BACKGROUND: The protective effect of mesenchymal stem cells (MSCs) on cardiac ischemia-reperfusion (I/R) injury has been widely reported. Dental pulp-derived mesenchymal stem cells (DP-MSCs) have therapeutic effects on various diseases, including diabetes and cirrhosis. This study aimed to determine the therapeutic effects of DP-MSCs on I/R injury and elucidate the underlying mechanism. METHODS: Myocardial I/R injury model mice were treated with DP-MSCs or a miR-19a-3p mimic. The infarct volume, fibrotic area, pyroptosis, inflammation level, and cardiac function were measured. Cardiomyocytes exposed to hypoxia-reoxygenation were transfected with the miR-19a-3p mimic, miR-19a-3p inhibitor, or negative control. Pyroptosis and protein expression in the interferon regulatory factor 8/mitogen-activated protein kinase (IRF-8/MAPK) pathway were measured. RESULTS: DP-MSCs protected cardiac function in cardiac I/R-injured mice and inhibited cardiomyocyte pyroptosis. The upregulation of miR-19a-3p protected cardiac function, inhibited cardiomyocyte pyroptosis, and inhibited IRF-8/MAPK signaling in cardiac I/R-injured mice. DP-MSCs inhibited cardiomyocyte pyroptosis and the IRF-8/MAPK signaling by upregulating the miR-19a-3p levels in cardiomyocytes injured by I/R. CONCLUSION DP-MSCs protected cardiac function by inhibiting cardiomyocyte pyroptosis through miR-19a-3p under I/R conditions.
Animals ; MicroRNAs/metabolism* ; Pyroptosis/genetics* ; Mesenchymal Stem Cells/metabolism* ; Myocytes, Cardiac/cytology* ; Mice ; Male ; Mice, Inbred C57BL ; Dental Pulp/cytology* ; Myocardial Reperfusion Injury/therapy* ; MAP Kinase Signaling System/physiology*

Mesenchymal stem cells are highly regarded for their potential in tissue repair and regenerative medicine due to their multipotency and self-renewal abilities. Recently, mesenchymal stem cells have been redefined as "medical signaling cells," with their primary biological effects mediated through exosome secretion. These exosomes, which contain lipids, proteins, RNA, and metabolites, are crucial in regulating various biological processes and enhancing regenerative therapies. Exosomes replicate the effects of their parent cells while offering benefits such as reduced side effects, low immunogenicity, excellent biocompatibility, and high drug-loading capacity. Dental stem cells, including those from apical papilla, gingiva, dental pulp, and other sources, are key contributors to exosome-mediated regenerative effects, such as tumor cell apoptosis, neuroprotection, angiogenesis, osteogenesis, and immune modulation. Despite their promise, clinical application of exosomes is limited by challenges in isolation techniques. Current methods face issues of complexity, inefficiency, and insufficient purity, hindering detailed analysis. Recent advancements, such as micro-electromechanical systems, alternating current electroosmosis, and serum-free three-dimensional cell cultures, have improved exosome isolation efficacy. This review synthesizes nearly 200 studies on dental stem cell-derived exosomes, highlighting their potential in treating a wide range of conditions, including periodontal diseases, cancer, neurodegenerative disorders, diabetes, and more. Optimized isolation methods offer a path forward for overcoming current limitations and advancing the clinical use of exosome-based therapies.
Exosomes/physiology* ; Humans ; Mesenchymal Stem Cells/cytology* ; Dental Pulp/cytology* ; Stem Cells/cytology* ; Tooth/cytology*

