Mechanisms underlying dental-derived stem cell-mediated neurorestoration in neurodegenerative disorders

Single-Cell RNA Sequencing in Organ and Cell Transplantation

Single-cell RNA sequencing is a high-throughput novel method that provides transcriptional profiling of individual cells within biological samples. This method typically uses microfluidics systems to uncover the complex intercellular communication networks and biological pathways buried within highly heterogeneous cell populations in tissues. One important application of this technology sits in the fields of organ and stem cell transplantation, where complications such as graft rejection and other post-transplantation life-threatening issues may occur. In this review, we first focus on research in which single-cell RNA sequencing is used to study the transcriptional profile of transplanted tissues. This technology enables the analysis of the donor and recipient cells and identifies cell types and states associated with transplant complications and pathologies. We also review the use of single-cell RNA sequencing in stem cell implantation. This method enables studying the heterogeneity of normal and pathological stem cells and the heterogeneity in cell populations. With their remarkably rapid pace, the single-cell RNA sequencing methodologies will potentially result in breakthroughs in clinical transplantation in the coming years.

Rutin promotes osteogenic differentiation of mesenchymal stem cells (MSCs) by increasing ECM deposition and inhibiting p53 expression

Mesenchymal stem cells (MSCs) are an important source of cells for bone regeneration. Although the utilization of MSCs along with growth factors and scaffolds is a beneficial clinical approach for bone tissue engineering, there is need for improvement on the effectiveness of MSC osteogenesis and differentiation. Rutin is a natural flavonoid and a major component for cell proliferation and bone development. However, studies on the mechanism through which rutin regulates osteogenesis and MSC differentiation are limited. Therefore, this study aimed to investigate the effect and mechanisms of rutin on osteogenic differentiation of MSCs. MSCs were extracted from umbilical cords and treated with rutin, followed by the examination of osteogenesis-related markers. Rutin treatment promoted the differentiation of MSCs towards the osteogenic lineage rather than the adipogenic lineage and increased the expression of osteogenic markers. RNA sequencing and bioinformatic analysis indicated that rutin regulated p53, a key gene in regulating the osteogenic differentiation of MSCs. Additionally, cellular experiments showed that rutin-induced decrease in p53 expression increased the formation of extracellular matrix (ECM) by promoting p65 phosphorylation and caspase-3 cleavage. Conclusively, this study demonstrates the importance of rutin in osteogenesis and indicates that rutin possesses potential pharmaceutical application for bone regeneration and bone tissue engineering.

Mesenchymal stem cell-derived exosomes: Shaping the next era of stroke treatment

Exosome-based treatments are gaining traction as a viable approach to addressing the various issues faced by an ischemic stroke. These extracellular vesicles, mainly produced by Mesenchymal Stem Cells (MSCs), exhibit many properties with substantial therapeutic potential. Exosomes are particularly appealing for stroke therapy because of their low immunogenicity, effective cargo transport, and ability to cross the blood-brain barrier. Their diverse effects include neuroprotection, angiogenesis stimulation, inflammatory response modulation, and cell death pathway attenuation, synergistically promoting neuronal survival, tissue regeneration, and functional recovery. Exosomes also show potential as diagnostic indicators for early stroke identification and customized treatment options. Despite these promising qualities, current exosome-based therapeutics have some limitations. The heterogeneity of exosome release among cell types, difficulty in standardization and isolation techniques, and complications linked to dosage and targeted administration necessitates extensive investigation. It is critical to thoroughly understand exosomal processes and their complicated interactions within the cellular milieu. To improve the practicality and efficacy of exosome-based medicines, research efforts must focus on improving production processes, developing robust evaluation criteria, and developing large-scale isolation techniques. Altogether, exosomes' multifunctional properties offer a new route for transforming stroke treatment and significantly improving patient outcomes.

