Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), Huntington’s disease (HD), and transmissible spongiform encephalopathies (TSEs), share fundamental mechanisms of protein misfolding, synaptic dysfunction, and progressive neuronal loss. The cellular prion protein (PrPC), long viewed through the lens of prion biology, is now recognized as a pleiotropic modulator of neuronal physiology and a central interaction hub for amyloidogenic proteins. PrPC undergoes tightly regulated proteolytic processing (α-, β-, γ-cleavage, and ectodomain shedding), generating soluble fragments and peptides with distinct and sometimes opposing biological activities. These derivatives modulate neurotrophic signaling, oxidative stress responses, and the uptake/toxicity of Alzheimer’s disease-relevant soluble amyloid-β (Aβ), α‑synuclein, and tau. Recent work highlights PrPC as a ligand for low-density lipoprotein receptor‑related protein‑1 (LRP1) and the NMDA receptor (NMDAR), with shed PrPC and PrP‑derived peptides capable of initiating cell signaling and attenuating inflammatory responses, including when PrPC is delivered via extracellular vesicles. In parallel, ultrasensitive seed amplification assays (SAA; RT‑QuIC/PMCA) have transformed prion diagnostics and underscore the biomarker potential of both full-length PrPC and of its proteolytic fragments. Here, we synthesize current knowledge on PrPC structure–function relationships, proteolytic processing, and crosstalk with disease‑ associated protein aggregates. We also outline emerging translational opportunities, ranging from PrP‑derived peptide therapeutics to fluid-based biomarkers that track disease onset and progression.

BackgroundMesenchymal stem cells, particularly those derived from dental pulp cells (DPSCs), hold promising potential for neuro-regenerative therapies due to their multipotency and accessibility. Neural differentiation is closely linked to cellular metabolic reprogramming, yet the specific metabolic shifts alterations involved in DPSC neurogenesis remain underexplored.MethodsNeural commitment was induced by 14 days of differentiation with EGF and bFGF. Untargeted proton nuclear magnetic resonance (1H NMR) metabolomics was performed to investigate the metabolic alterations occurring during the neural commitment of human DPSCs cells.ResultsFollowing 14 days of differentiation with EGF and bFGF, DPSCs exhibited a marked decrease in mesenchymal markers (CD44, CD90, CD105) and an increase in neural markers (β3-tubulin, NFH), alongside morphological changes toward a neuron-like phenotype. Metabolomics analysis revealed changes in metabolite levels, including increased aspartic acid and phosphocholine and reduced alanine, glutamate, and myo-inositol. Exploratory lipid analyses, suggested increased fatty acid and triacylglycerol content together with a higher PUFA/MUFA ratio. Pathway enrichment analyses highlighted amino acid metabolism and phosphoinositide signaling as potentially relevant. Understanding these changes enhances our knowledge of stem cell differentiation and supports the therapeutic potential of DPSCs in neuro-regenerative medicine.ConclusionThese findings provide a descriptive metabolic characterization of DPSC neural commitment and identify candidate metabolite changes associated with early neural differentiation. While the results support the occurrence of metabolic remodelling during neural induction, further studies integrating functional and flux-based approaches are required to define the biological significance of these alterations.

The journal retracts the article, "The Small Molecule Ephrin Receptor Inhibitor, GLPG1790, Reduces Renewal Capabilities of Cancer Stem Cells, Showing Anti-Tumour Efficacy on Preclinical Glioblastoma Models" [...].

Mesenchymal Stromal/Stem Cells (MSCs) have attracted considerable attention in the field of regenerative medicine. Their unique properties make them suitable for various therapeutic applications. This article reviews accepted methods and guidelines for the isolation and characterization of MSCs from various sources. Common sources include bone marrow, adipose tissue, perinatal and umbilical cord tissue, dental pulp, etc. Naturally, the techniques used to isolate MSCs can vary depending on the source from which they are derived. However, several methods have been widely accepted by the scientific community. These include enzymatic digestion, density gradient centrifugation, the use of Percoll, adherence-based techniques and selective culture conditions. To characterize MSCs, basic criteria established by the International Society for Cell and Tissue Transplantation and the International Federation for Adipose Tissue are routinely used. These criteria include the ability of MSCs to adhere to plastic surfaces under standard culture conditions, the expression of specific membrane markers and their differentiation potential. Various techniques are used to assess these characteristics, including mixed lymphocyte reactions, flow cytometry and immunophenotyping profiles. These assessments aim to confirm the purity of the MSCs and validate their mesenchymal properties. In summary, the isolation and characterization of MSCs requires careful consideration of the different available methods. Each source presents unique challenges and advantages. By following established guidelines, researchers can ensure successful isolation and characterization of MSCs. This knowledge will ultimately improve their use in regenerative medicine.

