Osteogenic Differentiation Of hDPSCs Research Articles

Dysregulation of lncRNA TFAP2A-AS1 is involved in the pathogenesis of pulpitis by the regulation of microRNA-32-5p.

This study was designed to evaluate TFAP2A-AS1 expression in the dental pulp of teeth with or without pulpitis and to determine the function of TFAP2A-AS1 in pulp cells. GSE92681 was analyzed to filter out differentially expressed lncRNAs. Pulp samples from teeth with pulpitis and healthy teeth (control) were examined using real-time (RT) quantitative polymerase chain reaction (qPCR). Human dental pulp stem cells (hDPSCs) were cultured in a specific medium for osteogenic induction, or treated with lipopolysaccharide (LPS) to simulate inflammation. The viability and apoptosis of human DPSCs (hDPSCs) were determined by XTT assay and apoptosis detection kit. Inflammation was induced by LPS and assessed by measuring the expression and release of inflammatory cytokines after TFAP2A-AS1 knockdown. Osteogenic differentiation of hDPSCs was investigated by determining expression levels of osteogenic markers and alkaline phosphatase (ALP) activity after TFAP2A-AS1 overexpression. The downstream microRNA (miRNA) was predicted. Dual-luciferase reporter was used to confirm the binding between miR-32-5p and TFAP2A-AS1. The expression of TFAP2A-AS1 was evaluated in inflamed pulp using RT-qPCR. TFAP2A-AS1 had a discriminatory ability for healthy individuals and patients with pulpitis. The expression of TFAP2A-AS1 decreased upon the osteogenic differentiation of hDPSCs, and increased upon the LPS induction. TFAP2A-AS1 can reverse the osteogenic differentiation of hDPSCs, as evidenced by decreased levels of dentine sialophosphoprotein, dentin matrix protein-1, and ALP activity. TFAP2A-AS1 knockdown can promote cell proliferation of hDPSCs and relieve LPS-induced inflammation, as evidenced by decreased levels of TNF-α, IL-1β, and IL-6. miR-32-5p was identified as a downstream miRNA of TFAP2A-AS1. This study demonstrated the expression and potential function of TFAP2A-AS1 in the human dental pulp. TFAP2A-AS1 can inhibit odontogenic differentiation but promote inflammation in pulp cells.

Hsa_circ_0036872 has an important promotional effect in enhancing osteogenesis of dental pulp stem cells by regulating the miR-143-3p/IGF2 axis

BackgroundCircular RNAs (circRNAs), an extremely stable group of RNAs, possess a covalent closed-loop configuration. Numerous studies have highlighted the involvement of circRNAs in physiological processes and the development of various diseases. The present study aimed to investigate how circRNA regulates the osteogenic differentiation of human dental pulp stem cells (hDPSCs). MethodsWe isolated hDPSCs from dental pulp and used next-generation sequencing analysis to determine the differentially-expressed circRNAs during osteogenic differentiation. Bioinformatics and dual-luciferase reporter assays identified the downstream targets. The role of circRNAs in osteogenic differentiation was further confirmed through the use of heterotopic bone models. ResultsWe found that hsa_circ_0036872 expression was increased during osteogenic differentiation of hDPSCs, and downregulation of hsa_circ_0036872 inhibited their osteogenic differentiation. Dual-luciferase reporter assays showed that both miR-143-3p and IGF2 were downstream targets of hsa_circ_0036872. Overexpression of IGF2 or inhibition of miR-143-3p restored the osteogenic differentiation ability of hDPSCs after silencing hsa_circ_0036872. Overexpression of IGF2 reversed the inhibitory effect of miR-143-3p on osteogenic differentiation. ConclusionTaken together, our results show that hsa_circ_0036872 exerts an important promotional effect in enhancing the osteogenesis of dental pulp stem cells by regulating the miR-143-3p/IGF2 axis. These data suggest a novel therapeutic strategy for osteoporosis treatment and periodontal tissue regeneration.