Nanomaterials Modulating the Fate of Dental-Derived Mesenchymal Stem Cells Involved in Oral Tissue Reconstruction: A Systematic Review

The critical challenges in repairing oral soft and hard tissue defects are infection control and the recovery of functions. Compared to conventional tissue regeneration methods, nano-bioactive materials have become the optimal materials with excellent physicochemical properties and biocompatibility. Dental-derived mesenchymal stem cells (DMSCs) are a particular type of mesenchymal stromal cells (MSCs) with great potential in tissue regeneration and differentiation. This paper presents a review of the application of various nano-bioactive materials for the induction of differentiation of DMSCs in oral and maxillofacial restorations in recent years, outlining the characteristics of DMSCs, detailing the biological regulatory effects of various nano-materials on stem cells and summarizing the material-induced differentiation of DMSCs into multiple types of tissue-induced regeneration strategies. Nanomaterials are different and complementary to each other. These studies are helpful for the development of new nanoscientific research technology and the clinical transformation of tissue reconstruction technology and provide a theoretical basis for the application of nanomaterial-modified dental implants. We extensively searched for papers related to tissue engineering bioactive constructs based on MSCs and nanomaterials in the databases of PubMed, Medline, and Google Scholar, using keywords such as "mesenchymal stem cells", "nanotechnology", "biomaterials", "dentistry" and "tissue regeneration". From 2013 to 2023, we selected approximately 150 articles that align with our philosophy.

Investigating the Therapeutics Effects of Oral Cavity Derived Stem Cells on Neurodegenerative Diseases: A Systematic Review

Introduction

Published data obtained from in vitro and in vivo studies was reviewed systematically and analyzed critically to evaluate the effect of oral cavity-derived stem cells (OCDSCs) on the recovery or therapy of neurodegenerative diseases (NDs), such as Alzheimer disease (AD), amyotrophic lateral sclerosis (ALS), Huntington (HD) diseases, and Parkinson disease (PD).

Methods

An electronic search was accomplished. References of included articles were also manually searched. Studies were critically evaluated for suitability against the inclusion/exclusion criteria and the data was extracted. Bias risk evaluation of the studies and evidence synthesis were conducted.

Results

A total of 14 in vivo and 10 in vitro studies met the inclusion criteria. PD was induced in 10 in vivo and 7 in vitro studies, while AD was induced in 2 in vivo and 4 in vitro studies. Two studies (1 in vitro and 1 in vivo) evaluated ALS disease and 1 in vivo study evaluated HD. Moderate evidence was found for in vitro studies reporting the positive effect of OCDSCs on PD or AD recovery. Strong evidence was found for in vivo studies in which PD animal models were used; meanwhile, moderate evidence was found for the impact of OCDSCs on AD recovery. Limited evidence was found for in vivo studies evaluating HD and ALS.

Conclusion

Although studies reported favorable data regarding the OCDSCs on NDs, they presented a considerable risk of bias. Because of heterogeneous study characteristics, the current study recommends improving standardized methods to evaluate the therapeutic effects of OCDSCs on the NDs.

Application of mesenchymal stem cells (MSCs) in neurodegenerative disorders: History, findings, and prospective challenges

Over the past few decades, the application of mesenchymal stem cells has captured the attention of researchers and practitioners worldwide. These cells can be obtained from practically every tissue in the body and are used to treat a broad variety of conditions, most notably neurological diseases such as Parkinson's disease, multiple sclerosis, amyotrophic lateral sclerosis, and Alzheimer's disease. Studies are still being conducted, and the results of these studies have led to the identification of several different molecular pathways involved in the neuroglial speciation process. These molecular systems are closely regulated and interconnected due to the coordinated efforts of many components that make up the machinery responsible for cell signaling. Within the scope of this study, we compared and contrasted the numerous mesenchymal cell sources and their cellular features. These many sources of mesenchymal cells included adipocyte cells, fetal umbilical cord tissue, and bone marrow. In addition, we investigated whether these cells can potentially treat and modify neurodegenerative illnesses.

