NaV1.1 contributes to the cell cycle of human mesenchymal stem cells by regulating AKT and CDK2.

Non-excitable cells express sodium voltage-gated channel alpha subunit 1 gene and protein (SCN1A/NaV1.1); however, the functions of NaV1.1 are unclear. SCN1A was expressed in human mesenchymal stem cells (MSCs). Nav1.1 was abundantly expressed in the endoplasmic reticulum of MSCs; however, its expression was not found to be related to sodium currents. SCN1A-silencing reduced MSC proliferation and delayed the cell cycle in the S phase. SCN1A-silencing also suppressed the protein levels of CDK2 and AKT, despite similar mRNA expression, and inhibited AKT phosphorylation in MSCs. Cycloheximide-chase assay showed that SCN1A-silencing induced CDK2 but not AKT protein degradation in MSCs. Proteolysis inhibition assay using epoxomicin, bafilomycin A1, and NH4Cl, revealed that the ubiquitin-proteasome and autophagy/endo-lysosome systems were irrelevant to CDK2 and AKT protein reduction in SCN1A-silenced MSCs. AKT inhibitor LY294002 did not affect the degradation and nuclear localization of CDK2 in MSCs. Likewise, AKT activator SC79 did not attenuate the SCN1A-silencing effects on CDK2 in MSCs. These results suggest that NaV1.1 contributes to the cell cycle of MSCs by regulating the post-translational control of AKT and CDK2.

Targeting of Deciduous Tooth Pulp Stem Cell-Derived Extracellular Vesicles on Telomerase-Mediated Stem Cell Niche and Immune Regulation in Systemic Lupus Erythematosus.

Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) is used to treat systemic lupus erythematosus (SLE)-like disorders in MRL/lpr mice. However, the mechanisms underlying the SHED-based therapy remain unclear. In this study, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) ameliorate the SLE-like phenotypes in MRL/lpr mice. SHED-EVs were isolated from the culture supernatant of SHED. SHED-EVs were treated with or without RNase and systemically administered to MRL/lpr mice. Subsequently, recipient bone marrow mesenchymal stem cells (BMMSCs) isolated from SHED-EV-administered MRL/lpr mice were examined for the in vitro and in vivo activity of hematopoietic niche formation and immunoregulation. Furthermore, the recipient BMMSCs were secondarily transplanted into MRL/lpr mice. The systemic SHED-EV infusion ameliorated the SLE-like phenotypes in MRL/lpr mice and improved the functions of recipient BMMSCs by rescuing Tert mRNA-associated telomerase activity, hematopoietic niche formation, and immunoregulation. The secondary transplantation of recipient BMMSCs recovered the immune condition and renal functions of MRL/lpr mice. The RNase treatment depleted RNAs, such as microRNAs, within SHED-EVs, and the RNA-depleted SHED-EVs attenuated the benefits of SHED-EVs in MRL/lpr mice. Collectively, our findings suggest that SHED-secreted RNAs, such as microRNAs, play a crucial role in treating SLE by targeting the telomerase activity of recipient BMMSCs.

Cutting-edge regenerative therapy for Hirschsprung disease and its allied disorders.

Hirschsprung disease (HSCR) and its associated disorders (AD-HSCR) often result in severe hypoperistalsis caused by enteric neuropathy, mesenchymopathy, and myopathy. Notably, HSCR involving the small intestine, isolated hypoganglionosis, chronic idiopathic intestinal pseudo-obstruction, and megacystis-microcolon-intestinal hypoperistalsis syndrome carry a poor prognosis. Ultimately, small-bowel transplantation (SBTx) is necessary for refractory cases, but it is highly invasive and outcomes are less than optimal, despite advances in surgical techniques and management. Thus, regenerative therapy has come to light as a potential form of treatment involving regeneration of the enteric nervous system, mesenchyme, and smooth muscle in affected areas. We review the cutting-edge regenerative therapeutic approaches for managing HSCR and AD-HSCR, including the use of enteric nervous system progenitor cells, embryonic stem cells, induced pluripotent stem cells, and mesenchymal stem cells as cell sources, the recipient intestine's microenvironment, and transplantation methods. Perspectives on the future of these treatments are also discussed.

