Cannabidiol Modulates the Immunophenotype and Inhibits the Activation of the Inflammasome in Human Gingival Mesenchymal Stem Cells

The Use of Compounds Derived from Cannabis sativa in the Treatment of Epilepsy, Painful Conditions, and Neuropsychiatric and Neurodegenerative Disorders

Neurological disorders present a wide range of symptoms and challenges in diagnosis and treatment. Cannabis sativa, with its diverse chemical composition, offers potential therapeutic benefits due to its anticonvulsive, analgesic, anti-inflammatory, and neuroprotective properties. Beyond cannabinoids, cannabis contains terpenes and polyphenols, which synergistically enhance its pharmacological effects. Various administration routes, including vaporization, oral ingestion, sublingual, and rectal, provide flexibility in treatment delivery. This review shows the therapeutic efficacy of cannabis in managing neurological disorders such as epilepsy, neurodegenerative diseases, neurodevelopmental disorders, psychiatric disorders, and painful pathologies. Drawing from surveys, patient studies, and clinical trials, it highlights the potential of cannabis in alleviating symptoms, slowing disease progression, and improving overall quality of life for patients. Understanding the diverse therapeutic mechanisms of cannabis can open up possibilities for using this plant for individual patient needs.

Antibiofilm and Immune-Modulatory Activity of Cannabidiol and Cannabigerol in Oral Environments-In Vitro Study

OBJECTIVE

To evaluate the in vitro antimicrobial and antibiofilm properties and the immune modulatory activity of cannabidiol (CBD) and cannabigerol (CBG) on oral bacteria and periodontal ligament fibroblasts (PLF).

METHODS

Cytotoxicity was assessed by propidium iodide flow cytometry on fibroblasts derived from the periodontal ligament. The minimum inhibitory concentration (MIC) of CBD and CBG for S. mutans and C. albicans and the metabolic activity of a subgingival 33-species biofilm under CBD and CBG treatments were determined. The Quantification of cytokines was performed using the LEGENDplex kit (BioLegend, Ref 740930, San Diego, CA, USA).

RESULTS

CBD-treated cell viability was greater than 95%, and for CBG, it was higher than 88%. MIC for S. mutans with CBD was 20 µM, and 10 µM for CBG. For C. albicans, no inhibitory effect was observed. Multispecies biofilm metabolic activity was reduced by 50.38% with CBD at 125 µg/mL (p = 0.03) and 39.9% with CBG at 62 µg/mL (p = 0.023). CBD exposure at 500 µg/mL reduced the metabolic activity of the formed biofilm by 15.41%, but CBG did not have an effect. CBG at 10 µM caused considerable production of anti-inflammatory mediators such as TGF-β and IL-4 at 12 h. CBD at 10 µM to 20 µM produced the highest amount of IFN-γ.

CONCLUSION

Both CBG and CBD inhibit S. mutans; they also moderately lower the metabolic activity of multispecies biofilms that form; however, CBD had an effect on biofilms that had already developed. This, together with the production of anti-inflammatory mediators and the maintenance of the viability of mammalian cells from the oral cavity, make these substances promising for clinical use and should be taken into account for future studies.

Acute and chronic cannabidiol treatment: In vitro toxicological aspects on human oral cells

Cannabidiol is gaining increasing interest for its potential anti-inflammatory, immunomodulatory, and antineoplastic effects. The purpose of this study is to investigate the biological effects of acute and chronic CBD administration on gingival fibroblasts and oral keratinocytes. Viability, morphology, migration, apoptosis and cell cycle, and expression of related genes (p53, BCL2, p21, and BAX) and of endocannabinoid system receptors (CB1, CB2 and GPR55) with real-time PCR and DNA damage with phospho-γ-H2AX immunofluorescence detection were analyzed. Concentrations between 100 μM and 0.001 μM were used: 50 μM (toxic dose), 25 μM (viability promoter), and 1 μM (nontoxic), were selected for subsequent chronic analysis. Acute treatment reveals significant effects than chronic, in particular in fibroblasts: concentrations ≥50 μM are highly cytotoxic, with increased apoptosis and reduced migration. Cell death correlates with increased p53 and BAX, followed by arrest in G0/G1 phase, with elevated p21 levels, suggesting a time- and dose-dependent damage. An increase in H2AX phosphorylation was observed with 25 μM and 50 μM, while 1 μM was biocompatible. Keratinocytes showed less cytotoxic effect than fibroblasts. Induced cell damage was dose- and time-related, with less damage after chronic treatment. Further investigations are needed with longer time frames to evaluate CBD dose- and time-dependent effects to identify an effective therapeutic dose.

The NLRP3 inflammasome: a vital player in inflammation and mediating the anti-inflammatory effect of CBD

BACKGROUND

The NLRP3 inflammasome is a vital player in the emergence of inflammation. The priming and activation of the NLRP3 inflammasome is a major trigger for inflammation which is a defense response against adverse stimuli. However, the excessive activation of the NLRP3 inflammasome can lead to the development of various inflammatory diseases. Cannabidiol, as the second-most abundant component in cannabis, has a variety of pharmacological properties, particularly anti-inflammation. Unlike tetrahydrocannabinol, cannabidiol has a lower affinity for cannabinoid receptors, which may be the reason why it is not psychoactive. Notably, the mechanism by which cannabidiol exerts its anti-inflammatory effect is still unclear.

METHODS

We have performed a literature review based on published original and review articles encompassing the NLRP3 inflammasome and cannabidiol in inflammation from central databases, including PubMed and Web of Science.

RESULTS AND CONCLUSIONS

In this review, we first summarize the composition and activation process of the NLRP3 inflammasome. Then, we list possible molecular mechanisms of action of cannabidiol. Next, we explain the role of the NLRP3 inflammasome and the anti-inflammatory effect of cannabidiol in inflammatory disorders. Finally, we emphasize the capacity of cannabidiol to suppress inflammation by blocking the NLRP3 signaling pathway, which indicates that cannabidiol is a quite promising anti-inflammatory compound.

Alzheimer's disease, aging, and cannabidiol treatment: a promising path to promote brain health and delay aging

Alzheimer's disease (AD) is the most common neurodegenerative disease characterized by progressive memory loss, neurodegeneration, and cognitive decline. Aging is one of the risk factors for AD. Although the mechanisms underlying aging and the incidence rate of AD are unclear, aging and AD share some hallmarks, such as oxidative stress and chronic inflammation. Cannabidiol (CBD), the major non-psychoactive phytocannabinoid extracted from Cannabis sativa, has recently emerged as a potential candidate for delaying aging and a valuable therapeutic tool for the treatment of aging-related neurodegenerative diseases due to its antioxidant and anti-inflammation properties. This article reviews the relevant literature on AD, CBD treatment for AD, cellular senescence, aging, and CBD treatment for aging in recent years. By analyzing these published data, we attempt to explore the complex correlation between cellular senescence, aging, and Alzheimer's disease, clarify the positive feedback effect between the senescence of neurocytes and Alzheimer's disease, and summarize the role and possible molecular mechanisms of CBD in preventing aging and treating AD. These data may provide new ideas on how to effectively prevent and delay aging, and develop effective treatment strategies for age-related diseases such as Alzheimer's disease.

Cannabidiol - Help and hype in targeting mucosal diseases

Cannabidiol (CBD) is one of the most commonly utilised phytocannabinoids due to its non-psychoactive and multiple potential therapeutic properties and its non-selective pharmacology. Recent studies have demonstrated efficacy of CBD in some types of drug resistant epilepsies in combination with other therapies; comparative efficacy to other agents or placebo has been hoped for anxiety, chronic pain, and inflammatory disorders based on animal data. Although CBD products are generally treated as a restricted substance, these are being eased, partially in response to significant growth in CBD product usage and increased production but more due to emerging evidence about its safety and pharmacological properties. Currently, only one CBD product (Epidiolex®) has been approved by the Australian Therapeutic Goods Administration and US Food and Drug Administration. CBD has demonstrated promise in alleviating gut and lung diseases in vitro; however, its physicochemical properties pose a significant barrier to achieving pharmacological effects in in vivo and clinical trials. Improving CBD formulations and delivery methods using technologies including self-emulsifying emulsion, nano and micro particles could overcome these shortfalls and improve its efficacy. This review focuses on the therapeutic potential of CBD in gastrointestinal and lung diseases from the available in vitro, in vivo, and clinical research. We report on identified research gaps and obstacles in the development of CBD-based therapeutics, including novel delivery methods.

Cannabinoids in Periodontology: Where Are We Now?

INTRODUCTION

Cannabinoids are a well-documented treatment modality for various immune and inflammatory diseases, including asthma, chronic obstructive pulmonary disease, Crohn's disease, arthritis, multiple sclerosis, and a range of neurodegenerative conditions. However, limited information is available regarding the therapeutic potential of cannabinoids in treating periodontal disease.