The journal retracts the article, "The Brain Penetrating and Dual TORC1/TORC2 Inhibitor, RES529, Elicits Anti-Glioma Activity and Enhances the Therapeutic Effects of Anti-Angiogenetic Compounds in Preclinical Murine Models" [...].

[This corrects the article DOI: 10.3389/fonc.2022.943064.].

Two-dimensional cell cultures are crucial research tools, and they have been widely used, although they are not completely representative of biological processes in vivo due to the lack of tissue architecture and complexity. Recent advances in organoid technology have addressed these limitations and are revolutionizing the tools available for in vitro culture. Although there are no unified protocols for generating organoids, they can be obtained with various techniques, leading to cell aggregation by promoting cell adhesion. This work aims to generate and characterise organoid models of dental pulp from dental pulp stem cells (DPSCs), a type of mesenchymal stem/stromal cells known for their high regenerative potential and ease of accessibility, to establish a model for translational studies. The organoids were subjected to osteogenic differentiation conditions. Cell viability was evaluated using a CCK-8 assay, while osteogenic morphology and mineralization were confirmed by Alizarin red analysis, Raman microspectroscopy, and by immunofluorescence for the lineage markers expression. The Alizarin red analysis indicated a higher presence of calcium phosphate deposits in the differentiated organoids than in the control group (CTR). These results were confirmed by spectral profiles obtained using Raman microspectroscopy, which were attributable to a hydroxyapatite-based biomaterial. Immunofluorescence analysis also revealed increased expression of odonto/osteogenic markers (RUNX and OSX), alongside reduced expression of stemness markers. In conclusion, the organoids appeared to have successfully differentiated into an osteogenic lineage, forming a mineralized matrix containing hydroxyapatite and showing increased expression of relevant lineage markers.

DPSCs are a valuable resource for creating three-dimensional (3D) in vitro models, such as organoids, due to their accessibility and differentiation potential. Organoids have revolutionized in vitro culture, thanks to their ability to more faithfully replicate the architecture and complexity of tissues compared to 2D cultures. This enables their use in a wide range of applications, including research on genetic diseases, innovative therapies, and tissue engineering. This project aims to establish an in vitro protocol for generating 3D models from DPSCs to study dental diseases and test new drugs for regenerative medicine and tissue reconstruction. To this end, the organoids underwent morphological, viability, and functional analyses, allowing us to evaluate the effectiveness of the protocol and the validity of the model. The protocol includes the culture of DPSCs in Matrigel® Matrix, an extracellular matrix that supports 3D-fabricated organoids formation and growth. These 3D structures are exposed to differentiation factors to generate dental pulp organoids. However, the presence of Matrigel® Matrix may interfere with subsequent molecular analyses. To overcome this limitation, an efficient method for removing the Matrigel® Matrix was developed to allow efficient extraction of nucleic acids and proteins. Immunohistochemical and immunofluorescence techniques were also optimized to visualize cellular structures and markers. Cell count and proliferation were assessed using a CCK-8 viability assay, as well as Trypan Blue staining. The feasibility and effectiveness of this protocol can provide a new tool for studying dental pulp biology, paving the way for future applications in the field of dental pulp regeneration research.

In the original publication [...].

Intercellular mitochondrial transfer (MT) is a newly discovered form of cell-to-cell signalling involving the active incorporation of healthy mitochondria into stressed/injured recipient cells, contributing to the restoration of bioenergetic profile and cell viability, reduction of inflammatory processes and normalisation of calcium dynamics. Recent evidence has shown that MT can occur through multiple cellular structures and mechanisms: tunneling nanotubes (TNTs), via gap junctions (GJs), mediated by extracellular vesicles (EVs) and other mechanisms (cell fusion, mitochondrial extrusion and migrasome-mediated mitocytosis) and in different contexts, such as under physiological (tissue homeostasis and stemness maintenance) and pathological conditions (hypoxia, inflammation and cancer). As Mesenchimal Stromal/ Stem Cells (MSC)-mediated MT has emerged as a critical regulatory and restorative mechanism for cell and tissue regeneration and damage repair in recent years, its potential in stem cell therapy has received increasing attention. In particular, the potential therapeutic role of MSCs has been reported in several articles, suggesting that MSCs can enhance tissue repair after injury via MT and membrane vesicle release. For these reasons, in this review, we will discuss the different mechanisms of MSCs-mediated MT and therapeutic effects on different diseases such as neuronal, ischaemic, vascular and pulmonary diseases. Therefore, understanding the molecular and cellular mechanisms of MT and demonstrating its efficacy could be an important milestone that lays the foundation for future clinical trials.

