2,3,5,4′-Tetrahydroxystilbene-2-O-β-glucoside potentiates self-renewal of human dental pulp stem cells via the AMPK/ERK/SIRT1 axis

Stem Cells: Present Understanding and Prospects for Regenerative Dentistry

Regenerative medicine in dentistry focuses on repairing damaged oral tissues using advanced tools like stem cells, biomaterials, and tissue engineering (TE). Mesenchymal stem cells (MSCs) from dental sources, such as dental pulp and periodontal ligament, show significant potential for tissue regeneration due to their proliferative and differentiative abilities. This systematic review, following PRISMA guidelines, evaluated fifteen studies and identified effective strategies for improving dental, periodontal, and bone tissue regeneration through scaffolds, secretomes, and bioengineering methods. Key advancements include the use of dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs) to boost cell viability and manage inflammation. Additionally, pharmacological agents like matrine and surface modifications on biomaterials improve stem cell adhesion and promote osteogenic differentiation. By integrating these approaches, regenerative medicine and TE can optimize dental therapies and enhance patient outcomes. This review highlights the potential and challenges in this field, providing a critical assessment of current research and future directions.

2,3,5,4'-Tetrahydroxystilbene (TG1), a Novel Compound Derived from 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-glucoside (THSG), Inhibits Colorectal Cancer Progression by Inducing Ferroptosis, Apoptosis, and Autophagy

BACKGROUND

Colorectal cancer (CRC) is one of the deadliest cancers worldwide and long-term survival is not guaranteed in metastatic disease despite current multidisciplinary therapies. A new compound 2,3,5,4'-Tetrahydroxystilbene (TG1), derived from THSG (2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside), has been developed, and its anticancer ability against CRC is verified in this study.

METHODS

HCT116, HT-29, and DLD-1 were treated with TG1 and the IC₅₀ was measured using a sulforhodamine B assay. A Xenograft mouse model was used to monitor tumor growth. Apoptosis and autophagy, induced by TG1 in CRC cells, were examined. RNA-sequencing analysis of CRC cells treated with TG1 was performed to discover underlying pathways and mechanisms.

RESULTS

The results demonstrated that treatment with TG1 inhibited CRC proliferation in vitro and in vivo and induced apoptotic cell death, which was confirmed by Annexin V-FITC/PI staining and Western blotting. Additionally, TG1 treatment increased the level of autophagy in cells. RNA-sequencing and GSEA analyses revealed that TG1 was associated with MYC and the induction of ferroptosis. Furthermore, the ferroptosis inhibitor Bardoxolone abrogated the cytotoxic effect of TG1 in CRC cells, indicating that ferroptosis played a crucial role in TG1-induced cytotoxicity.

CONCLUSIONS

These findings suggest that TG1 might be a potential and potent compound for clinical use in the treatment of CRC by inhibiting proliferation and inducing ferroptosis through the MYC pathway.

Dental follicle cells show potential for treating Parkinson's disease through dopaminergic-neuronogenic differentiation

Among all the adult stem cells, odontogenic stem cells inherit the characterization of neurogenic potential of their precursor ones-the cranial crest cells. Dental follicle cells (DFCs), one of the special kind of odontogenic stem cells, are raising interest in applying to regenerative medicine for they possess multi-differentiation potential, relatively free access and ethic-friendly characteristic. Parkinson's disease (PD), as one of the common neurodegenerative disorders, affects about 0.3% of the general population. Stem cell therapies are thought to be effective to treat it. Aiming at tackling ethical-concernings, confined sources and practically applicational limits, we made use of dopaminergic neurongenic differentiation potential of the DFCs and dedicated every effort to applying them as promising cell source for treating PD. Dental follicle cells were cultured from human dental follicle tissues collected from 12 to 18-year-old teenagers' completely impacted third molars. Our data demonstrated that hDFCs were expressing mesenchymal stem cell-associated surface markers, and possessed the ability of osteogenic, adipogenic and neurogenic differentiation in vitro. Additionally, hDFCs formed neuron-like cells in vitro and in vivo, as well as expressing dopaminergic-neuronogenic marker-TH. Moreover, hDFCs survived in the transplanted areas of the Parkinson's disease model of mouse over six weeks post-surgery, and the number of TH-positive DFCs in the DFCs-Grafted group surpassed its counterpart of the MPTP group with statistically significant difference. This study indicated that hDFCs might be a promising source of dopaminergic neurons for functional transplantation, and encouraged further detailed studies on the potential of hDFCs for treating PD.

