Administration of Epidermal Growth Factor (EGF) and Basic Fibroblast Growth Factor (bFGF) to Induce Neural Differentiation of Dental Pulp Stem Cells (DPSC) Isolates

Assessment of Endocyn on Dental Pulp Stem Cells (DPSCs): A Pilot Study of Endodontic Irrigant Effects

Many endodontic procedures within the pediatric population are performed with patients aged 12 years and older, using intracanal irrigants to complement mechanical debridement for the removal of debris and to disinfect the root canal system. The use of antimicrobial irrigants that limit damage to the dental pulp are the goals of endodontic biomaterials research. Using an existing biorepository of dental pulp stem cells (DPSCs), Endocyn was evaluated in varying concentrations in proliferation and viability assays, and compared with positive (sodium hypochlorite or bleach) and negative (phosphate-buffered saline) controls. The DPSC viability was reduced in the range of -8.3% to -15.8%, p = 0.22 to p = 0.042, while the growth inhibition varied between -29.7% and -63%, p = 0.041 to p = 0.022. However, the RNA analysis revealed that no significant changes in biomarker mRNA expression (Nestin, NANOG, Sox2, Oct4, CD73, CD90, and CD105) were observed. These data demonstrated that all of the concentrations of Endocyn inhibited the DPSC viability and growth, although only high concentrations were statistically significant. Moreover, the administration of Endocyn did not alter the DPSC biomarker expression, which are novel and important findings not previously observed or reported that may assist with the development of clinical decision protocols and methods for the treatment of vital pulp tissue.

Human platelet lysate: a potential therapeutic for intracerebral hemorrhage

Intracerebral hemorrhage (ICH) is a major public health challenge worldwide, and is associated with elevated rates of mortality, disability, and morbidity, especially in low- and middle-income nations. However, our knowledge of the detailed molecular processes involved in ICH remains insufficient, particularly those involved in the secondary injury stage, resulting in a lack of effective treatments for ICH. Human platelet lysates (HPL) are abundant in bioactive factors, and numerous studies have demonstrated their beneficial effects on neurological diseases, including their anti-neuroinflammatory ability, anti-oxidant effects, maintenance of blood-brain barrier integrity, and promotion of neurogenesis. In this review, we thoroughly explore the potential of HPL for treating ICH from three critical perspectives: the rationale for selecting HPL as a treatment for ICH, the mechanisms through which HPL contributes to ICH management, and the additional measures necessary for HPL as a treatment for ICH. We elucidate the role of platelets in ICH pathophysiology and highlight the limitations of the current treatment options and advancements in preclinical research on the application of HPL in neurological disorders. Furthermore, historical developments and preparation methods of HPL in the field of biomedicine are discussed. Additionally, we summarize the bioactive molecules present in HPL and their potential therapeutic effects in ICH. Finally, we outline the issues that must be addressed regarding utilizing HPL as a treatment modality for ICH.

Comparative evaluation of divergent concoction of NGF, BDNF, EGF, and FGF growth factor's role in enhancing neuronal differentiation of adipose-derived mesenchymal stem cells

MSCs (Mesenchymal Stem Cells) can differentiate into various lineages, including neurons and glial cells. In the past few decades, MSCs have been well explored in the context of neuronal differentiation and have been reported to have the immense potential to form distinct kinds of neurons. The distinguishing features of MSCs make them among the most desired cell sources for stem cell therapy. This study involved the trans-differentiation of Adipose-derived human Mesenchymal Stem Cells (ADMSCs) into neurons. The protocol employs a cocktail of chemical inducers in different combinations, including Brain-derived neurotrophic factor (BDNF), epidermal growth factor (EGF), and Nerve growth factor (NGF) Fibroblastic growth factor (FGF), in induction media. Both types have been successfully differentiated into neurons, confirmed by morphological aspects and the presence of neural-specific markers through RT-PCR (Reverse transcription polymerase chain reaction) studies and immunocytochemistry assay. They have shown excellent morphology with long neurites, synaptic connections, and essential neural markers to validate their identity. The results may significantly contribute to cell replacement therapy for neurological disorders.

