In vivo hepatogenic capacity and therapeutic potential of stem cells from human exfoliated deciduous teeth in liver fibrosis in mice

Isolation and characterization of a new SHED cell line as a standard source for stem cell research and clinical translation

BACKGROUND AND AIMS

Stem cells from human exfoliated deciduous teeth (SHED) are multi-potent mesenchymal stem/stromal cells (MSCs) and are inspected a favorable, non-invasive source beneficial to stem cell-mediated regeneration of damaged tissues. Our aim was to establish and characterize a non-immortalized SHED cell line as an accessible resource and novel platform for stem cell research and tissue regeneration studies.

METHODS

A Healthy exfoliated deciduous molar was extracted from a 12-year-old girl and shipped to an animal cell culture laboratory. Outgrowing primary cells from explanted small pulp tissues were monitored daily and characterized after passage 3 both morphologically and functionally. The SHED cell line was characterized by calculation of doubling time, cytogenetic analyses, STR analysis, adherence to cell culture flasks under standard cell culture media, and immunophenotypic analysis of specific MSC markers (CD90+, CD73+, CD34- and CD45-) using flow cytometry method. Differentiation potential to osteoblast, adipocyte, and chondrocyte was evaluated under standard differentiation media Expression of OCT-4 and NANOG genes was also assessed using RT-PCR method.

RESULTS

After the third day, SHED cells were visible. SHED cells were subcultured when they reached 90 % confluence after approximately 17 days. The doubling time of SHED cells was forty seven hours. SHED immunophenotyping showed the high expression level of CD90 (99.2 %) and CD73 (45.9 %), and approximately no expression of CD34 (0.079 %) and CD45 (0.19 %). The human origin, female gender and chromosomal normality of SHED cells was confirmed by cytogenetic analysis. The STR matching analysis showed that SHED cells are well-identified and authentic. No genetic instability and cross-contamination were observed in SHED cells.

CONCLUSIONS

This study provides a new SHED cell line with a normal karyotype and all the characteristics of MSCs, which can be used as a favorable model cell line in biomedical research and a promising source for clinical translation.

Single-cell transcriptome analysis of stem cells from human exfoliated deciduous teeth investigating functional heterogeneity in immunomodulation

Mesenchymal stem cells (MSCs) have been widely used in the treatment of various inflammatory diseases. The inadequate understanding of MSCs and their heterogeneity can impact the immune environment, which may be the cause of the good outcomes of MSCs-based therapy that cannot always be achieved. Recently, stem cells from human exfoliated deciduous teeth (SHED) showed great potential in inflammatory and autoimmune diseases due to their immature properties compared with MSCs. In our study, single-cell RNA sequencing (scRNA-seq) revealed that SHED in a low differentiation state (S7) exhibited the powerful ability to recruit multiple immune cells. In contrast, SHED in a relatively high differentiation state (S1) may hold a solid ability to secret many factors with paracrine signaling capacity. The analysis result shows that SHED has more robust immunomodulatory properties than human bone marrow-derived mesenchymal stem cells (hBMSCs) or human umbilical cord-derived mesenchymal stem cells (hUCMSCs). When co-cultured with PBMCs, SHED can enhance the proliferation of Treg and down-regulate TNF-α in vitro. SHED may have some advantages in the treatment of inflammatory and autoimmune diseases.

Polydeoxyribonucleotide enhances the bioactivities of stem cells from human exfoliated deciduous teeth through Akt activation

Although numerous approaches have emerged to address the challenges of critical limb ischemia (CLI), their clinical trials have proven elusive. Stem cell therapy has been utilized for CLI; however, its efficacy is limited, resulting in low survival rates in patients. Here, we investigated the impact of polydeoxyribonucleotide (PDRN) on the bioactivities of stem cells derived from human exfoliated deciduous teeth (SHED) against oxidative stress. PDRN treatment increased the proliferation, migration, antioxidant properties, and mitochondrial respiration of SHED. These beneficial effects were regulated by Akt activation. Through a murine hindlimb ischemia model, PDRN treatment demonstrated augmented the survival and proliferation of transplanted SHED at ischemic injury sites, whereas the inhibition of Akt suppressed these effects. Our findings revealed that PDRN promoted the therapeutic potential of SHED via Akt phosphorylation, suggesting PDRN-primed SHED as promising candidates for the development of novel stem cell therapeutics.

Potential role of stem cells from human exfoliated deciduous teeth in inducing liver regeneration

BACKGROUND AND AIM

Even with advancement of medical technologies, liver transplantation still faces several major challenges. Hence, other treatment modalities are urgently needed for patients with end-stage liver disease. Stem cells from human exfoliated deciduous teeth (SHED) was discovered to have highly proliferative and pluripotent properties; including differentiation into hepatocyte-like cells. This study aims to investigate the capability of intrasplenic transplanted SHED and SHED-Hep cells in inducing proliferation of stem cells and native hepatocytes in order to accelerate liver regeneration in liver fibrosis mice models.

METHODS

Three carbon tetrachloride (CCl4)-injured male mice groups were used in this study. Two of those groups were transplanted with either SHED or SHED-Hep, while the other did not undergo transplantation. One age- and sex- matched healthy mice group was used as control. All specimens were immunohistochemically stained with anti-Ki-67 antibodies and anti-proliferating cell nuclear antigen (PCNA) antibodies before counter stained with hematoxylin-eosin.

RESULTS

Anti-Ki-67 antibodies staining: at both 8 and 12 weeks, proliferating activity was predominantly seen on both SHED- and SHED-Hep-transplanted CCl4-injured mice groups, while control and non-transplanted CCl4-injured mice group showed little to no sign of proliferation activity. Anti-PCNA staining: at both 8 and 12 weeks, significant proliferating activity was detected by PCNA staining, mainly on stem cells population area on SHED- and SHED-Hep-treated group.

CONCLUSIONS

In conclusion, this study has provided the evidence that transplantation of SHED or SHED-Hep on liver-injured mice induced proliferation of both transplanted stem cells and native liver cells in order to accelerate liver regeneration.

The Exosomes of Stem Cells from Human Exfoliated Deciduous Teeth Suppress Inflammation in Osteoarthritis

Hyaluronic acid injection is commonly used clinically to slow down the development of osteoarthritis (OA). A newly developed therapeutic method is to implant chondrocytes/stem cells to regenerate cartilage in the body. The curative effect of stem cell therapy has been proven to come from the paracrine of stem cells. In this study, exosomes secreted by stem cells from human exfoliated deciduous teeth (SHED) and hyaluronic acid were used individually to evaluate the therapeutic effect in slowing down OA. SHED was cultured in a serum-free medium for three days, and the supernatant was collected and then centrifuged with a speed difference to obtain exosomes containing CD9 and CD63 markers, with an average particle size of 154.1 nm. SW1353 cells were stimulated with IL-1β to produce the inflammatory characteristics of OA and then treated with 40 μg/mL exosomes and hyaluronic acid individually. The results showed that the exosomes successfully inhibited the pro-inflammatory factors, including TNF-α, IL-6, iNOS, NO, COX-2 and PGE2, induced by IL-1β and the degrading enzyme of the extrachondral matrix (MMP-13). Collagen II and ACAN, the main components of the extrachondral matrix, were also increased by 1.76-fold and 2.98-fold, respectively, after treatment, which were similar to that of the normal joints. The effect can be attributed to the partial mediation of SHED exosomes to the NF-κB pathway, and the ability of exosomes to inhibit OA is found not inferior to that of hyaluronic acid.

Mesenchymal Stromal Cell-Based Products: Challenges and Clinical Therapeutic Options

Mesenchymal stromal cell (MSC)-based advanced therapy medicinal products (ATMPs) are being tried in a vast range of clinical applications. These cells can be isolated from different donor tissues by using several methods, or they can even be derived from induced pluripotent stem cells or embryonic stem cells. However, ATMP heterogeneity may impact product identity and potency, and, consequently, clinical trial outcomes. In this review, we discuss these topics and the need to establish minimal criteria regarding the manufacturing of MSCs so that these innovative therapeutics may be better positioned to contribute to the advancement of regenerative medicine.

PAX6/CXCL14 regulatory axis promotes the repair of corneal injury by enhancing corneal epithelial cell proliferation

BACKGROUND

Corneal injuries, often leading to severe vision loss or blindness, have traditionally been treated with the belief that limbal stem cells (LSCs) are essential for repair and homeostasis, while central corneal epithelial cells (CCECs) were thought incapable of such repair. However, our research reveals that CCECs can fully heal and maintain the homeostasis of injured corneas in rats, even without LSCs. We discovered that CXCL14, under PAX6's influence, significantly boosts the stemness, proliferation, and migration of CCECs, facilitating corneal wound healing and homeostasis. This finding introduces CXCL14 as a promising new drug target for corneal injury treatment.