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.

A Review of Pharmacology, Toxicity and Pharmacokinetics of 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside

Polygonum multiflorum Thunb. (He-shou-wu in Chinese), a Chinese botanical drug with a long history, is widely used to treat a variety of chronic diseases in clinic, and has been given the reputation of “rejuvenating and prolonging life” in many places. 2,3,4′,5-tetrahydroxystilbene-2-O-β-D-glucoside (TSG, C₂₀H₂₂O₉) is the main and unique active ingredient isolated from Polygonum multiflorum Thunb., which has extensive pharmacological activities. Modern pharmacological studies have confirmed that TSG exhibits significant activities in treating various diseases, including inflammatory diseases, neurodegenerative diseases, cardiovascular diseases, hepatic steatosis, osteoporosis, depression and diabetic nephropathy. Therefore, this review comprehensively summarizes the pharmacological and pharmacokinetic properties of TSG up to 2021 by searching the databases of Web of Science, PubMed, ScienceDirect and CNKI. According to the data, TSG shows remarkable anti-inflammation, antioxidation, neuroprotection, cardiovascular protection, hepatoprotection, anti-osteoporosis, enhancement of memory and anti-aging activities through regulating multiple molecular mechanisms, such as NF-κB, AMPK, PI3K-AKT, JNK, ROS-NO, Bcl-2/Bax/Caspase-3, ERK1/2, TGF-β/Smad, Nrf2, eNOS/NO and SIRT1. In addition, the toxicity and pharmacokinetics of TSG are also discussed in this review, which provided direction and basis for the further development and clinical application of TSG.

Comparison of 2,3,5,4'-tetrahydroxystilbene-2-O-b-D-glucoside-induced proliferation and differentiation of dental pulp stem cells in 2D and 3D culture systems-gene analysis

Background/purpose

Culture environments play a critical role in stem cell expansion. This study aimed to evaluate the effects of 2,3,5,4′-tetrahydroxystilbene-2-O-b-D-glucoside (THSG) on the proliferation and differentiation of human dental pulp stem cells (DPSCs) in 2-dimensional (2D) and 3-dimensional (3D) culture systems.

Materials and methods

Human DPSCs were seeded in T25 flasks for 2D cultivation. For the 3D culture system, DPSCs were mixed with microcarriers and cultured in spinner flasks. Cells in both culture systems were treated with THSG, and cell proliferation was determined using a cell counter and a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide assay. In THSG-treated DPSCs, the genes associated with proliferation, adipogenesis, neurogenesis, osteogenesis, pluripotency, oncogenesis, and apoptosis were analyzed using real-time polymerase chain reactions.

Results

The spinner flask time-dependently improved cell numbers, cell viability, and expansion rates in THSG-treated DPSCs. In both the T25 and spinner flasks, the messenger RNA (mRNA) levels of proliferation, osteogenesis, and pluripotent-related genes had a significant maximum expression with 10 μM THSG treatment. However, 0.1 μM of THSG may be the most suitable condition for triggering neurogenesis and adipogenesis gene expression when DPSCs were cultured in spinner flasks. Furthermore, the number of oncogenes and apoptotic genes decreased considerably in the presence of THSG in both the T25 and spinner flasks.

Conclusion

The spinner flask bioreactor combined with THSG may upregulate proliferation and lineage-specific differentiation in DPSCs. Thus, the combination can be used to mass-produce and cultivate human DPSCs for regenerative dentistry.

Tetrahydroxystilbene glucoside alleviates angiotensin II induced HUVEC senescence via SIRT1

Tetrahydroxystilbene glucoside (TSG), an active ingredient of Polygonum multiflorum, has been known for certain anti-aging effects. In this study, the possible protective mechanism of TSG on human umbilical vein endothelial cell (HUVEC) senescence induced by angiotensin II (Ang II) was investigated. The results revealed that TSG pretreatment could reduce the percentage of senescence-associated β-galactosidase (SA-β-gal) positive cells and decrease the expression levels of the cellular senescence biomarker proteins p53 and PAI-1. At the same time, the expression of SIRT1 in senescent cells showed an upward trend due to TSG treatment. When inhibiting the expression of SIRT1 by EX527, our results showed that TSG reversed the effect of EX527 by promoting the expression level of SIRT1, reducing the expression of SA-β-gal positive cells and the expression level of p53 and PAI-1 proteins. The present study demonstrated that TSG could protect against HUVEC senescence induced by Ang II, potentially through modulation of SIRT1 activity.