Mesenchymal stem cells (MSCs) have garnered significant interest in the field of regenerative medicine for their ability to potentially treat various diseases, especially neurodegenerative disorders [...]

Purpose Age-related macular degeneration (AMD) is the leading cause of blindness in the elderly. To date, there are no effective therapies to counteract AMD towards the most severe stages characterised by a progressive loss of photoreceptors triggered by retinal pigmented epithelium dysfunction. Given their easy source and their high proliferative potential, Dental Pulp Stem Cells (DPSCs) are considered promising for regenerative medicine. The main advantage of DPSCs is related to their paracrine immunosuppressive and immunoregulatory abilities, including the capability to promote regeneration of damaged tissues. Recent studies demonstrated the therapeutic potential of DPSCs-conditioned media (CM) in neurodegenerative diseases. In addition, we have already shown a differential expression of some growth factors and cytokines in CM derived from DPSCs cultured in hypoxia and normoxia conditions. Aim In this study we evaluated the capability of DPSCs-CM to counteract retinal degeneration in an animal model of AMD. DPSCs-CM were intravitreally injected the day before the exposure of albino rats to high intensity light (LD). Results We evaluated the retinal function, and we performed morphological and molecular analysis a week after the LD, in accordance with the well-established protocol of our light damage model. DPSCs-CM obtained from hypoxia (HYPO-CM) or normoxia (NORM-CM), were able to preserve the retinal function, to reduce the damaged area and to counteract the upregulation of key factors involved in retinal degeneration, like FGF-2. Furthermore, we demonstrated that neither conditioned media modified inflammatory activation, as shown by both microglia activation and GFAP upregulation, but in vitro studies demonstrated a significant effect of both CM to counteract oxidative stress, one of the main causes of AMD. Conclusion Taken together, our study demonstrated that NORM-CM and HYPO-CM, albeit with a different chemical composition, could represent eligible candidates to counteract retinal degeneration in an animal model of AMD. Further studies are needed to obtain conditioned media with the best performance in term of retinal protection.

Mesenchymal stromal cells (MSCs) are non-specialized adult stem cells (ASCs), cells that reproduce to provide specific cytotypes [...].

Cell outer membranes contain glycosphingolipids and protein receptors, which are integrated into glycoprotein domains, known as lipid rafts, which are involved in a variety of cellular processes, including receptor-mediated signal transduction and cellular differentiation process. In this study, we analyzed the lipidic composition of human Dental Pulp-Derived Stem Cells (DPSCs), and the role of lipid rafts during the multilineage differentiation process. The relative quantification of lipid metabolites in the organic fraction of DPSCs, performed by Nuclear Magnetic Resonance (NMR) spectroscopy, showed that mono-unsaturated fatty acids (MUFAs) were the most representative species in the total pool of acyl chains, compared to polyunsatured fatty acids (PUFAs). In addition, the stimulation of DPSCs with different culture media induces a multilineage differentiation process, determining changes in the gangliosides pattern. To understand the functional role of lipid rafts during multilineage differentiation, DPSCs were pretreated with a typical lipid raft affecting agent (MβCD). Subsequently, DPSCs were inducted to differentiate into osteoblast, chondroblast and adipoblast cells with specific media. We observed that raft-affecting agent MβCD prevented AKT activation and the expression of lineage-specific mRNA such as OSX, PPARγ2, and SOX9 during multilineage differentiation. Moreover, this compound significantly prevented the tri-lineage differentiation induced by specific stimuli, indicating that lipid raft integrity is essential for DPSCs differentiation. These results suggest that lipid rafts alteration may affect the signaling pathway activated, preventing multilineage differentiation.

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

The TAR-DNA binding protein (TDP43) is a nuclear protein whose cytoplasmic inclusions are hallmarks of Amyotrophic Lateral Sclerosis (ALS). Acute stress in cells causes TDP43 mobilization to the cytoplasm and its aggregation through different routes. Although acute stress elicits a strong phenotype, is far from recapitulating the years-long aggregation process. We applied different chronic stress protocols and described TDP43 aggregation in a human neuroblastoma cell line by combining solubility assays, thioflavin-based microscopy and flow cytometry. This approach allowed us to detect, for the first time to our knowledge in vitro, the formation of 25 kDa C-terminal fragment of TDP43, a pathogenic hallmark of ALS. Our results indicate that chronic stress, compared to the more common acute stress paradigm, better recapitulates the cell biology of TDP43 proteinopathies. Moreover, we optimized a protocol for the detection of bona fide prions in living cells, suggesting that TDP43 may form amyloids as a stress response.

