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.

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.

When dysphoria is not a primary mental state: A case report of the role of the aromatic L-aminoacid decarboxylase.

RATIONALE: The aromatic L-amino acid decarboxylase (AADC) deficiency (AADCD) is a rare, autosomal recessive neurometabolic disorder caused by a deficit of the AADC that is involved in serotonin and dopamine biosynthesis, causing as a consequence, their deficits, but also a lack of norepinephrine and epinephrine, given that dopamine is their precursor. PATIENT CONCERNS: We report the case of a Caucasian 43-year-old woman heterozygous for p.Ser250Phe in DDC, encoding for AADC with a positive family history for behavioral problems. DIAGNOSES: Since adolescence, she manifested behavioral abnormalities. Three months before the admission to our hospital, she presented with a permanent dystonic posture at the 4 limbs with numbness and tingling, diplopia, and low potassium levels. She was treated with muscle relaxants and potassium, but with no results. Olanzapine was administrated, worsening mood problems. Later, after fever, low potassium levels, and increased difficulty to move, she was admitted to the neurology unit where, after bradycardia alternating with atrial and ventricular fibrillation, she had loss of consciousness. She started to complain involuntary parossistic eye and head movements, bilateral ptosis, oculogyric crises with dystonia of the head, muscle hypotrophy, and absent deep tendon reflexes. During the hospital stay, she continued having episodes of untreatable bradycardia and fever. INTERVENTIONS: Hemocultures were performed, resulting positive for Enterococcus faecalis and Acinetobacter baumanii. Whole exome sequencing was performed evidencing that the patient harbored the heterozygous p.Ser250Phe variant in the gene DDC. OUTCOMES: A treatment with Pyridoxine and Pramipexole was prescribed, but never started because she died. LESSONS: The heterozygosity for p.Ser250Phe may have influenced the clinical manifestations, given that the patient presented some overlapping symptoms with those in AADCD, but while AADCD normally is diagnosed during childhood, the fact that the patient carried the mutation in heterozygosity may have alleviated and delayed the clinical manifestations.

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.

Biotherapeutic Effect of Gingival Stem Cells Conditioned Medium in Bone Tissue Restoration.

Bone tissue engineering is one of the main branches of regenerative medicine. In this field, the use of a scaffold, which supported bone development, in combination with mesenchymal stem cells (MSCs), has promised better outcomes for bone regeneration. In particular, human gingival mesenchymal stem cells (hGMSCs) may present advantages compared to other MSCs, including the easier isolation. However, MSCs' secretome has attracted much attention for its potential use in tissue regeneration, such as conditioned medium (CM) that contains different soluble factors proved to be useful for the regenerative purposes. In this study, we evaluated the osteogenic capacity of a poly-(lactide) (3D-PLA) scaffold enriched with hGMSCs and hGMSCs derived CM and its ability to regenerate bone defects in rat calvarias. 3D-PLA alone, 3D-PLA + CM or 3D-PLA + hGMSCs with/without CM were implanted in Wistar male rats subjected to calvarial defects. We observed that 3D-PLA scaffold enriched with hGMSCs and CM showed a better osteogenic capacity, being able to repair the calvarial defect as revealed in vivo by morphological evaluation. Moreover, transcriptomic analysis in vitro revealed the upregulation of genes involved in ossification and regulation of ossification in the 3D-PLA + CM + hGMSCs group. All of these results indicate the great osteogenic ability of 3D-PLA + CM + hGMSCs supporting its use in bone regenerative medicine, in particular in the repair of cranial bone defects. Especially, hGMSCs derived CM played a key role in the induction of the osteogenic process and in bone regeneration.

Transcriptomic analysis of gingival mesenchymal stem cells cultured on 3D bioprinted scaffold: A promising strategy for neuroregeneration.

The combined approach of mesenchymal stem cells (MSCs) and scaffolds has been proposed as a potential therapeutic tool for the treatment of neurodegenerative diseases. Indeed, even if MSCs can promote neuronal regeneration, replacing lost neurons or secreting neurotrophic factors, many limitations still exist for their application in regenerative medicine, including the low survival and differentiation rate. The scaffolds, by mimicking the endogenous microenvironment, have shown to promote cell survival, proliferation, and differentiation. In this work, gingival mesenchymal stem cells (GMSCs), isolated from healthy donors, were expanded in vitro, by culturing them adherent in plastic dishes (CTR-GMSCs) or on a poly(lactic acid) scaffold (SC-GMSCs). In order to evaluate the survival and the neurogenic differentiation potential, we performed a comparative transcriptomic analysis between CTR-GMSCs and SC-GMSCs by next generation sequencing. We found that SC-GMSCs showed an increased expression of neurogenic and prosurvival genes. In particular, genes involved in neurotrophin signaling and PI3K/Akt pathways were upregulated. On the contrary, proapoptotic and negative regulator of neuronal growth genes were downregulated. Moreover, nestin and GAP-43 protein levels increased in SC-GMSCs, confirming the neurogenic commitment of these cells. In conclusion, the scaffold, providing a trophic support for MSCs, may promote GMSCs differentiation toward a neuronal phenotype and survival. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 106A: 126-137, 2018.