2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside-stimulated dental pulp stem cells-derived conditioned medium enhances cell activity and anti-inflammation

Background/purpose

Dental pulp stem cells (DPSCs) contribute to the regeneration of various tissues and have superior proliferation, immune privilege, and anti-inflammation properties to other mesenchymal stem cells. 2,3,5,4'-tetrahydroxystilbene-2-O-β-D-glucoside (THSG) not only enhances the aforementioned properties of DPSCs but also promotes self-renewal and reprogramming-like ability. However, whether THSG enhances the aforementioned properties and abilities through direct or indirect interaction mechanisms remains unclear. To address this knowledge gap, we examined the effects of THSG-stimulated DPSC-derived conditioned medium (THSG-CM) on the activity and anti-inflammation properties of cells.

Materials and methods

DPSCs were treated with various concentrations of THSG to produce THSG-CM, which was then collected, analyzed, and lyophilized. A cytokine profiling antibody assay was used to compare protein components between THSG-treated and nontreated CM. Human skin fibroblasts (HSFs) and human gingival fibroblasts (HGFs) were used to investigate the effect of THSG-CM on cell proliferation, anti-inflammation, and wound healing abilities; for this investigation, MTS assay, quantitative real-time PCR analysis, and 2-well silicone inserts wound model were conducted.

Results

We observed that THSG enhanced the secretion of growth- and immune-associated proteins in THSG-CM and increased the proliferation of HSFs and HGFs. Furthermore, THSG-CM significantly attenuated lipopolysaccharide-stimulated mRNA levels of cytokines in both cells and improved wound healing abilities.

Conclusion

We conclude that THSG-CM had more beneficial effects on cell activity and anti-inflammation in the HSFs and HGFs than DPSC-derived CM. DPSC-derived CM can be developed into a cell-free regenerative strategy in the future, and its therapeutic efficacy may be improved by THSG-CM.

2,3,5,4'-tetrahydroxystilbene-2-O-b-D-glucoside triggers the pluripotent-like possibility of dental pulp stem cells by activating the JAK2/STAT3 axis: Preliminary observations

Abstract

Background/Purpose

Although 2,3,5,4′-Tetrahydroxystilbene-2-O-beta-glucoside (THSG) reportedly has anti-inflammatory properties, its role in inducing the dedifferentiation of human dental pulp stem cells (DPSC) into pluripotent-like stem cells remains to be determined. The purpose of this study is to evaluate the effects of THSG on the pluripotent-like possibility and mechanism of DPSC.

Materials and methods

DPSCs were treated with THSG, and cell viability was determined using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide (MTS) assay. Real-time polymerase chain reaction was used to analyze the mRNA expression levels of pluripotency-associated genes and oncogenes and to detect telomerase activity in the cells. Embryoid body formation assay was conducted, and pluripotency-related proteins were identified using Western blotting. Data were analyzed using one-way analysis of variance.

Results

Cell viability, telomerase activity, and embryoid body formation were enhanced in THSG-treated DPSCs. The mRNA expression levels of pluripotent-like genes (including Nanog homeobox [NANOG], SRY-box 2 [SOX2], and POU class 5 homeobox 1 [POU5F1/OCT4]) significantly increased after THSG treatment. The expression levels of pluripotency-related genes (Janus kinase-signal transducer 2 [JAK2] and signal transducer and activator of transcription 3 [STAT3]) increased, whereas those of oncogenes (Ras, SRC, HER2, and C-sis) decreased. Furthermore, the expression levels of the phosphorylated JAK2 and STAT3 proteins significantly increased after THSG treatment.

Conclusion

THSG treatment may enhance the pluripotent-like possibility of DPSC through the JAK2/STAT3 axis. Hence, it may be used as an alternative cell-based therapeutic strategy in regenerative dentistry.

Proteomic profiling of various human dental stem cells - a systematic review

BACKGROUND

The proteomic signature or profile best describes the functional component of a cell during its routine metabolic and survival activities. Additional complexity in differentiation and maturation is observed in stem/progenitor cells. The role of functional proteins at the cellular level has long been attributed to anatomical niches, and stem cells do not deflect from this attribution. Human dental stem cells (hDSCs), on the whole, are a combination of mesenchymal and epithelial coordinates observed throughout craniofacial bones to pulp.