Preparation of PDA-GO/CS composite scaffold and its effects on the biological properties of human dental pulp stem cells

Reduced graphene oxide (rGO) is an graphene oxide (GO) derivative of graphene, which has a large specific surface area and exhibited satisfactory physicochemical characteristics. In this experiment, GO was reduced by PDA to generate PDA-GO complex, and then PDA-GO was combined with Chitosan (CS) to synthesize PDA-GO/CS composite scaffold. PDA-GO was added to CS to improve the degradation rate of CS, and it was hoped that PDA-GO/CS composite scaffolds could be used in bone tissue engineering. Physicochemical and antimicrobial properties of the different composite scaffolds were examined to find the optimal mass fraction. Besides, we examined the scaffold’s biocompatibility by Phalloidin staining and Live and Dead fluorescent staining.Finally, we applied ALP staining, RT-qPCR, and Alizarin red S staining to detect the effect of PDA-GO/CS on the osteogenic differentiation of human dental pulp stem cells (hDPSCs). The results showed that PDA-GO composite was successfully prepared and PDA-GO/CS composite scaffold was synthesized by combining PDA-GO with CS. Among them, 0.3%PDA-GO/CS scaffolds improves the antibacterial activity and hydrophilicity of CS, while reducing the degradation rate. In vitro, PDA-GO/CS has superior biocompatibility and enhances the early proliferation, migration and osteogenic differentiation of hDPSCs. In conclusion, PDA-GO/CS is a new scaffold materialsuitable for cell culture and has promising application prospect as scaffold for bone tissue engineering.

In vitro response of dental pulp stem cells to dural substitute grafts: Analysis of cytocompatibility and bioactivity.

The objective of this study was to assess and compare the cytocompatibility of decellularized porcine small intestine submucosal dural graft from Biodesign (BD) and polyester urethane-based Neuro-Patch (NP) dural substitute with the mineral trioxide aggregate (MTA) and the cyanoacrylate-based Histoacryl surgical adhesive. Furthermore, the study evaluated the inflammatory response and osteogenic differentiation of human dental pulp stem cells (hDPSCs) when cultured in direct contact with the dural substitutes in comparison with MTA. The viability of hDPSCs in direct contact with the tested materials was investigated in vitro by a CCK-8 assay. Additionally, the effects of dural substitutes and MTA on the expression of the inflammatory mediator interleukin-6 (IL-6) was investigated via enzyme-linked immunosorbent assay (ELISA), whilst effects on the differentiation were evaluated using alizarin red staining, alkaline phosphatase staining, ELISA and energy-dispersive X-ray elemental mapping. The dural substitutes were cytocompatible and promoted cellular adhesion. The Histoacryl and MTA demonstrated cytotoxicity in fresh preparations but showed a more favourable cellular reaction when set. Investigations of biological activity indicated that dural substitute membranes did not induce an inflammatory response or osteogenic differentiation of hDPSCs. In contrast, MTA induced the expression of IL-6 and alkaline phosphatase activity contributing to enhanced differentiation and mineralization. The dural substitute membranes showed cytocompatibility, did not provoke an inflammatory response and maintained the stemness of hDPSCs better than MTA. Additionally, the set Histoacryl surgical adhesive demonstrated good biocompatibility. Taken together, these results highlight the potential use of dural substitutes in regenerative endodontic procedures as coronal barriers alternative to MTA to reduce the incidence of intracanal calcifications.

Lysophosphatidic acid induces proliferation and osteogenic differentiation of human dental pulp stem cell through lysophosphatidic acid receptor 3/extracellular signal-regulated kinase signaling axis

