Diagnostic Cytokines and Comparative Analysis Secreted from Exfoliated Deciduous Teeth, Dental Pulp, and Bone Marrow Derived Mesenchymal Stem Cells for Functional Cell-Based Therapy

Circular RNA-Mediated Regulation of Oral Tissue-Derived Stem Cell Differentiation: Implications for Oral Medicine and Orthodontic Applications

Circular RNAs (circRNAs) are a novel class of endogenous non-coding RNAs (ncRNAs) which unlike linear RNAs, have a covalently closed continuous loop structure. circRNAs are found abundantly in human cells and their biology is complex. They feature unique expression to different types of cells, tissues, and developmental stages. To the present, the functional roles of circular RNAs are not fully understood. They reportedly act as microRNA (miRNA) sponges, therefore having key regulatory functions in diverse physiological and pathological processes. As for dentistry field, lines of evidence indicate that circRNAs play vital roles in the odontogenic and osteogenic differentiation of dental pulp stem cells (DPSCs) and periodontal ligament stem cells (PDLSCs). Abnormal expression of circRNAs have been found in other areas of pathology frequently reflected also in the oral environment, such as inflammation or bone and soft tissue loss. Therefore, circRNAs could be of significant importance in various fields in dentistry, especially in bone and soft tissue engineering and regeneration. Understanding the molecular mechanisms occurring during the regulation of oral biological and tissue remodeling processes could augment the discovery of novel diagnostic biomarkers and therapeutic strategies that will improve orthodontic and other oral therapeutic protocols.

Advances in oral mesenchymal stem cell-derived extracellular vesicles in health and disease

Extracellular vesicles (EVs) are nano-size vesicles secreted naturally by all cells into the extracellular space and have been recognized as important cell-cell mediators in multicellular organisms. EVs contain nucleic acids, proteins, lipids, and other cellular components, regulating many basic biological processes and playing an important role in regenerative medicine and diseases. EVs can be traced to their cells of origin and exhibit a similar function. Moreover, EVs demonstrate low immunogenicity, good biocompatibility, and fewer side effects, compared to their parent cells. Mesenchymal stem cells (MSCs) are one of the most important resource cells for EVs, with a great capacity for self-renewal and multipotent differentiation, and play an essential role in stem cell therapy. The mechanism of MSC therapy was thought to be attributed to the differentiation of MSCs after targeted migration, as previously noted. However, emerging evidence shows the previously unknown role of MSC-derived paracrine factors in stem cell therapy. Especially EVs derived from oral tissue MSCs (OMSC-EVs), show more advantages than those of all other MSCs in tissue repair and regeneration, due to their lower invasiveness and easier accessibility for sample collection. Here, we systematically review the biogenesis and biological characteristics of OMSC-EVs, as well as the role of OMSC-EVs in intercellular communication. Furthermore, we discuss the potential therapeutic roles of OMSC-EVs in oral and systemic diseases. We highlight the current challenges and future directions of OMSC-EVs to focus more attention on clinical translation. We aim to provide valuable insights for the explorative clinical application of OMSC-EVs.

Dental Pulp Stem Cells for Bone Tissue Engineering: A Literature Review

Bone tissue engineering (BTE) is a promising approach for repairing and regenerating damaged bone tissue, using stem cells and scaffold structures. Among various stem cell sources, dental pulp stem cells (DPSCs) have emerged as a potential candidate due to their multipotential capabilities, ability to undergo osteogenic differentiation, low immunogenicity, and ease of isolation. This article reviews the biological characteristics of DPSCs, their potential for BTE, and the underlying transcription factors and signaling pathways involved in osteogenic differentiation; it also highlights the application of DPSCs in inducing scaffold tissues for bone regeneration and summarizes animal and clinical studies conducted in this field. This review demonstrates the potential of DPSC-based BTE for effective bone repair and regeneration, with implications for clinical translation.