METHODS

To investigate the PAX6/CXCL14 regulatory axis's role in CCECs wound healing, we cultured human corneal epithelial cell lines with either increased or decreased expression of PAX6 and CXCL14 using adenovirus transfection in vitro. Techniques such as coimmunoprecipitation, chromatin immunoprecipitation, immunofluorescence staining, western blot, real-time PCR, cell colony formation, and cell cycle analysis were employed to validate the axis's function. In vivo, a rat corneal epithelial injury model was developed to further confirm the PAX6/CXCL14 axis's mechanism in repairing corneal damage and maintaining corneal homeostasis, as well as to assess the potential of CXCL14 protein as a therapeutic agent for corneal injuries.

RESULTS

Our study reveals that CCECs naturally express high levels of CXCL14, which is significantly upregulated by PAX6 following corneal damage. We identified SDC1 as CXCL14's receptor, whose engagement activates the NF-κB pathway to stimulate corneal repair by enhancing the stemness, proliferative, and migratory capacities of CCECs. Moreover, our research underscores CXCL14's therapeutic promise for corneal injuries, showing that recombinant CXCL14 effectively accelerates corneal healing in rat models.

CONCLUSION

CCECs play a critical and independent role in the repair of corneal injuries and the maintenance of corneal homeostasis, distinct from that of LSCs. The PAX6/CXCL14 regulatory axis is pivotal in this process. Additionally, our research demonstrates that the important function of CXCL14 in corneal repair endows it with the potential to be developed into a novel therapeutic agent for treating corneal injuries.

A review of the therapeutic potential of dental stem cells as scaffold-free models for tissue engineering application

In the realm of regenerative medicine, tissue engineering has introduced innovative approaches to facilitate tissue regeneration. Specifically, in pulp tissue engineering, both scaffold-based and scaffold-free techniques have been applied. Relevant articles were meticulously chosen from PubMed, Scopus, and Google Scholar databases through a comprehensive search spanning from October 2022 to December 2022. Despite the inherent limitations of scaffolding, including inadequate mechanical strength for hard tissues, insufficient vents for vessel penetration, immunogenicity, and suboptimal reproducibility-especially with natural polymeric scaffolds-scaffold-free tissue engineering has garnered significant attention. This methodology employs three-dimensional (3D) cell aggregates such as spheroids and cell sheets with extracellular matrix, facilitating precise regeneration of target tissues. The choice of technique aside, stem cells play a pivotal role in tissue engineering, with dental stem cells emerging as particularly promising resources. Their pluripotent nature, non-invasive extraction process, and unique properties render them highly suitable for scaffold-free tissue engineering. This study delves into the latest advancements in leveraging dental stem cells and scaffold-free techniques for the regeneration of various tissues. This paper offers a comprehensive summary of recent developments in the utilization of dental stem cells and scaffold-free methods for tissue generation. It explores the potential of these approaches to advance tissue engineering and their effectiveness in therapies aimed at tissue regeneration.

Adult Mesenchymal Stem Cells from Oral Cavity and Surrounding Areas: Types and Biomedical Applications

Adult mesenchymal stem cells are those obtained from the conformation of dental structures (DMSC), such as deciduous and permanent teeth and other surrounding tissues. Background: The self-renewal and differentiation capacities of these adult stem cells allow for great clinical potential. Because DMSC are cells of ectomesenchymal origin, they reveal a high capacity for complete regeneration of dental pulp, periodontal tissue, and other biomedical applications; their differentiation into other types of cells promotes repair in muscle tissue, cardiac, pancreatic, nervous, bone, cartilage, skin, and corneal tissues, among others, with a high predictability of success. Therefore, stem and progenitor cells, with their exosomes of dental origin and surrounding areas in the oral cavity due to their plasticity, are considered a fundamental pillar in medicine and regenerative dentistry. Tissue engineering (MSCs, scaffolds, and bioactive molecules) sustains and induces its multipotent and immunomodulatory effects. It is of vital importance to guarantee the safety and efficacy of the procedures designed for patients, and for this purpose, more clinical trials are needed to increase the efficacy of several pathologies. Conclusion: From a bioethical and transcendental anthropological point of view, the human person as a unique being facilitates better clinical and personalized therapy, given the higher prevalence of dental and chronic systemic diseases.

Young Exosome Bio-Nanoparticles Restore Aging-Impaired Tendon Stem/Progenitor Cell Function and Reparative Capacity

Aging impairs tendon stem/progenitor cell function and tendon homeostasis, however, effective treatments for aging-induced tendon diseases are lacking. Exosomes are naturally derived nanoparticles that contain bioactive molecules, and therefore, have attracted great interest in tissue engineering and regenerative medicine. In this study, it is shown that young exosomes secreted by stem cells from human exfoliated deciduous teeth (SHED-Exos) possess abundant anti-aging signals. These young bio-nanoparticles can alleviate the aging phenotypes of aged tendon stem/progenitor cells (AT-SCs) and maintain their tenogenic capacity. Mechanistically, SHED-Exos modulate histone methylation and inhibit nuclear factor-κB to reverse AT-SC aging. In a naturally aging mouse model, systemic administration of SHED-Exo bio-nanoparticles retards tendon degeneration. Interestingly, local delivery of SHED-Exos-loaded microspheres confers anti-aging phenotypes, including reduced senescent cells and decreased ectopic bone formation, thereby functionally and structurally rescuing endogenous tendon regeneration and repair capacity in aged rats. Overall, SHED-Exos, as natural bioactive nanoparticles, have promising translational and therapeutic potential for aging-related diseases.

Neurological Disease Modeling Using Pluripotent and Multipotent Stem Cells: A Key Step towards Understanding and Treating Mucopolysaccharidoses

Despite extensive research, the links between the accumulation of glycosaminoglycans (GAGs) and the clinical features seen in patients suffering from various forms of mucopolysaccharidoses (MPSs) have yet to be further elucidated. This is particularly true for the neuropathology of these disorders; the neurological symptoms are currently incurable, even in the cases where a disease-specific therapeutic approach does exist. One of the best ways to get insights on the molecular mechanisms driving that pathogenesis is the analysis of patient-derived cells. Yet, not every patient-derived cell recapitulates relevant disease features. For the neuronopathic forms of MPSs, for example, this is particularly evident because of the obvious inability to access live neurons. This scenario changed significantly with the advent of induced pluripotent stem cell (iPSC) technologies. From then on, a series of differentiation protocols to generate neurons from iPSC was developed and extensively used for disease modeling. Currently, human iPSC and iPSC-derived cell models have been generated for several MPSs and numerous lessons were learnt from their analysis. Here we review most of those studies, not only listing the currently available MPS iPSC lines and their derived models, but also summarizing how they were generated and the major information different groups have gathered from their analyses. Finally, and taking into account that iPSC generation is a laborious/expensive protocol that holds significant limitations, we also hypothesize on a tempting alternative to establish MPS patient-derived neuronal cells in a much more expedite way, by taking advantage of the existence of a population of multipotent stem cells in human dental pulp to establish mixed neuronal and glial cultures.

Clinical trials using dental stem cells: 2022 update

For nearly 20 years, dental stem cells (DSCs) have been successfully isolated from mature/immature teeth and surrounding tissue, including dental pulp of permanent teeth and exfoliated deciduous teeth, periodontal ligaments, dental follicles, and gingival and apical papilla. They have several properties (such as self-renewal, multidirectional differentiation, and immunomodulation) and exhibit enormous potential for clinical applications. To date, many clinical articles and clinical trials using DSCs have reported the treatment of pulpitis, periapical lesions, periodontitis, cleft lip and palate, acute ischemic stroke, and so on, and DSC-based therapies obtained satisfactory effects in most clinical trials. In these studies, no adverse events were reported, which suggested the safety of DSC-based therapy. In this review, we outline the characteristics of DSCs and summarize clinical trials and their safety as DSC-based therapies. Meanwhile, we also present the current limitations and perspectives of DSC-based therapy (such as harvesting DSCs from inflamed tissue, applying DSC-conditioned medium/DSC-derived extracellular vesicles, and expanding-free strategies) to provide a theoretical basis for their clinical applications.