OBJECTIVE: To construct a model of Enterococcus faecalis (E. faecalis) infection in dentinal tubules by gradient centrifugation and to evaluate the antibacterial effect of low-temperature plasma on E. faecalis in dentinal tubules. METHODS: Standard dentin blocks of 4 mm×4 mm×2 mm size were prepared from single root canal isolated teeth without caries, placed in the E. faecalis bacterial solution, centrifuged in gradient and incubated for 24 h to establish the model of dentinal tubule infection with E. faecalis. The twenty dentin blocks of were divided into five groups, low-temperature plasma jet treatment for 0, 5 and 10 min, calcium hydroxide paste sealing for 7 d and 2% chlorhexidine gel sealing for 7 d. Scanning electron microscopy and confocal laser scanning microscope were used to assess the infection in the dentinal tubules and the antibacterial effect of low-temperature plasma. RESULTS: The results of scanning electron microscopy and confocal laser scanning microscopy showed that after 24 h of incubation by gradient centrifugation, E. faecalis could fully enter the dentinal tubules to a depth of more than 600μm indicating that this method was time-saving and efficient and could successfully construct a model of E. faecalis infection in dentinal tubules. Low-temperature plasma could enter the dentinal tubules and play a role, the structure of E. faecalis was still intact after 5 min of low-temperature plasma treatment, with no obvious damage, and after 10 min of low-temperature plasma treatment, the surface morphology of E. faecalis was crumpled and deformed, the cell wall was seriously collapsed, and the normal physiological morphology was damaged indicating that the majority of E. faecalis was killed in the dentinal tubules. The antibacterial effect of low-temperature plasma treatment for 10 min exceeded that of the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d. These two chemicals had difficulty entering deep into the dentinal tubules, and therefore only had a few of antibacterial effect on the bacterial biofilm on the root canal wall, and there was also no significant damage to the E. faecalis bacterial structure. CONCLUSION Gradient centrifugation could establish the model of E. faecalis dentin infection successfully. Low-temperature plasma treatment for 10 min could kill E. faecalis in dentinal tubules effectively, which is superior to the calcium hydroxide paste sealing for 7 d and the 2% chlorhexidine gel sealing for 7 d.
Chlorhexidine/pharmacology* ; Calcium Hydroxide/pharmacology* ; Enterococcus faecalis/physiology* ; Temperature ; Dentin ; Biofilms ; Anti-Bacterial Agents/pharmacology* ; Root Canal Irrigants/pharmacology* ; Dental Pulp Cavity

Therapeutic dentin regeneration remains difficult to achieve, and a majority of the attention has been given to anabolic strategies to promote dentinogenesis directly, whereas, the available literature is insufficient to understand the role of inflammation and inflammatory complement system on dentinogenesis. The aim of this study is to determine the role of complement C5a receptor (C5aR) in regulating dental pulp stem cells (DPSCs) differentiation and in vivo dentin regeneration. Human DPSCs were subjected to odontogenic differentiation in osteogenic media treated with the C5aR agonist and C5aR antagonist. In vivo dentin formation was evaluated using the dentin injury/pulp-capping model of the C5a-deficient and wild-type mice. In vitro results demonstrate that C5aR inhibition caused a substantial reduction in odontogenic DPSCs differentiation markers such as DMP-1 and DSPP, while the C5aR activation increased these key odontogenic genes compared to control. A reparative dentin formation using the C5a-deficient mice shows that dentin regeneration is significantly reduced in the C5a-deficient mice. These data suggest a positive role of C5aR in the odontogenic DPSCs differentiation and tertiary/reparative dentin formation. This study addresses a novel regulatory pathway and a therapeutic approach for improving the efficiency of dentin regeneration in affected teeth.
Animals ; Cell Differentiation/physiology* ; Cells, Cultured ; Complement C5a/metabolism* ; Dental Pulp/physiology* ; Dentin ; Mice ; Receptor, Anaphylatoxin C5a ; Stem Cells

Mesenchymal stem cells (MSCs) are a promising tool in regenerative medicine due to their capacity to differentiate into multiple lineages. In addition to MSCs isolated from bone marrow (BMSCs), adult MSCs are isolated from craniofacial tissues including dental pulp tissues (DPs) using various stem cell surface markers. However, there has been a lack of consensus on a set of surface makers that are reproducibly effective at isolating putative multipotent dental mesenchymal stem cells (DMSCs). In this study, we used different combinations of surface markers (CD51/CD140α, CD271, and STRO-1/CD146) to isolate homogeneous populations of DMSCs from heterogeneous dental pulp cells (DPCs) obtained from DP and compared their capacity to undergo multilineage differentiation. Fluorescence-activated cell sorting revealed that 27.3% of DPCs were CD51(+)/CD140α(+), 10.6% were CD271(+), and 0.3% were STRO-1(+)/CD146(+). Under odontogenic conditions, all three subsets of isolated DMSCs exhibited differentiation capacity into odontogenic lineages. Among these isolated subsets of DMSCs, CD271(+) DMSCs demonstrated the greatest odontogenic potential. While all three combinations of surface markers in this study successfully isolated DMSCs from DPCs, the single CD271 marker presents the most effective stem cell surface marker for identification of DMSCs with high odontogenic potential. Isolated CD271(+) DMSCs could potentially be utilized for future clinical applications in dentistry and regenerative medicine.
Adult ; Adult Stem Cells ; cytology ; Antigens, CD ; analysis ; Antigens, Surface ; analysis ; Biomarkers ; analysis ; CD146 Antigen ; analysis ; Cell Culture Techniques ; Cell Differentiation ; physiology ; Cell Lineage ; Cell Separation ; methods ; Cells, Cultured ; Chondrogenesis ; physiology ; Dental Pulp ; cytology ; Flow Cytometry ; methods ; Humans ; Integrin alphaV ; analysis ; Mesenchymal Stromal Cells ; cytology ; Multipotent Stem Cells ; cytology ; Nerve Tissue Proteins ; analysis ; Odontogenesis ; physiology ; Receptor, Platelet-Derived Growth Factor alpha ; analysis ; Receptors, Nerve Growth Factor ; analysis