Anti-inflammatory effect of interleukin-6 highly enriched in secretome of two clinically relevant sources of mesenchymal stromal cells

Despite several advances in the field of regenerative medicine, clinical management of extensive skin wounds or burns remains a major therapeutic issue. During the past few years, Mesenchymal Stromal Cells (MSCs) have emerged as a novel therapeutic tool to promote tissue repair through their anti-inflammatory, pro-trophic and pro-remodeling effects. They exert their biological activity mainly via the secretion of soluble bioactive molecules such as cytokines, growth factors, proteins and microRNAs which can be encapsulated within extracellular vesicles (EV). The recent discovery of their high plasticity to external stimuli has fostered the development of new targeted therapies known as priming strategies, to enhance their potential. Our team recently showed that Interleukin-1β (IL-1β)-primed gingival MSCs promote wound healing and epidermal engraftment in vitro, and in vivo through their secreted products that contain extracellular vesicles. In the present work, we investigated whether two common sources of MSCs, gingiva and bone marrow, could respond similarly to IL-1β to favor pro-healing capabilities of their secretome. We showed that both primed-MSC sources, or their related secreted products, are able to reduce inflammation in LPS-challenged human monocytic THP-1 cell line. IL-1β priming enhanced MSC secretion of wound healing-related growth factors, cytokines and miRNAs in both sources. Among them, interleukin 6 was shown to be involved in the anti-inflammatory effect of MSC secreted products. Overall, these results underline the pro-healing properties of both MSC sources and their secretome upon IL-1β priming and their potential to improve the current medical treatment of severe wounds.

From Teeth to Therapy: A Review of Therapeutic Potential within the Secretome of Stem Cells from Human Exfoliated Deciduous Teeth

Stem cells derived from human exfoliated deciduous teeth (SHED) have emerged as an alternative stem cell source for cell therapy and regenerative medicine because they are readily available, pose fewer ethical concerns, and have low immunogenicity and tumourigenicity. SHED offer a number of advantages over other dental stem cells, including a high proliferation rate with the potential to differentiate into multiple developmental lineages. The therapeutic effects of SHED are mediated by multiple mechanisms, including immunomodulation, angiogenesis, neurogenesis, osteogenesis, and adipogenesis. In recent years, there is ample evidence that the mechanism of action of SHED is mainly due to its paracrine action, releasing a wide range of soluble factors such as cytokines, chemokines, and trophic factors (also known as 'secretome') into the local tissue microenvironment to promote tissue survival and recovery. This review provides an overview of the secretome derived from SHED and highlights the bioactive molecules involved in tissue regeneration and their potential applications in regenerative medicine.

Dental Pulp Stem Cells (DPSCs) and Tissue Regeneration: Mechanisms Mediated by Direct, Paracrine, or Autocrine Effects

Among mesenchymal stem cells, dental pulp stem cells (DPSCs) were discovered most recently [...].

Bone marrow mesenchymal stem cells in premature ovarian failure: Mechanisms and prospects

Premature ovarian failure (POF) is a common female reproductive disorder and characterized by menopause, increased gonadotropin levels and estrogen deficiency before the age of 40 years old. The etiologies and pathogenesis of POF are not fully clear. At present, hormone replacement therapy (HRT) is the main treatment options for POF. It helps to ameliorate perimenopausal symptoms and related health risks, but can't restore ovarian function and fertility fundamentally. With the development of regenerative medicine, bone marrow mesenchymal stem cells (BMSCs) have shown great potential for the recovery of ovarian function and fertility based on the advantages of abundant sources, high capacity for self-renewal and differentiation, low immunogenicity and less ethical considerations. This systematic review aims to summarize the possible therapeutic mechanisms of BMSCs for POF. A detailed search strategy of preclinical studies and clinical trials on BMSCs and POF was performed on PubMed, MEDLINE, Web of Science and Embase database. A total of 21 studies were included in this review. Although the standardization of BMSCs need more explorations, there is no doubt that BMSCs transplantation may represent a prospective therapy for POF. It is hope to provide a theoretical basis for further research and treatment for POF.