Extracellular vesicles rejuvenate the microenvironmental modulating function of recipient tissue-specific mesenchymal stem cells in osteopenia treatment

Systemic transplantation of mesenchymal stem cells (MSCs), such as bone marrow MSCs (BMMSCs) and stem cells from human exfoliated deciduous teeth (SHED), is considered a prominent treatment for osteopenia. However, the mechanism of action of the transplanted MSCs has been poorly elucidated. In the recipient target tissue, including bone and bone marrow, only a few donor MSCs can be detected, suggesting that the direct contribution of donor MSCs may not be expected for osteopenia treatment. Meanwhile, secretomes, especially contents within extracellular vesicles (EVs) released from donor MSCs (MSC-EVs), play key roles in the treatment of several diseases. In this context, administrated donor MSC-EVs may affect bone-forming function of recipient cells. In this review, we discuss how MSC-EVs contribute to bone recovery recipient tissue in osteopenia. We also summarize a novel mechanism of action of systemic administration of SHED-derived EVs (SHED-EVs) in osteopenia. We found that reduced telomerase activity in recipient BMMSCs caused the deficiency of microenvironmental modulating function, including bone and bone marrow-like niche formation and immunomodulation in estrogen-deficient osteopenia model mice. Systemic administration of SHED-EVs could exert therapeutic effects on bone reduction via recovering the telomerase activity, leading to the rejuvenation of the microenvironmental modulating function in recipient BMMSCs, as seen in systemic transplantation of SHED. RNase-preconditioned donor SHED-EVs diminished the therapeutic benefits of administrated SHED-EVs in the recipient osteopenia model mice. These facts suggest that MSC-EV therapy targets the recipient BMMSCs to rejuvenate the microenvironmental modulating function via telomerase activity, recovering bone density. We then introduce future challenges to develop the reproducible MSC-EV therapy in osteopenia.

Botanicals and Oral Stem Cell Mediated Regeneration: A Paradigm Shift from Artificial to Biological Replacement

Stem cells are a well-known autologous pluripotent cell source, having excellent potential to develop into specialized cells, such as brain, skin, and bone marrow cells. The oral cavity is reported to be a rich source of multiple types of oral stem cells, including the dental pulp, mucosal soft tissues, periodontal ligament, and apical papilla. Oral stem cells were useful for both the regeneration of soft tissue components in the dental pulp and mineralized structure regeneration, such as bone or dentin, and can be a viable substitute for traditionally used bone marrow stem cells. In recent years, several studies have reported that plant extracts or compounds promoted the proliferation, differentiation, and survival of different oral stem cells. This review is carried out by following the PRISMA guidelines and focusing mainly on the effects of bioactive compounds on oral stem cell-mediated dental, bone, and neural regeneration. It is observed that in recent years studies were mainly focused on the utilization of oral stem cell-mediated regeneration of bone or dental mesenchymal cells, however, the utility of bioactive compounds on oral stem cell-mediated regeneration requires additional assessment beyond in vitro and in vivo studies, and requires more randomized clinical trials and case studies.

Stem cells for treatment of liver fibrosis/cirrhosis: clinical progress and therapeutic potential

Cost-effective treatment strategies for liver fibrosis or cirrhosis are limited. Many clinical trials of stem cells for liver disease shown that stem cells might be a potential therapeutic approach. This review will summarize the published clinical trials of stem cells for the treatment of liver fibrosis/cirrhosis and provide the latest overview of various cell sources, cell doses, and delivery methods. We also describe the limitations and strengths of various stem cells in clinical applications. Furthermore, to clarify how stem cells play a therapeutic role in liver fibrosis, we discuss the molecular mechanisms of stem cells for treatment of liver fibrosis, including liver regeneration, immunoregulation, resistance to injury, myofibroblast repression, and extracellular matrix degradation. We provide a perspective for the prospects of future clinical implementation of stem cells.

The therapeutic effect of stem cells from human exfoliated deciduous teeth on a rat model of tracheal fistula

Background

Tracheal fistulas (TF) can be dangerous and even fatal in patients. The current treatment is really challenging. Previous studies reported that mesenchymal stem cells (MSCs) could be used to treat respiratory tract fistulas. Stem cells from human exfoliated deciduous teeth (SHED) are considered to be MSC-like cells that may also have the potential to treat the tracheal fistulas. In this study, we investigated the therapeutic effects of SHED in rat tracheal fistula models.

Methods

A total of 80 SD rats were randomly divided into five groups: a sham-operated group, a local PBS group (L-PBS), an intravenous PBS group (I-PBS), a local SHED treatment group (L-SHED), and an intravenous SHED treatment group (I-SHED). The L-SHED and I-SHED groups were given a topical application around the fistula or an intravenous injection of 1*10⁷ SHED via the tail vein, respectively, while the L-PBS and I-PBS groups were given an equivalent volume of PBS through local or intravenous administration. A stereomicroscope was used to observe fistula healing on the 2nd, 3rd, and 5th days following transplantation. On the 7th day, the survival of SHED was observed by immunofluorescence. The pathology of the lungs and fistulas was observed by hematoxylin and eosin (H&E) and Masson staining. The expression levels of the Toll-like receptor 4 (TLR4), interleukin (IL)-1β, IL-33, and IL-4 were measured using immunohistochemistry. The expression levels of TLR4, high mobility group box 1 (HMGB1), and myeloid differentiation factor 88 (MYD88) were studied using western blotting. On day 14, airway responsiveness of rats was detected and analyzed.

Results

Fistula healing in the L-SHED and I-SHED groups was faster than that in their respective PBS groups after transplantation. The fistula diameters in the L-SHED and I-SHED groups were significantly smaller than those in the L-PBS and I-PBS groups on the 3rd day. Moreover, the phenomenon of fibroblast proliferation and new blood vessel growth around the fistula seemed more pronounced in the L-SHED and I-SHED groups. Although no discernible difference was found in airway responsiveness after SHED treatment, the degree of inflammation in the lungs was reduced by intravenous SHED treatment. However, there was no significant reduction in lung inflammation by local SHED treatment. The expression levels of IL-1β and IL-33 were decreased in the I-SHED group, while IL-4 was elevated compared with the I-PBS group. Interestingly, intravenous SHED treatment inhibited the activation of HMGB1/TLR4/MYD88 in the lung tissues of TF rats.

Conclusions

SHED transplantation accelerated the rate of fistula healing in rats. Intravenous SHED treatment reduced lung inflammation. Thus, SHED may have potential in the treatment of tracheal fistula, providing hope for future therapeutic development for TF.

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).

The effects of combination therapy by solid lipid nanoparticle and dental stem cells on different degenerative diseases

Stem cells have multiple therapeutic applications, as well as solid lipid nanoparticles. Solid lipid nanoparticle has appeared as a field of nano lipid technology with various potential applications in drug delivery, clinical medicine and research. Besides, the stem cells have a high proliferation rate and could differentiate into a variety of tissues. Stem cells derived from human dental pulp tissue differ from other sources of mesenchymal stem cells due to their embryonic neural crest source and neurotrophic potential. These consist of both dental pulp stem cells from dental pulp tissues of human permanent teeth and stem cells from human exfoliated deciduous teeth. With the emergence of stem cell banks, stem cells are considering for tissue engineering with respect to therapies attitude and regenerative medicine. The present study aimed to evaluate the advantages and disadvantages of the solid lipid nanoparticle and stem cells combination therapy in different therapeutic applications. The solid lipid nanoparticles have anticancer activity against tumors, induce neural differentiation in pluripotent stem cells, and regulate the mesenchymal stem cells. They also have immunomodulatory effects on human mesenchymal stem cells, the gene transfection efficiency, osteogenic differentiation and bone regeneration. But, the crucial health hazards related to stem cell transplantation such as immune rejection reactions and the interaction with other tissues and the effect of solid lipid nanoparticles must not be neglected. Overall, more experiments need to approve the synergism and antagonism effects of the stem cells and solid lipid nanoparticle combination therapy on different degenerative diseases.

Stem Cells From Human Exfoliated Deciduous Teeth Alleviate Liver Cirrhosis via Inhibition of Gasdermin D-Executed Hepatocyte Pyroptosis

Liver cirrhosis represents a type of end-stage liver disease with few effective therapies, which was characterized by damaged functional liver tissue due to long-term inflammation. Gasdermin D (GSDMD)-executed programmed necrosis is reported to be involved in inflammation. However, the role of GSDMD in liver cirrhosis remains unclear. In this study, we used a CCl₄-induced cirrhosis model and found stem cells from human exfoliated deciduous teeth (SHED) infusion showed profound therapeutic effects for liver cirrhosis. Mechanistically, NLRP3 inflammasome-activated GSDMD and its pyroptosis were upregulated in liver cirrhosis, while SHED infusion could suppress the expression of GSDMD and Caspase-1, resulting in reduced hepatocyte pyroptosis and inflammatory cytokine IL-1β release. Consistently, SHED could inhibit the elevated expression of NLRP3, GSDMD and Caspase-1 induced by CCl₄ treatment in vitro co-culture system, which was mediated by decreasing reactive oxygen species (ROS) generation. Moreover, the pyroptosis inhibitor disulfiram showed similar therapeutic effects for liver cirrhosis as SHED. In conclusion, SHED alleviates CCl₄-induced liver cirrhosis via inhibition of hepatocytes pyroptosis. Our findings could provide a potential treatment strategy and novel target for liver cirrhosis.