Dental Pulp-Derived Mesenchymal Stem Cells for Modeling Genetic Disorders.

A subpopulation of mesenchymal stem cells, developmentally derived from multipotent neural crest cells that form multiple facial tissues, resides within the dental pulp of human teeth. These stem cells show high proliferative capacity in vitro and are multipotent, including adipogenic, myogenic, osteogenic, chondrogenic, and neurogenic potential. Teeth containing viable cells are harvested via minimally invasive procedures, based on various clinical diagnoses, but then usually discarded as medical waste, indicating the relatively low ethical considerations to reuse these cells for medical applications. Previous studies have demonstrated that stem cells derived from healthy subjects are an excellent source for cell-based medicine, tissue regeneration, and bioengineering. Furthermore, stem cells donated by patients affected by genetic disorders can serve as in vitro models of disease-specific genetic variants, indicating additional applications of these stem cells with high plasticity. This review discusses the benefits, limitations, and perspectives of patient-derived dental pulp stem cells as alternatives that may complement other excellent, yet incomplete stem cell models, such as induced pluripotent stem cells, together with our recent data.

Positive effect of exogenous brain-derived neurotrophic factor on impaired neurite development and mitochondrial function in dopaminergic neurons derived from dental pulp stem cells from children with attention deficit hyperactivity disorder.

Attention deficit hyperactivity disorder (ADHD) is one of the most common neurodevelopmental disorders and is characterized by impaired attention, hyperactivity, and impulsivity. While multiple etiologies are implicated in ADHD, its underlying mechanism(s) remain unclear. Although previous studies have suggested dysregulation of dopaminergic signals, mitochondria, and brain-derived neurotrophic factor (BDNF) in ADHD, few studies have reported these associations directly. Stem cells from human exfoliated deciduous teeth (SHED) can efficiently differentiate into dopaminergic neurons (DNs) and are thus a useful disease-specific cellular model for the study of neurodevelopmental disorders associated with DN dysfunction. This study aimed to elucidate the relationships between DNs, mitochondria, and BDNF in ADHD by analyzing DNs differentiated from SHED obtained from three boys with ADHD and comparing them to those from three typically developing boys. In the absence of exogenous BDNF in the cell culture media, DNs derived from boys with ADHD (ADHD-DNs) exhibited impaired neurite outgrowth and branching, decreased mitochondrial mass in neurites, and abnormal intracellular ATP levels. In addition, BDNF mRNA was significantly decreased in ADHD-DNs. Supplementation with BDNF, however, significantly improved neurite development and mitochondrial function in ADHD-DNs. These results suggest that ADHD-DNs may have impaired neurite development and mitochondrial function associated with insufficient production of BDNF, which may be improved by exogenous BDNF supplementation. Findings such as these, from patient-derived SHED, may contribute to the future development of treatment strategies for aberrant dopaminergic signaling, mitochondrial functioning, and BDNF levels implicated in ADHD pathogenesis.

Folic acid-mediated mitochondrial activation for protection against oxidative stress in human dental pulp stem cells derived from deciduous teeth.

Enzymatic antioxidant systems, mainly involving mitochondria, are critical for minimizing the harmful effects of reactive oxygen species, and these systems are enhanced by interactions with nonenzymatic antioxidant nutrients. Because fetal growth requires extensive mitochondrial respiration, pregnant women and fetuses are at high risk of exposure to excessive reactive oxygen species. The enhancement of the antioxidant system, e.g., by nutritional management, is therefore critical for both the mother and fetus. Folic acid supplementation prevents homocysteine accumulation and epigenetic dysregulation associated with one-carbon metabolism. However, few studies have examined the antioxidant effects of folic acid for healthy pregnancy outcomes. The purpose of this study was to elucidate the association between the antioxidant effect of folic acid and mitochondria in undifferentiated cells during fetal growth. Neural crest-derived dental pulp stem cells of human exfoliated deciduous teeth were used as a model of undifferentiated cells in the fetus. Pyocyanin induced excessive reactive oxygen species, resulting in a decrease in cell growth and migration accompanied by mitochondrial fragmentation and inactivation in dental pulp stem cells. This damage was significantly improved by folic acid, along with decreased mitochondrial reactive oxygen species, PGC-1α upregulation, DRP1 downregulation, mitochondrial elongation, and increased ATP production. Folic acid may protect undifferentiated cells from oxidative damage by targeting mitochondrial activation. These results provide evidence for a new benefit of folic acid in pregnant women and fetuses.

