success of MSC-mediated cartilage regeneration therapies. The objectives of this study were to: (1) develop a novel co-delivery system based on TGF-beta 1 loaded RGD-coupled alginate microspheres encapsulating periodontal ligament stem cells (PDLSCs) or gingival mesenchymal stem cells (GMSCs); and (2) investigate dental MSC viability and chondrogenic differentiation in alginate microspheres. The results revealed the sustained release of TGF-beta 1 from the alginate microspheres. After 4 weeks of chondrogenic differentiation in vitro, PDLSCs and GMSCs as well as human bone marrow mesenchymal stem cells (hBMMSCs) (as positive control) revealed chondrogenic gene expression markers (Col II and Sox-9) via qPCR, as well as matrix positively stained by Toluidine Blue and Safranin-O. In animal studies, ectopic cartilage tissue regeneration was observed inside and around the transplanted microspheres, confirmed by histochemical and immunofluorescent staining. Interestingly, PDLSCs showed more chondrogenesis than GMSCs and hBMMSCs (p < 0.05). Taken together, these results suggest that RGD-modified alginate microencapsulating dental MSCs make a promising candidate for cartilage regeneration. Our results highlight the vital role played by the microenvironment, as well as value of presenting inductive signals for viability and differentiation of MSCs. (C) 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.actbio.2013.07.023

Ossifying fibroma tumor stem cells are maintained by epigenetic regulation of a TSP1/TGF-β/SMAD3 autocrine loop. 査読国際誌

Qin H, Qu C, Yamaza T, Yang R, Lin X, Duan XY, Akiyama K, Liu Y, Zhang Q, Chen C, Chen Y, Qi HH, Feng XH, Le AD, Shi S

Cell stem cell 13 ( 5 ) 577 - 589 2013年11月

Encapsulated dental-derived mesenchymal stem cells in an injectable and biodegradable scaffold for applications in bone tissue engineering 査読

Alireza Moshaverinia, Chider Chen, Kentaro Akiyama, Xingtian Xu, Winston W. L. Chee, Scott R. Schricker, Songtao Shi

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A 101 ( 11 ) 3285 - 3294 2013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：WILEY-BLACKWELL

Bone grafts are currently the major family of treatment options in modern reconstructive dentistry. As an alternative, stem cell-scaffold constructs seem to hold promise for bone tissue engineering. However, the feasibility of encapsulating dental-derived mesenchymal stem cells in scaffold biomaterials such as alginate hydrogel remains to be tested. The objectives of this study were, therefore, to: (1) develop an injectable scaffold based on oxidized alginate microbeads encapsulating periodontal ligament stem cells (PDLSCs) and gingival mesenchymal stem cells (GMSCs); and (2) investigate the cell viability and osteogenic differentiation of the stem cells in the microbeads both in vitro and in vivo. Microbeads with diameters of 1 +/- 0.1 mm were fabricated with 2 x 10(6) stem cells/mL of alginate. Microbeads containing PDLSCs, GMSCs, and human bone marrow mesenchymal stem cells as a positive control were implanted subcutaneously and ectopic bone formation was analyzed by micro CT and histological analysis at 8-weeks postimplantation. The encapsulated stem cells remained viable after 4 weeks of culturing in osteo-differentiating induction medium. Scanning electron microscopy and X-ray diffraction results confirmed that apatitic mineral was deposited by the stem cells. In vivo, ectopic mineralization was observed inside and around the implanted microbeads containing the immobilized stem cells. These findings demonstrate for the first time that immobilization of PDLSCs and GMSCs in alginate microbeads provides a promising strategy for bone tissue engineering. (c) 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 101A: 3285-3294, 2013.

DOI： 10.1002/jbm.a.34546

Mesenchymal stem cells inhibit multiple myeloma cells via the Fas/Fas ligand pathway 査読

Ikiru Atsuta, Shiyu Liu, Yasuo Miura, Kentaro Akiyama, Chider Chen, Ying An, Songtao Shi, Fa-Ming Chen