Amelioration of aflatoxin acute hepatitis rat model by bone marrow mesenchymal stem cells and their hepatogenic differentiation

Background and Aim:

Bone marrow-derived mesenchymal stem cells (BM-MSCs) transplantation and their hepatogenic differentiated cells (HDCs) can be applied for liver injury repair by tissue grafting. Regenerative potentiality in liver cirrhosis models was widely investigated; however, immunomodulation and anti-inflammation in acute hepatitis remain unexplored. This study aimed to explore the immunomodulatory and evaluate twice intravenous (IV) or intrahepatic (IH) administration of either BM-MSCs or middle-stage HDCs on aflatoxin (AF) acute hepatitis rat model.

Materials and Methods:

BM-MSCs viability, phenotypes, and proliferation were evaluated. Hepatogenic differentiation, albumin, and mmmmmmmm-fetoprotein gene expression were assessed. AF acute hepatitis was induced in rats using AFB1 supplementation. The transplantation of BM-MSCs or their HDCs was done either by IV or IH route. Hepatic ultrasound was performed after 3-weeks of therapy. Cytokines profile (tumor necrosis factor-α [TNF-α], interleukin [IL]-4, and IL-10) was assessed. Hepatic bio-indices, serum, and hepatic antioxidant activity were evaluated, besides examining liver histological sections.

Results:

Acute AFB1 showed a significant increase in TNF-α (p<0.01), liver enzyme activities (p<0.05), as well as decrease in IL-4, IL-10, and antioxidant enzyme activities (p<0.05). Cytokines profile was ameliorated in groups treated with IV and IH BM-MCs, showed a negative correlation between IL-4 and TNF-α (p<0.05), and a positive correlation between IL-10 upregulation and TNF-α (p<0.01). In IV HDCs treated group, positive correlations between IL-4 and IL-10 downregulation and TNF-α were observed. However, in IH HDCs group, a significant positive correlation between IL-4 and IL-10 upregulation and TNF-α, were recorded (p<0.05). In addition, IV BM-MSCs and IH HDCs treatments significantly increased antioxidant enzymes activity (p<0.05). IV and IH BM-MSCs significantly ameliorated liver transaminase levels, whereas IH HDCs significantly ameliorated alanine aminotransferase activity and nitric oxide concentration (p<0.05).

Conclusion:

The administration routes of BM-MSCs did not demonstrate any significant difference; however, the IH route of HDCs showed significant amelioration from the IV route. On the other hand, it showed noticeable anti-inflammatory and immunomodulatory improvements in aflatoxicosis rats. Therefore, it can be concluded that acute hepatitis can be treated by a noninvasive IV route without the expense of hepatogenic differentiation. Further research using clinical trials that address several problems regarding engraftment and potentiation are needed to determine the optimal manipulation strategy as well as to achieve better long term effects.

The therapeutic effects of stem cells from human exfoliated deciduous teeth on clinical diseases: a narrative review study

INTRODUCTION

Stem cells isolated from human dental pulp tissue are different from other sources of Mesenchymal stem cells because of their embryonic neural crest sources and neuro-trophic potential. These stem cells consist of dental pulp stem cells from human permanent teeth and stem cells from human exfoliated deciduous teeth.

AIM

In this study, we survey the advantages and disadvantages of these stem cells with therapies attitude.

MAIN TEXT

Stem cells from human exfoliated deciduous teeth with a high proliferation rate could distinguish into a wide types of cells. After stem cell banking appearance, stem cells from human exfoliated deciduous teeth can preserve and use for treatment, especially in regenerative medicine. But the crucial health hazards related to stem cell transplantation, such as immune rejection reactions and the interaction with other tissues, should not be neglected.

CONCLUSION

Further experiments are required to approve the impact of these stem cells on different human disorders.

Dental pulp stem cells as a therapy for congenital entero-neuropathy

Hirschsprung's disease is a congenital entero-neuropathy that causes chronic constipation and intestinal obstruction. New treatments for entero-neuropathy are needed because current surgical strategies have limitations5. Entero-neuropathy results from enteric nervous system dysfunction due to incomplete colonization of the distal intestine by neural crest-derived cells. Impaired cooperation between the enteric nervous system and intestinal pacemaker cells may also contribute to entero-neuropathy. Stem cell therapy to repair these multiple defects represents a novel treatment approach. Dental pulp stem cells derived from deciduous teeth (dDPSCs) are multipotent cranial neural crest-derived cells, but it remains unknown whether dDPSCs have potential as a new therapy for entero-neuropathy. Here we show that intravenous transplantation of dDPSCs into the Japanese Fancy-1 mouse, an established model of hypoganglionosis and entero-neuropathy, improves large intestinal structure and function and prolongs survival. Intravenously injected dDPSCs migrate to affected regions of the intestine through interactions between stromal cell-derived factor-1α and C-X-C chemokine receptor type-4. Transplanted dDPSCs differentiate into both pacemaker cells and enteric neurons in the proximal colon to improve electrical and peristaltic activity, in addition to their paracrine effects. Our findings indicate that transplanted dDPSCs can differentiate into different cell types to correct entero-neuropathy-associated defects.

Hydrogel supplemented with human platelet lysate enhances multi-lineage differentiation of mesenchymal stem cells

Stem cells from human exfoliated deciduous teeth (SHED) can be used as a potential clinical material. But the use of xenogeneic ingredients will increase the risk of zoonotic disease transmission. Human platelet lysate (HPL) is a potential surrogate and used in human cell expansion with reliability in clinical applications. In this study, we synthesized chitosan/gelatin/gellan gum hydrogel supplemented with HPL and investigated the effect of 3D culture for SHED. TMT-tagged proteomics was used to decipher the secretome protein profiles of SHEDs and a total of 3209 proteins were identified, of which 23 were up-regulated and 192 were down-regulated. The results showed that hydrogel supplemented with HPL promoted SHED proliferation. After induction, the hydrogel coating contributed to osteogenic differentiation, adipogenic differentiation and differentiation into neural-like cells of SHED. SHED encapsulated in a hydrogel promotes migration and angiogenesis of HUVEC. In conclusion, our research found that hydrogel supplemented with HPL can be used as a method for SHED in standardized production and can contribute to the clinical application of SHED in cell therapy.

A New Target of Dental Pulp-Derived Stem Cell-Based Therapy on Recipient Bone Marrow Niche in Systemic Lupus Erythematosus

Recent advances in mesenchymal stem/stromal cell (MSC) research have led us to consider the feasibility of MSC-based therapy for various diseases. Human dental pulp-derived MSCs (hDPSCs) have been identified in the dental pulp tissue of deciduous and permanent teeth, and they exhibit properties with self-renewal and in vitro multipotency. Interestingly, hDPSCs exhibit superior immunosuppressive functions toward immune cells, especially T lymphocytes, both in vitro and in vivo. Recently, hDPSCs have been shown to have potent immunomodulatory functions in treating systemic lupus erythematosus (SLE) in the SLE MRL/lpr mouse model. However, the mechanisms underlying the immunosuppressive efficacy of hDPSCs remain unknown. This review aims to introduce a new target of hDPSC-based therapy on the recipient niche function in SLE.

Angiogenic and Migratory Gene Expression Analysis of Stem Cells From Exfoliated Deciduous Teeth for Wound Repair Application

BACKGROUND

The migration and differentiation of stem cells take place during the reparative phase of the healing cascade. Chemokine ligands and receptors are the key players in the homing process dur-ing the early stage of capillary morphogenesis. Stem cells from exfo-liated deciduous teeth are known to possess a huge potential benefit for tissue regeneration. However, the gene expression of SHED en-gaging in angiogenesis and migratory activity during tissue healing is not fully understood. This study aims to assess the gene expression of SHED following in-vitro angiogenesis and migratory induction protocol.

METHODS

Scratch test assay was conducted following an angiogenic induction of SHED by supplementation of EGM-2 and VEGF. For the detection of migratory cell markers, angiogenic markers, and stem cell markers, RNA samples were extracted on day 1, 3, 7, 10, and 14 after the angiogenic induction in a transwell chamber, followed by RT-PCR analysis.