Regenerative medicine using stem cells from human exfoliated deciduous teeth (SHED): a promising new treatment in pediatric surgery.

Stem cells from human exfoliated deciduous teeth (SHEDs), being a type of mesenchymal stem cell, are an ideal cell source for regenerative medicine. They have minimal risk of oncogenesis, high proliferative capacity, high multipotency, and immunosuppressive ability. Stem cell transplantation using SHED has been found to have an anti-fibrotic effect on liver fibrosis in mice. SHED transplantation and the bio 3D printer, which can create scaffold-free 3-D images of the liver and diaphragm, provide a new innovative treatment modality for intractable pediatric surgical diseases such as biliary atresia and diaphragmatic hernia.

Therapeutic potential of spheroids of stem cells from human exfoliated deciduous teeth for chronic liver fibrosis and hemophilia A.

PURPOSE: Mesenchymal stem cell (MSC)-based cell therapies have emerged as a promising treatment option for various diseases. Due to the superior survival and higher differentiation efficiency, three-dimensional spheroid culture systems have been an important topic of MSC research. Stem cells from human exfoliated deciduous teeth (SHED) have been considered an ideal source of MSCs for regenerative medicine. Thus, in the present study, we introduce our newly developed method for fabricating SHED-based micro-hepatic tissues, and demonstrate the therapeutic effects of SHED-based micro-hepatic tissues in mouse disease models. METHODS: SHED-converted hepatocyte-like cells (SHED-HLCs) were used for fabricating spherical micro-hepatic tissues. The SHED-HLC-based spheroids were then transplanted both into the liver of mice with CCl4-induced chronic liver fibrosis and the kidney of factor VIII (F8)-knock-out mice. At 4 weeks after transplantation, the therapeutic efficacy was investigated. RESULTS: Intrahepatic transplantation of SHED-HLC-spheroids improved the liver dysfunction in association with anti-fibrosis effects in CCl4-treated mice. Transplanted SHED-converted cells were successfully engrafted in the recipient liver. Meanwhile, renal capsular transplantation of the SHED-HLC-spheroids significantly extended the bleeding time in F8-knock-out mice. CONCLUSIONS: These findings suggest that SHED-HLC-based micro-hepatic tissues might be a promising source for treating pediatric refractory diseases, including chronic liver fibrosis and hemophilia A.

Accelerated dentinogenesis by inhibiting the mitochondrial fission factor, dynamin related protein 1.

Undifferentiated odontogenic epithelium and dental papilla cells differentiate into ameloblasts and odontoblasts, respectively, both of which are essential for tooth development. These differentiation processes involve dramatic functional and morphological changes of the cells. For these changes to occur, activation of mitochondrial functions, including ATP production, is extremely important. In addition, these changes are closely related to mitochondrial fission and fusion, known as mitochondrial dynamics. However, few studies have focused on the role of mitochondrial dynamics in tooth development. The purpose of this study was to clarify this role. We used mouse tooth germ organ cultures and a mouse dental papilla cell line with the ability to differentiate into odontoblasts, in combination with knockdown of the mitochondrial fission factor, dynamin related protein (DRP)1. In organ cultures of the mouse first molar, tooth germ developed to the early bell stage. The amount of dentin formed under DRP1 inhibition was significantly larger than that of the control. In experiments using a mouse dental papilla cell line, differentiation into odontoblasts was enhanced by inhibiting DRP1. This was associated with increased mitochondrial elongation and ATP production compared to the control. These results suggest that DRP1 inhibition accelerates dentin formation through mitochondrial elongation and activation. This raises the possibility that DRP1 might be a therapeutic target for developmental disorders of teeth.