STEM CELL RESEARCH & THERAPY 4 ( 5 ) 111 2013年9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: Cell-based therapy represents a new frontier in the treatment of a wide variety of human diseases traditionally associated with morbidity outcomes, including those involving inflammation, autoimmunity, tissue damage, and cancer. However, the use of mesenchymal stem cells (MSCs) to treat multiple myeloma (MM) bone disease has raised concerns. Specifically, evidence has shown that infused MSCs might support tumor growth and metastasis.
Methods: In this study, we used a standard disseminated MM model in mice to identify the in vivo effects of intravenous MSC infusion. In addition, a series of in vitro co-culture assays were preformed to explore whether Fas/Fas ligand (Fas-L) is involved in the inhibitory effects of MSCs on MM cells.
Results: In the MM mouse model, treatment of MSCs with highly expressed Fas ligand (Fas-Lhigh MSCs) showed remarkable inhibitory effects on MM indenization in terms of extending the mouse survival rate and inhibiting tumor growth, bone resorption in the lumbus and collum femoris, and MM cell metastasis in the lungs and kidneys. In addition, reduced proliferation and increased apoptosis of MM cells was observed when co-cultured with Fas-Lhigh MSCs in vitro. Furthermore, mechanistically, the binding between Fas and Fas-L significantly induced apoptosis in MM cells, as evidenced through an increase in the expression of apoptosis marker and Fas in MM cells. In contrast, Fas-Lnull MSCs promote MM growth.
Conclusions: These data suggest that Fas/Fas-L-induced MM apoptosis plays a crucial role in the MSC-based inhibition of MM growth. Although whether MSCs inhibit or promote cancer growth remains controversial, the levels of Fas-L expression in MSCs determine, at least partially, the effects of MSCs on MM cell growth.

DOI： 10.1186/scrt322

Co-encapsulation of anti-BMP2 monoclonal antibody and mesenchymal stem cells in alginate microspheres for bone tissue engineering 査読

Alireza Moshaverinia, Sahar Ansari, Chider Chen, Xingtian Xu, Kentaro Akiyama, Malcolm L. Snead, Homayoun H. Zadeh, Songtao Shi

BIOMATERIALS 34 ( 28 ) 6572 - 6579 2013年9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 SCI LTD

Recently, it has been shown that tethered anti-BMP2 monoclonal antibodies (mAbs) can trap BMP ligands and thus provide BMP inductive signals for osteo-differentiation of progenitor cells. The objectives of this study were to: (1) develop a co-delivery system based on murine anti-BMP2 mAb-loaded alginate microspheres encapsulating human bone marrow mesenchymal stem cells (hBMMSCs); and (2) investigate osteogenic differentiation of encapsulated stem cells in alginate microspheres in vitro and in vivo. Alginate microspheres of 1 +/- 0.1 mm diameter were fabricated with 2 x 10(6) hBMMSCs per mL of alginate. Critical-size calvarial defects (5 mm diameter) were created in immune-compromised mice and alginate microspheres preloaded with anti-BMP mAb encapsulating hBMMSCs were transplanted into defect sites. Alginate microspheres pre-loaded with isotype-matched non-specific antibody were used as the negative control. After 8 weeks, micro CT and histologic analyses were used to analyze bone formation. In vitro analysis demonstrated that anti-BMP2 mAbs tethered BMP2 ligands that can activate the BMP receptors on hBMMSCs. The co-delivery system described herein, significantly enhanced hBMMSC-mediated osteogenesis, as confirmed by the presence of BMP signal pathway-activated osteoblast determinants Runx2 and ALP. Our results highlight the importance of engineering the microenvironment for stem cells, and particularly the value of presenting inductive signals for osteo-differentiation of hBMMSCs by tethering BMP ligands using mAbs. This strategy of engineering the microenvironment with captured BMP signals is a promising modality for repair and regeneration of craniofacial, axial and appendicular bone defects. (C) 2013 Elsevier Ltd. All rights reserved.

DOI： 10.1016/j.biomaterials.2013.05.048

IFN-γ and TNF-α synergistically induce mesenchymal stem cell impairment and tumorigenesis via NFκB signaling. 査読

Wang L, Zhao Y, Liu Y, Akiyama K, Chen C, Qu C, Jin Y, Shi S

Stem cells (Dayton, Ohio) 31 ( 7 ) 1383 - 1395 2013年7月

Immune therapeutic potential of stem cells from human supernumerary teeth. 査読

Makino Y, Yamaza H, Akiyama K, Ma L, Hoshino Y, Nonaka K, Terada Y, Kukita T, Shi S, Yamaza T

Journal of dental research 92 ( 7 ) 609 - 615 2013年7月

Mesenchymal progenitors residing close to the bone surface are functionally distinct from those in the central bone marrow 査読

Valerie A. Siclari, Ji Zhu, Kentaro Akiyama, Fei Liu, Xianrong Zhang, Abhishek Chandra, Hyun-Duck Nah, Songtao Shi, Ling Qin

BONE 53 ( 2 ) 575 - 586 2013年4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