AIM

To specify the proteomic profile and compare each type of hDSC with other mesenchymal stem cells (MSCs) of various niches. Furthermore, we analyzed the characteristics of the microenvironment and preconditioning changes associated with the proteomic profile of hDSCs and their influence on committed lineage differentiation.

METHODS

Literature searches were performed in PubMed, EMBASE, Scopus, and Web of Science databases, from January 1990 to December 2018. An extra inquiry of the grey literature was completed on Google Scholar, ProQuest, and OpenGrey. Relevant MeSH terms (PubMed) and keywords related to dental stem cells were used independently and in combination.

RESULTS

The initial search resulted in 134 articles. Of the 134 full-texts assessed, 96 articles were excluded and 38 articles that met the eligibility criteria were reviewed. The overall assessment of hDSCs and other MSCs suggests that differences in the proteomic profile can be due to stem cellular complexity acquired from varied tissue sources during embryonic development. However, our comparison of the proteomic profile suffered inconsistencies due to the heterogeneity of various hDSCs. We believe that the existence of a heterogeneous population of stem cells at a given niche determines the modalities of regeneration or tissue repair. Added prominences to the differences present between various hDSCs have been reasoned out.

CONCLUSION

Systematic review on proteomic studies of various hDSCs are promising as an eye-opener for revisiting the proteomic profile and in-depth analysis to elucidate more refined mechanisms of hDSC functionalities.

Effects of Sapindus mukorossi Seed Oil on Proliferation, Osteogenetic/Odontogenetic Differentiation and Matrix Vesicle Secretion of Human Dental Pulp Mesenchymal Stem Cells

Stem cells have attracted great interest in the development of tissue engineering. However, the self-regeneration and multi-differentiation capabilities of stem cells are easily impaired during cell transplantation. Recent studies have demonstrated that Sapindus mukorossi (S. mukorossi) seed oil has various positive biological effects. However, it is not yet clear whether S. mukorossi seed oil can increase the growth and differentiation of dental pulp mesenchymal stem cells (DPSCs). The aim of this study is to investigate the effects of S. mukorossi seed oil on the proliferation and differentiation of DPSCs. DPSCs with and without S. mukorossi seed oil, respectively, were evaluated and compared. The viabilities of the cells were assessed by MTT tests. The osteogenetic and odontogenetic capacities of the DPSCs were tested using Alizarin red S staining and alkaline phosphatase (ALP) activity assays. In addition, real-time PCR was performed to examine the gene expression of ALP, BMP-2 and DMP-1. Finally, extracellular matrix vesicle secretion was detected via scanning electron microscopy. No significant difference was observed in the viabilities of the DPSCs with and without S. mukorossi seed oil, respectively. However, under osteogenic and odontogenic induction, S. mukorossi seed oil increased the secretion of mineralized nodules and the ALP activity of the DPSCs (p < 0.05). The ALP gene expression of the differentiation-induced DPSCs was also enhanced. Finally, a greater secretion of extracellular matrix vesicles was detected in the DPSCs following odontogenic induction complemented with S. mukorossi seed oil. Overall, the present results show that S. mukorossi seed oil promotes the osteogenic/odontogenic differentiation and matrix vesicle secretion of DPSCs.

SIRT1 Is the Target Gene for 2,3,5,4'-Tetrahydroxystilbene-2-O-β-D-Glucoside Alleviating the HUVEC Senescence

This study aimed to explore the effects of 2,3,5,4'-tetrahydroxy-stilbene-2-O-β-d-glucoside (TSG) on the senescence of human umbilical vein cells (HUVEC) induced by hydrogen peroxide (H₂O₂) and to identify the potential targets mediating its protective action. HUVEC cells pre-treated with TSG for 24 h were exposed to H₂O₂ treatment. TSG significantly decreased H₂O₂-induced cellular senescence, as indicated by reduced senescence-associated β-galactosidase (SA-β-gal) positive staining, the proportion of cells in the G1 phase, cell apoptosis, p21, and plasminogen activator inhibitor-1 (PAI-1) expression. Moreover, TSG promoted Sirtuin 1 (SIRT1) expression. When SIRT1 was inhibited by EX527 or SIRT1 siRNA, the effect of TSG is diminished according to the increased proportion of cells in the G1 phase, cell apoptosis, p21, and PAI-1 expression. Overall, our study established TSG as an anti-senescence compound that exerts its protective action by regulating SIRT1 expression.