The involvement of Neuregulin-1 in the process of facial nerve injury repair through the utilization of dental pulp stem cells

BACKGROUND

Facial nerve injury often results in poor prognosis due to the challenging process of nerve regeneration. Neuregulin-1, a human calmodulin, is under investigation in this study for its impact on the reparative capabilities of Dental Pulp Stem Cells (DPSCs) in facial nerve injury.

METHODS

Lentivirus was used to transfect and construct Neuregulin-1 overexpressed DPSCs. Various techniques assessed the effects of Neuregulin-1: osteogenic induction, lipid induction, Reverse Transcription Polymerase Chain Reaction, Western Blot, Cell Counting Kit-8 assay, wound healing, immunofluorescence, Phalloidin staining, nerve stem action potential, Hematoxylin-eosin staining, transmission electron microscopy, and immunohistochemistry.

RESULTS

Neuregulin-1 effectively enhanced the proliferation, migration, and cytoskeletal rearrangement of DPSCs, while simultaneously suppressing the expression of Ras homolog gene family member A (RhoA) and Microfilament actin (F-actin). These changes facilitated the neural differentiation of DPSCs. Additionally, in vivo experiments showed that Neuregulin-1 expedited the restoration of action potential in the facial nerve trunk, increased the thickness of the myelin sheath, and stimulated axon regeneration.

CONCLUSION

Neuregulin-1 has the capability to facilitate the repair of facial nerve injuries by promoting the regenerative capacity of DPSCs. Thus, Neuregulin-1 is a significant potential gene in the reparative processes of nerve damage.

Differential Expression of MicroRNA (MiR-27, MiR-145) among Dental Pulp Stem Cells (DPSCs) Following Neurogenic Differentiation Stimuli

This study sought to evaluate the expression of previously identified microRNAs known to regulate neuronal differentiation in mesenchymal stem cells (MSCs), including miR-27, miR-125, miR-128, miR-135, miR-140, miR-145, miR-218 and miR-410, among dental pulp stem cells (DPSCs) under conditions demonstrated to induce neuronal differentiation. Using an approved protocol, n = 12 DPSCs were identified from an existing biorepository and treated with basic fibroblast growth factor (bFGF) and epidermal growth factor (EGF), which were previously demonstrated to induce neural differentiation markers including Sox1, Pax6 and NFM among these DPSCs. This study revealed that some microRNAs involved in the neuronal differentiation of MSCs were also differentially expressed among the DPSCs, including miR-27 and miR-145. In addition, this study also revealed that administration of bFGF and EGF was sufficient to modulate miR-27 and miR-145 expression in all of the stimulus-responsive DPSCs but not among all of the non-responsive DPSCs-suggesting that further investigation of the downstream targets of these microRNAs may be needed to fully evaluate and understand these observations.

[Effect of Wnt/β-catenin signaling pathway in neural differentiation of human bone marrow mesenchymal stem cells]

Objective

To explore the effect of basic fibroblast growth factor (bFGF), epidermal growth factor (EGF), and the combination of bFGF and EGF in the neural differentiation of human bone marrow mesenchymal stem cells (hBMSCs), and the role of Wnt/β-catenin signaling pathway in this process.