Long bone is an anatomically complicated tissue with trabecular-rich metaphyses at two ends and cortical-rich diaphysis at the center. The traditional flushing method isolates only mesenchymal progenitor cells from the central region of long bones and these cells are distant from the bone surface. We propose that mesenchymal progenitors residing in endosteal bone marrow that is close to the sites of bone formation, such as trabecular bone and endosteum, behave differently from those in the central bone marrow. In this report, we separately isolated endosteal bone marrow using a unique enzymatic digestion approach and demonstrated that it contained a much higher frequency of mesenchymal progenitors than the central bone marrow. Endosteal mesenchymal progenitors express common mesenchymal stem cell markers and are capable of multi-lineage differentiation. However, we found that mesenchymal progenitors isolated from different anatomical regions of the marrow did exhibit important functional differences. Compared with their central marrow counterparts, endosteal mesenchymal progenitors have superior proliferative ability with reduced expression of cell cycle inhibitors. They showed greater immunosuppressive activity in culture and in a mouse model of inflammatory bowel disease. Aging is a major contributing factor for trabecular bone loss. We found that old mice have a dramatically decreased number of endosteal mesenchymal progenitors compared with young mice. Parathyroid hormone (PTH) treatment potently stimulates bone formation. A single PTH injection greatly increased the number of endosteal mesenchymal progenitors, particularly those located at the metaphyseal bone, but had no effect on their central counterparts. In summary, endosteal mesenchymal progenitors are more metabolically active and relevant to physiological bone formation than central mesenchymal progenitors. Hence, they represent a biologically important target for future mesenchymal stem cell studies. (C) 2012 Elsevier Inc. All rights reserved.

DOI： 10.1016/j.bone.2012.12.013

A subset of IL-17(+) mesenchymal stem cells possesses anti-Candida albicans effect 査読

Ruili Yang, Yi Liu, Peyman Kelk, Cunye Qu, Kentaro Akiyama, Chider Chen, Ikiru Atsuta, WanJun Chen, Yanheng Zhou, Songtao Shi

CELL RESEARCH 23 ( 1 ) 107 - 121 2013年1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：INST BIOCHEMISTRY & CELL BIOLOGY

Bone marrow mesenchymal stem cells (MSCs) comprise a heterogeneous population of postnatal progenitor cells with profound immunomodulatory properties, such as upregulation of Foxp3(+) regulatory T cells (Tregs) and downregulation of Th17 cells. However, it is unknown whether different MSC subpopulations possess the same range of immunomodulatory function. Here, we show that a subset of single colony-derived MSCs producing IL-17 is different from bulk MSC population in that it cannot upregulate Tregs, downregulate Th17 cells, or ameliorate disease phenotypes in a colitis mouse model. Mechanistically, we reveal that IL-17, produced by these MSCs, activates the NF kappa B pathway to downregulate TGF-beta production in MSCs, resulting in abolishment of MSC-based immunomodulation. Furthermore, we show that NF kappa B is able to directly bind to TGF-beta promoter region to regulate TGF-beta expression in MSCs. Moreover, these IL-17(+) MSCs possess anti-Candida albicans growth effects in vitro and therapeutic effect in C. albicans-infected mice. In summary, this study shows that MSCs contain an IL-17(+) subset capable of inhibiting C. albicans growth, but attenuating MSC-based immunosuppression via NF kappa B-mediated downregulation of TGF-beta.

DOI： 10.1038/cr.2012.179

Alginate hydrogel as a promising scaffold for dental-derived stem cells: an in vitro study 査読

Alireza Moshaverinia, Chider Chen, Kentaro Akiyama, Sahar Ansari, Xingtian Xu, Winston W. Chee, Scott R. Schricker, Songtao Shi

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE 23 ( 12 ) 3041 - 3051 2012年12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：SPRINGER

The objectives of this study were to: (1) develop an injectable and biodegradable scaffold based on oxidized alginate microbeads encapsulating periodontal ligament (PDLSCs) and gingival mesenchymal stem cells (GMSCs); and (2) investigate the stem cell viability, and osteogenic differentiation of the stem cells in vitro. Stem cells were encapsulated using alginate hydrogel. The stem cell viability, proliferation and differentiation to adipogenic and osteogenic tissues were studied. To investigate the expression of both adipogenesis and ontogenesis related genes, the RNA was extracted and RT-PCR was performed. The degradation behavior of hydrogel based on oxidized sodium alginate with different degrees of oxidation was studied in PBS at 37 A degrees C as a function of time by monitoring the changes in weight loss. The swelling kinetics of alginate hydrogel was also investigated. The results showed that alginate is a promising candidate as a non-toxic scaffold for PDLSCs and GMSCs. It also has the ability to direct the differentiation of these stem cells to osteogenic and adipogenic tissues as compared to the control group in vitro. The encapsulated stem cells remained viable in vitro and both osteo-differentiated and adipo-differentiated after 4 weeks of culturing in the induction media. It was found that the degradation profile and swelling kinetics of alginate hydrogel strongly depends on the degree of oxidation showing its tunable chemistry and degradation rate. These findings demonstrate for the first time that immobilization of PDLSCs and GMSCs in the alginate microspheres provides a promising strategy for bone tissue engineering.