2,3,5,4'-Tetrahydroxystilbene-2-O-β-d-glucoside promotes the effects of dental pulp stem cells on rebuilding periodontal tissues in experimental periodontal defects

BACKGROUND

This study aimed to investigate the regenerative effects of 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucoside (THSG)-treated human dental pulp stem cells (DPSC) on the healing of experimental periodontal defects in rats.

METHODS

The maxillary first molars of 30 male Sprague-Dawley rats were extracted, and after healing, bilateral periodontal defects were surgically created mesially in second molars. The defects were treated with Matrigel (as control), DPSC, or DPSC + THSG. After 2 weeks, the healed defects were evaluated using microcomputed tomography and through histological and immunohistochemical analyses.

RESULTS

In the microcomputed tomography analysis, more new bone formation in the DPSC and DPSC + THSG groups was observed compared with the control group. The periodontal bone supporting ratio in site with DPSC + THSG was significantly higher than that in DPSC. Histologically, an enhanced new bone formation and more significant periodontal attachment were observed in the DPSC + THSG group. The expression levels of proliferating cell nuclear antigen (PCNA), vascular endothelial growth factor (VEGF), and osteopontin (OPN) in the DPSC + THSG group were significantly greater than those in other groups.

CONCLUSIONS

THSG-revolutionized DPSCs significantly shortened the regenerative period of periodontal defects by enhancing the cell recruitment and possibly the angiogenesis in rat models, which illustrate the critical implications for a clinical application and provide a novel tactic for periodontitis treatment.

AICAR Stimulates the Pluripotency Transcriptional Complex in Embryonic Stem Cells Mediated by PI3K, GSK3β, and β-Catenin

Pluripotent stem cells maintain the property of self-renewal and differentiate into all cell types under clear environments. Though the gene regulatory mechanism for pluripotency has been investigated in recent years, it is still not completely understood. Here, we show several signaling pathways involved in the maintenance of pluripotency. To investigate whether AMPK is involved in maintaining the pluripotency in mouse embryonic stem cells (mESCs) and elucidating the possible molecular mechanisms, implicated D3 and R1/E mESC lines were used in this study. Cells were cultured in the absence or presence of LIF and treated with 1 mM and 0.5 mM 5-aminoimidazole-4-carboxamide-1-β-d-ribofuranoside (AICAR), 2 mM metformin, compound C, and the PI3K inhibitor LY294002 for 24, 72, and 120 h. The levels of Nanog, Oct3/4, and REX1 and Brachyury, Notch2, and Gata4 mRNAs and Nanog or OCT3/4 protein levels were analyzed. Alkaline phosphatase and the cellular cycle were determined. The pGSK3β, GSK3β, p-β-catenin, and β-catenin protein levels were also investigated. We found that AMPK activators such as AICAR and metformin increase mRNA expression of pluripotency markers and decrease mRNA expression of differentiation markers in R1/E and D3 ES cells. AICAR increases phosphatase activity and arrests the cellular cycle in the G1 phase in these cells. We describe that AICAR effects were mediated by AMPK activation using a chemical inhibitor or by silencing this gene. AICAR effects were also mediated by PI3K, GSK3β, and β-catenin in R1/E ES cells. According to our findings, we provide a mechanism by which AICAR increases and maintains a pluripotency state through enhanced Nanog expression, involving AMPK/PI3K and p-GSK3β Ser21/9 pathways backing up the AICAR function as a potential target for this drug controlling pluripotency. The highlights of this study are that AICAR (5-aminoimidazole-4-carboxamied-1-b-riboside), an AMP protein kinase (AMPK) activator, blocks the ESC differentiation and AMPK is a key enzyme for pluripotency and shows valuable data to clarify the molecular pluripotency mechanism.