Methods

The identified 4th-generation hBMSCs were divided into five groups according to different induction conditions, namely control group (group A), EGF induction group (group B), bFGF induction group (group C), EGF and bFGF combined induction group (group D), and EGF, bFGF, and Dickkopf-related protein 1 (DKK-1) combined induction group (group E). After 7 days of continuous induction, the cell morphology was observed by inverted fluorescence phase contrast microscopy, levels of genes that were related to neural cells [Nestin, neuron-specific enolase (NSE), microtubule-associated protein 2 (MAP-2), and glial fibrillary acidic protein (GFAP)] and key components of the Wnt/β-catenin signaling pathway (β-catenin and Cyclin D1) were detected by RT-PCR, and the levels of proteins that were related to neural cells (Nestin and GFAP) as well as genes that were involved in Wnt/β-catenin signaling pathway [β-catenin, phosphorylation β-catenin (P-β-catenin), Cytoplasmic β-catenin, and Nuclear β-catenin] were explored by cellular immunofluorescence staining and Western blot.

Results

When compared to groups A and B, the typical neuro-like cell changes were observed in groups C-E, and most obviously in group D. RT-PCR showed that the relative expressions of Nestin, NSE, and MAP-2 genes in groups C-E, the relative expressions of GFAP gene in groups D and E, the relative expression of NSE gene in group B, the relative expressions of β-catenin gene in groups C and D, and the relative expressions of Cyclin D1 gene in groups B-D significantly increased when compared with group A ( P<0.05). Compared with group E, the relative expressions of Nestin, NSE, MAP-2, GFAP, β-catenin, and CyclinD1 genes significantly increased in group D ( P<0.05); compared with group C, the relative expression of Nestin gene in group D significantly decreased ( P<0.05), while NSE, MAP-2, and GFAP genes significantly increased ( P<0.05). The cellular immunofluorescence staining showed that the ratio of NSE- and GFAP-positive cells significantly increased in groups C-E than in group A, in group D than in groups C and E ( P<0.05). Western blot assay showed that the relative expression of NSE protein was significantly higher in groups C and D than in group A and in group D than in groups C and E ( P<0.05). In addition, the relative expression of GFAP protein was significantly higher in groups C-E than in group A and in group D than in group E ( P<0.05). Besides, the relative expressions of β-catenin, Cytoplasmic β-catenin, Nuclear β-catenin, and the ratio of Nuclear β-catenin to Cytoplasmic β-catenin were significantly higher in groups C and D than in group A and in group D than in group E ( P<0.05), whereas the relative expression of P-β-catenin protein was significantly lower in groups C and D than in group A and in group D than in group E ( P<0.05).

Conclusion

Different from EGF, bFGF can induce neural differentiation of hBMSCs. In addition, EGF can enhance the hBMSCs neural differentiation of bFGF, while the Wnt/β-catenin signaling pathway may play a positive regulatory role in these processes.

Chitosan Resin-Modified Glass Ionomer Cement Containing Epidermal Growth Factor Promotes Pulp Cell Proliferation with a Minimum Effect on Fluoride and Aluminum Release

The development of biomaterials that are able to control the release of bioactive molecules is a challenging task for regenerative dentistry. This study aimed to enhance resin-modified glass ionomer cement (RMGIC) for the release of epidermal growth factor (EGF). This RMGIC was formulated from RMGIC powder supplemented with 15% (w/w) chitosan at a molecular weight of either 62 or 545 kDa with 5% bovine serum albumin mixed with the same liquid component as the Vitrebond. EGF was added while mixing. ELISA was used to determine EGF release from the specimen immersed in phosphate-buffered saline at 1 h, 3 h, 24 h, 3 d, 1 wk, 2 wks, and 3 wks. Fluoride and aluminum release at 1, 3, 5, and 7 d was measured by electrode and inductively coupled plasma optical emission spectrometry. Pulp cell viability was examined through MTT assays and the counting of cell numbers using a Coulter counter. The RMGIC with 65 kDa chitosan is able to prolong the release of EGF for significantly longer than RMGIC for at least 3 wks due to its retained bioactivity in promoting pulp cell proliferation. This modified RMGIC can prolong the release of fluoride, with a small amount of aluminum also released for a limited time. This biomaterial could be useful in regenerating pulp-dentin complexes.