OBJECTIVE

The objective of this study is to analyze the current evidence on the antibacterial and immunomodulatory effects of cannabis and its role in the healing and regeneration processes within periodontal tissues.

RESULTS

This review discusses the potential role of cannabinoids in restoring periodontal tissue homeostasis.

CONCLUSIONS

The examination of the endocannabinoid system and the physiological effects of cannabinoids in the periodontium suggests that they possess immunomodulatory and antibacterial properties, which could potentially promote proper tissue healing and regeneration.

Perturbation of 3D nuclear architecture, epigenomic dysregulation and aging, and cannabinoid synaptopathy reconfigures conceptualization of cannabinoid pathophysiology: part 1-aging and epigenomics

Much recent attention has been directed toward the spatial organization of the cell nucleus and the manner in which three-dimensional topologically associated domains and transcription factories are epigenetically coordinated to precisely bring enhancers into close proximity with promoters to control gene expression. Twenty lines of evidence robustly implicate cannabinoid exposure with accelerated organismal and cellular aging. Aging has recently been shown to be caused by increased DNA breaks. These breaks rearrange and maldistribute the epigenomic machinery to weaken and reverse cellular differentiation, cause genome-wide DNA demethylation, reduce gene transcription, and lead to the inhibition of developmental pathways, which contribute to the progressive loss of function and chronic immune stimulation that characterize cellular aging. Both cell lineage-defining superenhancers and the superanchors that control them are weakened. Cannabis exposure phenocopies the elements of this process and reproduces DNA and chromatin breakages, reduces the DNA, RNA protein and histone synthesis, interferes with the epigenomic machinery controlling both DNA and histone modifications, induces general DNA hypomethylation, and epigenomically disrupts both the critical boundary elements and the cohesin motors that create chromatin loops. This pattern of widespread interference with developmental programs and relative cellular dedifferentiation (which is pro-oncogenic) is reinforced by cannabinoid impairment of intermediate metabolism (which locks in the stem cell-like hyper-replicative state) and cannabinoid immune stimulation (which perpetuates and increases aging and senescence programs, DNA damage, DNA hypomethylation, genomic instability, and oncogenesis), which together account for the diverse pattern of teratologic and carcinogenic outcomes reported in recent large epidemiologic studies in Europe, the USA, and elsewhere. It also accounts for the prominent aging phenotype observed clinically in long-term cannabis use disorder and the 20 characteristics of aging that it manifests. Increasing daily cannabis use, increasing use in pregnancy, and exponential dose-response effects heighten the epidemiologic and clinical urgency of these findings. Together, these findings indicate that cannabinoid genotoxicity and epigenotoxicity are prominent features of cannabis dependence and strongly indicate coordinated multiomics investigations of cannabinoid genome-epigenome-transcriptome-metabolome, chromatin conformation, and 3D nuclear architecture. Considering the well-established exponential dose-response relationships, the diversity of cannabinoids, and the multigenerational nature of the implications, great caution is warranted in community cannabinoid penetration.

Molecular and Cellular Mechanisms of Action of Cannabidiol

Cannabidiol (CBD) is the primary non-psychoactive chemical from Cannabis Sativa, a plant used for centuries for both recreational and medicinal purposes. CBD lacks the psychotropic effects of Δ9-tetrahydrocannabinol (Δ9-THC) and has shown great therapeutic potential. CBD exerts a wide spectrum of effects at a molecular, cellular, and organ level, affecting inflammation, oxidative damage, cell survival, pain, vasodilation, and excitability, among others, modifying many physiological and pathophysiological processes. There is evidence that CBD may be effective in treating several human disorders, like anxiety, chronic pain, psychiatric pathologies, cardiovascular diseases, and even cancer. Multiple cellular and pre-clinical studies using animal models of disease and several human trials have shown that CBD has an overall safe profile. In this review article, we summarize the pharmacokinetics data, the putative mechanisms of action of CBD, and the physiological effects reported in pre-clinical studies to give a comprehensive list of the findings and major effects attributed to this compound.

Cannabidiol for Oral Health: A New Promising Therapeutical Tool in Dentistry

The medical use of cannabis has a very long history. Although many substances called cannabinoids are present in cannabis, Δ9tetrahydrocannabinol (Δ9-THC), cannabidiol (CBD) and cannabinol (CBN) are the three main cannabinoids that are most present and described. CBD itself is not responsible for the psychotropic effects of cannabis, since it does not produce the typical behavioral effects associated with the consumption of this drug. CBD has recently gained growing attention in modern society and seems to be increasingly explored in dentistry. Several subjective findings suggest some therapeutic effects of CBD that are strongly supported by research evidence. However, there is a plethora of data regarding CBD's mechanism of action and therapeutic potential, which are in many cases contradictory. We will first provide an overview of the scientific evidence on the molecular mechanism of CBD's action. Furthermore, we will map the recent developments regarding the possible oral benefits of CBD. In summary, we will highlight CBD's promising biological features for its application in dentistry, despite exiting patents that suggest the current compositions for oral care as the main interest of the industry.

The impact of cannabinoids on inflammasome signaling in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) is a chronic disease that afflicts over 38 million people worldwide without a known cure. The advent of effective antiretroviral therapies (ART) has significantly decreased the morbidity and mortality associated with HIV-1 infection in people living with HIV-1 (PWH), thanks to durable virologic suppression. Despite this, people with HIV-1 experience chronic inflammation associated with co-morbidities. While no single known mechanism accounts for chronic inflammation, there is significant evidence to support the role of the NLRP3 inflammasome as a key driver. Numerous studies have demonstrated therapeutic impact of cannabinoids, including exerting modulatory effects on the NLRP3 inflammasome. Given the high rates of cannabinoid use in PWH, it is of great interest to understand the intersecting biology of the role of cannabinoids in HIV-1-associated inflammasome signaling. Here we describe the literature of chronic inflammation in people with HIV, the therapeutic impact of cannabinoids in PWH, endocannabinoids in inflammation, and HIV-1-associated inflammation. We describe a key interaction between cannabinoids, the NLRP3 inflammasome, and HIV-1 viral infection, which supports further investigation of the critical role of cannabinoids in HIV-1 infection and inflammasome signaling.

Inflammasomes as mediators of inflammation in HIV-1 infection

Human immunodeficiency virus type 1 (HIV-1) infection is a chronic disease without a known cure. The advent of effective antiretroviral therapy (ART) has enabled people with HIV (PWH) to have significantly prolonged life expectancies. As a result, morbidity and mortality associated with HIV-1 infection have declined considerably. However, these individuals experience chronic systemic inflammation whose multifaceted etiology is associated with other numerous comorbidities. Inflammasomes are vital mediators that contribute to inflammatory signaling in HIV-1 infection. Here, we provide an overview of the inflammatory pathway that underlies HIV-1 infection, explicitly highlighting the role of the NLRP3 inflammasome. We also delineate the current literature on inflammasomes and the therapeutic targeting strategies aimed at the NLRP3 inflammasome to moderate HIV-1 infection-associated inflammation. Here we describe the NLRP3 inflammasome as a key pathway in developing novel therapeutic targets to block HIV-1 replication and HIV-1-associated inflammatory signaling. Controlling the inflammatory pathways is critical in alleviating the morbidities and mortality associated with chronic HIV-1 infection in PWH.

Receptor-mediated effects of Δ9 -tetrahydrocannabinol and cannabidiol on the inflammatory response of alveolar macrophages

Δ⁹ -Tetrahydrocannabinol (Δ⁹ -THC) and cannabidiol (CBD) are cannabinoids found in Cannabis sativa. While research supports cannabinoids reduce inflammation, the consensus surrounding receptor(s)-mediated effects has yet to be established. Here, we investigated the receptor-mediated properties of Δ⁹ -THC and CBD on alveolar macrophages, an important pulmonary immune cell in direct contact with cannabinoids inhaled by cannabis smokers. MH-S cells, a mouse alveolar macrophage cell line, were exposed to Δ⁹ -THC and CBD, with and without lipopolysaccharide (LPS). Outcomes included RNA-sequencing and cytokine analysis. Δ⁹ -THC and CBD alone did not affect the basal transcriptional response of MH-S cells. In response to LPS, Δ⁹ -THC and CBD significantly reduced the expression of numerous proinflammatory cytokines including tumor necrosis factor-alpha, interleukin (IL)-1β and IL-6, an effect that was dependent on CB₂ . The anti-inflammatory effects of CBD but not Δ⁹ -THC were mediated through a reduction in signaling through nuclear factor-kappa B and extracellular signal-regulated protein kinase 1/2. These results suggest that CBD and Δ⁹ -THC have potent immunomodulatory properties in alveolar macrophages, a cell type important in immune homeostasis in the lungs. Further investigation into the effects of cannabinoids on lung immune cells could lead to the identification of therapies that may ameliorate conditions characterized by inflammation.