Background/purposeHuman dental pulp stem cells (hDPSCs) possess excellent proliferative and osteogenic differentiation potentials. This study aimed to elucidate the role of lysophosphatidic acid (LPA) signaling in the proliferation and osteogenic differentiation of hDPSCs. Materials and methodshDPSCs were treated with LPA and proliferation was measured using the cell counting kit-8 assay. Following the osteogenic differentiation of hDPSCs using osteogenic medium in the presence or absence of LPA, alkaline phosphatase (ALP) staining, ALP activity measurements, and RT-qPCR were performed to analyze the osteoblast differentiation. Small interfering RNA (siRNA)-mediated LPAR3 silencing and extracellular signal-regulated (ERK)/mitogen-activated protein (MAP) kinase inhibitors were used to elucidate the molecular mechanisms underlying LPA-induced proliferation and differentiation of hDPSCs. ResultsLPA treatment significantly induced proliferation and osteogenic differentiation of hDPSCs. The depletion of LPAR3 expression by LPAR3-speicifc siRNA in hDPSCs diminished LPA-induced proliferation and osteogenic differentiation. The LPAR3-mediated proliferation and osteogenic differentiation of hDPSCs in response to LPA were significantly suppressed by U0126, a selective inhibitor of ERK. ConclusionThese findings suggest that LPA induces the proliferation and osteogenic differentiation of hDPSCs via LPAR3-ERK-dependent pathways.

Lidocaine intensifies the anti-osteogenic effect on inflammation-induced human dental pulp stem cells via mitogen-activated protein kinase inhibition

Human dental pulp stem cells (hDPSCs) are an emerging source of mesenchymal stem cells (MSCs) for bone tissue regeneration and engineering. In bone regeneration using transplanted MSCs, the extracellular environment or co-injected drugs can affect their success or failure. In this study, we investigated the effects and signaling mechanisms of lidocaine on osteogenic differentiation of hDPSCs after inducing inflammatory conditions with lipopolysaccharide (LPS) and tumor necrosis factor-alpha (TNF-α). To investigate the effect of lidocaine on the osteogenic differentiation of LPS/TNF-α-treated hDPSCs, alkaline phosphatase (ALP) and Alizarin red S (ARS) staining were conducted. The expression of osteogenesis-related genes was assessed using quantitative real-time polymerase chain reaction and western blotting. The expression of mitogen-activated protein kinases was analyzed to evaluate the effect of lidocaine on osteogenic differentiation of LPS/TNF-α-treated hDPSCs. Various concentrations of lidocaine (0.05, 0.2, and 1mM) further decreased ALP and ARS staining of LPS/TNF-α-treated hDPSCs. Similarly, the mRNA and protein expression of osteogenesis-related genes was suppressed via lidocaine treatment in LPS/TNF-α-treated hDPSCs. Lidocaine treatment downregulated the protein expression of p-ERK and p-JNK in LPS/TNF-α-treated hDPSCs. Lidocaine intensified the inhibition of osteogenic differentiation on inflammation-induced hDPSCs by inhibiting the ERK and JNK signaling pathways. This invitro study suggested that lidocaine may have an inhibitory effect on bone regeneration.

CircFKBP5 Suppresses Apoptosis and Inflammation and Promotes Osteogenic Differentiation

Dental pulp stem cells (DPSCs) are a type of mesenchymal stem cell possessing self-renewal and multilineage differentiation capabilities. The dysfunction of DPSCs is related to the pathologic process of pulpitis. The participation of circular RNAs (circRNAs) in DPSC differentiation has been identified. This work focussed on exploring the functions and mechanism of circFKBP5 in DPSC dysfunction evoked by lipopolysaccharide (LPS). The viability and apoptosis of human DPSCs (hDPSCs) were determined using Cell Counting Kit-8 assay and flow cytometry. Inflammation was analysed by measuring the release of inflammatory cytokines. The osteogenic differentiation of hDPSCs was investigated by performing alkaline phosphatase (ALP) staining and alizarin red S staining and detecting the changes of ALP and runt-related transcription factor 2 (RUNX2) proteins. The dual-luciferase reporter, RNA immunoprecipitation (RIP), and pull-down assays were used to confirm the binding between miR-708-5p and circFKBP5 or G-protein-coupled receptor (GPCR)-kinase interacting protein 2 (GIT2). CircFKBP5 expression was decreased in hDPSCs and, functionally, reexpression of circFKBP5 attenuated LPS-induced apoptosis, inflammation, and inhibition of proliferation ability and osteogenic differentiation in hDPSCs. Mechanistically, circFKBP5 acted as a sponge for miR-708-5p, which was verified to target GIT2. LPS induced miR-708-5p expression in hDPSCs, and knockdown of miR-708-5p protected against LPS-evoked hDPSC dysfunction. Besides, GIT2 expression was decreased in hDPSCs after LPS treatment. Rescue experiments showed that GIT2 could mediate the protective functions of circFKBP5 on hDPSCs under LPS treatment. CircFKBP5 could protect against LPS-induced apoptosis, inflammation, and osteogenic differentiation inhibition in hDPSCs via the miR-708-5p/GIT2 axis.