The NG2-glia is a potential target to maintain the integrity of neurovascular unit after acute ischemic stroke

The neurovascular unit (NVU) plays a critical role in health and disease. In the current review, we discuss the critical role of a class of neural/glial antigen 2 (NG2)-expressing glial cells (NG2-glia) in regulating NVU after acute ischemic stroke (AIS). We first introduce the role of NG2-glia in the formation of NVU during development as well as aging-induced damage to NVU and accompanying NG2-glia change. We then discuss the reciprocal interactions between NG2-glia and the other component cells of NVU, emphasizing the factors that could influence NG2-glia. Damage to the NVU integrity is the pathological basis of edema and hemorrhagic transformation, the most dreaded complication after AIS. The role of NG2-glia in AIS-induced NVU damage and the effect of NG2-glia transplantation on AIS-induced NVU damage are summarized. We next discuss the role of NG2-glia and the effect of NG2-glia transplantation in oligodendrogenesis and white matter repair as well as angiogenesis which is associated with the outcome of the patients after AIS. Finally, we review the current strategies to promote NG2-glia proliferation and differentiation and propose to use the dental pulp stem cells (DPSC)-derived exosome as a promising strategy to reduce AIS-induced injury and promote repair through maintaining the integrity of NVU by regulating endogenous NG2-glia proliferation and differentiation.

MCC950 Regulates Stem Cells Destiny Through Modulating SIRT3-NLRP3 Inflammasome Dynamics During Oxygen Glucose Deprivation

Ischemic stroke is the major cause of death and morbidity worldwide. Stem cell treatment is at the forefront of ischemic therapeutic interventions. However, the fate of these cells following transplantation is mostly unknown. The current study examines the influence of oxidative and inflammatory pathological events associated with experimental ischemic stroke (oxygen glucose deprivation (OGD)) on the stem cell population (human Dental Pulp Stem Cells, and human Mesenchymal Stem Cells) through the involvement of the NLRP3 inflammasome. We explored the destiny of the above-mentioned stem cells in the stressed micro (-environment) and the ability of MCC950 to reverse the magnitudes. An enhanced expression of NLRP3, ASC, cleaved caspase1, active IL-1β and active IL-18 in OGD-treated DPSC and MSC was observed. The MCC950 significantly reduced NLRP3 inflammasome activation in the aforementioned cells. Further, in OGD groups, oxidative stress markers were shown to be alleviated in the stem cells under stress, which was effectively relieved by MCC950 supplementation. Interestingly, whereas OGD increased NLRP3 expression, it decreased SIRT3 levels, implying that these two processes are intertwined. In brief, we discovered that MCC950 inhibits NLRP3-mediated inflammation by inhibiting the NLRP3 inflammasome and increasing SIRT3. To conclude, according to our findings, inhibiting NLRP3 activation while enhancing SIRT3 levels with MCC950 reduces oxidative and inflammatory stress in stem cells under OGD-induced stress. These findings shed light on the causes of hDPSC and hMSC demise following transplantation and point to strategies to lessen therapeutic cell loss under ischemic-reperfusion stress.

The potential roles of dental pulp stem cells in peripheral nerve regeneration

Peripheral nerve diseases are significantly correlated with severe fractures or trauma and surgeries, leading to poor life quality and impairment of physical and mental health. Human dental pulp stem cells (DPSCs) are neural crest stem cells with a strong multi-directional differentiation potential and proliferation capacity that provide a novel cell source for nerve regeneration. DPSCs are easily extracted from dental pulp tissue of human permanent or deciduous teeth. DPSCs can express neurotrophic and immunomodulatory factors and, subsequently, induce blood vessel formation and nerve regeneration. Therefore, DPSCs yield valuable therapeutic potential in the management of peripheral neuropathies. With the purpose of summarizing the advances in DPSCs and their potential applications in peripheral neuropathies, this article reviews the biological characteristics of DPSCs in association with the mechanisms of peripheral nerve regeneration.

Periodontal ligament stem cells as a promising therapeutic target for neural damage

BACKGROUND

The damaged neuronal cells of adult mammalian lack the regenerative ability to replace the neuronal connections. Periodontal ligament stem cells (PDLSCs) are the promising source for neuroregenerative applications that can improve the injured microenvironment of the damaged neural system. They provide neuronal progenitors and neurotrophic, anti-apoptotic and anti-inflammatory factors. In this study, we aimed to comprehensively explore the various neuronal differentiation potentials of PDLSCs for application in neural regeneration therapy.