RESULTS

The findings sug-gested that SHED forming endothelial cells at higher capacity under an immature state with higher seeding density. SHED undergoing angiogenesis and migratory activity showed elevated IL-8, CCR1, CXCR4 and CCL28 expression. CCR1 expression significantly in-creased in the A+M+ group (p<0.05).

CONCLUSION

The gene expres-sion of these chemokines, particularly CCR1, which closely represent cellular migration, suggests the potential use of SHED for cell-based therapy to enhance tissue repair.

Multipotency and Immunomodulatory Benefits of Stem Cells From Human Exfoliated Deciduous Teeth

Stem cells derived from human exfoliated deciduous teeth (SHEDs) are considered a promising cell population for cell-based or cell-free therapy and tissue engineering because of their proliferative, multipotency and immunomodulator. Based on recent studies, we find that SHEDs show the superior ability of nerve regeneration in addition to the potential of osteogenesis, odontogenesis owing to their derivation from the neural crest. Besides, much evidence suggests that SHEDs have a paracrine effect and can function as immunomodulatory regents attributing to their capability of secreting cytokines and extracellular vesicles. Here, we review the characteristic of SHEDs, their multipotency to regenerate damaged tissues, specifically concentrating on bones or nerves, following the paracrine activity or immunomodulatory benefits of their potential for clinical application in regenerative medicine.

Biliary atresia-specific deciduous pulp stem cells feature biliary deficiency

BACKGROUND

Biliary atresia (BA) is a severe hepatobiliary disease in infants that ultimately results in hepatic failure; however, its pathological mechanism is poorly elucidated. Current surgical options, including Kasai hepatoportoenterostomy and orthotopic liver organ transplantations, are palliative; thus, innovation in BA therapy is urgent.

METHODS

To examine whether BA-specific post-natal stem cells are feasible for autologous cell source for BA treatment, we isolated from human exfoliated deciduous teeth, namely BA-SHED, using a standard colony-forming unit fibroblast (CFU-F) method and compared characteristics as mesenchymal stem cells (MSCs) to healthy donor-derived control SHED, Cont-SHED. BA-SHED and Cont-SHED were intrasplenically transplanted into chronic carbon tetrachloride (CCl₄)-induced liver fibrosis model mice, followed by the analysis of bile drainage function and donor integration in vivo. Immunohistochemical assay was examined for the regeneration of intrahepatic bile ducts in the recipient's liver using anti-human specific keratin 19 (KRT19) antibody.

RESULTS

BA-SHED formed CFU-F, expressed MSC surface markers, and exhibited in vitro mesenchymal multipotency similar to Cont-SHED. BA-SHED showed less in vitro hepatogenic potency than Cont-SHED. Cont-SHED represented in vivo bile drainage function and KRT19-positive biliary regeneration in chronic carbon tetrachloride-induced liver fibrosis model mice. BA-SHED failed to show in vivo biliary potency and bile drainage function compared to Cont-SHED.

CONCLUSION

These findings indicate that BA-SHED are not feasible source for BA treatment, because BA-SHED may epigenetically modify the underlying prenatal and perinatal BA environments. In conclusion, these findings suggest that BA-SHED-based studies may provide a platform for understanding the underlying molecular mechanisms of BA development and innovative novel modalities in BA research and treatment.

Multidifferentiation potential of dental-derived stem cells

Tooth-related diseases and tooth loss are widespread and are a major public health issue. The loss of teeth can affect chewing, speech, appearance and even psychology. Therefore, the science of tooth regeneration has emerged, and attention has focused on tooth regeneration based on the principles of tooth development and stem cells combined with tissue engineering technology. As undifferentiated stem cells in normal tooth tissues, dental mesenchymal stem cells (DMSCs), which are a desirable source of autologous stem cells, play a significant role in tooth regeneration. Researchers hope to reconstruct the complete tooth tissues with normal functions and vascularization by utilizing the odontogenic differentiation potential of DMSCs. Moreover, DMSCs also have the ability to differentiate towards cells of other tissue types due to their multipotency. This review focuses on the multipotential capacity of DMSCs to differentiate into various tissues, such as bone, cartilage, tendon, vessels, neural tissues, muscle-like tissues, hepatic-like tissues, eye tissues and glands and the influence of various regulatory factors, such as non-coding RNAs, signaling pathways, inflammation, aging and exosomes, on the odontogenic/osteogenic differentiation of DMSCs in tooth regeneration. The application of DMSCs in regenerative medicine and tissue engineering will be improved if the differentiation characteristics of DMSCs can be fully utilized, and the factors that regulate their differentiation can be well controlled.

Potential therapeutic uses of intraoral mesenchymal stem cells in other tissues of the body: A review

BACKGROUND

Over the last few years, there has been a great advance in regenerative medicine, with various studies that have observed the ability to repair or regenerate dysfunctional tissues with the patient's own cells, such as with mesenchymal cells. In this area, mesenchymal stem cells (MSCs) from the oral cavity have attracted attention because of their easy access and multiple cellular differentiations. Multiple studies have shown the various clinical applications at the intraoral level, especially at the level of bone regeneration, but the potential applications of oral MSC at a systemic level have been scarcely described. Objective: The objective of this review was to describe the potential therapeutic uses of intraoral MSCs in other tissues of the organism.

MATERIAL AND METHODS

A review of the literature between 2000 and 2019. Only included those studies done on animals or humans.

RESULTS

Twenty five articles were selected, all performed on animals. The donor site most used were the temporary teeth exfoliated from humans, representing 56% of the total articles, followed by the dental pulp with 28% of the total articles included. Transplantation of intraoral mesenchymal cells in animals with neural tissue illness was the most studied therapy.

CONCLUSIONS

Although obtaining MSC of intraoral origin has proven to be a good alternative in regenerative medicine, achieving therapeutic uses in bone tissue, nervous tissue, liver tissue, skin tissue, ocular tissue, reperfusion of tissues and in autoimmune diseases, there is a lack of clinical studies that allow its safe use in humans. Key words:Mesenchymal stem cells, stem cell transplantation, regenerative medicine, dental component.

Bone marrow mesenchymal stem cell co-adjuvant therapy with albendazole for managing Toxocara vitulorum-rat model

Background and Aim:

Toxocara vitulorum is a bovine intestinal nematode. Immune pictures following infection are conflicting and stopping anthelmintic albendazole treatment recording reversed liver abnormalities. The purpose of this work was to evaluate the therapeutic potential of bone marrow mesenchymal stem cells (BMMSCs) therapy, subsequent to albendazole administration in rats infected with T. vitulorum.

Materials and Methods:

The ultrasonographic and histopathological examinations as well as serum liver enzymes activity and the kinetics of recovery were investigated. The correlation of cell-mediated and humoral immune pictures was assessed by assaying immunoglobulins, splenocytes viability, phagocytic index, and Th1/Th2 cytokines.

Results:

The cultured BMMSCs counting were 4.21×10⁴ cells/cm² with 96.03% viability. Flow-cytometric analysis indicated positive CD90 (82%), CD105 (79%) and negative CD34 (0.37%), CD45 (0.42%), attesting to the suitability of the isolated BMMSCs for use in therapy. Transplantation of BMMSCs after albendazole administration significantly reduced the release of liver enzymes (p<0.05) indicating liver cellularity improvement. The ultrasonographic, macroscopic, and histopathological findings confirmed the biochemical results. Significant elevation in the levels of tumor necrosis factor (TNF)-α and interferon (INF)-γ with a decline in interleukin (IL)-4 was observed in the untreated model (p<0.05). However, albendazole treatment followed by BMMSCs therapy significantly lowered the release of TNF-α and INF-γ, associated with significant production of IL-4 and IL-10 (p<0.05).

Conclusion:

The final results indicated that the liver functions, histopathological findings, and immune parameters were aggravated after experimental T. vitulorum infection. Albendazole treatment followed by BMMSCs therapy was found to assist in regeneration of injured hepatic tissue. Besides, it appeared to modulate host defensive immune responses against T. vitulorum antigens. This work could define more clearly the events that manipulate the host immune, histopathological, and biochemical responses to minimize obstacles in using stem cell therapy in animal toxocariosis.

Cholangiogenic potential of human deciduous pulp stem cell-converted hepatocyte-like cells

Background

Stem cells from human exfoliated deciduous teeth (SHED) have been reported to show the in vivo and in vitro hepatic differentiation, SHED-Heps; however, the cholangiogenic potency of SHED-Heps remains unclear. Here, we hypothesized that SHED-Heps contribute to the regeneration of intrahepatic bile duct system in chronic fibrotic liver.