Both bone morphogenetic protein 2 (BMP2) and the wingless-type MMTV integration site (WNT)/β-catenin signalling pathway play important roles in odontoblast differentiation and dentinogenesis. Cross-talk between BMP2 and WNT/β-catenin in osteoblast differentiation and bone formation has been identified. However, the roles and mechanisms of the canonical WNT pathway in the regulation of BMP2 in dental pulp injury and repair remain largely unknown. Here, we demonstrate that BMP2 promotes the differentiation of human dental pulp cells (HDPCs) by activating WNT/β-catenin signalling, which is further mediated by p38 mitogen-activated protein kinase (MAPK) in vitro. BMP2 stimulation upregulated the expression of β-catenin in HDPCs, which was abolished by SB203580 but not by Noggin or LDN193189. Furthermore, BMP2 enhanced cell differentiation, which was not fully inhibited by Noggin or LDN193189. Instead, SB203580 partially blocked BMP2-induced β-catenin expression and cell differentiation. Taken together, these data suggest a possible mechanism by which the elevation of β-catenin resulting from BMP2 stimulation is mediated by the p38 MAPK pathway, which sheds light on the molecular mechanisms of BMP2-mediated pulp reparative dentin formation.
Bone Morphogenetic Protein 2 ; physiology ; Cell Differentiation ; physiology ; Dental Pulp ; cytology ; Humans ; MAP Kinase Signaling System ; Wnt Proteins ; metabolism ; beta Catenin ; metabolism

The time domain entombment of bacteria by intratubular mineralization following orthograde canal obturation with mineral trioxide aggregate (MTA) was studied by scanning electron microscopy (SEM). Single-rooted human premolars (n=60) were instrumented to an apical size #50/0.06 using ProFile and treated as follows: Group 1 (n=10) was filled with phosphate buffered saline (PBS); Group 2 (n=10) was incubated with Enterococcus faecalis for 3 weeks, and then filled with PBS; Group 3 (n=20) was obturated orthograde with a paste of OrthoMTA (BioMTA, Seoul, Korea) and PBS; and Group 4 (n=20) was incubated with E. faecalis for 3 weeks and then obturated with OrthoMTA-PBS paste. Following their treatments, the coronal openings were sealed with PBS-soaked cotton and intermediate restorative material (IRM), and the roots were then stored in PBS for 1, 2, 4, 8 or 16 weeks. After each incubation period, the roots were split and their dentin/MTA interfaces examined in both longitudinal and horizontal directions by SEM. There appeared to be an increase in intratubular mineralization over time in the OrthoMTA-filled roots (Groups 3 and 4). Furthermore, there was a gradual entombment of bacteria within the dentinal tubules in the E. faecalis inoculated MTA-filled roots (Group 4). Therefore, the orthograde obturation of root canals with OrthoMTA mixed with PBS may create a favorable environment for bacterial entombment by intratubular mineralization.
Aluminum Compounds ; therapeutic use ; Calcification, Physiologic ; physiology ; Calcium Compounds ; therapeutic use ; Crystallization ; Dental Pulp Cavity ; microbiology ; Dentin ; microbiology ; Drug Combinations ; Enterococcus faecalis ; ultrastructure ; Humans ; Methylmethacrylates ; therapeutic use ; Microscopy, Electron, Scanning ; Oxides ; therapeutic use ; Root Canal Filling Materials ; therapeutic use ; Root Canal Obturation ; methods ; Root Canal Preparation ; instrumentation ; Silicates ; therapeutic use ; Time Factors ; Zinc Oxide-Eugenol Cement ; therapeutic use