Mitochondrial dysfunction in dopaminergic neurons differentiated from exfoliated deciduous tooth-derived pulp stem cells of a child with Rett syndrome.

Rett syndrome is an X-linked neurodevelopmental disorder associated with psychomotor impairments, autonomic dysfunctions and autism. Patients with Rett syndrome have loss-of-function mutations in MECP2, the gene encoding methyl-CpG-binding protein 2 (MeCP2). Abnormal biogenic amine signaling and mitochondrial function have been found in patients with Rett syndrome; however, few studies have analyzed the association between these factors. This study investigated the functional relationships between mitochondria and the neuronal differentiation of the MeCP2-deficient stem cells from the exfoliated deciduous teeth of a child with Rett syndrome. An enrolled subject in this study was a 5-year-old girl carrying a large deletion that included the methyl-CpG-binding domain, transcriptional repression domain, and nuclear localization signal of MECP2. Using the single-cell isolation technique, we found that the two populations of MeCP2-expressing and MeCP2-deficient stem cells kept their MECP2 expression profiles throughout the stages of cell proliferation and neuronal differentiation in vitro. Neurite outgrowth and branching were attenuated in MeCP2-deficient dopaminergic neurons. MeCP2-deficient cells showed reduced mitochondrial membrane potential, ATP production, restricted mitochondrial distribution in neurites, and lower expression of a central mitochondrial fission factor, dynamin-related protein 1 than MeCP2-expressing cells. These data indicated that MeCP2-deficiency dysregulates the expression of mitochondrial factors required for the maturation of dopaminergic neurons. This study also provides insight into the pathogenic mechanism underlying dysfunction of the intracerebral dopaminergic signaling pathway in Rett syndrome.

Altered development of dopaminergic neurons differentiated from stem cells from human exfoliated deciduous teeth of a patient with Down syndrome.

BACKGROUND: Down syndrome (DS) is a common developmental disorder resulting from the presence of an additional copy of chromosome 21. Abnormalities in dopamine signaling are suggested to be involved in cognitive dysfunction, one of the symptoms of DS, but the pathophysiological mechanism has not been fully elucidated at the cellular level. Stem cells from human exfoliated deciduous teeth (SHED) can be prepared from the dental pulp of primary teeth. Importantly, SHED can be collected noninvasively, have multipotency, and differentiate into dopaminergic neurons (DN). Therefore, we examined dopamine signaling in DS at the cellular level by isolating SHED from a patient with DS, differentiating the cells into DN, and examining development and function of DN. METHODS: Here, SHED were prepared from a normal participant (Ctrl-SHED) and a patient with DS (DS-SHED). Initial experiments were performed to confirm the morphological, chromosomal, and stem cell characteristics of both SHED populations. Next, Ctrl-SHED and DS-SHED were differentiated into DN and morphological analysis of DN was examined by immunostaining. Functional analysis of DN was performed by measuring extracellular dopamine levels under basal and glutamate-stimulated conditions. In addition, expression of molecules involved in dopamine homeostasis was examined by quantitative real-time polymerase chain reaction and immunostaining. Statistical analysis was performed using two-tailed Student's t-tests. RESULTS: Compared with Ctrl-SHED, DS-SHED showed decreased expression of nestin, a neural stem-cell marker. Further, DS-SHED differentiated into DN (DS-DN) exhibiting decreased neurite outgrowth and branching compared with Ctrl-DN. In addition, DS-DN dopamine secretion was lower than Ctrl-DN dopamine secretion. Moreover, aberrant expression of molecules involved in dopaminergic homeostasis was observed in DS-DN. CONCLUSIONS: Our results suggest that there was developmental abnormality and DN malfunction in the DS-SHED donor in this study. In the future, to clarify the detailed mechanism of dopamine-signal abnormality due to DN developmental and functional abnormalities in DS, it is necessary to increase the number of patients for analysis. Non-invasively harvested SHED may be very useful in the analysis of DS pathology.

