Transcriptome analysis of basic fibroblast growth factor treated stem cells isolated from human exfoliated deciduous teeth

Efficient improvement of the proliferation, differentiation, and anti-arthritic capacity of mesenchymal stem cells by simply culturing on the immobilized FGF2 derived peptide, 44-ERGVVSIKGV-53

INTRODUCTION

The stem cell microenvironment has been evidenced to robustly affect its biological functions and clinical grade. Natural or synthetic growth factors, especially, are essential for modulating stem cell proliferation, metabolism, and differentiation via the interaction with specific extracellular receptors. Fibroblast growth factor-2 (FGF-2) possesses pleiotropic functions in various tissues and organs. It interacts with the FGF receptor (FGFR) and activates FGFR signaling pathways, which involve numerous biological functions, such as angiogenesis, wound healing, cell proliferation, and differentiation.

OBJECTIVES

Here, we aim to explore the molecular functions, mode of action, and therapeutic activity of yet undetermined function, FGF-2-derived peptide, FP2 (44-ERGVVSIKGV-53) in promoting the proliferation, differentiation, and therapeutic application of human Wharton's jelly mesenchymal stem cells (hWJ-MSCs) in comparison to other test peptides, canofin1 (FP1), hexafin2 (FP3), and canofin3 (FP4) with known functions.

METHODS

The immobilization of test peptides that are fused with mussel adhesive proteins (MAP) on the culture plate was carried out via EDC/NHS chemistry. Cell Proliferation assay, colony-forming unit, western blotting analysis, gene expression analysis, RNA-Seq. analysis, osteogenic, and chondrogenic differentiation capacity were applied to test the activity of the test peptides. We additionally utilized three-dimensional (3D) structural analysis and artificial intelligence (AI)-based AlphaFold2 and CABS-dock programs for receptor interaction prediction of the peptide receptor. We also verified the in vivo therapeutic capacity of FP2-cultured hWJ-MSCs using an osteoarthritis mice model.

RESULTS

Culture of hWJ-MSC onto an FP2-immobilized culture plate showed a significant increase in cell proliferation (n = 3; *p < 0.05, **p < 0.01) and the colony-forming unit (n = 3; *p < 0.05, **p < 0.01) compared with the test peptides. FP2 showed a significantly upregulated phosphorylation of FRS2α and FGFR1 and activated the AKT and ERK signaling pathways (n = 3; *p < 0.05, **p < 0.01, ***p < 0.001). Interestingly, we detected efficient FP2 receptor binding that was predicted using AI-based tools. Treatment with an AKT inhibitor significantly abrogated the FP2-mediated enhancement of cell differentiation (n = 3; *p < 0.05, **p < 0.01, ***p < 0.001). Intra-articular injection of FP2-cultured MSCs significantly mitigated arthritis symptoms in an osteoarthritis mouse model, as shown through the functional tests (n = 10; *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001), modulation of the expression level of the pro-inflammatory and anti-inflammatory genes, and improved osteochondral regeneration as demonstrated by tissue sections.

CONCLUSION

Our study identified the FGF-2-derived peptide FP2 as a promising candidate peptide to improve the therapeutic potential of hWJ-MSCs, especially in bone and cartilage regeneration.

Fibroblast test cells of embryo of Super Java Chicken as an indicator to test toxicity and malignancy

Fibroblast is one component of connective tissue cells in polygonal or stellate with cytoplasmic processes or projections. In vitro, tissue culture is an excellent medium used in biomedical research. The goal of this study was to analyze Toxicity and Malignancy in Embryo of Super Java Chicken as Potential Candidates of Strong Poultry in Indonesia. This study used Preparation of fibroblast primary cell culture of Java super chicken embryos, Pathogenicity test using fibroblast cells from Super Java chicken, Toxicity test using fibroblast cells from Super Java Chicken. Primary fibroblast cell culture of Java super chicken embryos was prepared from 10-day-old brood chicken eggs free of pathogens. Cells were prepared in 96-well microplates with minimal essential medium (MEM) containing 10 % fetal calf serum (FCS) 100 IU/ug penicillin/streptomycinVirus isolates were diluted in stages from 10-2 to 10-5 and inoculated into Java Super Chicken Fibroblast cell culture. The result showed that the negative control of the samples had a faster proliferative power than the fibroblast cell culture of Java super chicken, which was treated with concentrations of 10-2; 10-3; 10-4; 10-5. Moreover, before being inoculated with the virus, the confluent fibroblast cells of Java super chicken looked oval and regular. The day after infection, syncytia (large multinucleated cells) began to form on a small scale and became more pronounced on the second and third post-infection days. CPE was found in the 10-2,10-3 and 10-4 virus dilutions, and CPE was not found in the 10-5 dilution.