The role of different macrophages-derived conditioned media in dental pulp tissue regeneration

Macrophages have been reported to play important roles in tissue repair and regeneration. While it is known that macrophages are present in the dental pulp, their role in dental pulp regeneration is not fully understood. In the present study, we investigated the effects of different phenotype macrophages conditioned medium on the cellular behaviors of hDPSCs and their extracellular matrix (cell sheets) in vitro. Moreover, twenty-four root fragments inserted with cell sheets cultured with different conditioned media were placed into the back subcutaneous space of 6–8-week-old male BALB/c nude mouse. The regenerated tissues in the root fragments were assessed via histologic analysis after 8 weeks of transplantation. M2 macrophages could promote the proliferation, migration, and osteogenic differentiation of hDPSCs. Dental pulp-like tissue with an odontoblast-like layer lining the dentinal surface and well-arranged collagen fibers was harvested in root fragment combined with M2 conditioned medium cultured cell sheet, whereas a large amount of calcium salt deposition and disorganization of collagen fibers were observed in root fragments combined with M1 conditioned medium cultured cell sheet. Therefore, promoting the transformation of M1 into M2 macrophage in dental pulp tissue regeneration may be a potential way for dental pulp regeneration via functional healing.

Low-level controllable blue LEDs irradiation enhances human dental pulp stem cells osteogenic differentiation via transient receptor potential vanilloid 1.

Human dental pulp stem cells (hDPSCs) have attracted tremendous attention in tissue regeneration engineering due to their excellent multidirectional differentiation potential. Photobiomodulation (PBM) using low-level light-emitting diodes (LEDs) or lasers has been proved to promote the osteogenesis of mesenchymal stem cells. However, the effect of LEDs on osteogenic differentiation of hDPSCs has little published data. In this work, the effect of blue LEDs with different energy densities of 2, 4, 6, 8, 10J/cm2 on osteogenic differentiation of hDPSCs was examined by using in vitro ALP staining, ALP activity, mineralization, and real-time PCR. The results showed that compared with the control group, osteogenic differentiation was significantly enhanced in blue LEDs treated groups. As the energy density increased, the level of osteogenesis initially increased and then decreased reaching the highest level at 6J/cm2. Transient receptor potential vanilloid 1 (TRPV1), a Ca2+ ion channel, was believed to be a potential player in osteogenesis by photobiomodulation. By immunofluorescence assay, calcium influx assay, PCR, and ALP staining, it was shown that blue LEDs irradiation can increase the activity of TRPV1 and intracellular calcium levels similarly to the agonist of TRPV1 capsaicin. Additionally, pretreatment with capsazepine, a selective TRPV1 inhibitor, was able to abrogate the osteogenic effect of blue LEDs. In conclusion, these findings proposed that blue LEDs can promote the osteogenesis of hDPSCs within the appropriate range (4-8J/cm2) during culture of osteogenic medium, and TRPV1/Ca2+ may be an essential signaling pathway involved in blue LEDs-induced osteogenesis, providing new insights for the use of hDPSCs in tissue regeneration engineering.

Effect of MicroRNA-138 on Tumor Necrosis Factor-Alpha-Induced Suppression of Osteogenic Differentiation of Dental Pulp Stem Cells and Underlying Mechanism.