Mitochondria Regulate the Differentiation of Stem Cells from Human Exfoliated Deciduous Teeth.

Stem cells from human exfoliated deciduous teeth (SHED) are isolated from the dental pulp tissue of primary teeth and can differentiate into neuronal cells. Although SHED are a desirable type of stem cells for transplantation therapy and for the study of neurological diseases, a large part of the neuronal differentiation machinery of SHED remains unclear. Recent studies have suggested that mitochondrial activity is involved in the differentiation of stem cells. In the present work, we investigated the neuronal differentiation machinery of SHED by focusing on mitochondrial activity. During neuronal differentiation of SHED, we observed increased mitochondrial membrane potential, increased mitochondrial DNA, and elongated mitochondria. Furthermore, to examine the demand for mitochondrial activity in neuronal differentiation, we then differentiated SHED into neuronal cells in the presence of rotenone, an inhibitor of mitochondrial respiratory chain complex I, and carbonyl cyanide m-chlorophenyl hydrazone (CCCP), a mitochondrial uncoupler, and found that neuronal differentiation was inhibited by treatment with rotenone and CCCP. These results indicated that increased mitochondrial activity was crucial for the neuronal differentiation of SHED.Key words: mitochondria, differentiation, stem cells, dental pulp, exfoliated deciduous teeth.

Direct effects of mitochondrial dysfunction on poor bone health in Leigh syndrome.

Mitochondrial diseases are the result of aberrant mitochondrial function caused by mutations in either nuclear or mitochondrial DNA. Poor bone health has recently been suggested as a symptom of mitochondrial diseases; however, a direct link between decreased mitochondrial function and poor bone health in mitochondrial disease has not been demonstrated. In this study, stem cells from human exfoliated deciduous teeth (SHED) were isolated from a child with Leigh syndrome (LS), a mitochondrial disease, and the effects of decreased mitochondrial function on poor bone health were analyzed. Compared with control SHED, LS SHED displayed decreased osteoblastic differentiation and calcium mineralization. The intracellular and mitochondrial calcium levels were lower in LS SHED than in control SHED. Furthermore, the mitochondrial activity of LS SHED was decreased compared with control SHED both with and without osteoblastic differentiation. Our results indicate that decreased osteoblast differentiation potential and osteoblast function contribute to poor bone health in mitochondrial diseases.

Dihydroorotate dehydrogenase depletion hampers mitochondrial function and osteogenic differentiation in osteoblasts.

Mutation of the dihydroorotate dehydrogenase (DHODH) gene is responsible for Miller syndrome, which is characterized by craniofacial malformations with limb abnormalities. We previously demonstrated that DHODH was involved in forming a mitochondrial supercomplex and that mutated DHODH led to protein instability, loss of enzyme activity, and increased levels of reactive oxygen species in HeLa cells. To explore the etiology of Miller syndrome in more detail, we investigated the effects of DHODH inhibition in the cells involved in skeletal structure. Dihydroorotate dehydrogenase in MC3T3-E1 cells derived from mouse calvaria osteoblast precursor cells was knocked down by specific small interfering RNAs (siRNAs), and cell proliferation, ATP production, and expression of bone-related genes were investigated in these cells. After depletion of DHODH using specific siRNAs, inhibition of cell proliferation and cell cycle arrest occurred in MC3T3-E1 cells. In addition, ATP production was reduced in whole cells, especially in mitochondria. Furthermore, the levels of runt-related transcription factor 2 (Runx2) and osteocalcin (Ocn) mRNAs were lower in DHODH siRNA-treated cells compared with controls. These data suggest that depletion of DHODH affects the differentiation and maturation of osteoblasts. This study shows that mitochondrial dysfunction by DHODH depletion in osteoblasts can be directly linked to the abnormal bone formation in Miller syndrome.