Prolonged Expansion Induces Spontaneous Neural Progenitor Differentiation from Human Gingiva-Derived Mesenchymal Stem Cells.

Neural crest-derived mesenchymal stem cells (MSCs) obtained from dental tissues received considerable interest in regenerative medicine, particularly in nerve regeneration owing to their embryonic origin and ease of harvest. Proliferation efficacy and differentiation capacity into diverse cell lineages propose dental MSCs as an in vitro tool for disease modeling. In this study, we investigated the spontaneous differentiation efficiency of dental MSCs obtained from human gingiva tissue (hGMSCs) into neural progenitor cells after extended passaging. At passage 41, the morphology of hGMSCs changed from typical fibroblast-like shape into sphere-shaped cells with extending processes. Next-generation transcriptomics sequencing showed increased expression of neural progenitor markers such as NES, MEIS2, and MEST. In addition, de novo expression of neural precursor genes, such as NRN1, PHOX2B, VANGL2, and NTRK3, was noticed in passage 41. Immunocytochemistry results showed suppression of neurogenesis repressors TP53 and p21, whereas Western blot results revealed the expression of neurotrophic factors BDNF and NT3 at passage 41. Our results showed the spontaneous efficacy of hGMSCs to differentiate into neural precursor cells over prolonged passages and that these cells may assist in producing novel in vitro disease models that are associated with neural development.

Reprogramming of Oncogene Expression in Gingival Mesenchymal Stem Cells Following Long-Term Culture In Vitro.

Mesenchymal stem cells (MSCs) are a promising resource for stem cell therapy for the treatment of different neurodegenerative disorders. In particular, dental MSCs, given their origin from neural crest and their proneness toward neuronal differentiation, may be more suitable for transplantation. However, if MSCs can undergo spontaneous transformation and give rise to tumor is still debated. Data about transcriptional regulation of oncogenes in MSCs following in vitro expansion are not available. In this work, we compared gene expression levels of oncogenes in gingival-derived MSCs at passage number 10 and 41. We found that the expression of 22 oncogenes was abolished in gingival MSCs at passage number 41 compared to those at passage number 10, and this may indicate a greater safety of high number passage MSCs.

Gingival Stromal Cells as an In Vitro Model: Cannabidiol Modulates Genes Linked With Amyotrophic Lateral Sclerosis.

Research in recent years has extensively investigated the therapeutic efficacy of mesenchymal stromal cells in regenerative medicine for many neurodegenerative diseases at preclinical and clinical stages. However, the success rate of stem cell therapy remains less at translational phase. Lack of relevant animal models that potentially simulate the molecular etiology of human pathological symptoms might be a reason behind such poor clinical outcomes associated with stem cell therapy. Apparently, self-renewal and differentiation ability of mesenchymal stem cells may help to study the early developmental signaling pathways connected with the diseases, such as Alzheimer's disease, Amyotrophic lateral sclerosis (ALS), etc., at in vitro level. Cannabidiol, a non-psychotrophic cannabinoid, has been demonstrated as a potent anti-inflammatory and neuroprotective agent in neurological preclinical models. In the present study, we investigated the modulatory role of cannabidiol on genes associated with ALS using human gingiva-derived mesenchymal stromal cells (hGMSCs) as an in vitro model system. Next generation transcriptomic sequencing analysis demonstrated considerable modifications in the expression of genes connected with ALS pathology, oxidative stress, mitochondrial dysfunction, and excitotoxicity in hGMSCs treated with cannabidiol. Our results suggest the efficacy of cannabidiol to delineate the unknown molecular pathways, which may underlie ALS pathology at an early stage using hGMSCs as a compelling in vitro system. J. Cell. Biochem. 118: 819-828, 2017. © 2016 Wiley Periodicals, Inc.

Cannabidiol Activates Neuronal Precursor Genes in Human Gingival Mesenchymal Stromal Cells.