The NLRP3 Inflammasome in Stress Response: Another Target for the Promiscuous Cannabidiol

Many psychiatric patients do not respond to conventional therapy. There is a vast effort to investigate possible mechanisms involved in treatment resistance, trying to provide better treatment options, and several data points toward a possible involvement of inflammatory mechanisms. Microglia, glial, and resident immune cells are involved in complex responses in the brain, orchestrating homeostatic functions, such as synaptic pruning and maintaining neuronal activity. In contrast, microglia play a major role in neuroinflammation, neurodegeneration, and cell death. Increasing evidence implicate microglia dysfunction in neuropsychiatric disorders. The mechanisms are still unclear, but one pathway in microglia has received increased attention in the last 8 years, i.e., the NLRP3 inflammasome pathway. Stress response and inflammation, including microglia activation, can be attenuated by Cannabidiol (CBD). CBD has antidepressant, anti-stress, antipsychotic, anti-inflammatory, and other properties. CBD effects are mediated by direct or indirect modulation of many receptors, enzymes, and other targets. This review will highlight some findings for neuroinflammation and microglia involvement in stress-related psychiatric disorders, particularly addressing the NLRP3 inflammasome pathway. Moreover, we will discuss evidence and mechanisms for CBD effects in psychiatric disorders and animal models and address its potential effects on stress response via neuroinflammation and NLRP3 inflammasome modulation.

Anti-Cancer Activity of Cannabis sativa Phytocannabinoids: Molecular Mechanisms and Potential in the Fight against Ovarian Cancer and Stem Cells

Ovarian cancer (OC) is the most lethal gynecological malignancy, with about 70% of cases diagnosed only at an advanced stage. Cannabis sativa, which produces more than 150 phytocannabinoids, is used worldwide to alleviate numerous symptoms associated with various medical conditions. Recently, studies across a range of cancer types have demonstrated that the phytocannabinoids Δ9-trans-tetrahydrocannabinol (THC) and cannabidiol (CBD) have anti-cancer activity in vitro and in vivo, but also the potential to increase other drugs’ adverse effects. THC and CBD act via several different biological and signaling pathways, including receptor-dependent and receptor-independent pathways. However, very few studies have examined the effectiveness of cannabis compounds against OC. Moreover, little is known about the effectiveness of cannabis compounds against cancer stem cells (CSCs) in general and OC stem cells (OCSCs) in particular. CSCs have been implicated in tumor initiation, progression, and invasion, as well as tumor recurrence, metastasis, and drug resistance. Several hallmarks and concepts describe CSCs. OCSCs, too, are characterized by several markers and specific drug-resistance mechanisms. While there is no peer-reviewed information regarding the effect of cannabis and cannabis compounds on OCSC viability or development, cannabis compounds have been shown to affect genetic pathways and biological processes related to CSCs and OCSCs. Based on evidence from other cancer-type studies, the use of phytocannabinoid-based treatments to disrupt CSC homeostasis is suggested as a potential intervention to prevent chemotherapy resistance. The potential benefits of the combination of chemotherapy with phytocannabinoid treatment should be examined in ovarian cancer patients.

Cannabidiol (CBD) Protects Adipose-Derived Mesenchymal Stem Cells (ASCs) against Endoplasmic Reticulum Stress Development and Its Complications

BACKGROUND

Recent studies suggested that individuals with metabolic disorders have altered function of adipocytes and adipose stem cell subpopulations, which impairs tissue homeostasis, promoting insulin resistance and diabetes development. The non-psychoactive phytocannabinoid CBD was found to modulate adipose tissue metabolism, however, its exact role in controlling ASCs' fate is still poorly understood.

OBJECTIVES

This investigation aimed to elucidate whether pretreatment of ASCs with CBD can protect against ER stress development and maintain the cytophysiological properties of cells.

METHODS

Human ASCs were cultured under control and adipogenic conditions. Prior to the experiments, cells in the experimental group were pretreated with CBD following the addition of an ER stress inducer-tunicamycin. After the experiments, the cells were subsequently tested for expression of the apoptotic, ER stress, and anti-inflammatory-related genes using RT-qPCR. Oxidative stress was analysed with flow cytometric assays.

RESULTS

Cells pretreated with CBD displayed decreased apoptosis and enhanced proliferation rate. Additionally, the expression of pro-inflammatory cytokines and miRNAs was significantly reduced. The obtained results also demonstrated an obvious reduction in intracellular accumulated ROS and NO, as well as mitigated ER stress through the down-regulation of IRE-1, PERK, CHOP, and ATF6 transcripts upon CBD treatment.

CONCLUSION

The presented data provide the evidence that CBD protects ASCs against ER stress development and its complications and, thus, offers new insights for the management of obesity through the regulation of adipose tissue dynamics.

Cannabidiol and periodontal inflammatory disease: A critical assessment

Cannabidiol (CBD), a non-psychotropic cannabinoid produced by the genus Cannabis, is a phytoceutical that activates the endocannabinoid system (ECS) through binding to CB1 and CB2 receptors. The ECS is involved in cellular homeostasis and regulates metabolic processes in virtually all mammalian tissues. Published studies on CBD focus, inter alia, on its use in prophylaxis and as an anti-inflammatory agent. Here the authors present a critical assessment of the effects of CBD on inflammatory periodontal diseases caused by bacterial virulence factors, and evaluate critically the possible benefits and drawbacks of CBD use in dentistry. Particular attention is paid to the interaction of CBD with microbially colonized oral tissues, the inflammatory response in relation to the immune response, and the destruction/regeneration of hard and soft tissues of the periodontium.

Cannabidiol selectively modulates interleukin (IL)-1β and IL-6 production in toll-like receptor activated human peripheral blood monocytes

Cannabidiol (CBD) is a major non-euphoric cannabis-derived compound that has become popular in its over-the-counter use. CBD possesses low affinity for cannabinoid receptors, while the primary molecular target(s) by which it mediates biological activity remain poorly defined. Individuals commonly self-medicate using CBD products with little knowledge of its specific immunopharmacological effects on the human immune system; however, research has established primarily in rodent models that CBD possesses immune modulating properties. The objective of this study was to evaluate whether CBD modulates the innate immune response by human primary monocytes activated through toll-like receptors (TLR) 1-9. Monocytes were activated through each TLR and treated with CBD (0.5-10 μM) for 22 h. Monocyte secretion profiles for 13 immune mediators were quantified including: IL-4, IL-2, IP-10, IL-1β, TNFα, MCP-1, IL-17a, IL-6, IL-10, IFNγ, IL-12p70, IL-8, and TGF-β1. CBD treatment significantly suppressed secretion of proinflammatory cytokine IL-1β by monocytes activated through most TLRs, apart from TLRs 3 and 8. Additionally, CBD treatment induced significant modulation of IL-6 production by monocytes activated through most TLRs, except for TLRs 1 and 3. Most other monocyte-derived factors assayed were refractory to CBD modulation. Overall, CBD selectively altered monocyte-derived IL-1β and IL-6 when activated through most TLRs. This study is of particular importance as it provides a direct and comprehensive assessment of the effects of CBD on TLR-activated primary human monocytes at a time when CBD containing products are being widely used by the public.

Role of ascorbic acid in the regulation of epigenetic processes induced by Porphyromonas gingivalis in endothelial-committed oral stem cells

Periodontitis is a common inflammatory disease that affects the teeth-supporting tissue and causes bone and tooth loss. Moreover, in a worldwide population, periodontal disease is often associated with cardiovascular diseases. Emerging studies have reported that one of the major pathogens related to periodontitis is Porphyromonas gingivalis (P. gingivalis), which triggers the inflammatory intracellular cascade. Here, we hypothesized a possible protective effect of ascorbic acid (AA) in the restoration of the physiological molecular pathway after exposure to lipopolysaccharide derived from P. gingivalis (LPS-G). In particular, human gingiva-derived mesenchymal stem cells (hGMSCs) and endothelial-differentiated hGMSCs (e-hGMSCs) exposed to LPS-G showed upregulation of p300 and downregulation of DNA methyltransferase 1 (DNMT1), proteins associated with DNA methylation and histone acetylation. The co-treatment of AA and LPS-G showed a physiological expression of p300 and DNMT1 in hGMSCs and e-hGMSCs. Moreover, the inflammatory process triggered by LPS-G was demonstrated by evaluation of reactive oxygen species (ROS) and their intracellular localization. AA exposure re-established the physiological ROS levels. Despite the limitations of in vitro study, these findings collectively expand our knowledge regarding the molecular pathways involved in periodontal disease, and suggest the involvement of epigenetic modifications in the development of periodontitis.