Methods

SHED were induced into SHED-Heps under cytokine stimulation. SHED-Heps were intrasplenically transplanted into chronically CCl₄-treated liver fibrosis model mice, followed by the analysis of donor integration and hepatobiliary metabolism in vivo. Immunohistochemical assay was examined for the regeneration of intrahepatic bile duct system in the recipient liver. Furthermore, SHED-Heps were induced under the stimulation of tumor necrosis factor alpha (TNFA).

Results

The intrasplenic transplantation of SHED-Heps into CCl₄-treated mice showed that donor SHED-Heps behaved as human hepatocyte paraffin 1- and human albumin-expressing hepatocyte-like cells in situ and ameliorated CCl₄-induced liver fibrosis. Of interest, the integrated SHED-Heps not only expressed biliary canaliculi ATP-binding cassette transporters including ABCB1, ABCB11, and ABCC2, but also recruited human keratin 19- (KRT19-) and KRT17-positive cells, which are considered donor-derived cholangiocytes, regenerating the intrahepatic bile duct system in the recipient liver. Furthermore, the stimulation of TNFA induced SHED-Heps into KRT7- and SRY-box 9-positive cells.

Conclusions

Collectively, our findings demonstrate that infused SHED-Heps showed cholangiogenic ability under the stimulation of TNFA in CCl₄-damaged livers, resulting in the regeneration of biliary canaliculi and interlobular bile ducts in chronic fibrotic liver. Thus, the present findings suggest that SHED-Heps may be a novel source for the treatment of cholangiopathy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-020-02113-8.

Stem cells from human exfoliated deciduous teeth ameliorate concanavalin A-induced autoimmune hepatitis by protecting hepatocytes from apoptosis

BACKGROUND

Autoimmune hepatitis is a serious autoimmune liver disease that threatens human health worldwide, which emphasizes the urgent need to identify novel treatments. Stem cells from human exfoliated deciduous teeth (SHED), which are easy to obtain in a non-invasive manner, show pronounced proliferative and immunomodulatory capacities.

AIM

To investigate the protective effects of SHED on concanavalin A (ConA)-induced hepatitis in mice, and to elucidate the associated regulatory mechanisms.

METHODS

We used a ConA-induced acute hepatitis mouse model and an in vitro co-culture system to study the protective effects of SHED on ConA-induced autoimmune hepatitis, as well as the associated underlying mechanisms.

RESULTS

SHED infusion could prevent aberrant histopathological liver architecture caused by ConA-induced infiltration of CD3⁺, CD4⁺, tumor necrosis-alpha⁺, and interferon-gamma⁺ inflammatory cells. Alanine aminotransferase and aspartate aminotransferase were significantly elevated in hepatitis mice. SHED infusion could therefore block ConA-induced alanine aminotransferase and aspartate aminotransferase elevations. Mechanistically, ConA upregulated tumor necrosis-alpha and interferon-gamma expression, which was activated by the nuclear factor-kappa B pathway to induce hepatocyte apoptosis, resulting in acute liver injury. SHED administration protected hepatocytes from ConA-induced apoptosis.

CONCLUSION

SHED alleviates ConA-induced acute liver injury via inhibition of hepatocyte apoptosis mediated by the nuclear factor-kappa B pathway. Our findings could provide a potential treatment strategy for hepatitis.

Unveiling diversity of stem cells in dental pulp and apical papilla using mouse genetic models: a literature review

The dental pulp, a non-mineralized connective tissue uniquely encased within the cavity of the tooth, provides a niche for diverse arrays of dental mesenchymal stem cells. Stem cells in the dental pulp, including dental pulp stem cells (DPSCs), stem cells from human exfoliated deciduous teeth (SHEDs) and stem cells from apical papilla (SCAPs), have been isolated from human tissues with an emphasis on their potential application to regenerative therapies. Recent studies utilizing mouse genetic models shed light on the identities of these mesenchymal progenitor cells derived from neural crest cells (NCCs) in their native conditions, particularly regarding how they contribute to homeostasis and repair of the dental tissue. The current concept is that at least two distinct niches for stem cells exist in the dental pulp, e.g., the perivascular niche and the perineural niche. The precise identities of these stem cells and their niches are now beginning to be unraveled thanks to sophisticated mouse genetic models, which lead to better understanding of the fundamental properties of stem cells in the dental pulp and the apical papilla in humans. The new knowledge will be highly instrumental for developing more effective stem cell-based regenerative therapies to repair teeth in the future.

Comparative characterization and osteogenic / adipogenic differentiation of mesenchymal stem cells derived from male rat hair follicles and bone marrow

Clinical applications of cell therapy and tissue regeneration under different conditions need a multiplicity of adult stem cell sources. Up to date, little is available on the comparative isolation, characterization, proliferation, rapid amplification, and osteogenic/adipogenic differentiation of rat mesenchymal stem cells (MSCs) isolated from living bulge cells of the hair follicle (HF) and bone marrow (BM) from the same animal. This work hopes to use HF-MSCs as an additional adult stem cell source for research and application. After reaching 80% confluence, the cell counting, viability %, and yields of HF-MSCs and BM-MSCs were nearly similar. The viability % was 91.41 ± 2.98 and 93.11 ± 3.06 while the cells yield of initial seeding was 33.15 ± 2.76 and 34.22 ± 3.99 and of second passage was 28.76 ± 1.01 and 29.56 ± 3.11 for HF-MSCs and BM-MSCs respectively. Clusters of differentiation (CDs) analysis revealed that HF-MSCs were positively expressed CD34, CD73 and CD200 and negatively expressed CD45. BM-MSCs were positively expressed CD73 and CD200 and negatively expressed of CD34 and CD45. The proliferation of HF-MSCs and BM-MSCs was determined by means of incorporation of Brd-U, population doubling time (PDT) assays and the quantity of formazan release. The percentage of Brd-U positive cells and PDT were relatively similar in both types of cells. The proliferation, as expressed by the quantity of formazan assay in confluent cells, revealed that the quantity of release by BM-MSCs was slightly higher than HF-MSCs. Adipogenic differentiated BM-MSCs showed moderate accumulation of oil red-O stained lipid droplets when compared to that of HF-MSCs which exhibited high stain. The total lipid concentration was significantly higher in adipogenic differentiated HF-MSCs than BM-MSCs (P < 0.05). It was found that activity of bone alkaline phosphatase and calcium concentration were significantly higher (P < 0.01 and P < 0.05 respectively) in osteogenic differentiated BM-MSCs than that of HF-MSCs. The present findings demonstrate that the HF-MSCs are very similar in most tested characteristics to BM-MSCs with the exception of differentiation. Additionally; no issues have been reported during the collection of HF-MSCs. Therefore, the HF may represent a suitable and accessible source for adult stem cells and can be considered an ideal cell source for adipogenesis research.

Extracellular vesicles from deciduous pulp stem cells recover bone loss by regulating telomerase activity in an osteoporosis mouse model

BACKGROUND

Systemic transplantation of stem cells from human exfoliated deciduous teeth (SHED) recovers bone loss in animal models of osteoporosis; however, the mechanisms underlying this remain unclear. Here, we hypothesized that trophic factors within SHED-releasing extracellular vesicles (SHED-EVs) rescue osteoporotic phenotype.

METHODS

EVs were isolated from culture supernatant of SHED. SHED-EVs were treated with or without ribonuclease and systemically administrated into ovariectomized mice, followed by the function of recipient bone marrow mesenchymal stem cells (BMMSCs) including telomerase activity, osteoblast differentiation, and sepmaphorine-3A (SEMA3A) secretion. Subsequently, human BMMSCs were stimulated by SHED-EVs with or without ribonuclease treatment, and then human BMMSCs were examined regarding the function of telomerase activity, osteoblast differentiation, and SEMA3A secretion. Furthermore, SHED-EV-treated human BMMSCs were subcutaneously transplanted into the dorsal skin of immunocompromised mice with hydroxyapatite tricalcium phosphate (HA/TCP) careers and analyzed the de novo bone-forming ability.

RESULTS

We revealed that systemic SHED-EV-infusion recovered bone volume in ovariectomized mice and improved the function of recipient BMMSCs by rescuing the mRNA levels of Tert and telomerase activity, osteoblast differentiation, and SEMA3A secretion. Ribonuclease treatment depleted RNAs, including microRNAs, within SHED-EVs, and these RNA-depleted SHED-EVs attenuated SHED-EV-rescued function of recipient BMMSCs in the ovariectomized mice. These findings were supported by in vitro assays using human BMMSCs incubated with SHED-EVs.