MAIN TEXT

PDLSCs have superior potential to differentiate into various neural-like cells through a dedifferentiation stage followed by differentiation process without need for cell division. Diverse combination of nutritional factors can be used to induce the PDLSCs toward neural lineage. PDLSCs when coupled with biomaterials could have significant implications for neural tissue repair. PDLSCs can be a new clinical research target for Alzheimer's disease treatment, multiple sclerosis and cerebral ischemia. Moreover, PDLSCs have beneficial effects on retinal ganglion cell regeneration and photoreceptor survival. PDLSCs can be a great source for the repair of injured peripheral nerve through the expression of several neural growth factors and differentiation into Schwann cells.

CONCLUSION

In conclusion, these cells are an appealing source for utilizing in clinical treatment of the neuropathological disorders. Although significant in vitro and in vivo investigations were carried out in order for neural differentiation evaluation of these cells into diverse types of neurons, more preclinical and clinical studies are needed to elucidate their therapeutic potential for neural diseases.

Dental Pulp Stem Cell-Derived Secretome and Its Regenerative Potential

The therapeutic potential of the dental pulp stem (DSC) cell-derived secretome, consisting of various biomolecules, is undergoing intense research. Despite promising in vitro and in vivo studies, most DSC secretome-based therapies have not been implemented in human medicine because the paracrine effect of the bioactive factors secreted by human dental pulp stem cells (hDPSCs) and human exfoliated deciduous teeth (SHEDs) is not completely understood. In this review, we outline the current data on the hDPSC- and SHED-derived secretome as a potential candidate in the regeneration of bone, cartilage, and nerve tissue. Published reports demonstrate that the dental MSC-derived secretome/conditional medium may be effective in treating neurodegenerative diseases, neural injuries, cartilage defects, and repairing bone by regulating neuroprotective, anti-inflammatory, antiapoptotic, and angiogenic processes through secretome paracrine mechanisms. Dental MSC-secretomes, similarly to the bone marrow MSC-secretome activate molecular and cellular mechanisms, which determine the effectiveness of cell-free therapy. Many reports emphasize that dental MSC-derived secretomes have potential application in tissue-regenerating therapy due to their multidirectional paracrine effect observed in the therapy of many different injured tissues.

Oxidative Stress Enhances Autophagy-Mediated Death Of Stem Cells Through Erk1/2 Signaling Pathway - Implications For Neurotransplantations

Stem cell therapies are becoming increasingly popular solutions for neurological disorders. However, there is a lower survival rate of these cells after transplantation. Oxidative stress is linked to brain damage, and it may also impact transplanted stem cells. To better understand how transplanted cells respond to oxidative stress, the current study used H₂O₂. We briefly illustrated that exogenous H₂O₂ treatment exaggerated oxidative stress in the human dental pulp and mesenchymal stem cells. 2',7'-Dichlorofluorescin diacetate (DCFDA), MitoSOX confirms the reactive oxygen species (ROS) involvement, which was remarkably subsided by the ROS inhibitors. The findings showed that H₂O₂ activates autophagy by enhancing pro-autophagic proteins, Beclin1 and Atg7. Increased LC3II/I expression (which co-localized with lysosomal proteins, LAMP1 and Cathepsin B) showed that H₂O₂ treatment promoted autophagolysosome formation. In the results, both Beclin1 and Atg7 were observed co-localized in mitochondria, indicating their involvement in mitophagy. The evaluation of Erk1/2 in the presence and absence of Na-Pyruvate, PEG-Catalase, and PD98059 established ROS-Erk1/2 participation in autophagy regulation. Further, these findings showed a link between apoptosis and autophagy. The results conclude that H₂O₂ acts as a stressor, promoting autophagy and mitophagy in stem cells under oxidative stress. The current study may help understand better cell survival and death approaches for transplanted cells in various neurological diseases. The current study uses human Dental Pulp and Mesenchymal Stem cells to demonstrate the importance of H₂O₂-driven autophagy in deciding the fate of these cells in an oxidative microenvironment. To summarise, we discovered that exogenous H₂O₂ treatment causes oxidative stress. Exogenous H₂O₂  treatment also increased ROS production, especially intracellular H₂O₂. H₂O₂ stimulated the ErK1/2 signaling pathway and autophagy. Erk1/2 was found to cause autophagy. Further, the function of mitophagy appeared to be an important factor in the H₂O₂-induced regulation of these two human stem cell types. In a nutshell, by engaging in autophagy nucleation, maturation, and terminal phase proteins, we elucidated the participation of autophagy in cell dysfunction and death.

