||Shoko Fujino, Sayuri Hamano, Atsushi Tomokiyo, Tomohiro Itoyama, Daigaku Hasegawa, Hideki Sugii, Shinichiro Yoshida, Ayako Washio, Aoi Nozu, Taiga Ono, Naohisa Wada, Chiaki Kitamura, Hidefumi Maeda, Expression and function of dopamine in odontoblasts, Journal of cellular physiology, 10.1002/jcp.29314, 2019.01, Dopamine (DA) is produced from tyrosine by tyrosine hydroxylase (TH). A recent study has reported that DA promotes the mineralization of murine preosteoblasts. However, the role of DA in odontoblasts has not been examined. Therefore, in this investigation, we researched the expression of TH and DA in odontoblasts and the effects of DA on the differentiation of preodontoblasts (KN-3 cells). Immunostaining showed that TH and DA were intensely expressed in odontoblasts and preodontoblasts of rat incisors and molars. KN-3 cells expressed D1-like and D2-like receptors for DA. Furthermore, DA promoted odontoblastic differentiation of KN-3 cells, whereas an antagonist of D1-like receptors and a PKA signaling blocker, inhibited such differentiation. However, antagonists of D2-like receptors promoted differentiation. These results suggested that DA in preodontoblasts and odontoblasts might promote odontoblastic differentiation through D1-like receptors, but not D2-like receptors, and PKA signaling in an autocrine or paracrine manner and plays roles in dentinogenesis..
||Aoi Nozu, Sayuri Hamano, Atsushi Tomokiyo, Daigaku Hasegawa, Hideki Sugii, Shinichiro Yoshida, Hiromi Mitarai, Shuntaro Taniguchi, Naohisa Wada, Hidefumi Maeda, Senescence and odontoblastic differentiation of dental pulp cells, Journal of cellular physiology, 10.1002/jcp.26905, 234, 1, 849-859, 2018.01, Cellular senescence has been suggested to be involved in physiological changes of cytokine production. Previous studies showed that the concentration of tumor necrosis factor-α (TNF-α) is higher in the blood of aged people compared with that of young people. So far, the precise effects of TNF-α on the odontoblastic differentiation of pulp cells have been controversial. Therefore, we aimed to clarify how this cytokine affected pulp cells during aging. Human dental pulp cells (HDPCs) were cultured until reaching the plateau of their growth, and the cells were isolated at actively (young HDPCs; yHDPCs) or inactively (senescent HDPCs; sHDPCs) proliferating stages. sHDPCs expressed senescence-related molecules while yHDPCs did not. When these HDPCs were cultured in an odontoblast-inductive medium, both young and senescent cells showed mineralization, but mineralization in sHDPCs was lower compared with yHDPCs. However, the administration of TNF-α to this culture medium altered these responses: yHDPCs showed downregulated mineralization, while sHDPCs exhibited significantly increased mineralization. Furthermore, the expression of tumor necrosis factor receptor 1 (TNFR1), a receptor of TNF-α, was significantly upregulated in sHDPCs compared with yHDPCs. Downregulation of TNFR1 expression led to decreased mineralization of TNF-α-treated sHDPCs, whereas restored the reduction in TNF-α-treated yHDPCs. These results suggested that sHDPCs preserved the odontoblastic differentiation capacity and TNF-α promoted odontoblastic differentiation of HDPCs with the progress of their population doublings through increased expression of TNFR1. Thus, TNF-α might exert a different effect on the odontoblastic differentiation of HDPCs depending on their proliferating activity. In addition, the calcification of pulp chamber with age may be related with increased reactivity of pulp cells to TNF-α..
||Atsushi Tomokiyo, Shinichiro Yoshida, Sayuri Hamano, Daigaku Hasegawa, Hideki Sugii, Hidefumi Maeda, Detection, characterization, and clinical application of mesenchymal stem cells in periodontal ligament tissue, Stem Cells International, 10.1155/2018/5450768, 2018, 2018.01, Mesenchymal stem cells (MSCs) are a kind of somatic stem cells that exert a potential to differentiate into multiple cell types and undergo robust clonal self-renewal; therefore, they are considered as a highly promising stem cell population for tissue engineering. MSCs are identified in various adult organs including dental tissues. Periodontal ligament (PDL) is a highly specialized connective tissue that surrounds the tooth root. PDL also contains MSC population, and many researchers have isolated them and performed their detailed characterization. Here, we review the current understanding of the features and functions of MSC population in PDL tissues and discuss their possibility for the application of PDL regeneration..