The Effect of Liposomal Curcumin as an Anti-Inflammatory Strategy on Lipopolysaccharide e from Porphyromonas gingivalis Treated Endothelial Committed Neural Crest Derived Stem Cells: Morphological and Molecular Mechanisms

Curcumin, a yellow polyphenol extracted from the turmeric root is used as a diet supplement. It exhibits anti-inflammatory, antioxidant, and antitumor properties by modulating different intracellular mechanisms. Due to their low solubility in water, the curcumin molecules must be encapsulated into liposomes to improve the bioavailability and biomedical potential. For the periodontal tissue and systemic health, it is essential to regulate the local inflammatory response. In this study, the possible beneficial effect of liposomes loaded with curcumin (CurLIP) in neural crest-derived human periodontal ligament stem cells (hPDLSCs) and in endothelial-differentiated hPDLSCs (e-hPDLSCs) induced with an inflammatory stimulus (lipopolysaccharide obtained from Porphyromonas gingivalis, LPS-G) was evaluated. The CurLIP formulation exhibited a significant anti-inflammatory effect by the downregulation of Toll-like receptor-4 (TLR4)/Myeloid differentiation primary response 88 (MyD88)/nuclear factor kappa light chain enhancer of activated B cells (NFkB)/NLR Family Pyrin Domain Containing 3 (NLRP3)/Caspase-1/Interleukin (IL)-1β inflammation cascade and reactive oxygen species (ROS) formation. Moreover, the exposure to LPS-G caused significant alterations in the expression of epigenetic modifiers, such as DNA Methyltransferase 1 (DNMT1) and P300, while the CurLIP treatment showed physiological expression. Overall, our in vitro study provides novel mechanistic insights into the intracellular pathway exert by CurLIP in the regulation of inflammation and epigenetic modifications.

Hypothesis: Febrile infection-related epilepsy syndrome is a microglial NLRP3 inflammasome/IL-1 axis-driven autoinflammatory syndrome

FIRES (febrile infection-related epilepsy syndrome) is a protracted neuroinflammatory condition of obscure cause. It mainly afflicts school-age children and often leads to permanent neurological sequelae. Most treatments to date have been of limited efficacy, while ketogenic diet and anti-interleukin-1 therapy appear beneficial for some patients. Research into this clinical entity is hampered by its rarity and complexity. Nonetheless, accumulating evidence derived from basic investigations and clinical observations converges to implicate the autoinflammatory nature of this syndrome. A closer analysis of current literature suggests that microglia and the NLRP3 inflammasome might be the pivotal cellular and molecular players in FIRES pathogenesis, respectively. Through evidence synthesis, herein we formulate the working hypothesis of overactivation of microglial NLRP3 inflammasome/interleukin-1 axis as the driving event in FIRES by creating a proinflammatory and proconvulsive milieu. The reverberation between neuroinflammation and seizure forms a vicious cycle. The unique properties of microglia might also contribute to unopposed IL-1 signalling and incessant sterile neuroinflammation in this context. The potential therapeutic relevance of the proposed conceptual framework is discussed.

SARS-CoV-2 and mitochondrial health: implications of lifestyle and ageing

Infection with SARs-COV-2 displays increasing fatality with age and underlying co-morbidity, in particular, with markers of the metabolic syndrome and diabetes, which seems to be associated with a "cytokine storm" and an altered immune response. This suggests that a key contributory factor could be immunosenescence that is both age-related and lifestyle-induced. As the immune system itself is heavily reliant on mitochondrial function, then maintaining a healthy mitochondrial system may play a key role in resisting the virus, both directly, and indirectly by ensuring a good vaccine response. Furthermore, as viruses in general, and quite possibly this new virus, have also evolved to modulate immunometabolism and thus mitochondrial function to ensure their replication, this could further stress cellular bioenergetics. Unlike most sedentary modern humans, one of the natural hosts for the virus, the bat, has to "exercise" regularly to find food, which continually provides a powerful adaptive stimulus to maintain functional muscle and mitochondria. In effect the bat is exposed to regular hormetic stimuli, which could provide clues on how to resist this virus. In this paper we review the data that might support the idea that mitochondrial health, induced by a healthy lifestyle, could be a key factor in resisting the virus, and for those people who are perhaps not in optimal health, treatments that could support mitochondrial function might be pivotal to their long-term recovery.

Biological effects of Cannabidiol on normal human healthy cell populations: Systematic review of the literature

A systematic review was performed to evaluate the biological effects of Cannabidiol (CBD), one of the major components of Cannabis Sativa, on normal human healthy cell populations in terms of cell viability, proliferation, migration, apoptosis and inflammation. Inclusion criteria were: studies on cell lines and primary cell culture from healthy donors, CBD exposure as variable, no CBD exposure as control and published in English language. Quality assessment was based on ToxR tool, with a score of reliability ranging from 15 to 18.Following the PRISMA statement, three independent reviewers performed both a manual and an electronic search using MEDLINE via PubMed, Scopus, Web of Science and Cochrane. From a total of 9437eligible articles, 29 studies have been selected. The average quality assessment score was 16.48.Theresults showed heterogeneous CBD concentration exposure (0.01-50 μM or 0.1 nmol/mL-15 mg/mL). The definition of a threshold limit would allow the identification of specific effects on expected outcomes. From the data obtained CBD resulted to inhibit cell viability in a dose-dependent manner above 2 μM, while in oral cell populations the inhibitory concentration is higher than 10 μM. Moreover, it was observed a significantly inhibition of cell migration and proliferation. On the contrary, it was highlighted a stimulation of apoptosis only at high doses (from 10 μM).Finally, CBD produced an anti-inflammatory effect, with a reduction of the pro-inflammatory cytokine gene expression and secretion. CBD down-regulated ROS production, although at high concentrations (16 μM) increased ROS-related genes expression. The diffusion of CBD for therapeutic and recreational uses require a precise definition of its potential biological effects. A thorough knowledge of these aspects would allow a safe use of this substance without any possible side effects.

Cannabidiol as a Novel Therapeutic for Immune Modulation

The immune-suppressive effects of cannabidiol (CBD) are attributed to the modulation of essential immunological signaling pathways and receptors. Mechanistic understanding of the pharmacological effects of CBD emphasizes the therapeutic potential of CBD as a novel immune modulator. Studies have observed that the antagonists of CB₁ and CB₂ receptors and transient receptor potential vanilloid 1 reverse the immunomodulatory effects of CBD. CBD also inhibits critical activators of the Janus kinase/signal transducer and activator of transcription signaling pathway, as well as the nucleotide-binding oligomerization domain-like receptor signaling pathway, in turn decreasing pro-inflammatory cytokine production. Furthermore, CBD protects against cellular damage incurred during immune responses by modulating adenosine signaling. Ultimately, the data overwhelmingly support the immunosuppressive effects of CBD and this timely review draws attention to the prospective development of CBD as an effective immune modulatory therapeutic.

Inhibitory Effect of Cannabidiol on the Activation of NLRP3 Inflammasome Is Associated with Its Modulation of the P2X7 Receptor in Human Monocytes

Cannabidiol (CBD), a phytocannabinoid, has been reported to have anti-inflammatory effects associated with NLRP3 inflammasome activation, but its mechanism of anti-inflammasome action remains unclear. Herein, we report CBD's effect on NLRP3 inflammasome activation and its modulation of P2X7, an inflammasome activation-related receptor, in human THP-1 monocytes. CBD (0.1, 1, and 10 μM) exerted anti-inflammasome activity in LPS-nigericin-stimulated THP-1 monocytes by reducing media IL-1β concentration (by 63.9%, 64.1%, and 83.1%, respectively), which was similar to the known NLRP3 inflammasome inhibitors oridonin and MCC950 (16.9% vs 20.8% and 17.4%, respectively; at 10 μM). CBD (10 μM) decreased nigericin-alone- and nigericin-lipopolysaccharide-induced potassium efflux by 13.7% and 13.0%, respectively, in THP-1 monocytes, strongly suggesting P2X7 receptor modulation. Computational docking data supported the potential for CBD binding to the P2X7 receptor via interaction with GLU 172 and VAL 173 residues. Overall, the observed CBD suppressive effect on NLRP3 inflammasome activation in THP-1 monocytes was associated with decreased potassium efflux, as well as in silico prediction of P2X7 receptor binding. CBD inhibitory effects on the NLRP3 inflammasome may contribute to the overall anti-inflammatory effects reported for this phytocannabinoid.