Complete resolution of a calcifying cystic odontogenic tumor with physiological eruption of a dislocated permanent tooth after marsupialization in a child with a mixed dentition: a case report.

Here, we report the complete resolution of a calcifying cystic odontogenic tumor (CCOT) in the right mandible after marsupialization in an 8-year-old girl with a mixed dentition. Clinical, radiographic, and histopathological findings showed a simple cystic variant of CCOT in the region of the deciduous second molar, with dislocation of the permanent second premolar tooth germ. Initial treatment involved marsupialization, including extraction of the involved deciduous tooth, incision of pathological tissue, and creation of a window in the extraction socket. The crown of the dislocated second premolar was exposed at the base of the cystic cavity after marsupialization. One year and nine months later, complete bone healing and spontaneous eruption of the second premolar were observed, providing evidence of the bone regeneration capacity and tooth germ eruption potential in children. No recurrence was observed after 7 years. The findings from this case suggest that marsupialization can be successfully applied for the treatment of CCOT in children with a mixed dentition.

Erythropoietin receptor signal is crucial for periodontal ligament stem cell-based tissue reconstruction in periodontal disease.

Alveolar bone loss caused by periodontal disease eventually leads to tooth loss. Periodontal ligament stem cells (PDLSCs) are the tissue-specific cells for maintaining and repairing the periodontal ligament, cementum, and alveolar bone. Here, we investigated the role of erythropoietin receptor (EPOR), which regulates the microenvironment-modulating function of mesenchymal stem cells, in PDLSC-based periodontal therapy. We isolated PDLSCs from patients with chronic periodontal disease and healthy donors, referred to as PD-PDLSCs and Cont-PDLSCs, respectively. PD-PDLSCs exhibited reduced potency of periodontal tissue regeneration and lower expression of EPOR compared to Cont-PDLSCs. EPOR-silencing suppressed the potency of Cont-PDLSCs mimicking PD-PDLSCs, whereas EPO-mediated EPOR activation rejuvenated the reduced potency of PD-PDLSCs. Furthermore, we locally transplanted EPOR-silenced and EPOR-activated PDLSCs into the gingiva around the teeth of ligament-induced periodontitis model mice and demonstrated that EPOR in PDLSCs participated in the regeneration of the periodontal ligament, cementum, and alveolar bone in the ligated teeth. The EPOR-mediated paracrine function of PDLSCs maintains periodontal immune suppression and bone metabolic balance via osteoclasts and osteoblasts in the periodontitis model mice. Taken together, these results suggest that EPOR signaling is crucial for PDLSC-based periodontal regeneration and paves the way for the development of novel options for periodontal therapy.

Multiple functional involvement of thymosin beta-4 in tooth germ development.

Thymosin beta-4 (Tß4) is known to be ubiquitously involved in the actin monomer sequestering on the cytoskeleton. Our previous study showed specific temporal and special in situ expression pattern of Tß4 mRNA in dental epithelial and mesenchymal cells in the developing tooth germ of the mouse lower first molar. In this study, we examined the functional implications of Tß4 in the developmental course of the mouse lower first molar. An inhibition assay using Tß4 antisense sulfur-substituted oligodeoxynucleotide (AS S-ODN) in cultured embryonic day 11.0 (E11.0) mandibles showed a significant growth inhibition of the tooth germ. However, no growth arrest of the cultured E15.0 tooth germ was observed by using Tß4 AS S-ODN. The Tß4 knockdown led to significantly decreased expression levels of type II/III runt-related transcription factor 2 (Runx2) and nucleolin (Ncl) in the cultured E11.0 mandibles. Since our previous studies proved that the inhibition of type II/III Runx2 and Ncl translations resulted in the developmental arrest of the tooth germ in the cultured E11.0 mandible, Tß4 appears to play roles in tooth germ development via the regulation of the type II/III Runx2 and Ncl expressions. Tß4 knockdown also resulted in decreased secretion of matrix metalloproteinase (Mmp)-2, a reduced cell motility activity and upregulation of E-cadherin in dental epithelial mDE6 cells. These results suggest that Tß4 plays multiple functional roles in odontogenic epithelial cells in the early stages of tooth germ development by regulating the expression of odontogenesis-related genes.