||Yuxing Guo, Yuan Yuan, Ling Wu, Thach Vu Ho, Junjun Jing, Hideki Sugii, Jingyuan Li, Xia Han, Jifan Feng, Chuanbin Guo, Yang Chai, BMP-IHH-mediated interplay between mesenchymal stem cells and osteoclasts supports calvarial bone homeostasis and repair, Bone Research, 10.1038/s41413-018-0031-x, 6, 1, 2018.12, Calvarial bones are connected by fibrous sutures. These sutures provide a niche environment that includes mesenchymal stem cells (MSCs), osteoblasts, and osteoclasts, which help maintain calvarial bone homeostasis and repair. Abnormal function of osteogenic cells or diminished MSCs within the cranial suture can lead to skull defects, such as craniosynostosis. Despite the important function of each of these cell types within the cranial suture, we have limited knowledge about the role that crosstalk between them may play in regulating calvarial bone homeostasis and injury repair. Here we show that suture MSCs give rise to osteoprogenitors that show active bone morphogenetic protein (BMP) signalling and depend on BMP-mediated Indian hedgehog (IHH) signalling to balance osteogenesis and osteoclastogenesis activity. IHH signalling and receptor activator of nuclear factor kappa-Β ligand (RANKL) may function synergistically to promote the differentiation and resorption activity of osteoclasts. Loss of Bmpr1a in MSCs leads to downregulation of hedgehog (Hh) signalling and diminished cranial sutures. Significantly, activation of Hh signalling partially restores suture morphology in Bmpr1a mutant mice, suggesting the functional importance of BMP-mediated Hh signalling in regulating suture tissue homeostasis. Furthermore, there is an increased number of CD200+ cells in Bmpr1a mutant mice, which may also contribute to the inhibited osteoclast activity in the sutures of mutant mice. Finally, suture MSCs require BMP-mediated Hh signalling during the repair of calvarial bone defects after injury. Collectively, our studies reveal the molecular and cellular mechanisms governing cell–cell interactions within the cranial suture that regulate calvarial bone homeostasis and repair..
||Mai Arima, Daigaku Hasegawa, Shinichiro Yoshida, Hiromi Mitarai, Atsushi Tomokiyo, Sayuri Hamano, Hideki Sugii, Naohisa Wada, Hidefumi Maeda, R-spondin 2 promotes osteoblastic differentiation of immature human periodontal ligament cells through the Wnt/β-catenin signaling pathway, Journal of Periodontal Research, 10.1111/jre.12611, 54, 2, 143-153, 2019.04, Objective: In this study, we measured the expression of R-spondin 2 (RSPO2) in periodontal ligament (PDL) tissue and cells. Further, we examined the effects of RSPO2 on osteoblastic differentiation of immature human PDL cells (HPDLCs). Background: R-spondin (RSPO) family proteins are secreted glycoproteins that play important roles in embryonic development and tissue homeostasis through activation of the Wnt/β-catenin signaling pathway. RSPO2, a member of the RSPO family, has been reported to enhance osteogenesis in mice. However, little is known regarding the roles of RSPO2 in PDL tissues. Methods: Expression of RSPO2 in rat PDL tissue and primary HPDLCs was examined by immunohistochemical and immunofluorescence staining, as well as by semiquantitative RT-PCR. The effects of stretch loading on the expression of RSPO2 and Dickkopf-related protein 1 (DKK1) were assessed by quantitative RT-PCR. Expression of receptors for RSPOs, such as Leucine-rich repeat-containing G-protein-coupled receptors (LGRs) 4, 5, and 6 in immature human PDL cells (cell line 2-14, or 2-14 cells), was investigated by semiquantitative RT-PCR. Mineralized nodule formation in 2-14 cells treated with RSPO2 under osteoblastic inductive condition was examined by Alizarin Red S and von Kossa stainings. Nuclear translocation of β-catenin and expression of active β-catenin in 2-14 cells treated with RSPO2 were assessed by immunofluorescence staining and Western blotting analysis, respectively. In addition, the effect of Dickkopf-related protein 1 (DKK1), an inhibitor of Wnt/β-catenin signaling, was also examined. Results: Rat PDL tissue and HPDLCs expressed RSPO2, and HPDLCs also expressed RSPO2, while little was found in 2-14 cells. Expression of RSPO2 as well as DKK1 in HPDLCs was significantly upregulated by exposure to stretch loading. LGR4 was predominantly expressed in 2-14 cells, which expressed low levels of LGR5 and LGR6. RSPO2 enhanced the Alizarin Red S and von Kossa-positive reactions in 2-14 cells. In addition, DKK1 suppressed nuclear translocation of β-catenin, activation of β-catenin, and increases of Alizarin Red S and von Kossa-positive reactions in 2-14 cells, all of which were induced by RSPO2 treatment. Conclusion: RSPO2, which is expressed in PDL tissue and cells, might play an important role in regulating the osteoblastic differentiation of immature human PDL cells through the Wnt/β-catenin signaling pathway..
||Hamano S, Tomokiyo A, Hasegawa D, Yoshida S, Sugii H, Mitarai H, Fujino S, Wada N, Maeda H.
, Extracellular Matrix from Periodontal Ligament Cells Could Induce the Differentiation of Induced Pluripotent Stem Cells to Periodontal Ligament Stem Cell-Like Cells., Stem cells and development, 15;27(2):100-111., 2018.01.
||Hasegawa D, Wada N, Yoshida S, Mitarai H, Arima M, Tomokiyo A, Hamano S, Sugii H, Maeda H.