Enhanced VEGF/VEGF-R and RUNX2 Expression in Human Periodontal Ligament Stem Cells Cultured on Sandblasted/Etched Titanium Disk

Bone formation, in skeletal development or in osseointegration processes, is the result of interaction between angiogenesis and osteogenesis. To establish osseointegration, cells must attach to the implant in a direct way without any deposition of soft tissue. Structural design and surface topography of dental implants enhance the cell attachment and can affect the biological response. The aim of the study was to evaluate the cytocompatibility, osteogenic and angiogenic markers involved in bone differentiation of human periodontal ligament stem cells (hPDLSCs) on different titanium disks surfaces. The hPDLSCs were cultured on pure titanium surfaces modified with two different procedures, sandblasted (Control—CTRL) and sandblasted/etched (Test—TEST) as experimental titanium surfaces. After 1 and 8 weeks of culture VEGF, VEGF-R, and RUNX2 expression was evaluated under confocal laser scanning microscopy. To confirm the obtained data, RT-PCR and WB analyses were performed in order to evaluate the best implant surface performance. TEST surfaces compared to CTRL titanium surfaces enhanced cell adhesion and increased VEGF and RUNX2 expression. Moreover, titanium TEST surfaces showed a different topographic morphology that promoted cell adhesion, proliferation, and osteogenic/angiogenic commitment. To conclude, TEST surfaces performed more efficiently than CTRL surfaces; furthermore, TEST surface results showed them to be more biocompatible, better tolerated, and appropriate for allowing hPDLSC growth and proliferation. This fact could also lead to more rapid bone–titanium integration.

Immune Responses Regulated by Cannabidiol

Introduction: Cannabidiol (CBD) as Epidiolex^® (GW Pharmaceuticals) was recently approved by the U.S. Food and Drug Administration (FDA) to treat rare forms of epilepsy in patients 2 years of age and older. Together with the increased societal acceptance of recreational cannabis and CBD oil for putative medical use in many states, the exposure to CBD is increasing, even though all of its biological effects are not understood. Once such example is the ability of CBD to be anti-inflammatory and immune suppressive, so the purpose of this review is to summarize effects and mechanisms of CBD in the immune system. It includes a consideration of reports identifying receptors through which CBD acts, since the “CBD receptor,” if a single one exists, has not been definitively identified for the myriad immune system effects. The review then provides a summary of in vivo and in vitro effects in the immune system, in autoimmune models, with a focus on experimental autoimmune encephalomyelitis, and ends with identification of knowledge gaps.

Conclusion: Overall, the data overwhelmingly support the notion that CBD is immune suppressive and that the mechanisms involve direct suppression of activation of various immune cell types, induction of apoptosis, and promotion of regulatory cells, which, in turn, control other immune cell targets.

AEDG Peptide (Epitalon) Stimulates Gene Expression and Protein Synthesis during Neurogenesis: Possible Epigenetic Mechanism

It was shown that AEDG peptide (Ala-Glu-Asp-Gly, Epitalon) regulates the function of the pineal gland, the retina, and the brain. AEDG peptide increases longevity in animals and decreases experimental cancerogenesis. AEDG peptide induces neuronal cell differentiation in retinal and human periodontal ligament stem cells. The aim of the study was to investigate the influence of AEDG peptide on neurogenic differentiation gene expression and protein synthesis in human gingival mesenchymal stem cells, and to suggest the basis for the epigenetic mechanism of this process. AEDG peptide increased the synthesis of neurogenic differentiation markers: Nestin, GAP43, β Tubulin III, Doublecortin in hGMSCs. AEDG peptide increased Nestin, GAP43, β Tubulin III and Doublecortin mRNA expression by 1.6–1.8 times in hGMSCs. Molecular modelling method showed, that AEDG peptide preferably binds with H1/6 and H1/3 histones in His-Pro-Ser-Tyr-Met-Ala-His-Pro-Ala-Arg-Lys and Tyr-Arg-Lys-Thr-Gln sites, which interact with DNA. These results correspond to previous experimental data. AEDG peptide and histones H1/3, H1/6 binding may be one of the mechanisms which provides an increase of Nestin, GAP43, β Tubulin III, and Doublecortin neuronal differentiation gene transcription. AEDG peptide can epigenetically regulate neuronal differentiation gene expression and protein synthesis in human stem cells.

Role of gingival mesenchymal stem cell exosomes in macrophage polarization under inflammatory conditions

OBJECTIVE

Exosomes have been shown to play a strong role in intercellular communication. While GMSCs have been extensively studied, less research exists on exosomes derived from GMSCs, especially on how exosomes affect macrophages. This study aimed to investigate the impact of GMSC-derived exosomes on macrophage polarization and phenotype under inflammatory conditions.

METHODS

Exosomes were isolated from GMSCs-conditioned media by ultracentrifugation (UC) and characterized by transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA) and western blot (WB). In vitro, GMSC-derived exosomes were co-incubated with macrophages for 24 h in the absence or presence of M1 polarizing conditions in the six-well plate. The protein and mRNA expression levels of M1 and M2 macrophage markers were detected and the supernatants were collected for an enzyme-linked immunosorbent assay (ELISA).

RESULTS

Exosomes were successfully isolated from GMSCs. Macrophages co-cultured with exosomes showed significantly decreased levels of the M1 markers Tumor Necrosis Factor-α (TNF-α), Interleukin-12 (IL-12), CD86 and Interleukin-1β (IL-1β). By contrast, M2 marker Interleukin-10 (IL-10) levels moderately increased. Meanwhile, similar results were acquired in the cell culture supernatants.

CONCLUSION

GMSC-derived exosomes may promote M1 macrophage transformation into M2 macrophages, reducing the pro-inflammatory factors produced by M1 macrophages.

Transcriptomic Analysis of Stem Cells Treated with Moringin or Cannabidiol: Analogies and Differences in Inflammation Pathways

Inflammation is a common feature of many neurodegenerative diseases. The treatment of stem cells as a therapeutic approach to repair damage in the central nervous system represents a valid alternative. In this study, using Next-Generation Sequencing (NGS) technology, we analyzed the transcriptomic profile of human Gingival Mesenchymal Stem Cells (hGMSCs) treated with Moringin [4-(α-l-ramanosyloxy)-benzyl isothiocyanate] (hGMSCs-MOR) or with Cannabidiol (hGMSCs-CBD) at dose of 0.5 or 5 µM, respectively. Moreover, we compared their transcriptomic profiles in order to evaluate analogies and differences in pro- and anti-inflammatory pathways. The hGMSCs-MOR selectively downregulate TNF-α signaling from the beginning, reducing the expression of TNF-α receptor while hGMSCs-CBD limit its activity after the process started. The treatment with CBD downregulates the pro-inflammatory pathway mediated by the IL-1 family, including its receptor while MOR is less efficient. Furthermore, both the treatments are efficient in the IL-6 signaling. In particular, CBD reduces the effect of the pro-inflammatory JAK/STAT pathway while MOR enhances the pro-survival PI3K/AKT/mTOR. In addition, both hGMSCs-MOR and hGMSCs-CBD improve the anti-inflammatory activity enhancing the TGF-β pathway.

Bovine pericardium membrane, gingival stem cells, and ascorbic acid: a novel team in regenerative medicine

Recently, the development and the application of 3D scaffold able to promote stem cell differentiation represented an essential field of interest in regenerative medicine. In particular, functionalized scaffolds improve bone tissue formation and promote bone defects repair. This research aims to evaluate the role of ascorbic acid (AS) supplementation in an in vitro model, in which a novel 3D-scaffold, bovine pericardium collagen membrane called BioRipar (BioR) was functionalized with human Gingival Mesenchymal Stem Cells (hGMSCs). As extensively reported in the literature, AS is an essential antioxidant molecule involved in the extracellular matrix secretion and in the osteogenic induction. Specifically, hGMSCs were seeded on BioR and treated with 60 and 90 μg/mL of AS in order to assess their growth behavior, the expression of bone specific markers involved in osteogenesis (runt-related transcription factor 2, RUNX2; collagen1A1, COL1A1; osteopontin, OPN; bone morphogenetic protein2/4, BMP2/4), and de novo deposition of calcium. The expression of COL1A1, RUNX2, BMP2/4 and OPN was evaluated by RT-PCR, Western blotting and immunocytochemistry, and proved to be upregulated. Our results demonstrate that after three weeks of treatment AS at 60 and 90 μg/mL operates as an osteogenic inductor in hGMSCs. These data indicate that the AS supplementation produces an enhancement of osteogenic phenotype commitment in an in vitro environment. For this reason, AS could represent a valid support for basic and translational research in tissue engineering and regenerative medicine.