Induced Neural Cells from Human Dental Pulp Ameliorate Functional Recovery in a Murine Model of Cerebral Infarction

Human mesenchymal stem cells are a promising cell source for the treatment of stroke. Their primary mechanism of action occurs via neuroprotective effects by trophic factors, anti-inflammatory effects, and immunomodulation. However, the regeneration of damaged neuronal networks by cell transplantation remains challenging. We hypothesized that cells induced to neural lineages would fit the niche, replace the lesion, and be more effective in improving symptoms compared with stem cells themselves. We investigated the characteristics of induced neural cells from human dental pulp tissue and compared the transplantation effects between these induced neural cells and uninduced dental pulp stem cells. Induced neural cells or dental pulp stem cells were intracerebrally transplanted 5 days after cerebral infarction induced by permanent middle cerebral artery occlusion in immunodeficient mice. Effects on functional recovery were also assessed through behavior testing. We used immunohistochemistry and neuron tracing to analyze the differentiation, axonal extension, and connectivity of transplanted cells to the host's neural circuit. Transplantation of induced neural cells from human dental pulp ameliorated functional recovery after cerebral infarction compared with dental pulp stem cells. The induced neural cells comprised both neurons and glia and expressed functional voltage, and they were more related to neurogenesis in terms of transcriptomics. Induced neural cells had a higher viability than did dental pulp stem cells in hypoxic culture. We showed that induced neural cells from dental pulp tissue offer a novel therapeutic approach for recovery after cerebral infarction.

'Primed' Mesenchymal Stem Cells: a Potential Novel Therapeutic for COVID19 Patients

The COVID19 pandemic, designated as a public health crisis by the World Health Organization (WHO), is rapidly spreading around the world impacting the health and economy of almost all the countries. The data of hospitalized COVID19 patients, especially those with serious illness, indicate the involvement of immunopathological complications. As no effective treatment is currently available, we propose ‘Primed’ Mesenchymal Stem Cells (MSCs) as a therapeutic alternative to tackle devastating epidemic. The individual response to MSCs treatment is heterogeneous. During the treatment of infectious pathology, the effectiveness of the treatment may vary based on the disease scenario. Interestingly, when transplanted in vivo, MSCs are governed by the locally regulated microenvironment, suggesting that the restorative variability could be tailored by choosing a priming regimen to specifically correct a given pathology. Therefore, in our opinion, the priming of MSCs could be a novel approach to improve the responses of COVID19 patients.

Neuro-regenerative potential of dental stem cells: a concise review

This review will summarize the research information regarding the regenerative potential of dental stem cells for the treatment of neurodegenerative disorders. As compared to existing treatment modalities, the stem cell therapy seems promising, and accumulating evidences about the differentiation of stem cells into various lineages are proving it. The incidence of neurodegenerative diseases such as Alzheimer's, Parkinson's, stroke, and peripheral neuropathy is increasing due to the rise in life expectancies of people which have put a huge burden on economies. Finding a promising treatment could benefit not only the patients but also the communities. Dental stem cells hold a great potential to differentiate into neuronal cells. Many studies have reported the differentiation potential of the dental stem cells with the presence of neuronal lineage markers. In this review, we conferred how the use of dental stem cells can benefit the above-mentioned bedridden diseases.