Effect of Active Ingredients of Chinese Herbal Medicine on the Rejuvenation of Healthy Aging: Focus on Stem Cells

Stem cells (SCs) are special types of cells with the ability of self-renewal and multidirectional differentiation. As the organism ages, the ability to maintain homeostasis and regeneration deteriorates and the number and activity of stem cells decline. Theoretically, the restoration of stem cells might reverse aging. However, due to their own aging, donor-derived immune rejection, and difficulties in stem cell differentiation control, a series of problems need to be solved to realize the potential for clinical application of stem cells. Chinese herbal medicine is a nature drug library which is suitable for the long-term treatment of aging-related diseases. Modern pharmacological studies have revealed that many active ingredients of Chinese herbal medicines with the effect of promoting stem cells growth and differentiation mainly belong to “reinforcing herbs.” In recent years, exploration of natural active ingredients from Chinese herbal medicines for delaying aging, improving the stem cell microenvironment, and promoting the proliferation and differentiation of endogenous stem cells has attracted substantial attention. This article will focus on active ingredients from Chinese herbs-mediated differentiation of stem cells into particular cell type, like neural cells, endothelial cells, cardiomyocytes, and osteoblasts. We will also discuss the effects of these small molecules on Wnt, Sonic Hedgehog, Notch, eNOS-cGMP, and MAP kinase signal transduction pathways, as well as reveal the role of estrogen receptor α and PPAR γ on selectively promoting or inhibiting stem cells differentiation. This review will provide new insights into the health aging strategies of active ingredients in Chinese herbal medicine in regenerative medicine.

Mesenchymal Stem Cells Derived from Human Inflamed Dental Pulp Exhibit Impaired Immunomodulatory Capacity In Vitro

INTRODUCTION

Dental pulp stem cells (DPSC) are very attractive in regenerative medicine. In this study, we focused on the characterization of the functional properties of mesenchymal stem cells derived from DPSCs. Currently, it is unknown whether inflammatory conditions present in an inflamed dental pulp tissue could alter the immunomodulatory properties of DPSCs. This study aimed to evaluate the immunomodulatory capacity in vitro of DPSCs derived from healthy and inflamed dental pulp.

METHODS

DPSCs from 10 healthy and inflamed dental pulps (irreversible pulpitis) were characterized according to the minimal criteria of the International Society for Cell Therapy, proliferation, differential potential, and colony-forming units. Furthermore, the immunomodulatory capacity of DPSCs was tested on the proliferation of T lymphocytes by flow cytometry and the in vitro enzyme activity of indoleamine 2, 3-dioxygenase.

RESULTS

There were no significant differences in the DPSC characteristics and properties such as immunophenotype, tridifferentiation, colony-forming units, and proliferation of the DPSCs derived from normal and inflamed pulp tissue. Furthermore, there were significant differences in the immunomodulatory capacity of DPSCs obtained from human healthy dental pulp and with the diagnosis of irreversible pulpitis.

CONCLUSIONS

Our results showed that DPSCs isolated from inflamed dental pulp showed typical characteristics of MSCs and diminished immunosuppressive capacity in vitro in comparison with MSCs derived from healthy dental pulp. Further investigation in vivo is needed to clarify the mechanism of this diminished immunosuppressive capacity.

Tetrahydroxystilbene Glucoside Regulates Proliferation, Differentiation, and OPG/RANKL/M-CSF Expression in MC3T3-E1 Cells via the PI3K/Akt Pathway

Tetrahydroxystilbene glucoside (TSG) is a unique component of the bone-reinforcing herb Radix Polygoni Multiflori Preparata (RPMP). It has the ability to promote bone formation and protect osteoblasts. However, the underlying mechanism remains unclear. To better understand its biological function, we determined TSG's effect on murine pre-osteoblastic MC3T3-E1 cells by the MTT assay, flow cytometry, FQ-PCR, Western blot, and ELISA. The results showed that TSG caused an elevation of the MC3T3-E1 cell number, the number of cells in the S phase, and the mRNA levels of the runt-related transcription factor-2 (Runx2), osterix (Osx), and collagen type I α1 (Col1a1). In addition, the osteoprotegerin (OPG) mRNA level was up-regulated, while the nuclear factor-κB ligand (RANKL) and macrophage colony-stimulating factor (M-CSF) mRNA levels were down-regulated by TSG. Furthermore, TSG activated the phosphoinosmde-3-kinase/protein kinase B (also known as PI3K/Akt) pathway, and blocking this pathway by the inhibitor LY-294002 could impair TSG's functions in relation to the MC3T3-E1 cells. In conclusion, TSG could activate the PI3K/Akt pathway and thus promote MC3T3-E1 cell proliferation and differentiation, and influence OPG/RANKL/M-CSF expression. TSG merits further investigation as a potential therapeutic agent for osteoporosis treatment.