The Differences in the Proteome Profile of Cannabidiol-Treated Skin Fibroblasts following UVA or UVB Irradiation in 2D and 3D Cell Cultures

Cannabidiol (CBD), as the only phytocannabinoid that has no psychoactive effect, has both antioxidant and anti-inflammatory effects, and thus might be suggested as a cytoprotective compound against UV-induced metabolic changes in skin cells. Therefore, the aim of this study was to investigate the level of protective CBD activity by evaluating the proteomic profile of 2D and 3D cultured skin fibroblasts models following exposure to UVA and UVB radiation. The CBD cytoprotective effect against UV-induced damage in 2D and 3D cultured fibroblasts were different. The main alterations focus on the range of cell reaction and involved different proteins associated with various molecular functions. In the 2D cultured cells, following UV radiation, the major changes were associated with proteins involved in antioxidant response and inflammation, while, in the 3D cultured fibroblasts, CBD action against UV induced changes were mainly associated with the activation of signalling pathways. Therefore, the knowledge of the CBD action in a multilayer skin cells model allowed for the prediction of changes in cell-cell interactions and skin cell metabolism. Knowledge about the lower protective effect of CBD in 3D cultured fibroblasts should be taken into account during the design of UV light protection.

3D Human Periodontal Stem Cells and Endothelial Cells Promote Bone Development in Bovine Pericardium-Based Tissue Biomaterial

Bone defects repair represents a public and urgent problem in clinical practice, in fact, every year, more than two million patients required new treatments for bone injuries. Today a complete vascularization is strategic in bone formation, representing a new frontier for clinical application. Aim of this research has been developed a three-dimensional (3D) coculture platform using a bovine pericardium collagen membrane (BioR) loaded with human periodontal ligament stem cells (hPDLSCs) and endothelial differentiated cells from hPDLSCs (E-hPDLSCs) able to undergo toward osteoangiogenesis differentiation process. First, we have characterized at confocal laser scanning microscopy (CLSM) level the E-hPDLSCs phenotype profile, through CD31 and CD34 markers expression and the ability to tube vessel formation. Real Time-Polimerase Chain Reaction (RT-PCR) and western blotting analyses revealed the upregulation of Runt-related transcription factor 2 (RUNX2), Collagen 1A1 (COL1A1), Vascular Endothelial Growth Factor-A (VEGF-A) genes and proteins in the living construct composed by hPDLSCs + E-hPDSCs/BioR. Human PDLSCs + E-hPDLSCs/BioR construct showed also an enhacement of de novo synthesis of osteocalcin. Given that, the extracellular-signal-regulated kinase (ERK)/mitogen activated protein kinase (MAPK) transduction signaling was involved in the osteogenesis and angiogenesis process, the ERK1/2 protein level at biochemical level, in our experimental model, has been investigated. Our results evidenced an upregulation of ERK1/2 proteins level born in the living construct. In conclusion, we believe that the use of the hPDLSCs and E-hPDLSCs coculture togheter with BioR as substrate, could represent an efficient model able to activate through ERK1/2 signaling pathway the osteoangiogenesis process, and then representing a new potential engineered platform for surgeons during the repair and the healing of bone defects.

Human gingival mesenchymal stem cells pretreated with vesicular moringin nanostructures as a new therapeutic approach in a mouse model of spinal cord injury

Spinal cord injury (SCI) is a neurological disorder that arises from a primary acute mechanical lesion, followed by a pathophysiological cascade of events that leads to further spinal cord tissue damage. Several preclinical and clinical studies have highlighted the ability of stem cell therapy to improve long-term functional recovery in SCI. Previously, we demonstrated that moringin (MOR) treatment accelerates the differentiation process in mesenchymal stem cells inducing an early up-regulation of neural development associated genes. In the present study, we investigated the anti-inflammatory, anti-apoptotic, and regenerative effects of gingival mesenchymal stem cells (GMSCs) pretreated with nanostructured liposomes enriched with MOR in an animal model of SCI. SCI was produced by extradural compression of the spinal cord at levels T6-T7 in ICR (CD-1) mice. Animals were randomly assigned to the following groups: Sham, SCI, SCI + GMSCs (1 × 106  cell/i.v.), SCI + MOR-GMSCs (1 × 106  cell/i.v.). Our data show that MOR-treated GMSCs exert anti-inflammatory and anti-apoptotic activities. In particular, MOR-treated GMSCs are able to reduce the spinal cord levels of COX-2, GFAP, and inflammatory cytokines IL-1β and IL-6 and to restore spinal cord normal morphology. Also, MOR-treated GMSCs influenced the apoptotic pathway, by reducing Bax, caspase 3, and caspase 9 expressions.

Curcumin/Liposome Nanotechnology as Delivery Platform for Anti-inflammatory Activities via NFkB/ERK/pERK Pathway in Human Dental Pulp Treated With 2-HydroxyEthyl MethAcrylate (HEMA)

Curcumin, primary component of the spice turmeric extracted from the rhizomes of Curcuma longa, represents the major anti-oxidant and anti-inflammatory substance found in turmeric, acting thought various mechanisms not completely understood. Curcumin modulates cytokines, growth factors, transcription factors, inflammatory molecules and cell signaling pathways. During restorative dentistry practice, free resin monomers of 2-hydroxyethyl methacrylate (HEMA) propagate through dentin micro-channel and pulp into the bloodstream affecting cellular integrity. The study highlights the significance of application of curcumin bioactive component into liposomal formulations (CurLIP) to restore the homeostasis of dental pulp stem cells (hDPSCs) in response to 3 and 5 mmol L^–1 HEMA treatment. Cell proliferation in combination with changes of the morphological features, proinflammatory cytokines secretion as Interleukin (IL) 6, IL8, Monocyte Chemoattractant Protein-1 (MCP1) and Interferon-gamma (IFNγ) were assayed along with the nuclear factor (NF)-kB, an inducible transcription factor involved in the activation of several cell processes associated to extracellular signal-regulated kinases (ERK) and posphorylated (p-) ERK pathway. Our results showed a decreased cell proliferation, morphological changes and upregulation of IL6, IL8, MCP1 and IFNγ in presence of 3 and 5 mmol L^–1 HEMA treatment. CurLIP therapy in hDPSCs provokes an increase in cell proliferation and the block of inflammatory cytokines secretion through the inhibitory regulation of NFkB/ERK and pERK signaling cascade. The natural nanocarrier CurLIP influences numerous biochemical and molecular cascades causing anti-inflammatory properties in response to HEMA treatment in human dental pulp stem cells, representing an innovative endodontic formulation able to improve the quality of dental care with a major human community impact.

Effect of short peptides on neuronal differentiation of stem cells

It has been demonstrated that short peptides play an important role in the transmission of biological information, modulation of transcription, and restoring genetically conditioned alterations occurring with age. Peptidergic regulation of homeostasis occupies an important place in physiological processes, which lead to the aging of cells, tissues, and organs, consisting in the involution of major regulatory systems-the nervous, the endocrine, and the immune. The effect of AED (Ala-Glu-Asp), KED (Lys-Glu-Asp), KE (Lys-Glu), AEDG (Ala-Glu-Asp-Gly) peptides and their compound on neuronal differentiation of human periodontal ligament stem cells (hPDLSCs) was studied by immunofluorescence and western blot analysis. Growth-Associated Protein 43 (GAP43), which implements neurotransmission mechanisms and neuroplasticity, demonstrated an increased expression in hPDLSCs cultured with a compound of all studied peptides and with KED alone. The peptide compound and KED, increase the expression of Nestin (neurofilament protein), expressed in early neuronal precursors in hPDLSCs cultures. Thus, the compound of peptides AEDG, KE, AED, and KED could promote the neuronal differentiation of hPDLSCs and be a promising tool for the study of peptides as a modulator of neurogenesis in neurodegenerative diseases studied in animal models.

Periodontal Ligament Stem Cells: Current Knowledge and Future Perspectives

Teeth represent a fascinating area of study in regenerative medicine, because of their unique and complex developmental origin. Several types of mesenchymal stem cells (MSCs) have been characterized in the oral cavity, and those derived from the periodontal ligament (PDL) first isolated by our group in 2005, can be expanded in a xeno-free medium preserving morphological features and markers associated with pluripotency. These postnatal MSCs can be easily recovered by noninvasive procedures and cultured. This could facilitate the use of adult stem cells in human clinical regeneration therapy. In this review we summarize the results of our studies describing morphofunctional features, surface markers, and multilineage differentiation capacity in vitro of PDL MSCs obtained in our laboratories. In vivo characterization of PDL stem cell (PDLSC) location and heterogeneity are still lacking. However, we describe studies exploring the potential use of PDLSC to treat both periodontal diseases and regeneration of other tissues. These MSCs may have an advantage in possessing also angiogenetic, immunoregulatory, and anti-inflammatory properties. The secretome of such cells contains several interesting molecules mimicking the effects of the producer cells. We describe some recent studies from our group on the use of conditioned medium from PDL MSCs, and purified extracellular vesicles therein contained, in animal models of experimental autoimmune encephalomyelitis and their potential application to human disease.