CONCLUSION

Collectively, our findings suggest that SHED-secreted RNAs, such as microRNAs, play a crucial role in treating postmenopausal osteoporosis by targeting the telomerase activity of recipient BMMSCs.

Insight into the Role of Dental Pulp Stem Cells in Regenerative Therapy

Mesenchymal stem cells (MSCs) have the capacity for self-renewal and multilineage differentiation potential, and are considered a promising cell population for cell-based therapy and tissue regeneration. MSCs are isolated from various organs including dental pulp, which originates from cranial neural crest-derived ectomesenchyme. Recently, dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHEDs) have been isolated from dental pulp tissue of adult permanent teeth and deciduous teeth, respectively. Because of their MSC-like characteristics such as high growth capacity, multipotency, expression of MSC-related markers, and immunomodulatory effects, they are suggested to be an important cell source for tissue regeneration. Here, we review the features of these cells, their potential to regenerate damaged tissues, and the recently acquired understanding of their potential for clinical application in regenerative medicine.

Pulp stem cells derived from human permanent and deciduous teeth: Biological characteristics and therapeutic applications

Human pulp stem cells (PSCs) include dental pulp stem cells (DPSCs) isolated from dental pulp tissues of human extracted permanent teeth and stem cells from human exfoliated deciduous teeth (SHED). Depending on their multipotency and sensitivity to local paracrine activity, DPSCs and SHED exert therapeutic applications at multiple levels beyond the scope of the stomatognathic system. This review is specifically concentrated on PSC-updated biological characteristics and their promising therapeutic applications in (pre)clinical practice. Biologically, distinguished from conventional mesenchymal stem cell markers in vitro, NG2, Gli1, and Celsr1 have been evidenced as PSC markers in vivo. Both perivascular cells and glial cells account for PSC origin. Therapeutically, endodontic regeneration is where PSCs hold the most promises, attributable of PSCs' robust angiogenic, neurogenic, and odontogenic capabilities. More recently, the interplay between cell homing and liberated growth factors from dentin matrix has endowed a novel approach for pulp-dentin complex regeneration. In addition, PSC transplantation for extraoral tissue repair and regeneration has achieved immense progress, following their multipotential differentiation and paracrine mechanism. Accordingly, PSC banking is undergoing extensively with the intent of advancing tissue engineering, disease remodeling, and (pre)clinical treatments.

A model study for the manufacture and validation of clinical-grade deciduous dental pulp stem cells for chronic liver fibrosis treatment

BACKGROUND

Human deciduous pulp stem cells (hDPSCs) have remarkable stem cell potency associated with cell proliferation, mesenchymal multipotency, and immunosuppressive function and have shown beneficial effects in a variety of animal disease models. Recent studies demonstrated that hDPSCs exhibited in vivo anti-fibrotic and anti-inflammatory action and in vivo hepatogenic-associated liver regeneration, suggesting that hDPSCs may offer a promising source with great clinical demand for treating liver diseases. However, how to manufacture ex vivo large-scale clinical-grade hDPSCs with the appropriate quality, safety, and preclinical efficacy assurances remains unclear.

METHODS

We isolated hDPSCs from human deciduous dental pulp tissues formed by the colony-forming unit-fibroblast (CFU-F) method and expanded them under a xenogeneic-free and serum-free (XF/SF) condition; hDPSC products were subsequently stored by two-step banking including a master cell bank (MCB) and a working cell bank (WCB). The final products were directly thawed hDPSCs from the WCB. We tested the safety and quality check, stem cell properties, and preclinical potentials of final hDPSC products and hDPSC products in the MCB and WCB.

RESULTS

We optimized manufacturing procedures to isolate and expand hDPSC products under a XF/SF culture condition and established the MCB and the WCB. The final hDPSC products and hDPSC products in the MCB and WCB were validated the safety and quality including population doubling ability, chromosome stability, microorganism safety, and stem cell properties including morphology, cell surface marker expression, and multipotency. We also evaluated the in vivo immunogenicity and tumorigenicity and validated in vivo therapeutic efficacy for liver regeneration in a CCl₄-induced chronic liver fibrosis mouse model in the final hDPSC products and hDPSC products in the WCB.

CONCLUSION

The manufacture and quality control results indicated that the present procedure could produce sufficient numbers of clinical-grade hDPSC products from a tiny deciduous dental pulp tissue to enhance clinical application of hDPSC products in chronic liver fibrosis.

An update on human periapical cyst-mesenchymal stem cells and their potential applications in regenerative medicine

The broad clinical applications of Mesenchymal Stem Cells (MSCs) in the regenerative medicine field is attributed to their ability to self-renew and differentiate into multiple cellular lineages. Nowadays, MSCs can be derived from a variety of adult and fetal tissues including bone marrow, adipose tissue, umbilical cord and placenta. The difficulties associated with the isolation of MSCs from certain tissues such as bone marrow promoted the search for alternative tissues which are easily accessible. Oral derived MSCs include dental pulp stem cells (DPSCs), dental follicle progenitor cells (DFPC), and periodontal ligament stem cells (PDLSC). Being abundant and easily accessible, oral derived MSCs represent an interesting alternative MSC type to be employed in regenerative medicine. Human periapical cyst-mesenchymal stem cells (hPCy-MSCs) correspond to a newly discovered and characterized MSC subtype. Interestingly, hPCy-MSCs are collected from periapical cysts, which are a biological waste, without any influence on the other healthy tissues in oral cavity. hPCy-MSCs exhibit cell surface marker profile similar to that of other oral derived MSCs, show high proliferative potency, and possess the potential to differentiate into different cell types such as osteoblasts, adipocytes and neurons-like cells. hPCy-MSCs, therefore, represent a novel promising MSCs type to be applied in regenerative medicine domain. In this review, we will compare the different types of dental derived MSCs, we will highlight the isolation technique, the characteristics, and the therapeutic potential of hPCy-MSCs.

Multi-lineage differentiation and clinical application of stem cells from exfoliated deciduous teeth

Stem cells from human exfoliated deciduous teeth (SHED) have now been considered one of the most promising sources of stem cells for tissue engineering and stem cell therapies due to their stemness and potential to differentiate into other cell lines. The high proliferation rate, the differentiation capacity, the easy access and less ethical concerns make SHED a brilliant solution for many diseases. The purpose of this review is to describe current knowledge of SHED's capability of differentiation, applications and immune status and to draw attention to further research on the mechanism and the dependability of stem cell therapy with SHED.

A study of the differentiation of stem cells from human exfoliated deciduous teeth on 3D silk fibroin scaffolds using static and dynamic culture paradigms

Stem cells from human exfoliated deciduous teeth (SHED) are considered the best current source of human stem cells due to their ability to differentiate into multiple cell lineages. Dynamic co-culture systems can improve the culture environment, as they provide cells with signaling factors, extracellular matrixes, and cellular shear force, as well as enable the formation of heterotypic clusters. We seeded SHED in 3D silk fibroin porous scaffolds under static and dynamic cultures for 28 days, using the NIH3T3 cultivated medium as an induction agent. Many hepatospheres formed in these porous scaffolds, and cellular viability was shown to continually increase by MTT assays. Hepatic AFP and ALB gene expression, as well as glycogen storage, albumin secretion, and urea synthesis, were greater in cells in the 3D porous scaffold under a dynamic culture than in those cultured under 3D static culture and petri dish conditions. However, the 3D static culture is still superior to the traditional petri dish culture. The NIH3T3 cultivated medium can significantly induce hepatic differentiation of SHED, while the 3D dynamic culture system significantly enhances hepatic differentiation of SHED. This study provides alternative sources of hepatocytes for liver disease treatment.

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.