High doses of tumor necrosis factor-α (TNF-α) suppress osteogenic differentiation of human dental pulp stem cells (hDPSCs). In the present study, we aimed to explore the role and potential regulatory mechanism of microRNA-138 (miR-138) in the osteogenic differentiation of hDPSCs after treatment with a high dose of TNF-α. The hDPSCs were cultured in osteogenic medium with or without 50 ng/ml TNF-α. The miR-138 levels were upregulated during osteogenic differentiation of the hDPSCs following TNF-α treatment. The miR-138 overexpression accelerated but miR-138 knockdown alleviated the TNF-α-induced suppression of the alkaline phosphatase activity, calcium deposition, and protein abundance of dentin sialophosphoprotein, dentin matrix protein 1, bone sialoprotein, and osteopontin during osteogenic differentiation induction of hDPSCs. Additionally, miR-138 overexpression accelerated but miR-138 knockdown alleviated the suppression of the focal adhesion kinase- (FAK-) extracellular signal-regulated kinase 1/2 (ERK1/2) signaling pathway during osteogenic differentiation induction of hDPSCs under TNF-α treatment. In conclusion, miR-138 accelerates TNF-α-induced suppression of osteogenic differentiation of hDPSCs. Inactivation of the FAK-ERK1/2 signaling pathway may be one of the mechanisms underlying the effect of miR-138. Inhibition of miR-138 expression may be a strategy to weaken the inhibitory effect of high-dose TNF-α on the osteogenic differentiation of hDPSCs.

Propofol attenuates odontogenic/osteogenic differentiation of human dental pulp stem cells in vitro

Background/purposeVarious studies have used stem cells in the field of bone tissue engineering to repair bone defects. Dental pulp stem cells (DPSCs) have multipotent properties and can be acquired in a noninvasive manner; therefore, they are frequently used in experiments in regenerative medicine. The objective of this study was to investigate the odontogenic/osteogenic differentiation of human DPSCs (hDPSCs) using propofol, a widely used intravenous anesthetic agent. Materials and methodsAlkaline phosphatase (ALP) staining was used to investigate the effects of various concentrations of propofol (5, 20, 50 and 100 μM) on the osteogenic differentiation of hDPSCs. Real-time qPCR and Western blot analysis were used to detect the effect of propofol on the expression of odontogenic/osteogenic genes, such as DMP1, RUNX2, OCN, and BMP2. Odontogenic/osteogenic differentiation of hDPSCs was estimated at days 7 and 14. ResultsALP staining of hDPSCs was significantly decreased by propofol treatment. The mRNA expression of DMP1, RUNX2, OCN, and BMP2 decreased after propofol treatment for 14 days. The protein expression of DMP1 and BMP2 was decreased by propofol at days 7 and 14, and that of RUNX2 was decreased by propofol at day 14 only. ConclusionPropofol attenuated odontogenic/osteogenic differentiation of hDPSCs in vitro. This result suggests that propofol, which is widely used for dental sedation, may inhibit the odontogenic/osteogenic differentiation of hDPSCs.

Angelica sinensis polysaccharide promotes the proliferation and osteogenic differentiation of human dental pulp stem cells (hDPSCs) by activating the wnt/β-catenin pathway

Human dental pulp stem cells (hDPSCs) are capable of forming mineralized nodules. The proliferation and osteogenic differentiation of hDPSCs are very important for alleviating tooth defects caused by related diseases. Angelica polysaccharide (ASP) is the main bioactive ingredient extracted from the angelica root. ASP has a variety of biological functions, including immune regulation, antitumor activity, and hematopoiesis. However, its possible effects on hDPSCs are still unclear. In this study, we aimed to investigate the role of ASP in periodontal diseases. We found that ASP promoted the proliferation of hDPSCs and osteogenic differentiation of hDPSCs. We further found that it promoted the expression of osteogenic-related genes, including ALP, RUNX2, Col1a1, and OCN. Mechanically, we found that ASP activated the Wnt/β-catenin pathway. In conclusion, our results suggested that ASP promoted the proliferation and osteogenic differentiation of hDPSCs via the Wnt/β-catenin pathway.