Engineered Extracellular Vesicles From Human Periodontal-Ligament Stem Cells Increase VEGF/VEGFR2 Expression During Bone Regeneration

Bone regeneration represents still a challenge, in particular for calvarium defects. Recently, the development of biomaterials with the addiction of stem cells is giving promising results for the treatment of bone defects. In particular, it was demonstrated that scaffolds enriched with mesenchymal stem cells (MSCs) and/or their derivatives, such as conditioned medium (CM) and extracellular vesicles (EVs), may improve bone regeneration. Moreover, given the deep link between osteogenesis and angiogenesis, a successful approach must also take into consideration the development of vascularization. In this work we evaluated the bone regeneration capacity of a collagen membrane (3D-COL) enriched with human periodontal-ligament stem cells (hPDLSCs) and CM or EVs or EVs engineered with polyethylenimine (PEI-EVs) in rats subjected to a calvarial defect. We evaluated also their capacity to induce angiogenic factors. At first, in vitro results showed an increased expression of osteogenic markers in hPDLSCs cultured with the 3D-COL and PEI-EVs, associated also with the increased protein levels of Vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). The increased expression of these proteins was confirmed also in vivo in rats implanted with the 3D-COL enriched with hPDLSCs and PEI-EVs. Moreover, histological examination evidenced in this group of rats the activation of bone regeneration and of the vascularization process. Also MicroCT imaging with morphometric analysis confirmed in rats transplanted with 3D-COL enriched with hPDLSCs and PEI-EVs an important regenerative process and a better integration level. All together, these results evidenced that the 3D-COL enriched with hPDLSCs and PEI-EVs may promote bone regeneration of calvaria defects, associated also with an increased vascularization.

The Role of Hypoxia on the Neuronal Differentiation of Gingival Mesenchymal Stem Cells: A Transcriptional Study

Mesenchymal stem cells (MSCs) are widely used in stem cell therapy for regenerative purposes. Oral-derived MSCs, such as gingival MSCs (GMSCs), deriving from the neural crest seem more suitable to differentiate toward the neuronal lineage. In addition, the preconditioning of MSCs may improve their beneficial effects. Since it is known that hypoxia may influence stem cell properties, we were interested in evaluating the effects of hypoxia preconditioning on the neuronal differentiation of GMSCs. With this aim, we evaluated the transcriptional profile of GMSCs exposed to basal and neuroinductive medium both in normoxia and in cells preconditioned for 48 h in hypoxia. We compared their transcriptional profile using Next Generation Sequencing. At first we observed that hypoxia did not alter cell morphology compared with the GMSCs cultured in a normoxic condition. In order to understand hypoxia preconditioning effects on neuronal differentiation, we screened genes with Log2 fold change ≥2 using the database Cortecon, that collects gene expression data set of in vitro corticogenesis. We observed that hypoxia preconditioning induced the expression of more genes associated with different stages of cortical development. The common genes, expressed both in normoxia and hypoxia preconditioning, were involved in developmental and neuronal processes. Interestingly, a larger number of genes associated with development biology and neuronal process was expressed in GMSCs differentiated after hypoxia preconditioning compared with those in normoxia. In addition, hypoxic-preconditioned differentiated GMSCs showed a higher expression of nestin, PAX6, and GAP43. Our data demonstrated that hypoxia preconditioning enhanced the differentiation potential of GMSCs and induced the activation of a higher number of genes associated with neuronal development. In conclusion, hypoxia may be used to improve MSCs’ properties for stem cell therapy.

MicroRNA 210 Mediates VEGF Upregulation in Human Periodontal Ligament Stem Cells Cultured on 3DHydroxyapatite Ceramic Scaffold

The aim of the present research was the evaluation of the behavior of human periodontal ligament stem cells (hPDLSCs), cultured in presence of Endobon^® Xenograft Granules (G), a fully deproteinated hydroxyapatite ceramic scaffold derived from cancellous bovine bone. hPDLSCs were seeded with and without G for 24 h to 1 week. The cell growth, morphological features, adhesiveness, differentiation ability, modulation of miR-210 and Vascular Endothelial Growth Factor (VEGF) secretion were analyzed by means of MTT assay, Scanning Electron Microscopy (SEM), Confocal Laser Scanning Microscopy (CLSM), Alizarin Red S assay, RT-PCR and ELISA test, respectively. hPDLSCs grown on the biomaterial showed the ability to form focal adhesion on the substrate, as demonstrated by vinculin expression. These data were supported by SEM analysis showing that an adhesiveness process associated to cell growth occurs between cells and biomaterials. The osteogenic differentiation, evaluated by morphological, biochemical, and RT-PCR analysis, was pronounced in the hPDLSCs grown in the three-dimensional inorganic bovine bone substitute in the presence of osteoinductive conditions. In addition, an upregulation of miR-210 and VEGF was evident in cells cultured in presence of the biomaterial. Our results inspire us to consider granules not only an adequate biocompatible three-dimensional biomaterial, but also an effective inductor of miR-210 and VEGF; in fact, the involvement of miR-210 in VEGF secretion could offer a novel regulatory system in the early steps of the bone-regeneration process.

5-Aza Exposure Improves Reprogramming Process Through Embryoid Body Formation in Human Gingival Stem Cells

Embryoid bodies (EBs) are three-dimensional aggregates formed by pluripotent stem cells, including embryonic stem cells and induced pluripotent stem cells. They are used as an in vitro model to evaluate early extraembryonic tissue formation and differentiation process. In the adult organisms, cell differentiation is controlled and realized through the epigenetic regulation of gene expression, which consists of various mechanisms including DNA methylation. One demethylating agent is represented by 5-Azacytidine (5-Aza), considered able to induce epigenetic changes through gene derepression. Human gingival mesenchymal stem cells (hGMSCs), an easily accessible stem cells population, migrated from neural crest. They are particularly apt as an in vitro study model in regenerative medicine and in systemic diseases. The ability of 5-Aza treatment to induce hGMSCs toward a dedifferentiation stage and in particular versus EBs formation was investigated. For this purpose hGMSCs were treated for 48 h with 5-Aza (5 μM). After treatment, hGMSCs are organized as round 3D structures (EBs-hGMSCs). At light and transmission electron microscopy, the cells at the periphery of EBs-hGMSCs appear elongated, while ribbon-shaped cells and smaller cells with irregular shape surrounded by extracellular matrix were present in the center. By RT-PCR, EBs-hGMSCs expressed specific transcription markers related to the three germ layers as MAP-2, PAX-6 (ectoderm), MSX-1, Flk-1 (mesoderm), GATA-4, and GATA-6 (endoderm). Moreover, in EB-hGMSCs the overexpression of DNMT1 and ACH3 other than the down regulation of p21 was detectable. Immunofluorescence staining also showed a positivity for specific etodermal and mesodermal markers. In conclusion, 5-Aza was able to induce the direct conversion of adult hGMSCs into cells of three embryonic lineages: endoderm, ectoderm, and mesoderm, suggesting their possible application in autologous cell therapy for clinical organ repair.

Cannabidiol induced apoptosis in human monocytes through mitochondrial permeability transition pore-mediated ROS production

Cannabidiol (CBD) has been reported to induce apoptosis in immune cells through oxidative stress-related mechanisms. The objective of the present study was to investigate the cellular mechanisms for CBD-induced apoptosis and oxidative stress in human monocytes. Exposure of freshly isolated human monocytes to CBD induced apoptosis in a time- and concentration-dependent manner. Time-course analyses revealed the induction of intracellular reactive oxygen species (ROS) at 1-2 h post CBD (16 μM) exposure. By comparison, the CBD treatment rapidly elicited the depolarization of mitochondrial membrane potential (MMP) within 5 min, and the oxidation of cardiolipin, a major lipid component of the mitochondrial inner membrane, within 15 min. Moreover, CBD induced the release of cytochrome c (Cyt c) from mitochondria. Mechanistic studies revealed that CBD-induced ROS production and apoptosis were not associated with the alteration of mitochondrial superoxide dismutase activity, the electron leakage through mitochondrial respiratory chain, and Fe²⁺- and Ca²⁺-mediated mechanisms. In contrast, CBD-induced apoptosis and MMP depolarization were markedly attenuated by the mitochondrial permeability transition pore (MPTP) inhibitor cyclosporin A (CsA), but not the calcineurin inhibitor FK506. Furthermore, CsA prevented cardiolipin oxidation and the MPTP opening induced by CBD. The present study suggests that CBD acts on the mitochondria to elicit ROS generation and apoptosis through MPTP opening and provides critical insights into the cellular mechanisms for CBD-induced oxidative stress in apoptotic monocytes.

