Prevascularization techniques for dental pulp regeneration: potential cell sources, intercellular communication and construction strategies

Single-cell RNA sequencing reveals vascularization-associated cell subpopulations in dental pulp: PDGFRβ+ DPSCs with activated PI3K/AKT pathway

BACKGROUND

This study aims to address challenges in dental pulp regeneration therapy. The heterogeneity of DPSCs poses challenges, especially in stem cell transplantation for clinical use, particularly when sourced from donors of different ages and conditions.

METHODS

Pseudotime analysis was employed to analyze single-cell sequencing data, and immunohistochemical studies were conducted to investigate the expression of fibronectin 1 (FN1). We performed in vitro sorting of PDGFRβ+ DPSCs using flow cytometry. A series of functional assays, including cell proliferation, scratch, and tube formation assays, were performed to experimentally validate the vasculogenic capabilities of the identified PDGFRβ+ DPSC subset. Furthermore, gene-edited mouse models were utilized to demonstrate the importance of PDGFRβ+ DPSCs. Transcriptomic sequencing was conducted to compare the differences between PDGFRβ+ DPSCs and P1-DPSCs.

RESULTS

Single-cell sequencing analysis unveiled a distinct subset, PDGFRβ+ DPSCs, characterized by significantly elevated FN1 expression during dental pulp development. Subsequent cell experiments demonstrated that this subset possesses remarkable abilities to promote HUVEC proliferation, migration, and tube formation. Gene-edited mouse models confirmed the vital role of PDGFRβ+ DPSCs in dental pulp development. Transcriptomic sequencing and in vitro experiments demonstrated that the PDGFR/PI3K/AKT signaling pathway is a crucial factor mediating the proliferation rate and pro-angiogenic properties of PDGFRβ+ DPSCs.

CONCLUSION

We defined a new subset, PDGFRβ+ DPSCs, characterized by strong proliferative activity and pro-angiogenic capabilities, demonstrating significant clinical translational potential.

Role and Molecular Mechanism of miR-586 in the Differentiation of Dental Pulp Stem Cells into Odontoblast-like Cells

Dental pulp stem cells (DPSCs) are a class of cells with the potential of self-replication and multi-directional differentiation, which are widely considered to have great application value. It was to investigate miR-586 in DPSCs differentiated into odontoblast-like cells. In this article, human dental pulp stem cells (hDPSCs) were used as samples, and hDPSCs were co-cultured with endothelial progenitor cells (EPCs). Furthermore, a lentiviral expression vector for the miR-586 inhibitor was established. The effect of miR-586 inhibitor expression vector on the activity of hDPSCs was detected by Cell Counting Kit-8 (CCK-8). The differentiation of hDPSCs was tested by mineralized nodule staining. The expression of miR-586 and a gene related to dental cell differentiation in the pulp was subjected to detection by real-time quantitative PCR (qRT-PCR). As against the normal hDPSCs and the empty vector, the miR-586 lentivirus expression inhibition vector could visibly raise the expression of dentin sialophosphoprotein (DSPP) in hDPSCs; and the cell proliferation activity was visibly enhanced; In addition, the mRNA expressions of dentin-matrix acidic phosphoprotein 1 (DMP-1) and alkaline phosphatase (ALP) were visibly raised in the miR-586 lentivirus expression inhibition vector (all P < 0.05). Additionally, ALP activity was significantly enhanced (P < 0.05). The number of mineralized nodules was significantly increased (P < 0.05). MiR-586 plays a key regulatory function in DPSCs differentiated into odontoblast-like cells and is associated with specific molecular mechanisms.

Immunological isolation and characterization of neuronal progenitors from human dental pulp: A laboratory-based investigation

AIMS

Dental pulp stem cells (DPSCs) contain a population of stem cells with a broad range of differentiation potentials, as well as more lineage-committed progenitors. Such heterogeneity is a significant obstacle to experimental and clinical applications. The aim of this study is to isolate and characterize a homogenous neuronal progenitor cell population from human DPSCs.

METHODOLOGY

Polysialylated-neural cell adhesion molecule (PSA-NCAM+) neural progenitors were isolated from the dental pulp of three independent donors using magnetic-activated cell sorting (MACS) technology. Immunofluorescent staining with a panel of neural and non-neural markers was used to characterize the magnetically isolated PSA-NCAM+ fraction. PSA-NCAM+ cells were then cultured in Neurobasal A supplemented with neurotrophic factors: dibutyryl cyclic-AMP, neurotrophin-3, B27 and N2 supplements to induce neuronal differentiation. Both PSA-NCAM+ and differentiated PSA-NCAM+ cells were used in Ca2+ imaging studies to assess the functionality of P2X3 receptors as well as membrane depolarization.

RESULTS

PSA-NCAM+ neural progenitors were isolated from a heterogeneous population of hDPSCs using magnetic-activated cell sorting and anti-PSA-NCAM MicroBeads. Flow cytometry analysis demonstrated that immunomagnetic sorting significantly increased the purity of PSA-NCAM+ cells. Immunofluorescent staining revealed expression of pan-neuronal and mature neuronal markers, PGP9.5 and MAP2, respectively, as well as weak expression of the mature sensory markers, peripherin and islet1. ATP-induced response was mediated predominately by P2X3 receptors in both undifferentiated and differentiated cells, with a greater magnitude observed in the latter. In addition, membrane depolarizations were also detected in cells before and after differentiation when loaded with fast-voltage-responding fluorescent molecule, FluoVolt™ in response to potassium chloride. Interestingly, only differentiated PSA-NCAM+ cells were capable of spontaneous membrane oscillations.