Comparison of Biological Properties and Clinical Application of Mesenchymal Stem Cells from the Mesoderm and Ectoderm

Since the discovery of mesenchymal stem cells (MSCs) in the 1970s, they have been widely used in the treatment of a variety of diseases because of their wide sources, strong differentiation potential, rapid expansion in vitro, low immunogenicity, and so on. At present, most of the related research is on mesoderm-derived MSCs (M-MSCs) such as bone marrow MSCs and adipose-derived MSCs. As a type of MSC, ectoderm-derived MSCs (E-MSCs) have a stronger potential for self-renewal, multidirectional differentiation, and immunomodulation and have more advantages than M-MSCs in some specific conditions. This paper analyzes the relevant research development of E-MSCs compared with that of M-MSCs; summarizes the extraction, discrimination and culture, biological characteristics, and clinical application of E-MSCs; and discusses the application prospects of E-MSCs. This summary provides a theoretical basis for the better application of MSCs from both ectoderm and mesoderm in the future.

The Migration and the Fate of Dental Pulp Stem Cells

Human dental pulp stem cells (hDPSCs) are adult mesenchymal stem cells (MSCs) obtained from dental pulp and derived from the neural crest. They can differentiate into odontoblasts, osteoblasts, chondrocytes, adipocytes and nerve cells, and they play a role in tissue repair and regeneration. In fact, DPSCs, depending on the microenvironmental signals, can differentiate into odontoblasts and regenerate dentin or, when transplanted, replace/repair damaged neurons. Cell homing depends on recruitment and migration, and it is more effective and safer than cell transplantation. However, the main limitations of cell homing are the poor cell migration of MSCs and the limited information we have on the regulatory mechanism of the direct differentiation of MSCs. Different isolation methods used to recover DPSCs can yield different cell types. To date, most studies on DPSCs use the enzymatic isolation method, which prevents direct observation of cell migration. Instead, the explant method allows for the observation of single cells that can migrate at two different times and, therefore, could have different fates, for example, differentiation and self-renewal. DPSCs use mesenchymal and amoeboid migration modes with the formation of lamellipodia, filopodia and blebs, depending on the biochemical and biophysical signals of the microenvironment. Here, we present current knowledge on the possible intriguing role of cell migration, with particular attention to microenvironmental cues and mechanosensing properties, in the fate of DPSCs.

Differential Effects of Extracellular Matrix Glycoproteins Fibronectin and Laminin-5 on Dental Pulp Stem Cell Phenotypes and Responsiveness

Dental pulp stem cells (DPSCs) are mesenchymal stem cells (MSCs) with the potential to differentiate in a limited number of other tissue types. Some evidence has suggested the modulation of DPSC growth may be mediated, in part, by exogenous extracellular matrix (ECM) glycoproteins, including fibronectin (FN) and laminin-5 (LN5). Although preliminary research suggests that some ECM glycoproteins may work as functional biomaterials to modulate DPSC growth responses, the primary goal of this project is to determine the specific effects of FN and LN5 on DPSC growth and viability. Using an existing DPSC repository, n = 16 DPSC isolates were cultured and 96-well growth assays were performed, which revealed FN, LN5 and the combination of these were sufficient to induce statistically significant changes in growth among five (n = 5) DPSC isolates. In addition, the administration of FN (either alone or in combination) was sufficient to induce the expression of alkaline phosphatase (ALP) and dentin sialophosphoprotein (DSPP), while LN5 induced the expression of ALP only, suggesting differential responsiveness among DPSCs. Moreover, these responses appeared to correlate with the expression of MSC biomarkers NANOG, Oct4 and Sox2. These results add to the growing body of evidence suggesting that functional biomaterials, such as ECM glycoproteins FN and LN5, are sufficient to induce phenotypic and differentiation-specific effects in a specific subset of DPSC isolates. More research will be needed to determine which biomarkers or additional factors are necessary and sufficient to induce the differentiation and development of DPSCs ex vivo and in vitro for biomedical applications.