Treatment of Periodontal Ligament Stem Cells with MOR and CBD Promotes Cell Survival and Neuronal Differentiation via the PI3K/Akt/mTOR Pathway

Periodontal ligament mesenchymal stem cells (hPDLSCs), as well as all mesenchymal stem cells, show self-renewal, clonogenicity, and multi-tissue differentiation proprieties and can represent a valid support for regenerative medicine. We treated hPDLSCs with a combination of Moringin (MOR) and Cannabidiol (CBD), in order to understand if treatment could improve their survival and their in vitro differentiation capacity. Stem cells survival is fundamental to achieve a successful therapy outcome in the re-implanted tissue of patients. Through NGS transcriptome analysis, we found that combined treatment increased hPDLSCs survival, by inhibition of apoptosis as demonstrated by enhanced expression of anti-apoptotic genes and reduction of pro-apoptotic ones. Moreover, we investigated the possible involvement of PI3K/Akt/mTOR pathway, emphasizing a differential gene expression between treated and untreated cells. Furthermore, hPDLSCs were cultured for 48 h in the presence or absence of CBD and MOR and, after confirming the cellular viability through MTT (3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazoliumbromide) assay, we examined the presence of neuronal markers, through immunofluorescence analysis. We found an increased expression of Nestin and GAP43 (growth associated protein 43) in treated cells. In conclusion, hPDLSCs treated with Moringin and Cannabidiol showed an improved survival capacity and neuronal differentiation potential.

A novel role in skeletal segment regeneration of extracellular vesicles released from periodontal-ligament stem cells

Purpose

The combination of oral derived stem cells and 3-D scaffolds is considered advantageous in bone repair. In particular, collagen membranes possess ideal biological properties and can support infiltration and proliferation of osteoblasts, promoting bone regeneration. Our study aimed to develop a new biocompatible osteogenic construct composed of a commercially available collagen membrane (Evolution [Evo]), human periodontal-ligament stem cells (hPDLSCs) enriched with extracellular vesicles (EVs), or polyethylenimine (PEI)-engineered EVs (PEI-EVs).

Methods

Osteogenic ability and expression of osteogenic genes were evaluated in vitro in hPDLSCs cultured with or without Evo, with Evo and EVs, or PEI-EVs. In addition, the bone-regeneration capacity of Evo, Evo enriched with hPDLSCs, Evo enriched with hPDLSCs and EVs/PEI-EVs was investigated in rats subjected to calvarial defects.

Results

Our results showed that Evo enriched with EVs and PEI-EVs showed high biocompatibility and osteogenic properties in vitro and in vivo. In addition, quantitative reverse-transcription polymerase chain reaction demonstrated the upregulation of osteogenic genes, such as TGFB1, MMP8, TUFT1, TFIP11, BMP2, and BMP4, in the presence of PEI-EVs. Upregulation of BMP2/4 was confirmed for Evo enriched with PEI-EVs and hPDLSCs both in vitro by Western blot and in vivo by immunofluorescence.

Conclusion

Our results indicated that Evo enriched with hPDLSCs and PEI-EVs is able to promote a bone-regeneration process for the treatment of calvarium and ossification defects caused by accidental or surgery trauma. In particular, PEI-EVs had a significant role in activation of the osteogenic process.

Moringin Induces Neural Differentiation in the Stem Cell of the Human Periodontal Ligament

The therapeutic strategies for neurodegenerative diseases still represent a vast research field because of the lack of targeted, effective and resolutive treatment for neurodegenerative diseases. The use of stem cell-based therapy is an alternative approach that could lead to the replacement of damaged neuronal tissue. For this purpose, adult mesenchymal stem cells (MSC), including periodontal ligament stem cells (PDLSCs), could be very useful for their differentiation capacity, easy isolation and the ability to perform an autologous implant. The aim of this work was to test whether the Moringin [4-(α-L-rhamnosyloxy) benzyl isothiocyanate; GMG-ITC], an isothiocyanate extracted from Moringa oleifera seeds, was able to induce PDLSCs toward neural progenitor differentiation. Next-generation transcriptomics sequencing showed that moringin treatment increased the expression of genes involved in neuron cortical development and in particular in neuron belonging to upper and deep cortical layers. Moreover, moringin treatment upregulated genes involved in osteogenesis and adipogenesis although with a lower fold change compared to upregulated genes involved in neuronal differentiation. Finally, moringin did not induce the expression of oncogenes resulting in a safe treatment.

Three-dimensional printed PLA scaffold and human gingival stem cell-derived extracellular vesicles: a new tool for bone defect repair

BACKGROUND

The role of bone tissue engineering in the field of regenerative medicine has been a main research topic over the past few years. There has been much interest in the use of three-dimensional (3D) engineered scaffolds (PLA) complexed with human gingival mesenchymal stem cells (hGMSCs) as a new therapeutic strategy to improve bone tissue regeneration. These devices can mimic a more favorable endogenous microenvironment for cells in vivo by providing 3D substrates which are able to support cell survival, proliferation and differentiation. The present study evaluated the in vitro and in vivo capability of bone defect regeneration of 3D PLA, hGMSCs, extracellular vesicles (EVs), or polyethyleneimine (PEI)-engineered EVs (PEI-EVs) in the following experimental groups: 3D-PLA, 3D-PLA + hGMSCs, 3D-PLA + EVs, 3D-PLA + EVs + hGMSCs, 3D-PLA + PEI-EVs, 3D-PLA + PEI-EVs + hGMSCs.

METHODS

The structural parameters of the scaffold were evaluated using both scanning electron microscopy and nondestructive microcomputed tomography. Nanotopographic surface features were investigated by means of atomic force microscopy. Scaffolds showed a statistically significant mass loss along the 112-day evaluation.

RESULTS

Our in vitro results revealed that both 3D-PLA + EVs + hGMSCs and 3D-PLA + PEI-EVs + hGMSCs showed no cytotoxicity. However, 3D-PLA + PEI-EVs + hGMSCs exhibited greater osteogenic inductivity as revealed by morphological evaluation and transcriptomic analysis performed by next-generation sequencing (NGS). In addition, in vivo results showed that 3D-PLA + PEI-EVs + hGMSCs and 3D-PLA + PEI-EVs scaffolds implanted in rats subjected to cortical calvaria bone tissue damage were able to improve bone healing by showing better osteogenic properties. These results were supported also by computed tomography evaluation that revealed the repair of bone calvaria damage.

CONCLUSION

The re-establishing of the integrity of the bone lesions could be a promising strategy in the treatment of accidental or surgery trauma, especially for cranial bones.

Biofunctionalized Scaffold in Bone Tissue Repair

Bone tissue engineering is based on bone grafting to repair bone defects. Bone graft substitutes can contribute to the addition of mesenchymal stem cells (MSCs) in order to enhance the rate and the quality of defect regeneration. The stem cell secretome contains many growth factors and chemokines, which could affect cellular characteristics and behavior. Conditioned medium (CM) could be used in tissue regeneration avoiding several problems linked to the direct use of MSCs. In this study, we investigated the effect of human periodontal ligament stem cells (hPDLSCs) and their CM on bone regeneration using a commercially available membrane scaffold Evolution (EVO) implanted in rat calvarias. EVO alone or EVO + hPDLSCs with or without CM were implanted in Wistar male rats subjected to calvarial defects. The in vivo results revealed that EVO membrane enriched with hPDLSCs and CM showed a better osteogenic ability to repair the calvarial defect. These results were confirmed by acquired micro-computed tomography (CT) images and the increased osteopontin levels. Moreover, RT-PCR in vitro revealed the upregulation of three genes (Collagen (COL)5A1, COL16A1 and transforming growth factor (TGF)β1) and the down regulation of 26 genes involved in bone regeneration. These results suggest a promising potential application of CM from hPDLSCs and scaffolds for bone defect restoration and in particular for calvarial repair in case of trauma.

Repeated stimulation by LPS promotes the senescence of DPSCs via TLR4/MyD88-NF-κB-p53/p21 signaling

Dental pulp stem cells (DPSCs), one type of mesenchymal stem cells, are considered to be a type of tool cells for regenerative medicine and tissue engineering. Our previous studies found that the stimulation with lipopolysaccharide (LPS) might introduce senescence of DPSCs, and this senescence would have a positive correlation with the concentration of LPS. The β-galactosidase (SA-β-gal) staining was used to evaluate the senescence of DPSCs and immunofluorescence to show the morphology of DPSCs. Our findings suggested that the activity of SA-β-gal has increased after repeated stimulation with LPS and the morphology of DPSCs has changed with the stimulation with LPS. We also found that LPS bound to the Toll-like receptor 4 (TLR4)/myeloid differentiation factor (MyD) 88 signaling pathway. Protein and mRNA expression of TLR4, MyD88 were enhanced in DPSCs with LPS stimulation, resulting in the activation of nuclear factor-κB (NF-κB) signaling, which exhibited the expression of p65 improved in the nucleus while the decreasing of IκB-α. Simultaneously, the expression of p53 and p21, the downstream proteins of the NF-κB signaling, has increased. In summary, DPSCs tend to undergo senescence after repeated stimulation in an inflammatory microenvironment. Ultimately, these findings may lead to a new direction for cell-based therapy in oral diseases and other regenerative medicines.