, Wnt5a suppresses osteoblastic differentiation of human periodontal ligament stem cell-like cells via Ror2/JNK signaling., Journal of cellular phisiology, 233(2):1752-1762., 2018.02.
||Hideki Sugii, Hidefumi Maeda, Atsushi Tomokiyo, Naohide Yamamoto, Naohisa Wada, Katsuaki Koori, Daigaku Hasegawa, Sayuri Hamano, Asuka Yuda, Satoshi Monnouchi, Akifumi Akamine, Effects of Activin A on the phenotypic properties of human periodontal ligament cells, Bone, 10.1016/j.bone.2014.05.021, 66, 62-71, 2014.09, Periodontal ligament (PDL) tissue plays an important role in tooth preservation by structurally maintaining the connection between the tooth root and the bone. The mechanisms involved in the healing and regeneration of damaged PDL tissue, caused by bacterial infection, caries and trauma, have been explored. Accumulating evidence suggests that Activin A, a member of the transforming growth factor-β (TGF-β) superfamily and a dimer of inhibinβa, contributes to tissue healing through cell proliferation, migration, and differentiation of various target cells. In bone, Activin A has been shown to exert an inhibitory effect on osteoblast maturation and mineralization. However, there have been no reports examining the expression and function of Activin A in human PDL cells (HPDLCs). Thus, we aimed to investigate the biological effects of Activin A on HPDLCs. Activin A was observed to be localized in HPDLCs and rat PDL tissue. When PDL tissue was surgically damaged, Activin A and IL-1β expression increased and the two proteins were shown to be co-localized around the lesion. HPDLCs treated with IL-1β or TNF-α also up-regulated the expression of the gene encoding inhibinβa. Activin A promoted chemotaxis, migration and proliferation of HPDLCs, and caused an increase in fibroblastic differentiation of these cells while down-regulating their osteoblastic differentiation. These osteoblastic inhibitory effects of Activin A, however, were only noted during the early phase of HPDLC osteoblastic differentiation, with later exposures having no effect on differentiation. Collectively, our results suggest that Activin A could be used as a therapeutic agent for healing and regenerating PDL tissue in response to disease, trauma or surgical reconstruction..
||Koori K, Maeda H, Fujii S, Tomokiyo A, Kawachi G, Hasegawa D, Hamano S, Sugii H, Wada N, Akamine A
, The roles of calcium-sensing receptor and calcium channel in osteogenic differentiation of undifferentiated periodontal ligament cells., Cell and Tissue Reserch, 357(3):707-18., 2014.09.
||Teramatsu Y, Maeda H, Sugii H, Tomokiyo A, Hamano S, Wada N, Yuda A, Yamamoto N, Koori K, Akamine A, Expression and effects of epidermal growth factor on human periodontal ligament cells., Cell and Tissue Research, 357(3):633-43, 2014.09.
||Mizumachi H, Yoshida S, Tomokiyo A, Hasegawa D, Hamano S, Yuda A, Sugii H, Serita S, Mitarai H, Koori K, Wada N, Maeda H.
, Calcium-sensing receptor-ERK signaling promotes odontoblastic differentiation of human dental pulp cells., Bone, 101:191-201., 2017.08.
||Hideki Sugii, Alexandre Grimaldi, Jingyuan Li, Carolina Parada, Thach Vu-Ho, Jifan Feng, Junjun Jing, Yuan Yuan, Yuxing Guo, Hidefumi Maeda, Yang Chai, The DLx5-FGF10 signaling cascade controls cranial neural crest and myoblast interaction during oropharyngeal patterning and development, Development (Cambridge), 10.1242/dev.155176, 144, 21, 4037-4045, 2017.11, Craniofacial development depends on cell-cell interactions, coordinated cellular movement and differentiation under the control of regulatory gene networks, which include the distal-less (Dlx) gene family. However, the functional significance of Dlx5 in patterning the oropharyngeal region has remained unknown. Here, we show that loss of Dlx5 leads to a shortened soft palate and an absence of the levator veli palatini, palatopharyngeus and palatoglossus muscles that are derived from the 4th pharyngeal arch (PA); however, the tensor veli palatini, derived from the 1st PA, is unaffected. Dlx5-positive cranial neural crest (CNC) cells are in direct contact with myoblasts derived from the pharyngeal mesoderm, and Dlx5 disruption leads to altered proliferation and apoptosis of CNC and muscle progenitor cells. Moreover, the FGF10 pathway is downregulated in Dlx5−/− mice, and activation of FGF10 signaling rescues CNC cell proliferation and myogenic differentiation in these mutant mice. Collectively, our results indicate that Dlx5 plays crucial roles in the patterning of the oropharyngeal region and development of muscles derived from the 4th PA mesoderm in the soft palate, likely via interactions between CNC-derived and myogenic progenitor cells..