Antibacterial and Immunomodulatory Properties of Stem Cells from Human Exfoliated Deciduous Teeth: An In Vitro Study

Stem cells from human exfoliated deciduous teeth (SHED) provide an important autologous source for stem cell-based regenerative therapies with their easy acquisition and multipotency. However, the understanding of their antibacterial and immunomodulatory properties is limited. This in vitro research aims to determine whether SHED inhibits the growth of Streptococcus mutans (S. mutans) and Enterococcus faecalis (E. faecalis), as well as whether or not it has immunomodulatory effects by measuring interleukins (ILs)-2 and -6 levels. SHEDs were derived from the pulp of deciduous teeth that had undergone up to two-thirds of their roots' resorption. Isolated SHEDs were characterized on their morphological features, viability, assessment of surface markers, and in vitro induction into osteocytes and adipocytes. SHED was tested for its antibacterial efficacy against S. mutans and E. faecalis using a colony-forming units (CFU) assay. Lastly, we checked the cytokine levels by enzyme-linked immune sorbent assay (ELISA) for assessing the immunomodulatory properties of SHED. The results showed that the established SHED had fibroblastic morphology with higher viability. The ability to differentiate into osteocytes and adipocytes, as well as the expression of stem cell-specific markers, demonstrated their potential and flexibility under in vitro settings. SHED demonstrated antibacterial characteristics by significantly (p < 0.05) lowering S. mutans CFU, whereas E. faecalis CFU was either unaffected by or just slightly affected by the cells. SHED also helped keep inflammatory indicators, including IL-2 and IL-6, at stable levels when compared to the control. The results indicate that SHED may aid in preventing or reducing an infection due to its antibacterial activity and may provide immunomodulatory activities by controlling the production of cytokines.

How to cite this article

Tyagi A, Shetty J, Shetty S, et al. Antibacterial and Immunomodulatory Properties of Stem Cells from Human Exfoliated Deciduous Teeth: An In Vitro Study. Int J Clin Pediatr Dent 2023;16(S-3):S240-S246.

Dissecting specific Wnt components governing osteogenic differentiation potential by human periodontal ligament stem cells through interleukin-6

Periodontal ligament stem cells (PDLSCs) play a significant role on periodontal tissue and alveolar bone homeostasis. During inflammation, interleukin (IL)-6 serves as one of key cytokine players controlling tissue reaction as well as alveolar bone tissue remodeling. It is believed that periodontal tissue inflammation causes periodontium degradation, especially alveolar bone. However, in this study, we show that an inflammatory mediator, IL-6, may serve another direction on alveolar bone homeostasis during inflammatory condition. We found that, IL-6 at 10 and 20 ng/mL was not cytotoxic and dose-dependently exerted beneficial effects on osteogenic differentiation of human PDLSCs (hPDLSCs), as demonstrated by increased alkaline phosphatase activity, mRNA expression of osteogenic markers, and matrix mineralization. The presence of physiological and inflammatory level of IL-6, the osteogenic differentiation potential by hPDLSCs was enhanced by several possible mechanisms including transforming growth factor (TGF), Wnt, and Notch pathways. After in-depth and thorough exploration, we found that Wnt pathway serves as key regulator controlling osteogenic differentiation by hPDLSCs amid the IL-6 presentation. Surprisingly, apart from other mesenchymal stem cells, distinct Wnt components are employed by hPDLSCs, and both canonical and non-canonical Wnt pathways are triggered by different mechanisms. Further validation by gene silencing, treatment with recombinant Wnt ligands, and β-catenin stabilization/translocation confirmed that IL-6 governed the canonical Wnt/β-catenin pathway via either WNT2B or WNT10B and employed WNT5A to activate the non-canonical Wnt pathway. These findings fulfill the homeostasis pathway governing periodontal tissue and alveolar bone regeneration and may serve for further therapeutic regimen design for restoring the tissues.

MicroRNA26a Overexpression Hastens Osteoblast Differentiation Capacity in Dental Stem Cells

Dental pulp stem cells (DPSCs) and stem cells from human exfoliated deciduous teeth (SHED) are a source of mesenchymal stem cells with the potential to differentiate into several cell types. We initially isolated SHED cells and compared their osteogenic capacity with commercially available DPSCs. Both cells exhibited similar capacities of growth and osteogenic differentiation. A fourfold to sixfold increase in endogenous microRNA26a (miR26a) expression during osteogenic differentiation of preosteoblasts and a similar but attenuated increase (twofold to fourfold) in differentiating SHED was observed, suggesting a role in the process. We, therefore, overexpressed miR26a in SHED to determine if the osteogenic differentiation capacity can be potentiated in vitro. SHED with a threefold increase in miR26a expression showed increased growth rate when compared with parent cells. When exposed to an osteogenic differentiating promoting medium, the miR26a overexpressing cells showed 100-fold increases in the expression of bone marker genes such as type 1 collagen, alkaline phosphatase, and Runx2. The mineralization capacity of these cells was also increased 15-fold. As miR26a targets regulate several bone-specific genes, we evaluated the effect of miR26a overexpression on established targets. We found a moderate decrease in SMAD1 and a profound decrease in PTEN expression. miR26a could potentiate its effect on osteoblast differentiation by its ability to inhibit PTEN and increase the viability of cells and their numbers, a process essential in osteoblast differentiation. Our studies suggest that the upregulation of miR26a can increase bone formation and may serve as an important target to further investigate its potential in tissue engineering applications.

