1,721,044 research outputs found
Effect of different growth factors on the chondrogenic potential of human bone marrow stromal cells
No full textA tissue engineering approach to bone repair in large animal models and in clinical practice.
No full textTransit Amplifying Cells (TACs): a still not fully understood cell population
Full text linkMaintenance of tissue homeostasis and tissue regeneration after an insult are essential functions of adult stem cells (SCs). In adult tissues, SCs proliferate at a very slow rate within “stem cell niches”, but, during tissue development and regeneration, before giving rise to differentiated cells, they give rise to multipotent and highly proliferative cells, known as transit-amplifying cells (TACs). Although differences exist in diverse tissues, TACs are not only a transitory phase from SCs to post-mitotic cells, but they also actively control proliferation and number of their ancestor SCs and proliferation and differentiation of their progeny toward tissue specific functional cells. Autocrine signals and negative and positive feedback and feedforward paracrine signals play a major role in these controls. In the present review we will consider the generation and the role played by TACs during development and regeneration of lining epithelia characterized by a high turnover including epidermis and hair follicles, ocular epithelial surfaces, and intestinal mucosa. A comparison between these different tissues will be made. There are some genes and molecular pathways whose expression and activation are common to most TACs regardless their tissue of origin. These include, among others, Wnt, Notch, Hedgehog and BMP pathways. However, the response to these molecular signals can vary in TACs of different tissues. Secondly, we will consider cultured cells derived from tissues of mesodermal origin and widely adopted for cell therapy treatments. These include mesenchymal stem cells and dedifferentiated chondrocytes. The possible correlation between cell dedifferentiation and reversion to a transit amplifying cell stage will be discussed
An early-stage 3D fibroblast-featured tumor model mimics the gene expression of the naïve tumor microenvironment, including genes involved in cancer progression and drug resistance
No full textIntroduction: The tumor microenvironment (TME) plays a crucial role in cancer progression, yet the interactions between tumor cells and stromal components, such as fibroblasts, remain poorly understood. Traditional two-dimensional (2D) culture models fail to accurately replicate the complexities of the TME, hindering progress in cancer research and drug development. Methods: This study presents a novel 3D spheroid model, generated using the hanging drop system, that incorporates both tumor cells (B16F10 mouse melanoma) and fibroblasts (NIH/3T3), and aimed at simulating the early-stage TME. Results: We demonstrate that fibroblasts are essential for ECM deposition, which is absent in spheroids composed only of tumor cells. Co-cultured spheroids exhibited a more organized structure, enhanced ECM deposition (type-VI collagen), and more closely resembled the morphology of native tumors compared to monocultures. RNA sequencing analysis revealed that the gene expression profile of B16F10–NIH/3T3 spheroids closely matched that of in vivo tumors, with 693 genes involved in critical pathways such as “pathways in cancer” and those linked to drug resistance. Discussion: These findings highlight the importance of fibroblast inclusion in 3D models to replicate the genetic and structural features of the TME. Our spheroid system provides a more accurate representation of early tumor stages and offers a promising platform for drug screening, reducing the need for in vivo models by allowing the selection of the most effective compounds for further testing. This work underscores the potential of 3D culture systems in advancing our understanding of tumor biology and improving the precision of cancer therapeutics
Platelet lysate favours in vitro expansion of human bone marrow stromal cells for bone and cartilage engineering.
No full textAllogeneic platelet-rich plasma affects monocyte differentiation to dendritic cells causing an anti-inflammatory microenvironment, putatively fostering wound healing
No full textAutologous platelet-rich plasma (PRP) is used clinically to induce repair of different tissues through the release of bioactive molecules. In some patients, the production of efficient autologous PRP is unfeasible due to their compromised health. Allogeneic PRP mismatched for AB0 and Rh antigens was developed. The effect of allogeneic PRP on immune response should be defined to use it in clinical practice avoiding side effects. Thus, whether PRP affects the differentiation of peripheral blood monocytes to dendritic cells upon stimulation with granulocyte monocyte colony stimulating factor and interleukin-4 was investigated. Indeed, these cells are the main players of immune response and tissue repair. PRP inhibited the differentiation of monocytes to CD1a+dendritic cells and favoured the expansion of phagocytic CD163+CD206+fibrocyte-like cells. These cells produced interleukin-10 and prostaglandin-E2, but not interferon-Î3, upon stimulation with lipopolysaccharides. Moreover, they promoted the expansion of regulatory CD4+CD25+FoxP3+T cells upon allostimulation or antigen specific priming. Finally, the conditioned medium harvested from monocytes differentiated with PRP triggered a strong chemotactic effect on mesenchymal cells in both scratch and transwell migration assays. These results strongly suggest that allogeneic PRP can foster the differentiation of monocytes to a regulatory anti-inflammatory population, possibly favouring wound healing. Copyright © 2016 John Wiley & Sons, Ltd
In Vitro and In Vivo Osteoinductive and Osteoconductive Properties of a Synthetic Bone Substitute.
No full text
- …