SIRT1 Promotes Osteogenic Differentiation in Human Dental Pulp Stem Cells through Counteracting the Activation of STAT3

Human dental pulp stem cells (hDPSCs), which are characterized by self-renewal capacity and the ability of multilineage differentiation, have gained increased attention in regenerative medicine recently. Histone acetylation modulator proteins (HAMPs) are a protein family that mediates the modification and identification of histone acetylation and participates in various critical cellular processes. Here, we comprehensively surveyed the expression profile of HAMPs during osteoblast differentiation of hDPSCs and found that the HDAC class III pathway was upregulated, whereas the signal transducer and activator of transcription 3 (STAT3) signaling was downregulated during osteogenesis. Further laboratory research demonstrated that Sirtuin-1 (SIRT1), a class III HDAC, was upregulated and STAT3 activation was downregulated during osteogenic differentiation. SIRT1 counteracted the activation of STAT3 to promote osteogenic differentiation of hDPSCs at 7 and 21 days in both Western blot assay and chemical staining, which highlights the promising utility of SIRT1 activators in hDPSCs-based therapies for bone augmentation strategies and provides clinical insights that may lead to the development of osteogenic agents.

SNHG7 promotes the osteo/dentinogenic differentiation ability of human dental pulp stem cells by interacting with hsa-miR-6512–3p in an inflammatory microenvironment

Excessive inflammation leads to periodontitis, which inhibits the osteogenic differentiation of human dental pulp stem cells (hDPSCs), irreversibly injured and difficultly repaired for the important dental pulp. Hence, it is necessary to study the functional gene to enhance the osteogenic differentiation of hDPSCs. Previous found that SNHG7 expression was increased in the osteogenic differentiation of hDPSCs. However, the regulatory functions of SNHG7 on osteogenic differentiation of hDPSCs in the inflammatory microenvironment still remains unknown. In this study, hDPSCs treatment with 50 ng/mL TNF-α to mimic the inflammatory microenvironment, then cultured in osteoblast differentiation medium for 14 days. SNHG7, miR-6512–3p, BSP, DSPP, DMP-1, RUNX2 and OPN in hDPSCs were detect by RT-qPCR. We found that SNHG7 expression was reduced during the osteogenic differentiation of hDPSCs after different concentrations TNF-α treatment. SNHG7 overexpression improved the TNF-α-induced suppression of calcium deposition, ALP activity, and the expression of BSP, DSPP, DMP-1, RUNX2 and OPN. Furthermore, SNHG7 can sponge with miR-6512–3p. miR-6512–3p expression was increased during the osteogenic differentiation of hDPSCs after different concentrations TNF-α treatment while inhibited after SNHG7 overexpression. knockdown of miR-6512–3p improved the TNF-α-induced suppression of calcium deposition, ALP activity, and the expression of BSP, DSPP, DMP-1, RUNX2 and OPN. Finally, miR-6512–3p overexpression reversed the effect of SNHG7 on the osteo/dentinogenic differentiation of TNF-α-treated hDPSCs. In conclusions, SNHG7 improves the osteogenic differentiation of hDPSCs by inhibiting miR-6512–3p expression under 50 ng/mL TNF-α-induced inflammatory environment, which provided potential targets for the treatment of periodontitis.

MiR-20a-5p contributes to osteogenic differentiation of human dental pulp stem cells by regulating BAMBI and activating the phosphorylation of Smad5 and p38

BackgroundHuman dental pulp stem cells (hDPSCs) are the preferable choice of seed cells for craniomaxillofacial bone tissue regeneration. As a member of the miR-17-92 cluster, miR-20a-5p functions as an important regulator during bone remodeling. This study aimed to investigate the roles and mechanisms of miR-20a-5p during osteogenesis of hDPSCs.MethodsQuantitative reverse transcription-polymerase chain reaction (qRT-PCR) was conducted to determine the expression of miR-20a-5p during osteogenesis of hDPSCs. We interfered with the expression of miR-20a-5p in hDPSCs to clarify the function of miR-20a-5p on osteogenesis both in vitro and vivo. Direct bind sites between miR-20a-5p and BAMBI were confirmed by dual-luciferase reporter assay, and the underlying mechanisms were investigated with cell co-transfections.ResultsThe expression of miR-20a-5p was showed to be upregulated during osteogenesis of hDPSCs. Inhibition of miR-20a-5p could weaken the intensity of ALP/ARS staining and downregulate the expression of mRNAs and proteins of osteogenic markers, while overexpression of miR-20a-5p could enhance the intensity of ALP/ARS staining and the expression of osteogenic markers. Both micro-CT reconstruction images and histological results showed that miR-20a-5p could promote the regeneration of calvarial defects. miR-20a-5p directly targeted bone morphogenetic protein and activin membrane-bound inhibitor (BAMBI), and the latter one was an inhibitor of hDPSC osteogenesis. Silencing BAMBI partially reversed the suppression effect of miR-20a-5p knockdown on osteogenesis. Phosphorylation of Smad5 and p38 was decreased when miR-20a-5p was silenced, whereas p-Smad5 and p-p38 were upregulated when miR-20a-5p was overexpressed or BAMBI was silenced.ConclusionsIt is demonstrated that miR-20a-5p functioned as a regulator of BAMBI to activate the phosphorylation of Smad5 and p38 during osteogenic differentiation of hDPSCs.