Osteogenic growth peptide enhances osteogenic differentiation of human periodontal ligament stem cells

Bone tissue engineering consists of three major components namely cells, scaffolds, and signaling molecules to improve bone regeneration. These integrated principles can be applied in patients suffered from bone resorption diseases, such as osteoporosis and periodontitis. Osteogenic growth peptide (OGP) is a fourteen-amino acid sequence peptide that has the potential to regenerate bone tissues. This study aimed to disseminate the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) with OGP treatment. OGP was elaborated for proliferation, cytotoxicity, osteogenic differentiation effects, and the involvement of osteogenic related signaling pathways in vitro. This study found that OGP at lower concentration shows better effects on cytotoxicity and proliferation. Moreover, OGP at concentration 0.01 nM had the most potential to differentiate hPDLSCs toward osteogenic lineage comparing with higher concentrations of OGP. The phenomenon was mainly involving transforming growth factor-beta (TGF-β), bone morphogenetic protein (BMP), Hedgehog, and Wingless-related (Wnt) pathways. Further, SB-431542 treatment demonstrated the partial involvement of OGP in regulating osteogenic differentiation of hPDLSCs. In conclusion, OGP at low concentration enhances osteogenic differentiation of hPDLSCs by governing TGF-β signaling pathway.

Anti-fibrotic effects of pharmacologic FGF-2: a review of recent literature

Fibrosis is a process of pathological tissue repair that replaces damaged, formerly functional tissue with a non-functional, collagen-rich scar. Complications of fibrotic pathologies, which can arise in numerous organs and from numerous conditions, result in nearly half of deaths in the developed world. Despite this, therapies that target fibrosis at its mechanistic roots are still notably lacking. The ubiquity of the occurrence of fibrosis in myriad organs emphasizes the fact that there are shared mechanisms underlying fibrotic conditions, which may serve as common therapeutic targets for multiple fibrotic diseases of varied organs. Thus, study of the basic science of fibrosis and of anti-fibrotic modalities is critical to therapeutic development and may have potential to translate across organs and disease states. Fibroblast growth factor 2 (FGF-2) is a broadly studied member of the fibroblast growth factors, a family of multipotent cytokines implicated in diverse cellular and tissue processes, which has previously been recognized for its anti-fibrotic potential. However, the mechanisms underlying this potential are not fully understood, nor is the potential for its use to ameliorate fibrosis in diverse pathologies and tissues. Presented here is a review of recent literature that sheds further light on these questions, with the hopes of inspiring further research into the mechanisms underlying the anti-fibrotic activities of FGF-2, as well as the disease conditions for which pharmacologic FGF-2 might be a useful option in the future.

The Regenerative Potential of bFGF in Dental Pulp Repair and Regeneration

Regenerative endodontic therapy intends to induce the host’s natural wound-healing process, which can restore the vitality, immunity, and sensitivity of the inflammatory or necrotic pulp tissue destroyed by infection or trauma. Myriads of growth factors are critical in the processes of pulp repair and regeneration. Among the key regulatory factors are the fibroblast growth factors, which have turned out to be the master regulators of both organogenesis and tissue homeostasis. Fibroblast growth factors, a family composed of 22 polypeptides, have been used in tissue repair and regeneration settings, in conditions as diverse as burns, ulcers, bone-related diseases, and spinal cord injuries. Meanwhile, in dentistry, the basic fibroblast growth factor is the most frequently investigated. Thereby, the aim of this review is 2-fold: 1) foremost, to explore the underlying mechanisms of the bFGF in dental pulp repair and regeneration and 2) in addition, to shed light on the potential therapeutic strategies of the bFGF in dental pulp–related clinical applications.

Platelet-derived biomaterials-mediated improvement of bone injury through migratory ability of embryonic fibroblasts: in vitro and in vivo evidence

Bony injuries lead to compromised skeletal functional ability which further increase in aging population due to decreased bone mineral density. Therefore, we aimed to investigate the therapeutic potential of platelet-derived biomaterials (PDB) against bone injury. Specifically, we assessed the impact of PDB on osteo-inductive characteristics and migration of mouse embryonic fibroblasts (MEFs). Osteogenic lineage, matrix mineralization and cell migration were determined by gene markers (RUNX2, OPN and OCN), alizarin Red S staining, and migration markers (FAK, pFAK and Src) and EMT markers, respectively. The therapeutic impact of TGF-β1, a key component of PDB, was confirmed by employing inhibitor of TGF-β receptor I (Ti). Molecular imaging-based in vivo cellular migration in mice was determined by establishing bone injury at right femurs. Results showed that PDB markedly increased expression of osteogenic markers, matrix mineralization, migration and EMT markers, revealing higher osteogenic and migratory potential of PDB-treated MEFs. In vivo cell migration was manifested by expression of migratory factors, SDF-1 and CXCR4. Compared to control, PDB-treated mice exhibited higher bone density and volume. Ti treatment inhibited both migration and osteogenic potential of MEFs, affirming impact of TGF-β1. Collectively, our study clearly indicated PDB-rescued bone injury through enhancing migratory potential of MEFs and osteogenesis.