The purpose of this study was to evaluate the effect of age on the ratio of pulp cavity/tooth width (P/T ratio) in healthy cats. The dental radiographs of 32 cats (16 males and 16 females) were generated with a digital dental X-ray unit with the animals under general anesthesia. Standardized measurement of the canine teeth was performed by drawing a line on the radiograph perpendicular to the cementoenamel junction (CEJ) of the tooth. There was an inversely proportional correlation between chronological age and the P/T ratio. Moreover, a strong Pearson squared correlation (gamma2 = 0.92) was identified by the curved regression model. No significant differences in the P/T ratio based on gender or breed were found. These results suggest that determination of age by P/T ratio could be clinically useful for estimating the chronological age of cats.
Age Determination by Teeth/*veterinary ; Animals ; Cats/*physiology ; Dental Pulp Cavity/anatomy & histology/*radiography ; Female ; Male ; Tooth/anatomy & histology/*radiography

OBJECTIVETo regenerate dentin-pulp complex by tissue engineering with human stem cells from apical papilla cells (SCAP) as the seed cells.

METHODSSCAP was separated from from normal human impacted third molars with immature roots by outgrowth culture. The cells were then cultured in the differentiation medium for 3 weeks or in normal medium for 60 days, and analyzed for mineralization potential by Alizarin red staining. The osteo/odontogenic markers including alkaline phosphatase (ALP), bone sialoprotein (BSP), osteocalcin (OC) and dentin sialoprotein (DSP) were investigated by immunofluorescence staining and reverse transcription-polymerase chain reaction. The co-cultured mixture of SCAP and HA/TCP, or HA/TCP alone was implanted subcutaneously on the back of nude mice for 8 weeks, and the implants were collected and examined by HE and immunohistochemical staining.

RESULTSRound alizarin red-positive nodules formed in the isolated cells after cell culture in the differentiation medium for 3 weeks or in normal medium for 60 days with positive staining for osteo/odontogenic markers. SCAP with HA/TCP could regenerate pulp-dentin complex-like tissue in nude mice. The cells near the dentin-like tissue were positive for DSP. No mineral tissue was found in mice receiving HA/TCP implantation.

CONCLUSIONSSCAP may serve as a promising seed cell for dentin-pulp complex tissue engineering.

Adolescent ; Adult ; Alkaline Phosphatase ; analysis ; Animals ; Cell Culture Techniques ; Cell Differentiation ; Coculture Techniques ; Dental Papilla ; cytology ; Dental Pulp ; cytology ; Extracellular Matrix Proteins ; analysis ; Female ; Humans ; Integrin-Binding Sialoprotein ; analysis ; Mice ; Mice, Nude ; Odontogenesis ; physiology ; Osteocalcin ; analysis ; Phosphoproteins ; analysis ; Sialoglycoproteins ; analysis ; Stem Cells ; chemistry ; physiology ; Tissue Engineering ; methods ; Young Adult

We developed a method that allows us to label nociceptive neurons innervating tooth-pulp in rat trigeminal ganglion neurons using a retrograde fluorescence-tracing method, to record ATP-activated current in freshly isolated fluorescence-labeled neurons and to conduct single cell immunohistochemical staining for P2X1 and P2X3 subunits in the same neuron. Three types of ATP-activated current in these neurons (F, I and S) were recorded. The cells exhibiting the type F current mainly showed positive staining for P2X3, but negative staining for P2X1. The results provide direct and convincing evidence at the level of single native nociceptive neurons for correlation of the characteristics of ATP-activated currents with their composition of P2X1 and P2X3 subunits and cell size. The results also suggest that the P2X3, but not P2X1, is the main subunit that mediates the fast ATP-activated current in nociceptive neurons.
Action Potentials ; physiology ; Adenosine Triphosphate ; metabolism ; Animals ; Dental Pulp ; innervation ; physiology ; Nociceptors ; cytology ; physiology ; Rats ; Rats, Sprague-Dawley ; Receptors, Purinergic P2X1 ; metabolism ; Receptors, Purinergic P2X3 ; metabolism ; Tissue Distribution ; Trigeminal Nerve ; cytology ; metabolism