3D-Printed Poly(ε-Caprolactone)/Hydroxyapatite Scaffolds Modified with Alkaline Hydrolysis Enhance Osteogenesis In Vitro.

The 3D-printed bioactive ceramic incorporated Poly(ε-caprolactone) (PCL) scaffolds show great promise as synthetic bone graft substitutes. However, 3D-printed scaffolds still lack adequate surface properties for cells to be attached to them. In this study, we modified the surface characteristics of 3D-printed poly(ε-caprolactone)/hydroxyapatite scaffolds using O2 plasma and sodium hydroxide. The surface property of the alkaline hydrolyzed and O2 plasma-treated PCL/HA scaffolds were evaluated using field-emission scanning microscopy (FE-SEM), Alizarin Red S (ARS) staining, and water contact angle analysis, respectively. The in vitro behavior of the scaffolds was investigated using human dental pulp-derived stem cells (hDPSCs). Cell proliferation of hDPSCs on the scaffolds was evaluated via immunocytochemistry (ICC) and water-soluble tetrazolium salt (WST-1) assay. Osteogenic differentiation of hDPSCs on the scaffolds was further investigated using ARS staining and Western blot analysis. The result of this study shows that alkaline treatment is beneficial for exposing hydroxyapatite particles embedded in the scaffolds compared to O2 plasma treatment, which promotes cell proliferation and differentiation of hDPSCs.

Behaviour of human dental pulp stem cell in high glucose condition: impact on proliferation and osteogenic differentiation

ObjectiveThe aim of this study is to investigate the changes of human dental pulp stem cell (hDPSC) viability, proliferation and osteogenic differentiation in high glucose condition. DesignAfter 21 days of culture in low (5.5 mM) and high (20 mM) glucose medium, hDPSC viability and proliferation were assessed with respectively the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) and Hoechst assays.To investigate the influence of glucose on osteogenic differentiation hDPSCs were cultured for 28 days in low or high glucose medium with osteoinductive cocktail. Mineralization was examined by alizarin red staining/quantification and the expression of osteogenic-related genes [Runt-related transcription factor 2 (RUNX2), Osteocalcin (OCN), Collagen 1A1 (COL1A1)] analyzed by RT-qPCR. ResultsWe observed no significant difference (p > 0.05) on hDPSC proliferation or cell viability between low or high glucose groups. We did not highlight a significant difference after alizarin red staining and quantification between hDPSCs cultured with high or low glucose concentration in the culture medium. In the same manner, high glucose concentration did not appear to modify osteogenic gene expression: there was no significant difference in osteogenic-related gene expression between high or low glucose groups. ConclusionProliferation, viability, and osteogenic differentiation of hDPSCs were not changed by high glucose environment.