Insights into the protective capacity of human dental pulp stem cells and its secretome in cisplatin-induced nephrotoxicity: effects on oxidative stress and histological changes

OBJECTIVES

Acute renal injury (AKI) is a major limiting factor for cisplatin administration. Recent evidence suggests the potential contribution of mesenchymal stem cells (MSCs) to rehabilitation from several disorders via both direct and indirect routes. Thus, the present study aimed, for the first time, to explore and compare the reno-protective potential of human dental pulp-derived stem cells (hDPSCs) vs. hDPSC-conditioned medium (hDPSC-CM) in recovery of impaired kidney tissues in a rat animal model of cisplatin-induced AKI.

METHODS

AKI was induced via cisplatin injection (n=36). One day after, 24 rats were treated with either hDPSCs or hDPSC-CM (n=12). An extra set of rats (n=12) served as sham group. On days 2 or 7 (n=6), rats were humanly sacrificed for further analysis. Renal injury was explored via measuring serum creatinine and BUN. Renal level of oxidative stress was assessed by determining malondialdehyde, and enzymatic activities of superoxide dismutase and catalase. Renal histopathological changes were scored for comparison among different experimental groups.

RESULTS

A single dose of cisplatin resulted in considerable renal dysfunction and oxidative stress. Treatment with hDPSCs or hDPSC-CM resulted in significantly restored renal function, reduced level of oxidative stress, and improved histopathological manifestations. Furthermore, as compared to hDPSC-CM, administration of hDPSCs led to superior results in AKI-induced animals.

CONCLUSIONS

The current study described the first comparative evidence of reno-protective potential of hDPSCs and their CM against cisplatin-induced nephrotoxicity in an AKI rat model, proposing them as useful adjunctive therapy in AKI. Yet, future explorations are still needed.

Global scientific trends on the immunomodulation of mesenchymal stem cells in the 21st century: A bibliometric and visualized analysis

Background

Since the discovery of the immunomodulatory functions of mesenchymal stem cells (MSCs), their application in immunomodulation has attracted considerable attention, and an increasing number of studies have been conducted worldwide. Our research aimed to investigate the global status and trends in this field.

Methods

Publications on the immunomodulatory functions of MSCs from 1 January 2000 to 7 March 2022 were retrieved from the Web of Science Core Collection. The data were studied and indexed using the bibliometric methodology. Visualization analysis, co-authorship, co-occurrence analysis, and publication trends in MSC immunomodulation were conducted using the VOSviewer software.

Results

In total, 4,227 papers were included in the study. The number of publications and research interests has significantly increased globally. China published the highest number of related articles, while the US published articles with the highest number of citations. Stem Cell Research & Therapy had the highest number of publications. Sun Yat-sen University, Shanghai Jiao Tong University, Harvard University, and Seoul National University were the most contributive institutions. Furthermore, the studies were divided into four research hotspots for MSC immunomodulation: MSC immunomodulation in regenerative medicine, the effects and mechanisms of MSC immunomodulation, MSC therapy for immune diseases, and the cell source of MSCs.

Conclusion

This study indicates that the number of publications on MSC immunomodulation will increase in the future, and MSC immunomodulation mechanisms and clinical applications of MSC immunotherapy should be the next hotspots in this research field.

The Therapeutic Potential of Secreted Factors from Dental Pulp Stem Cells for Various Diseases

An alternative source of mesenchymal stem cells has recently been discovered: dental pulp stem cells (DPSCs), including deciduous teeth, which can thus comprise potential tools for regenerative medicine. DPSCs derive from the neural crest and are normally implicated in dentin homeostasis. The clinical application of mesenchymal stem cells (MSCs) involving DPSCs contains various limitations, such as high cost, low safety, and cell handling issues, as well as invasive sample collection procedures. Although MSCs implantation offers favorable outcomes on specific diseases, implanted MSCs cannot survive for a long period. It is thus considered that their mediated mechanism of action involves paracrine effects. It has been recently reported that secreted molecules in DPSCs-conditioned media (DPSC-CM) contain various trophic factors and cytokines and that DPSC-CM are effective in models of various diseases. In the current study, we focus on the characteristics of DPSC-CM and their therapeutic potential against various disorders.