Mesenchymal Stem Cells: A new front emerge in COVID19 treatment

Currently, treating coronavirus disease 2019 (COVID-19) patients, particularly those afflicted with severe pneumonia, is challenging, as no effective pharmacotherapy for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) exists. Severe pneumonia is recognized as a clinical syndrome characterized by hyper-induction of pro-inflammatory cytokine production, which can induce organ damage, followed by edema, dysfunction of air exchange, acute respiratory distress syndrome, acute cardiac injury, secondary infection and increased mortality. Owing to the immunoregulatory and differentiation potential of mesenchymal stem cells (MSCs), we aimed to outline current insights into the clinical application of MSCs in COVID-19 patients. Based on results from preliminary clinical investigations, it can be predicted that MSC therapy for patients infected with SARS-CoV-2 is safe and effective, although multiple clinical trials with a protracted follow-up will be necessary to determine the long-term effects of the treatment on COVID-19 patients.

Resveratrol: Multi-Targets Mechanism on Neurodegenerative Diseases Based on Network Pharmacology

Resveratrol is a natural polyphenol in lots of foods and traditional Chinese medicines, which has shown promising treatment for neurodegenerative diseases (NDs). However, the molecular mechanisms of its action have not been systematically studied yet. In order to elucidate the network pharmacological prospective effects of resveratrol on NDs, we assessed of pharmacokinetics (PK) properties of resveratrol, studied target prediction and network analysis, and discussed interacting pathways using a network pharmacology method. Main PK properties of resveratrol were acquired. A total of 13,612 genes related to NDs, and 138 overlapping genes were determined through matching the 175 potential targets of resveratrol with disease-associated genes. Gene Ontology (GO) function analysis and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment were performed to obtain more in-depth understanding of resveratrol on NDs. Accordingly, nodes with high degrees were obtained according using a PPI network, and AKT1, TP53, IL6, CASP3, VEGFA, TNF, MYC, MAPK3, MAPK8, and ALB were identified as hub target genes, which showed better affinity with resveratrol in silico studies. In addition, our experimental results demonstrated that resveratrol markedly enhanced the decreased levels of Bcl-2 and significantly reduced the increased expression of Bax and Caspase-3 in hippocampal neurons induced by glutamate exposure. Western blot results confirmed that resveratrol inhibited glutamate-induced apoptosis of hippocampal neurons partly by regulating the PI3K/AKT/mTOR pathway. In conclusion, we found that resveratrol could target multiple pathways forming a systematic network with pharmacological effects.

Banking on teeth - Stem cells and the dental office

Science and commerce advance together and the stem cell field is no exception. With the promise of cures for conditions as diverse as cancer, autism, neural degeneration, organ replacement and addiction, long-term preservation of dental stem cells is a growth market. The discovery nearly twenty years ago, of viable, multipotent, stem cells in dental pulp from both baby and adult teeth initiated, and drives, this market.The dental stem cell preservation services, "tooth banks", focus on the collection of a child's baby teeth, as they are shed naturally, and storage of the stem cells from within the pulp for therapeutic use in later years should the child require them. This review focuses on the procedures related to these stem cell storage services and may serve as an introduction for many to the practice of "tooth banking".

Advances of tooth-derived stem cells in neural diseases treatments and nerve tissue regeneration

Nerous system diseases, both central and peripheral, bring an incredible burden onto patients and enormously reduce their quality of life. Currently, there are still no effective treatments to repair nerve lesions that do not have side effects. Stem cell-based therapies, especially those using dental stem cells, bring new hope to neural diseases. Dental stem cells, derived from the neural crest, have many characteristics that are similar to neural cells, indicating that they can be an ideal source of cells for neural regeneration and repair. This review summarizes the neural traits of all the dental cell types, including DPSCs, PDLCs, DFCs, APSCs and their potential applications in nervous system diseases. We have summed up the advantages of dental stem cells in neural repair, such as their neurotrophic and neuroprotective traits, easy harvest and low rejective reaction rate, among others. Taken together, dental stem cells are an ideal cell source for neural tissue regeneration and repair.