DOI： 10.1007/s10856-012-4759-3

Cryopreserved Dental Pulp Tissues of Exfoliated Deciduous Teeth Is a Feasible Stem Cell Resource for Regenerative Medicine 査読

Lan Ma, Yusuke Makino, Haruyoshi Yamaza, Kentaro Akiyama, Yoshihiro Hoshino, Guangtai Song, Toshio Kukita, Kazuaki Nonaka, Songtao Shi, Takayoshi Yamaza

PLOS ONE 7 ( 12 ) e51777 2012年12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

Human exfoliated deciduous teeth have been considered to be a promising source for regenerative therapy because they contain unique postnatal stem cells from human exfoliated deciduous teeth (SHED) with self-renewal capacity, multipotency and immunomodulatory function. However preservation technique of deciduous teeth has not been developed. This study aimed to evaluate that cryopreserved dental pulp tissues of human exfoliated deciduous teeth is a retrievable and practical SHED source for cell-based therapy. SHED isolated from the cryopreserved deciduous pulp tissues for over 2 years (25-30 months) (SHED-Cryo) owned similar stem cell properties including clonogenicity, self-renew, stem cell marker expression, multipotency, in vivo tissue regenerative capacity and in vitro immunomodulatory function to SHED isolated from the fresh tissues (SHED-Fresh). To examine the therapeutic efficacy of SHED-Cryo on immune diseases, SHED-Cryo were intravenously transplanted into systemic lupus erythematosus (SLE) model MRL/lpr mice. Systemic SHED-Cryo-transplantation improved SLE-like disorders including short lifespan, elevated autoantibody levels and nephritis-like renal dysfunction. SHED-Cryo amended increased interleukin 17-secreting helper T cells in MRL/lpr mice systemically and locally. SHED-Cryo-transplantation was also able to recover osteoporosis bone reduction in long bones of MRL/lpr mice. Furthermore, SHED-Cryo-mediated tissue engineering induced bone regeneration in critical calvarial bone-defect sites of immunocompromised mice. The therapeutic efficacy of SHED-Cryo transplantation on immune and skeletal disorders was similar to that of SHED-Fresh. These data suggest that cryopreservation of dental pulp tissues of deciduous teeth provide a suitable and desirable approach for stem cell-based immune therapy and tissue engineering in regenerative medicine. Citation: Ma L, Makino Y, Yamaza H, Akiyama K, Hoshino Y, et al. (2012) Cryopreserved Dental Pulp Tissues of Exfoliated Deciduous Teeth Is a Feasible Stem Cell Resource for Regenerative Medicine. PLoS ONE 7(12): e51777. doi:10.1371/journal.pone.0051777

DOI： 10.1371/journal.pone.0051777

Technetium-99 Conjugated with Methylene Diphosphonate Ameliorates Ovariectomy-Induced Osteoporotic Phenotype without Causing Osteonecrosis in the Jaw 査読

Yinghua Zhao, Lei Wang, Yi Liu, Kentaro Akiyama, Chider Chen, Ikiru Atsuta, Tao Zhou, Xiaohong Duan, Yan Jin, Songtao Shi

CALCIFIED TISSUE INTERNATIONAL 91 ( 6 ) 400 - 408 2012年12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：SPRINGER

Technetium-99 conjugated with methylene diphosphonate (Tc-99-MDP) is a novel bisphosphonate derivative without radioactivity and has been successfully used to treat arthritis in China for years. Since bisphosphonate therapy has the potential to induce bisphosphonate-related osteonecrosis of the jaw (BRONJ), we examined whether Tc-99-MDP represents a new class of bisphosphonate for antiresorptive therapy to ameliorate estrogen deficiency-induced bone resorption with less risk of causing BRONJ. We showed that Tc-99-MDP-treated, ovariectomized (OVX) mice had significantly improved bone mineral density and trabecular bone volume in comparison to the untreated OVX group by inhibiting osteoclasts and enhancing osteogenic differentiation of bone marrow mesenchymal stem cells. To determine the potential of inducing BRONJ, Tc-99-MDP/dexamethasone (Dex) or zoledronate/Dex was administered into C57BL/6J mice via the tail vein, followed by extraction of maxillary first molars. Interestingly, Tc-99-MDP treatment showed less risk to induce osteonecrosis in the maxillary bones compared to zoledronate treatment group, partially because Tc-99-MDP neither suppressed adaptive regulatory T cells nor activated the inflammatory T-helper-producing interleukin-17 cells. Taken together, our findings demonstrate that Tc-99-MDP therapy may be a promising approach in the treatment of osteoporosis with less risk of causing BRONJ.

DOI： 10.1007/s00223-012-9649-7