Multipotency and Immunomodulatory Benefits of Stem Cells From Human Exfoliated Deciduous Teeth

Stem cells derived from human exfoliated deciduous teeth (SHEDs) are considered a promising cell population for cell-based or cell-free therapy and tissue engineering because of their proliferative, multipotency and immunomodulator. Based on recent studies, we find that SHEDs show the superior ability of nerve regeneration in addition to the potential of osteogenesis, odontogenesis owing to their derivation from the neural crest. Besides, much evidence suggests that SHEDs have a paracrine effect and can function as immunomodulatory regents attributing to their capability of secreting cytokines and extracellular vesicles. Here, we review the characteristic of SHEDs, their multipotency to regenerate damaged tissues, specifically concentrating on bones or nerves, following the paracrine activity or immunomodulatory benefits of their potential for clinical application in regenerative medicine.

Distinctive cytokine profiles of stem cells from human exfoliated deciduous teeth and dental pulp stem cells

Background/purpose

SHED and DPSC have stem cell regenerative potential, but comparative research on their cytokine profile is rare. This study aimed to investigate and compare cytokine profiles secreted from stem cells from human exfoliated deciduous teeth (SHED) and dental pulp stem cells (DPSCs).

Materials and methods

SHED-conditioned medium (CM) and DPSC-CM were extracted using seven primary and permanent teeth each. Cytokine membrane array was performed for each CM to quantify and compare the secretomes of 120 cytokines. Enzyme-linked immunosorbent assay, immunocytochemistry, and immunohistochemistry analysis were performed to demonstrate cytokine membrane array analysis.

Results

Significant differences were observed in the expression levels of 68 cytokines–27 and 41 cytokines were 1.3-fold more strongly expressed in SHED-CM and DPSC-CM, respectively. Cytokines involved in immunomodulation, odontogenesis and osteogenesis were more strongly expressed in SHED-CM. Cytokines involved in angiogenesis were detected more strongly in DPSCs-CM. SHED and DPSCs have distinctive cytokine profiles and characteristics in terms of their stem cell regenerative potential.

Conclusion

These observations suggest that SHED may have a better cytokine profile related to inflammatory, proliferative, osteogenic, and odontogenic potential.

Application of dental pulp stem cells in oral maxillofacial tissue engineering

In the maxillofacial area, soft and hard tissue abnormalities are caused by trauma, tumors, infection, and other causes that expose the maxillofacial region to the surface of the human body. Patients' normal physiological function and appearance are interfered with, and their mental health is adversely impacted, reducing their overall life quality. The pursuit of appropriate medical treatments to correct these abnormalities is thus vital. Autologous stem cell regeneration technology mainly focused on tissues has lately emerged as a significant problem in the medical community. Because of the capacity of dental pulp stem cells (DPSCs) to self-renew, the use of DPSCs from the human pulp tissues of deciduous teeth or permanent teeth has gained popularity among scientists as a stem cell-based therapy option. Aside from that, they are simple to extract and have minimal immunogenicity. As a result, bone tissue engineering may be a critical component in treating maxillofacial and periodontal bone abnormalities. DPSCs activity in maxillofacial and periodontal tissue-engineered bone tissue was investigated in this research.

Platelet lysate functionalized gelatin methacrylate microspheres for improving angiogenesis in endodontic regeneration