In the last years, mesenchymal stromal cells (MSCs) from oral tissues have received considerable interest in regenerative medicine since they can be obtained with minimal invasive procedure and exhibit immunomodulatory properties. This study was aimed to investigate whether in vitro pre-treatment of MSCs obtained from human gingiva (hGMSCs) with Cannabidiol (CBD), a cannabinoid component produced by the plant Cannabis sativa, may promote human gingiva derived MSCs to differentiate toward neuronal precursor cells. Specifically, we have treated the hGMSCs with CBD (5 µM) for 24 h in order to evaluate the expression of genes involved in cannabidiol signaling, cell proliferation, self-renewal and multipotency, and neural progenitor cells differentiation. Next generation sequencing (NGS) demonstrated that CBD activates genes associated with G protein coupled receptor signaling in hGMSCs. Genes involved in DNA replication, cell cycle, proliferation, and apoptosis were regulated. Moreover, genes associated with the biological process of neuronal progenitor cells (NCPs) proliferation, neuron differentiation, neurogenesis, and nervous system development were significantly modulated. From our results, we hypothesize that human gingiva-derived MSCs conditioned with CBD could represent a valid method for improving the hGMSCs phenotype and thus might be a potential therapeutic tool in the treatment of neurodegenerative diseases. J. Cell. Biochem. 118: 1531-1546, 2017. © 2016 Wiley Periodicals, Inc.

Cannabidiol Modulates the Expression of Alzheimer's Disease-Related Genes in Mesenchymal Stem Cells.

Mesenchymal stem cells (MSCs) have emerged as a promising tool for the treatment of several neurodegenerative disorders, including Alzheimer's disease (AD). The main neuropathological hallmarks of AD are senile plaques, composed of amyloid beta (Aß), and neurofibrillary tangles, formed by hyperphosphorylated tau. However, current therapies for AD have shown limited efficacy. In this study, we evaluated whether pre-treatment with cannabidiol (CBD), at 5 µM concentration, modulated the transcriptional profile of MSCs derived from gingiva (GMSCs) in order to improve their therapeutic potential, by performing a transcriptomic analysis by the next-generation sequencing (NGS) platform. By comparing the expression profiles between GMSCs treated with CBD (CBD-GMSCs) and control GMSCs (CTR-GMSCs), we found that CBD led to the downregulation of genes linked to AD, including genes coding for the kinases responsible of tau phosphorylation and for the secretases involved in Aß generation. In parallel, immunocytochemistry analysis has shown that CBD inhibited the expression of GSK3ß, a central player in AD pathogenesis, by promoting PI3K/Akt signalling. In order to understand through which receptor CBD exerted these effects, we have performed pre-treatments with receptor antagonists for the cannabinoid receptors (SR141716A and AM630) or for the vanilloid receptor 1 (TRPVI). Here, we have proved that TRPV1 was able to mediate the modulatory effect of CBD on the PI3K/Akt/GSK3ß axis. In conclusion, we have found that pre-treatment with CBD prevented the expression of proteins potentially involved in tau phosphorylation and Aß production in GMSCs. Therefore, we suggested that GMSCs preconditioned with CBD possess a molecular profile that might be more beneficial for the treatment of AD.

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

Human Gingival Mesenchymal Stem Cells (hGMSCs) are multipotential cells that can expand and differentiate in culture under specific and standardized conditions. In the present study, we have investigated whether in vitro pre-treatment of hGMSCs with Cannabidiol (CBD) can influence their expression profile, improving the therapeutic potential of this cell culture. Following CBD treatment (5 µM) for 24 h, gene expression analysis through Next Generation Sequencing (NGS) has revealed several genes differentially expressed between CBD-treated hGMSCs (CBD-hGMSCs) and control cells (CTR-hGMSCs) that were linked to inflammation and apoptosis. In particular, we have demonstrated that CBD treatment in hGMSCs prevented the activation of the NALP3-inflammasome pathway by suppressing the levels of NALP3, CASP1, and IL18, and in parallel, inhibited apoptosis, as demonstrated by the suppression of Bax. CBD treatment was also able to modulate the expression of the well-known mesenchymal stem cell markers (CD13, CD29, CD73, CD44, CD90, and CD166), and other surface antigens. Specifically, CBD led to the downregulation of genes codifying for antigens involved in the activation of the immune system (CD109, CD151, CD40, CD46, CD59, CD68, CD81, CD82, CD99), while it led to the upregulation of those implicated in the inhibition of the immune responses (CD47, CD55, CD276). In conclusion, the present study will provide a new simple and reproducible method for preconditioning hGMSCs with CBD, before transplantation, as an interesting strategy for improving the hGMSCs molecular phenotype, reducing the risk of immune or inflammatory reactions in the host, and in parallel, for increasing their survival and thus, their long-term therapeutic efficacy.