Long non-coding RNA maternally expressed gene 3 inhibits osteogenic differentiation of human dental pulp stem cells via microRNA-543/smad ubiquitin regulatory factor 1/runt-related transcription factor 2 axis

ObjectiveThe aim of the present study was to investigate the biological roles and underlying mechanism of the long non-coding RNA maternally expressed gene 3 (MEG3) on osteogenic differentiation of human dental pulp stem cells (hDPSCs). MethodsThe expression levels of MEG3, microRNA-543 (miR-543), osterix, osteopontin, osteocalcin and runt-related transcription factor 2 (RUNX2) were measured by quantitative real-time PCR (qRT-PCR). Alkaline phosphatase (ALP) activity assay and alizarin red S staining (ARS) were used to measure the impacts exerted by MEG3, miR-543 on osteogenic differentiation. Cell proliferation was measured by MTT assay. In addition, the targeted relationships between miR-543, MEG3, and Smad ubiquitin regulatory factor 1 (SMURF1) were assessed through dual luciferase reporter assay. ResultsDuring osteogenic induction, the expression of MEG3 was gradually reduced, whereas the expression of miR-543, osterix, osteopontin, osteocalcin and RUNX2 were gradually increased. Functional analysis implied that MEG3 overexpression or miR-543 inhibition reduced the cell proliferation, ALP activity, ARS levels, and decreased the expression of osteoblast-related proteins. Moreover, MEG3 promoted SMURF1 expression by directly targeting miR-543 as a competing endogenous RNA. Furthermore, overexpression of miR-543 or silencing SMURF1 could reverse the inhibitory effects of MEG3 on the osteogenic differentiation of hDPSCs. ConclusionsIn conclusion, our study revealed that overexpression of MEG3 inhibited hDPSCs osteogenic differentiation via miR-543/SMURF1/RUNX2 regulatory network, which may contribute to the functional regulation and clinical applications of hDPSCs.

MiR-217 Suppresses Osteogenic Differentiation of Human Dental Pulp Stem Cells by Down-Regulating Sirtuin 1

The paper is committed to uncovering the effect of miR-217 on osteogenic differentiation of human dental pulp stem cells (hDPSCs) and its mechanism. hDPSCs were separated from human dental pulp tissues for measurement of stemness. The osteogenic differentiation of hDPSCs was induced in an osteogenic induction medium. The hDPSCs were transfected with miR-217 mimic, miR-217 inhibitor and/or sh-SIRT1 accordingly. The expressions of miR-217 and SIRT1 were detected in hDPSCs after cell transfection and osteogenic differentiation. Calcium nodules were showed by alizarin red staining. Moreover, the expressions of osteogenic differentiation-related genes were also assessed. The binding of miR-217 to SIRT1 was predicted on starBase and further determined by dual-luciferase reporter assay. Down-regulated miR-217 and up-regulated SIRT1 were found during osteogenic differentiation of hDPSCs. The osteogenic differentiation of hDPSCs was suppressed after transfection of miR-217 mimic or sh-SIRT1 while promoted by miR-217 inhibition. Taken together, miR-217 can suppress osteogenic differentiation of hDPSCs by negatively regulating SIRT1.

Towards osteogenic differentiation of human dental pulp stem cells on PCL-PEG-PCL/zeolite nanofibrous scaffolds

Presently, tissue engineering has been developed as an effective option in the restoration and repair of tissue defects. One of the tissue engineering strategies is to use both biodegradable scaffolds and stimulating factors for enhancing cell responses. In this study, the effect of zeolite was assessed on cell viability, proliferation, osteo/odontogenic differentiation, and mineralization of human dental pulp stem cells (hDPSCs) cultured on poly (ε-coprolactone) – poly (ethylene glycol)-poly (ε-caprolactone) (PCL-PEG-PCL) nanofibers. For this purpose, PCL-PEG-PCL nanofibrous scaffolds incorporated with zeolite were prepared via electrospinning. Both PCL-PEG-PCL and PCL-PEG-PCL/Zeolite nanofibrous scaffolds revealed bead-less constructions with average diameters of 430 nm and 437 nm, respectively. HDPSCs were transferred to PCL-PEG-PCL nanofibrous scaffolds containing zeolite nanoparticles. Cell adhesion and proliferation of hDPSCs and their osteo/odontogenic differentiation on these scaffolds were evaluated using MTT assay, Alizarin red S staining, and qRT-PCR assay. The results revealed that PCL-PEG-PCL/Zeolite nanofibrous scaffolds could support better cell adhesion, proliferation and osteogenic differentiation of hDPSCs and as such is expected to be a promising scaffold for bone tissue engineering applications.