Rapid angiogenesis is one of the challenges in endodontic regeneration. Recently, tailored polymeric microsphere system that loaded pro-angiogenic growth factors (GFs) is promising in facilitating vascularization in dental pulp regeneration. In addition, the synergistic effect of multiple GFs is considered more beneficial, but combination usage of them is rather complex and costly. Herein, we aimed to incorporate human platelet lysate (PL), a natural-derived pool of multiple GFs, into gelatin methacrylate (GelMA) microsphere system (GP), which was further modified by Laponite (GPL), a nanoclay with efficient drug delivery ability. These hybrid microspheres were successfully fabricated by electrostatic microdroplet technique with suitable size range (180∼380 µm). After incorporation of the PL and Laponite with GelMA, the Young's modulus of the hybrid hydrogel increased up to about 3-fold and the swelling and degradation rate decreased simultaneously. The PL-derived GFs continued to release up to 28 days from both the GP and GPL microspheres, while the latter released relatively more slowly. What's more, the released GFs could effectively induce tubule formation of human umbilical endothelial cells (HUVECs) and also promote human dental pulp stem cells (hDPSCs) migration. Additionally, the PL component in the GelMA microspheres significantly improved the proliferation, spreading, and odontogenic differentiation of the encapsulated hDPSCs. As further verified by the subcutaneous implantation results, both of the GP and GPL groups enhanced microvascular formation and pulp-like tissue regeneration. This work demonstrated that PL-incorporating GelMA microsphere system was a promising functional vehicle for promoting vascularized endodontic regeneration. STATEMENT OF SIGNIFICANCE: Polymeric microsphere system loaded with pro-angiogenic growth factors (GFs) shows great promise for regeneration of vascularized dental pulp. Herein, we prepared a functional GelMA microsphere system incorporated with human platelet lysates (PL) and nanoclay Laponite by the electrostatic microdroplet method. The results demonstrated that the GelMA/PL/Laponite microspheres significantly improved the spreading, proliferation, and odontogenic differentiation of the encapsulated hDPSCs compared with pure GelMA microspheres. Moreover, they also enhanced microvascular formation and pulp-like tissue regeneration in vivo. This hybrid microsphere system has great potential to accelerate microvessel formation in regenerated dental pulp and other tissues.

Advances in Research on Stem Cell-Based Pulp Regeneration

Although root canal therapy is the most common and widely used treatment at clinical presentation, there are still some postoperative complications. As cell biology and tissue engineering techniques advance rapidly, the use of biological therapy to regenerate dental pulp has become a new trend; Relevant literatures in recent five years were searched using key words such as "root canal therapy", "Dental pulp stem cells", "Dental pulp regeneration", and "Cell homing" in PubMed, Web of Science, etc; Dental pulp stem cells (DPSCs) have multi-differentiation potential, self-renewal capability, and high proliferative ability. Stem cell-based dental pulp regeneration has emerged as a new research hot spot in clinical therapy. Recently, dental pulp-like structures have been generated by the transplantation of exogenous DPSCs or the induction of homing of endogenous DPSCs. Studies on DPSCs are important and significant for dental pulp regeneration and dental restoration; In this review, the existing clinical treatment methods, dental pulp regeneration, and DPSC research status are revealed, and their application prospects are discussed. The stem cell-based pulp regeneration exerts promising potential in clinical therapy for pulp regeneration.

Matrix Metalloproteinase 3: A Promoting and Destabilizing Factor in the Pathogenesis of Disease and Cell Differentiation

Cells must alter their expression profiles and morphological characteristics but also reshape the extracellular matrix (ECM) to fulfill their functions throughout their lifespan. Matrix metalloproteinase 3 (MMP-3) is a member of the matrix metalloproteinase (MMP) family, which can degrade multiple ECM components. MMP-3 can activate multiple pro-MMPs and thus initiates the MMP-mediated degradation reactions. In this review, we summarized the function of MMP-3 and discussed its effects on biological activities. From this point of view, we emphasized the positive and negative roles of MMP-3 in the pathogenesis of disease and cell differentiation, highlighting that MMP-3 is especially closely involved in the occurrence and development of osteoarthritis. Then, we discussed some pathways that were shown to regulate MMP-3. By writing this review, we hope to provide new topics of interest for researchers and attract more researchers to investigate MMP-3.

Cytokine Consistency Between Bone Marrow and Peripheral Blood in Patients With Philadelphia-Negative Myeloproliferative Neoplasms

Background: Inflammation might play a critical role in the pathogenesis and progression of Philadelphia-negative myeloproliferative neoplasms (Ph⁻MPNs) with elevated inflammatory cytokines in peripheral blood (PB). However, the inflammatory status inside the bone marrow (BM), which is the place of malignancy origin and important microenvironment of neoplasm evolution, has not yet been elucidated.

Methods: Inflammatory cytokine profiles in PB and BM of 24 Ph-MPNs patients were measured by a multiplex quantitative inflammation array. Cytokines that correlated between PB and BM were selected and then validated by ELISA in a separate cohort of 52 MPN patients. Furthermore, a panel of cytokines was identified and examined for potential application as non-invasive markers for the diagnosis and prediction of fibrosis progress of MPN subtypes.