CONCLUSIONS

In summary, DPSCs contain a population of neuronal progenitors with enhanced neural differentiation and functional neural-like properties that can be effectively isolated with magnetic-activated cell sorting (MACS).

Electrical stimulation induced pre-vascularization of engineered dental pulp tissue

Vascularization is a key step to achieve pulp tissue regeneration and in vitro pre-vascularized dental pulp tissue could be applied as a graft substitute for dental pulp tissue repair. In this study, human dental pulp stem cells (DPSCs) and human umbilical vein endothelial cells (hUVECs) were co-cultured in 3D Matrigel and 150 mV/mm electric fields (EFs) were used to promote the construction of pre-vascularized dental pulp tissue. After optimizing co-cultured ratio of two cell types, immunofluorescence staining, and live/dead detection were used to investigate the effect of EFs on cell survival, differentiation and vessel formation in 3D engineered dental pulp tissue. RNA sequencing was used to investigate the potential molecular mechanisms by which EF regulates vessel formation in 3D engineered dental pulp tissue. Here we identified that EF-induced pre-vascularized engineered dental pulp tissue not only had odontoblasts, but also had a rich vascular network, and smooth muscle-like cells appeared around the blood vessels. The GO enrichment analysis showed that these genes were significantly enriched in regulation of angiogenesis, cell migration and motility. The most significant term of the KEGG pathway analysis were NOTCH signaling pathway and Calcium signaling pathway etc. The PPI network revealed that NOTCH1 and IL-6 were central hub genes. Our study indicated that EFs significantly promoted the maturation and stable of blood vessel in 3D engineered pulp tissue and provided an experimental basis for the application of EF in dental pulp angiogenesis and regeneration.

Enhancing Vasculogenesis in Dental Pulp Development: DPSCs-ECs Communication via FN1-ITGA5 Signaling

BACKGROUND

Dental pulp regeneration therapy is a challenge to achieve early vascularization during treatment. Studying the regulatory mechanisms of vascular formation during human dental pulp development may provide insights for related therapies. In this study, we utilized single-cell sequencing analysis to compare the gene expression of dental pulp stem cells (DPSCs) and vascular endothelial cells (ECs) from developing and mature dental pulps.

METHOD

Immunohistochemistry, Western blot, and real-time polymerase chain reaction (RT-PCR) were used to detect fibronectin 1 (FN1) expression and molecules, such as PI3K/AKT. Cell proliferation assay, scratch assay, tube formation assay and were used to investigate the effects of DPSCs on the vasculogenetic capability of ECs. Additionally, animal experiments involving mice were conducted.

RESULT

The results revealed that DPSCs exist around dental pulp vasculature. FN1 expression was significantly higher in DPSCs from young permanent pulps than mature pulps, promoting HUVEC proliferation, migration, and tube formation via ITGA5 and the downstream PI3K/AKT signaling pathway.

CONCLUSION

Our data indicate that intercellular communication between DPSCs and ECs mediated by FN1-ITGA5 signaling is crucial for vascularizationduring dental pulp development, laying an experimental foundation for future clinical studies.

Technology for the formation of engineered microvascular network models and their biomedical applications

Tissue engineering and regenerative medicine have made great progress in recent decades, as the fields of bioengineering, materials science, and stem cell biology have converged, allowing tissue engineers to replicate the structure and function of various levels of the vascular tree. Nonetheless, the lack of a fully functional vascular system to efficiently supply oxygen and nutrients has hindered the clinical application of bioengineered tissues for transplantation. To investigate vascular biology, drug transport, disease progression, and vascularization of engineered tissues for regenerative medicine, we have analyzed different approaches for designing microvascular networks to create models. This review discusses recent advances in the field of microvascular tissue engineering, explores potential future challenges, and offers methodological recommendations.

Unlocking the Potential of Cellular Guidance in Endodontics: Advancing the Process of Pulp Regeneration and Beyond

Regenerative endodontics represents a paradigm shift in dental therapy, with the potential to not only restore damaged dental tissues but also to preserve the vitality of teeth. At the heart of this innovative approach is cell homing, a technique that harnesses the body's own healing mechanisms by recruiting endogenous stem cells to the site of dental injury for effective tissue regeneration. This review delves into the intricate processes of cell homing in the context of regenerative endodontics, particularly focusing on its application in immature teeth with open apices. It examines the role of bioactive molecules, scaffolds, and growth factors in orchestrating cell migration and differentiation within the root canal space. In addition, the review addresses the current limitations in clinical practice, such as the challenges in completely regenerating the pulp-dentin complex and the unpredictability in long-term outcomes. It also explores future possibilities, including the potential for more refined and effective regenerative strategies. By providing a comprehensive overview of the current state of cell homing in regenerative endodontics, this article aims to contribute to the ongoing development of advanced therapeutic techniques that could revolutionize endodontic treatment and improve patient care.