Bone marrow-derived mesenchymal stem cell (BM-MSC): A tool of cell therapy in hydatid experimentally infected rats

This study aimed to clarify the potentiality of bone marrow mesenchymal stem cells (BM-MSC) transplantation with albendazole (ABZ) on the modulation of immune responses against hydatid cyst antigens and the regeneration of injured livers in experimentally infected rats. Three different antigens of hydatid cyst fluid (HCF), hydatid cyst protoscolex (HCP) and hydatid cyst germinal layer (HCG) were isolated and their antigenic potencies were determined. The ultrasound, immunological and pathological criteria were investigated. Counting of 80% confluence BM-MSC was 4.68 × 104 cells/cm2 with 92.24% viability. Final population doublings score was 65.31 that indicated proliferation and self-renewability. Phenotyping of BM-MSC showed expression of CD73 and CD29 without exhibition of CD34 and CD14. Ultrasound examination showed multiple hydatid cysts in liver with low blood flow and spleenomegaly 8 weeks' post infection. No significant differences were noted in cystic diameter in uni-cyst liver at 2nd and 4th weeks following ABZ treatment while it was significantly decreased (P < 0.05) following transplantation of BM-MSC + ABZ treatment comparing to experimentally infected untreated group. Igs and IgG responses to the three antigens were significantly elevated while elevation in IgM response was only to HCG (P < 0.05). ABZ treatment accompanied with significant decrease in Igs and IgG titers against HCF and HCG only at 4th week post treatment (P < 0.05). However, Igs titer against HCF, HCP and HCG was significantly decreased at the 4th week following transplantation of BM-MSC + ABZ. Interestingly, the combination of BM-MSC + ABZ treatment resulted in reduction of Igs response to HCP to normal level as that of healthy control. Experimental infection resulted in elevation of TNF-α and IL-6 (P < 0.05) while, IL-4 and IL-10 decreased (P < 0.01). After transplantation of BM-MSC + ABZ treatment, serum TNF-α and IL-6 concentrations were reduced (P < 0.05) at both the 2nd and 4th weeks. However, IL-4 and IL-10 concentrations were significantly elevated (P < 0.05) only at 4th week following transplantation of BM-MSC + ABZ treatment. In conclusion, BM-MSC transplantation following ABZ administration can regenerate injured liver tissue without complete disappearance of hydatid cyst. In addition, it can modulate host protective humeral and cell mediated immune responses against hydatid cyst antigens. Therefore, the current study encourages to move to the step of performing clinical trials in humans.

Exosomes of stem cells from human exfoliated deciduous teeth as an anti-inflammatory agent in temporomandibular joint chondrocytes via miR-100-5p/mTOR

Objectives

Temporomandibular joint osteoarthritis (TMJOA) is an inflammatory joint disease. This study investigated whether exosomes (Exos) of stem cells from human exfoliated deciduous teeth (SHEDs) have a therapeutic effect on TMJ inflammation and elucidated the underlying mechanisms.

Materials and methods

SHEDs were verified by flow cytometry. SHED-Exos were identified by western blotting, nanoparticle tracking analysis, and transmission electron microscopy. Western blot and RT-qPCR were performed to verify the anti-inflammatory effects of SHED-Exos. MicroRNA (miRNA) array analysis was conducted to determine the miRNA expression profiles of SHED-Exos, and the key pathways were analyzed. After chondrocytes were treated with an miR-100-5p mimic or rapamycin, relative expression of genes was measured by RT-qPCR and western blotting. A luciferase reporter assay was performed to reveal the molecular role of the exosomal miR-100 target, mTOR.

Results

MiR-100-5p was enriched in the SHED-Exos. Treatment with SHED-Exos suppressed the expression of interleukin-6 (IL-6), IL-8, matrix metalloproteinase 1 (MMP1), MMP3, MMP9, MMP13, and disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS5). Chondrocytes treated with the miR-100 mimic showed lower expression of MMP1, MMP9, MMP13, ADAMTS5, and mTOR. In contrast, miR-100 downregulation upregulated the MMPs and mTOR. Rapamycin treatment upregulated miR-100 and downregulated MMPs and ADAMTS5. Furthermore, the luciferase reporter assay demonstrated that miR-100-5p directly targeted the mTOR 3′ untranslated region and that SHED-Exos miR-100-5p repressed mTOR expression.

Conclusions

This study demonstrated that SHED-Exos suppress inflammation in TMJ chondrocytes and may thus be a novel therapeutic agent for TMJ inflammation.

Stem cells from exfoliated deciduous teeth alleviate hyposalivation caused by Sjögren syndrome

OBJECTIVES

To evaluate the effect of stem cells  from  exfoliated  deciduous  teeth on the hyposalivation caused by Sjögren syndrome (SS) and investigate the mechanism.

METHODS

Stem cells were injected into the tail veins of non-obese diabetic mice, the animal model of SS. The saliva flow was measured after pilocarpine intraperitoneal injection. Apoptosis and autophagy were evaluated by TUNEL and Western blot. Lymphocyte proportions were detected by flow cytometer.

RESULTS

Fluid secretion was decreased in 21-week-old mice. Stem cell treatment increased fluid secretion, alleviated inflammation in the submandibular glands and reduced inflammatory cytokine levels in the serum, submandibular glands and saliva. Stem cells decreased the apoptotic cell number and the expressions of ATG5 and Beclin-1 in the submandibular glands. Stem cells have no effect on other organs. Furthermore, the infused stem cells migrated to the spleen and liver, not the submandibular gland. Stem cells directed T cells towards Treg cells and suppressed Th1 and Tfh cells in spleen lymphocytes.

CONCLUSION

Stem cells  from  exfoliated  deciduous  teeth alleviate the hyposalivation caused by SS via decreasing the inflammatory cytokines, regulating the inflammatory microenvironment and decreasing the apoptosis and autophagy. The stem cells regulated in T-cell differentiation are involved in the immunomodulatory effects.

Clinical Potential and Current Progress of Dental Pulp Stem Cells for Various Systemic Diseases in Regenerative Medicine: A Concise Review

Dental pulp stem cells (DPSCs) are mesenchymal stem cells (MSCs) that have multipotent differentiation and a self-renewal ability. They have been useful not only for dental diseases, but also for systemic diseases. Extensive studies have suggested that DPSCs are effective for various diseases, such as spinal cord injuries, Parkinson's disease, Alzheimer's disease, cerebral ischemia, myocardial infarction, muscular dystrophy, diabetes, liver diseases, eye diseases, immune diseases, and oral diseases. DPSCs have the potential for use in a cell-therapeutic paradigm shift to treat these diseases. It has also been reported that DPSCs have higher regenerative potential than the bone marrow-derived mesenchymal stem cells known as representative MSCs. Therefore, DPSCs have recently gathered much attention. In this review, the therapeutic potential of DPSCs, the latest progress in the pre-clinical study for treatment of these various systemic diseases, and the clinical applications of DPSCs in regenerative medicine, are all summarized. Although challenges, including mechanisms of the effects and establishment of cell processing and transplantation methods for clinical use, still remain, DPSCs could be promising stem cells sources for various clinical applications, because of their easy isolation by a noninvasive procedure without ethical concerns.

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.

Stem cells from human exfoliated deciduous teeth ameliorate type II diabetic mellitus in Goto-Kakizaki rats

BACKGROUND

By 2030, diabetes mellitus (DM) will be the 7th leading cause of death worldwide. Type 2 DM (T2DM) is the most common type of DM and is characterized by insulin resistance and defective β-cell secretory function. Stem cells from human exfoliated deciduous teeth (SHED) are favorable seed cells for mesenchymal stem cells (MSCs)-based therapy due to their higher proliferation rates and easier access to retrieval. Currently, no study has revealed the therapeutic efficiency of MSCs for T2DM in Goto-Kakizaki (GK) rats. Hence, we aimed to explore the effect of SHED on T2DM in GK rats.

MATERIALS AND METHODS

We investigated the effects of SHED on the progression of T2DM in GK rats. SHED and bone marrow mesenchymal stem cells (BMSCs) were injected via the tail vein. Body weight, fasting blood glucose and non-fasting blood glucose were measured before and after administration. At 8 weeks after injection, intraperitoneal insulin tolerance tests (IPITTs) and insulin release tests (IRTs) were performed. Additionally, hematoxylin-eosin (HE) staining, periodic acid-Schiff (PAS) staining and double-label immunofluorescence staining were used to explore the pathological changes in pancreatic islets and the liver. Immunohistochemistry (IHC) was employed to detect SHED engraftment in the liver. Additionally, real-time PCR and western blotting were used to explore glycogen synthesis, glycolysis and gluconeogenesis in the liver.

RESULTS

At 8 weeks after SHED injection, T2DM was dramatically attenuated, including hyperglycemia, IPGTT and IRT. Additionally, histological analysis showed that SHED injection improved pancreatic islet and liver damage. Real-time PCR analysis showed that SHED significantly reversed the diabetic-induced increase of G-6-Pase, Pck1 and PK; and significantly reversed the diabetic-induced decrease of GSK3β, GLUT2, and PFKL. In addition, western blotting demonstrated that SHED significantly reversed the diabetic-induced increase of G-6-Pase and reversed the diabetic-induced decrease of GLUT2, GSK3β and PFKM.

CONCLUSION

Stem cells from human exfoliated deciduous teeth offers a potentially effective therapeutic modality for ameliorating T2DM, including hyperglycemia, insulin resistance, pancreatic islets and liver damage, and decreased glycogen synthesis, inhibited glycolysis and increased gluconeogenesis in the liver.