Results: The levels of G-CSF, I-309, IL-1β, IL-1ra, IL-12p40, IL-15, IL-16, M-CSF, MIG, PDGF-BB, and TIMP-1 in BM supernatants were significantly higher than those in PB (all p < 0.05). Linear correlations between BM and PB levels were found in 13 cytokines, including BLC, Eotaxin-2, I-309, sICAM-1, IL-15, M-CSF, MIP-1α, MIP-1δ, RANTES, TIMP-1, TIMP-2, sTNFRI, and sTNFRII (all R > 0.4 and p < 0.05). Levels of BLC, Eotaxin-2, M-CSF, and TIMP-1 in PB were significantly different from those in health controls (all p < 0.05). In PB, levels of TIMP-1 and Eotaxin-2 in essential thrombocythemia (ET) group were significantly lower than those in groups of prefibrotic primary myelofibrosis (pre-PMF) [TIMP-1: 685.2 (322.2–1,229) ng/ml vs. 1,369 (1,175–1,497) ng/ml, p = 0.0221; Eotaxin-2: 531.4 (317.9–756.6) pg/ml vs. 942.4 (699.3–1,474) pg/ml, p = 0.0393] and primary myelofibrosis (PMF) [TIMP-1: 685.2 (322.2–1229) ng/ml vs. 1,365 (1,115–1,681) ng/ml, p = 0.0043; Eotaxin-2: 531.4 (317.9–756.6) pg/ml vs. 1,010 (818–1,556) pg/ml, p = 0.0030]. The level of TIMP-1 in myelofibrosis (MF) >1 group was significantly higher than that in MF ≤ 1 group.

Conclusion: Abnormal inflammatory status is present in MPN, especially in its BM microenvironment. Consistency between PB and BM levels was found in multiple inflammatory cytokines. Circulating cytokine levels of BLC, M-CSF, Eotaxin-2, and TIMP-1 reflected inflammation inside BM niche, suggesting potential diagnostic value for MPN subtypes and prognostic value for fibrosis progression.

Clinical-grade human dental pulp stem cells suppressed the activation of osteoarthritic macrophages and attenuated cartilaginous damage in a rabbit osteoarthritis model

BACKGROUND

Although increasing evidence has demonstrated that human dental pulp stem cells (hDPSCs) are efficacious for the clinical treatment of skeletal disorders, the underlying mechanisms remain incompletely understood. Osteoarthritis (OA) is one of the most common degenerative disorders in joints and is characterized by gradual and irreversible cartilaginous tissue damage. Notably, immune factors were newly identified to be closely related to OA development. In this study, we explored the modulatory effects of clinical-grade hDPSCs on osteoarthritic macrophages and their protective effects on cartilaginous tissues in OA joints.

METHODS

The cell morphology, immunophenotype, and inflammatory factor expression of osteoarthritic macrophages were explored by phase contrast microscope, transmission electron microscopy, immunostaining, flow cytometry, quantitative polymerase chain reaction, and enzyme linked immunosorbent assay, respectively. Additionally, the factors and signaling pathways that suppressed macrophage activation by hDPSCs were determined by enzyme-linked immunosorbent assay and western-blotting. Furthermore, hDPSCs were administered to a rabbit knee OA model via intra-articular injection. Macrophage activation in vivo and cartilaginous tissue damage were also evaluated by pathological analysis.

RESULTS

We found that hDPSCs markedly inhibited osteoarthritic macrophage activation in vitro. The cell morphology, immunophenotype, and inflammatory factor expression of osteoarthritic macrophages changed into less inflammatory status in the presence of hDPSCs. Mechanistically, we observed that hDPSC-derived hepatocyte growth factor and transforming growth factor β1 mediated the suppressive effects on osteoarthritic macrophages. Moreover, phosphorylation of MAPK pathway proteins contributed to osteoarthritic macrophage activation, and hDPSCs suppressed their activation by partially inactivating those pathways. Most importantly, injected hDPSCs inhibited macrophage activation in osteochondral tissues in a rabbit knee OA model in vivo. Further histological analysis showed that hDPSCs alleviated cartilaginous damage to knee joints.

