1,720,979 research outputs found
Potenziali applicazioni delle DPSC nella medicina rigenerativa: capacità di differenziamento e supporto nel processo di angiogenesi
No full textDental pulp has been revealed as an accessible and rich source of mesenchymal stem cells (MSCs), and its biological potential is currently under intense investigation. MSCs from dental pulp stem/stromal cells (DPSCs) have been indicated as a heterogeneous population, originating from the neural crest, and physiologically involved in dentin homeostasis; moreover, they contribute to bone remodeling and differentiation into several tissues including cartilage, bone, adipose, hepatic, and nervous tissues. DPSCs have also been shown to influence the angiogenesis process, for example through the release of secretory factors or by differentiating into vascular and/or perivascular cells. This multifaceted nature underscores the potential therapeutic applications of DPSCs across various fields, ranging from tissue regeneration to vascular pathology.
Based on this information, the primary goal of this study was to investigate the capacity of DPSCs to differentiate into various cell types, including osteo-odontogenic, hepatic, neurogenic, and perivascular phenotypes. This investigation utilized both traditional two-dimensional (2D) and advanced three-dimensional (3D) culture methods. The ultimate aim of this research is to showcase the potential versatility of DPSCs for future applications in regenerative medicine research.
For the experiments, DPSCs were subjected to various treatments (osteo-odontogenic and hepatic differentiation media, hypoxia at 1%, and MACS separation). At the same time, a stationary technique was employed to generate organoids.
The results revealed a significant ability of DPSCs to differentiate into the osteo-odontogenic phenotype. Notably, these cells exhibited high expression levels of genes characteristic of osteo-odontoblasts and produced a matrix containing dentin and calcium phosphates, both in 2D and 3D environments.
DPSCs possess the capacity to differentiate in neuronal cells by specific media. Additionally, they can be influenced by the environment to differentiate into specific neuronal cells of the nervous system, such as under hypoxic conditions. In light of this, DPSCs were exposed to hypoxia (1% O2) for 5 and 16 days, revealing that hypoxia-induced DPSCs differentiation was time-dependent. Moreover, conditioned media (CM) derived from DPSCs stimulated by hypoxia had the ability to induce neural differentiation in both SH-SY5Y neuroblastoma cells and undifferentiated DPSCs. This suggests that the differentiation of DPSCs mediated by hypoxia is likely to occur through an autocrine/paracrine mechanism.
To investigate the potential to differentiate into the peri-vascular cells were subjected to immunomagnetic separation (MACS) targeting the pericytic marker NG2, resulting in the isolation of three subpopulations of interest (Total, NG2-, and NG2+ DPSCs). The data showed that NG2+ DPSCs, displaying a pericyte-like phenotype, were able to stabilize tubules in vitro for 14 days by directly interacting with endothelial cells. This suggests that DPSCs have the capability to differentiate into different cell types, making them a valuable resource for regenerative medicine. Their potential offers hope for the treatment of various medical conditions
Hypoxia Induces DPSC Differentiation versus a Neurogenic Phenotype by the Paracrine Mechanism
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Regenerative Potential of DPSCs and Revascularization: Direct, Paracrine or Autocrine Effect?
Full text linkA new source of mesenchymal stem cells has recently been discovered, the so-called dental pulp derived stem cells (DPSCs) which therefore could represent potentially tools for regenerative medicine. DPSC originate from the neural crest and are physiologically involved in dentin homeostasis; moreover, they contribute to bone remodeling and differentiation into several tissues including cartilage, bone, adipose and nervous tissues. DPSCs have also been shown to influence the angiogenesis process, for example through the release of secretory factors or by differentiating into vascular and/or perivascular cells. Angiogenesis, that has a pivotal role in tissue regeneration and repair, is defined as the formation of new vessels from preexisting vessels and is mediated by mutual and reciprocal interactions between endothelial cells and perivascular cells. It is also known that co-cultures of perivascular and endothelial cells (ECs) can form a vascular network in vitro and also in vivo. Since DPSCs seem to have characteristics similar to pericytes, understanding the possible mechanism of interaction between DPSCs and ECs during neo-angiogenesis is dramatically important for the development of advanced clinical application in the field of regeneration
Methylglyoxal-Dependent Glycative Stress Is Prevented by the Natural Antioxidant Oleuropein in Human Dental Pulp Stem Cells through Nrf2/Glo1 Pathway
Full text linkMethylglyoxal (MG) is a potent precursor of glycative stress (abnormal accumulation of advanced glycation end products, AGEs), a relevant condition underpinning the etiology of several diseases, including those of the oral cave. At present, synthetic agents able to trap MG are known; however, they have never been approved for clinical use because of their severe side effects. Hence, the search of bioactive natural scavengers remains a sector of strong research interest. Here, we investigated whether and how oleuropein (OP), the major bioactive component of olive leaf, was able to prevent MG-dependent glycative stress in human dental pulp stem cells (DPSCs). The cells were exposed to OP at 50 µM for 24 h prior to the administration of MG at 300 µM for additional 24 h. We found that OP prevented MG-induced glycative stress and DPSCs impairment by restoring the activity of Glyoxalase 1 (Glo1), the major detoxifying enzyme of MG, in a mechanism involving the redox-sensitive transcription factor Nrf2. Our results suggest that OP holds great promise for the development of preventive strategies for MG-derived AGEs-associated oral diseases and open new paths in research concerning additional studies on the protective potential of this secoiridoid
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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