Mesenchymal stem cells (MSCs) are well known for their beneficial effects, differentiation capacity and regenerative potential. Dental-derived MSCs (DSCs) are more easily accessible and have a non-invasive isolation method rather than MSCs isolated from other sources (umbilical cord, bone marrow, and adipose tissue). In addition, DSCs appear to have a relevant neuro-regenerative potential due to their neural crest origin. However, it is now known that the beneficial effects of MSCs depend, at least in part, on their secretome, referring to all the bioactive molecules (neurotrophic factors) released in the conditioned medium (CM) or in the extracellular vesicles (EVs) in particular exosomes (Exos). In this review, we described the similarities and differences between various DSCs. Our focus was on the secretome of DSCs and their applications in cell therapy for neurological disorders. For neuro-regenerative purposes, the secretome of different DSCs has been tested. Among these, the secretome of dental pulp stem cells and stem cells from human exfoliated deciduous teeth have been the most widely studied. Both CM and Exos obtained from DSCs have been shown to promote neurite outgrowth and neuroprotective effects as well as their combination with scaffold materials (to improve their functional integration in the tissue). For these reasons, the secretome obtained from DSCs in combination with scaffold materials may represent a promising tissue engineering approach for neuroprotective and neuro-regenerative treatments.

Indoor air quality has become a topic of great concern. Burning incense has recently been identified as one of the primary sources of volatile organic compounds, specifically benzene, in an indoor setting. The current paper aims to evaluate volatile organic compound (VOC) emissions, particularly benzene, within indoor environments through the utilization of an experimental clean room. Experimental findings showed that 10 types of incense sticks emitted benzene in concentrations between 11.1 and 66.5 μg m−3, which were 2.5 lower than the limit suggested for non-occupation indoor exposure (160 μg m−3), identified by the American Association of Industrial Hygienists (ACGIH). Furthermore, a correlation between the dimensions (diameter and length) of the combustible parts in an incense stick was investigated and indicated a slight influence on the release of benzene. Taking into consideration the substantial influence benzene has on human health, coupled with a lack of precise legislation regarding indoor air quality in residential settings, this research serves as an initial investigation into the noteworthy effects of burning incense in private and public indoor settings.

BACKGROUND:Heparanase (HPSE) is an endo-β-glucuronidase that cleaves heparan sulfate side chains, leading to the disassembly of the extracellular matrix, facilitating cell invasion and metastasis dissemination. In this research, we investigated the role of a new HPSE inhibitor, RDS 3337, in the regulation of the autophagic process and the balance between apoptosis and autophagy in U87 glioblastoma cells.METHODS:After treatment with RDS 3337, cell lysates were analyzed for autophagy and apoptosis-related proteins by Western blot.RESULTS:We observed, firstly, that LC3II expression increased in U87 cells incubated with RDS 3337, together with a significant increase of p62/SQSTM1 levels, indicating that RDS 3337 could act through the inhibition of autophagic-lysosomal flux of LC3-II, thereby leading to accumulation of lipidated LC3-II form. Conversely, the suppression of autophagic flux could activate apoptosis mechanisms, as revealed by the activation of caspase 3, the increased level of cleaved Parp1, and DNA fragmentation.CONCLUSIONS:These findings support the notion that HPSE promotes autophagy, providing evidence that RDS 3337 blocks autophagic flux. It indicates a role for HPSE inhibitors in the balance between apoptosis and autophagy in U87 human glioblastoma cells, suggesting a potential role for this new class of compounds in the control of tumor growth progression.

Despite decades of research, no therapies are available to halt or slow down the course of neuro-degenerative disorders. Most of the drugs developed to fight neurodegeneration are aimed to alleviate symptoms, but none has proven adequate in altering the course of the pathologies. Cell therapy has emerged as an intriguing alternative to the classical pharmacological approach. Cell therapy consists of the transplantation of stem cells that can be obtained from various embryonal and adult tissues. Whereas the former holds notable ethical issue, adult somatic stem cells can be obtained without major concerns. However, most adult stem cells, such as those derived from the bone marrow, are committed toward the mesodermal lineage, and hence need to be reprogrammed to induce the differentiation into the neurons. The discovery of neural crest stem cells in the dental pulp, both in adults' molar and in baby teeth (dental pulp stem cells and stem cells from human exfoliated deciduous teeth, respectively) prompted researchers to investigate their utility as therapy in nervous system disorders. In this review, we recapitulate the advancements on the application of these stem cells in preclinical models of neurodegenerative diseases, highlighting differences and analogies in their maintenance, differentiation, and potential clinical application.