CONCLUSIONS

In summary, our findings reveal a novel function for hDPSCs in suppressing osteoarthritic macrophages and suggest that macrophages are efficient cellular targets of hDPSCs for alleviation of cartilaginous damage in OA. hDPSCs treat OA via an osteoarthritic macrophages-dependent mechanisms. hDPSCs suppress the activation of osteoarthritic macrophages in vitro and in vivo and alleviate cartilaginous lesions in OA models.

Dental Pulp Stem Cells on Implant Surface: An In Vitro Study

In the field of biology and medicine, one hears often about stem cells and their potential. The dental implant new surfaces, subjected to specific treatments, perform better and allow for quicker healing times and better clinical performance. The purpose of this study is to evaluate from a biological point of view the interaction and cytotoxicity between stem cells derived from dental pulp (DPSCs) and titanium surfaces. Through the creation of complex cells/implant, this study is aimed at analyzing the cytotoxicity of dental implant surfaces (Myth (Maipek Manufacturer Industrial Care, Naples, Italy)) and the adhesion capacity of cells on them and at considering the essential factors for implant healing such as osteoinduction and vasculogenesis. These parameters are pointed out through histology (3D cell culture), immunofluorescence, proliferation assays, scanning electron microscopy, and PCR investigations. The results of the dental implant surface and its interaction with the DPSCs are encouraging, obtaining results increasing the mineralization of the tissues. The knowledge of this type of interaction, highlighting its chemical and biological features, is certainly also an excellent starting point for the development of even more performing surfaces for having better healing in the oral surgical procedures related to dental implant positioning.

Secreted factors from dental pulp stem cells improve Sjögren's syndrome via regulatory T cell-mediated immunosuppression

Background

Sjögren’s syndrome (SS) is a chronic autoimmune disease primarily characterized by inflammation in the salivary and lacrimal glands. Activated T cells contribute to disease pathogenesis by producing proinflammatory cytokines, which leads to a positive feedback loop establishment. The study aimed to evaluate the effects of secreted factors derived from dental pulp stem cells (DPSCs) or bone marrow mesenchymal stem cells (BMMSCs) on hyposalivation in SS and to investigate the mechanism involved.

Methods

Eighty percent confluent stem cells were replenished with serum-free Dulbecco’s modified Eagle’s medium and incubated for 48 h; following which, conditioned media from DPSCs (DPSC-CM) and BMMSCs (BMMSC-CM) were collected. Cytokine array analysis was performed to assess the types of cytokines present in the media. Flow cytometric analysis was performed to evaluate the number of activated T cells cultured in DPSC-CM or BMMSC-CM. Subsequently, DPSC-CM or BMMSC-CM was administered to an SS mouse model. The mice were categorized into the following groups (n = 6 each): non-treatment, Dulbecco’s modified Eagle’s medium (−), BMMSC-CM, and DPSC-CM. Histological analysis of the salivary glands was performed. The gene and protein expression levels of cytokines associated with T helper subsets in the submandibular glands (SMGs) were evaluated.

Results

DPSC-CM contained more secreted factors with tissue-regenerating mechanisms, such as cell proliferation, anti-inflammatory effects, and immunomodulatory effects. DPSC-CM was more effective in suppressing the activated T cells than other groups in the flow cytometric analysis. The stimulated salivary flow rate increased in SS mice with DPSC-CM compared with that in the other groups. In addition, the number of inflammation sites in SMGs of the mice administered with DPSC-CM was lower than that in the other groups. The expression levels of interleukin (Il)-10 and transforming growth factor-β1 were upregulated in the DPSC-CM group, whereas those of Il-4 and Il-17a were downregulated. The DPSC-CM-administered group presented with a significantly increased percentage of regulatory T (Treg) cells and a significantly decreased percentage of type 17 Th (Th17) cells compared with the other groups.

Conclusions

These results indicated that DPSC-CM ameliorated SS by promoting Treg cell differentiation and inhibiting Th17 cell differentiation in the mouse spleen.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-021-02236-6.