Protocol to generate xenogeneic-free/serum-free human dental pulp stem cells.

Human dental pulp stem cell (hDPSCs)-based therapy is a feasible option for regenerative medicine, such as dental pulp regeneration. Here, we show the steps needed to colony-forming unit-fibroblasts (CFU-F)-based isolation, expansion, and cryopreservation of hDPSCs for manufacturing clinical-grade products under a xenogeneic-free/serum-free condition. We also demonstrate the characterization of hDPSCs by CFU-F, flow cytometric, and in vitro multipotent assays. For complete details on the use and execution of this protocol, please refer to Iwanaka et al. (2020).

GSK3beta inhibitor-induced dental mesenchymal stem cells regulate ameloblast differentiation.

OBJECTIVES: Epithelial-mesenchymal interactions are extremely important in tooth development and essential for ameloblast differentiation, especially during tooth formation. We aimed to identify the type of mesenchymal cells important in ameloblast differentiation. METHODS: We used two types of cell culture systems with chambers and found that a subset of debtal mesenchimal cells is important for the differentiatiuon of dental spithelial cells into ameloblasts. Further, we induced dental pulp stem cell-like cells from dental pulp stem cells using the small molecule compound BIO ( a GSK-3 inhibitor IX) to clarify the mechanism involved in ameloblast differentiation induced by dental pulp stem cells. RESULTS: The BIO-induced dental pulp cells promoted the expression of mesenchymal stem cell markers Oct3/4 and Bcrp1. Furthermore, we used artificial dental pulp stem cells induced by BIO to identify the molecules expressed in dental pulp stem cells required for ameloblast differentiation. Panx3 expression was induced in the dental pulp stem cell through interaction with the dental epithelial cells. In addition, ATP release from cells increased in Panx3-expressing cells. We also confirmed that ATP stimulation is accepted in dental epithelial cells. CONCLUSIONS: These results showed that the Panx3 expressed in dental pulp stem cells is important for ameloblast differentiation and that ATP release by Panx3 may play a role in epithelial-mesenchymal interaction.

Targeting hepatic oxidative stress rescues bone loss in liver fibrosis.

OBJECTIVE: Chronic liver diseases often involve metabolic damage to the skeletal system. The underlying mechanism of bone loss in chronic liver diseases remains unclear, and appropriate therapeutic options, except for orthotopic liver transplantation, have proved insufficient for these patients. This study aimed to investigate the efficacy and mechanism of transplantation of immature hepatocyte-like cells converted from stem cells from human exfoliated deciduous teeth (SHED-Heps) in bone loss of chronic liver fibrosis. METHODS: Mice that were chronically treated with CCl4 received SHED-Heps, and trabecular bone density, reactive oxygen species (ROS), and osteoclast activity were subsequently analyzed in vivo and in vitro. The effects of stanniocalcin 1 (STC1) knockdown in SHED-Heps were also evaluated in chronically CCl4 treated mice. RESULTS: SHED-Hep transplantation (SHED-HepTx) improved trabecular bone loss and liver fibrosis in chronic CCl4-treated mice. SHED-HepTx reduced hepatic ROS production and interleukin 17 (Il-17) expression under chronic CCl4 damage. SHED-HepTx reduced the expression of both Il-17 and tumor necrosis factor receptor superfamily 11A (Tnfrsf11a) and ameliorated the imbalance of osteoclast and osteoblast activities in the bone marrow of CCl4-treated mice. Functional knockdown of STC1 in SHED-Heps attenuated the benefit of SHED-HepTx including anti-bone loss effect by suppressing osteoclast differentiation through TNFSF11-TNFRSF11A signaling and enhancing osteoblast differentiation in the bone marrow, as well as anti-fibrotic and anti-ROS effects in the CCl4-injured livers. CONCLUSIONS: These findings suggest that targeting hepatic ROS provides a novel approach to treat bone loss resulting from chronic liver diseases.