Osteogenic potential of dental and oral derived stem cells in bone tissue engineering among animal models: An update

Small bone defects can heal spontaneously through the bone modeling process due to their physiological environmental conditions. The bone modeling cycle preserves the reliability of the skeleton through the well-adjusted activities of its fundamental cell. Stem cells are a source of pluripotent cells with a capacity to differentiate into any tissue in the existence of a suitable medium. The concept of bone engineering is based on stem cells that can differentiate into bone cells. Mesenchymal stromal cells have been evaluated in bone tissue engineering due to their capacity to differentiate in osteoblasts. They can be isolated from bone marrow and from several adults oral and dental tissues such as permanent or deciduous teeth dental pulp, periodontal ligament, apical dental papilla, dental follicle precursor cells usually isolated from the follicle surrounding the third molar, gingival tissue, periosteum-derived cells, dental alveolar socket, and maxillary sinus Schneiderian membrane-derived cells. Therefore, a suitable animal model is a crucial step, as preclinical trials, to study the outcomes of mesenchymal cells on the healing of bone defects. We will discuss, through this paper, the use of mesenchymal stem cells obtained from several oral tissues mixed with different types of scaffolds tested in different animal models for bone tissue engineering. We will explore and link the comparisons between human and animal models and emphasized the factors that we need to take into consideration when choosing animals. The pig is considered as the animal of choice when testing large size and multiple defects for bone tissue engineering.

Dental pulp-derived stem cell-conditioned media attenuates secondary Sjögren's syndrome via suppression of inflammatory cytokines in the submandibular glands

Introduction

Sjögren's syndrome (SS) is a chronic inflammatory autoimmune disease, which affects the exocrine glands. Its primary symptoms are decreased moisture in the mouth and eyes. Therapies are limited to treatment with steroids, which has unpleasant side effects, so new treatments would be beneficial. One possibility might be stem cells, such as bone marrow mesenchymal stem cells (BMMSCs) or dental pulp-derived stem cells (DPSCs); these have been reported to exert immunomodulatory effects on activated lymphoid cells. This study aimed to evaluate the effects of conditioned media from DPSCs (DPSC-CM) or BMMSCs (BMMSC-CM) on salivary functions in SS.

Methods

Cytokine array analysis was performed to assess the types of cytokines present in the media. DPSC-CM or BMMSC-CM was administered in an SS mouse model. Histological analysis of the salivary glands was performed, and gene expression levels of inflammatory and anti-inflammatory cytokines in the submandibular glands (SMGs) were evaluated.

Results

DPSC-CM contained more anti-inflammatory factors than BMMSC-CM. The mice that were given DPSC-CM had a lower number of inflammation sites in the SMGs than those in the other experimental groups, and their salivary flow rate increased. The expression levels of interleukin (IL)-10 and transforming growth factor-β1 increased in the DPSC-CM group, while those of Il-4, Il-6, and Il-17a decreased. The mice that received DPSC-CM showed a significantly increased percentage of regulatory T cells and a significantly decreased percentage of type T helper 17 cells compared to other groups.

Conclusions

These results indicate that DPSC-CM could be an effective therapy for SS-induced hyposalivation, since it decreases the number of inflammatory cytokines and regulates the local inflammatory microenvironment in the SMGs.

Comparing the osteogenic potential of schneiderian membrane and dental pulp mesenchymal stem cells: an in vitro study

Mesenchymal stem cells, being characterized by high self-renewal capacity and multi-lineage differentiation potential, are widely used in regenerative medicine especially for repair of bone defects in patients with poor bone regenerative capacity. In this study, we aimed to compare the osteogenic potential of human maxillary schneiderian sinus membrane (hMSSM)-derived stem cells versus permanent teeth dental pulp stem cells (DPSCs). Both cells types were cultivated in osteogenic and non-osteogenic inductive media. Alkaline phosphatase (ALP) activity assay and quantitative real-time PCR analysis were carried out to assess osteogenic differentiation. We showed that ALP activity and osteoblastic markers transcription levels were more striking in hMSSM-derived stem cells than DPSCs. Our results highlight hMSSM-derived stem cells as a recommended stem cell type for usage during bone tissue regenerative therapy.