China
Africa
Explore chapters and articles related to this topic
Selection of Human Hemopoietic Stem Cells
Published in Adrian P. Gee, BONE MARROW PROCESSING and PURGING, 2020
Peter M. Lansdorp, Terry E. Thomas
Blood-forming (hemopoietic) cells represent a continuum of differentiating cells that are often subdivided into three sequential compartments.1 In this model of hemopoiesis the vast majority of cells are in the terminally maturing or differentiation compartment. These cells have limited or no proliferative capacity, and are thought to be in transit towards their final destination as specialized end cells in the peripheral blood. Typically, these cells can be uniquely recognized as belonging to a particular differentiation lineage by their morphology. The immediate precursors of the cells of the differentiation compartment make up the progenitor cell compartment. The cells of this compartment represent only a few percent of all the cells in the hemopoietic tissues. Most are already restricted to differentiate along a single lineage, but may have quite extensive proliferative capacity (yielding 10 to 10,000 mature progeny). The cells of the progenitor cell compartment appear morphologically as blast cells, without specific features indicative of the hemopoietic lineage to which they are committed. Progenitor cells are not, however, a selfsustaining population, and are derived from cells of the stem cell compartment. Stem cells are thus operationally defined by their ability to self-renew as well as to generate daughter cells of any of the hemopoietic lineages.
A Biophysical View on the Function and Activity of Endotoxins
Published in Helmut Brade, Steven M. Opal, Stefanie N. Vogel, David C. Morrison, Endotoxin in Health and Disease, 2020
Ulrich Seydel, Andre Wiese, Andra B. Schromm, Klaus Brandenburg
Membranes, in general, constitute the boundary between a cell or a cell compartment and its environment. They are composed of (glyco)lipids and proteins, function as permeability barriers, maintain constant ion gradients across the membrane, and guarantee a controlled steady state of fluxes in the cell. Furthermore, the vast majority of cell membranes carry recognition sites for components of the immune system and for interaction/communication with other cells.
In Vivo Modulation of Lymphohemopoietic Stem Cell Populations with Cytokines
Published in Thomas F. Kresina, Immune Modulating Agents, 2020
Cytokines are obviously attractive candidates to be used in all of these settings. Several growth factors with assumed lineage-restricted potential are at present administered to patients, mainly to increase the recovery rate of peripheral blood cells. Several novel cytokines appear to have the potential to affect more primitive, undifferentiated hemopoietic cells. In this chapter data on the effects of these growth factors on the primitive cell compartments will be discussed. It is likely that the manipulation of pluripotent stem cells in vivo will be more complicated than that of mature blood cells. Before further substantial progress in this field can be realized, additional information is needed on the biological characteristics of several fundamental features of the stem cell compartment; discussion of some of these aspects follows.
Antioxidant Effects of Resveratrol in Intervertebral Disk
Published in Journal of Investigative Surgery, 2022
Yachong Huo, Dalong Yang, Kaitao Lai, Ji Tu, Yibo Zhu, Wenyuan Ding, Sidong Yang
Apoptosis is characterized by the changes on cell morphology, nuclear pyknosis, mounts of apoptotic factors and reduction of cell connections.17 Oxidative stress and mitochondrial dysfunction both play a vital role in NPCs apoptosis and the regulation of apoptosis might be more benefit on NPCs survival.18 Increasing in vitro evidences have shown that hydrogen peroxide (H2O2), one of the apoptosis inducers, can cause significant NPCs apoptosis via oxidative stress by reducing cellular viability.19,20 Meanwhile, H2O2 can induce mitochondrial dysfunction with excessive ROS production, thus causing oxidative damage.21,22 Oxidative stress is closely related to mitochondrial function.23 Mitochondria are the organelles in the cell compartment that supply the energy needed to run cells. However, the damage of mitochondrial function would cause severe metabolic disorders, eventually causing excessive ROS production.24 Evidence has shown that NPCs apoptosis can be induced by the over-production of ROS through the mitochondrial apoptosis pathway.25 Thus, mitochondria are the target organelles that ROS damages and the major organelles that generate ROS.26,27
Inulin-grown Faecalibacterium prausnitzii cross-feeds fructose to the human intestinal epithelium
Published in Gut Microbes, 2021
Raphael R. Fagundes, Arno R. Bourgonje, Ali Saeed, Arnau Vich Vila, Niels Plomp, Tjasso Blokzijl, Mehdi Sadaghian Sadabad, Julius Z. H. von Martels, Sander S. van Leeuwen, Rinse K. Weersma, Gerard Dijkstra, Hermie J. M. Harmsen, Klaas Nico Faber
Bacterial growth in the HoxBan tube was assessed by visual inspection of colony formation close to the coverslip with the Caco-2 cell monolayer (Figure 1d). Both in the absence and presence of Caco-2 cells, F. prausnitzii growth is enhanced (forming a rim of colonies, red arrows in Figure 1d) close to the interphase between the bottom anaerobic (bacterial) compartment and the upper oxygenated (human cell) compartment (black arrows in Figure 1d). This was observed for all fibers, as also observed earlier for glucose-grown F. prausnitzii in the HoxBan system.23 Importantly, the distance between the F. prausnitzii rim and the coverslip in the human cell compartment was smaller in all conditions in the presence of Caco-2 cells (red arrows in bottom panels Figure 1d) when compared to empty coverslips (red arrows in top panels Figure 1d). Thus, Caco-2 cells promote growth of fiber-fed F. prausnitzii closer to the epithelial oxygen-anaerobic interphase.
Design of experiment (DoE)-driven in vitro and in vivo uptake studies of exosomes for pancreatic cancer delivery enabled by copper-free click chemistry-based labelling
Published in Journal of Extracellular Vesicles, 2020
Lizhou Xu, Farid N. Faruqu, Revadee Liam-or, Omar Abu Abed, Danyang Li, Kerrie Venner, Rachel J Errington, Huw Summers, Julie Tzu-Wen Wang, Khuloud T. Al-Jamal
Culture supernatants of B16-F10, PANC-1 and HEK-293 cells were harvested after 1-week culture in CELLine AD1000 bioreactor flasks (WHEATON UK). Cells from 4 × T75 flasks (80% confluent) in 15 mL medium supplemented with 10% exosome-depleted FBS were seeded into the cell compartment of 1 bioreactor flask. The medium reservoir compartment of the flask was filled with 500 mL of the medium supplemented with 10% normal FBS. Culture supernatant or conditioned medium (CM) was harvested from the cell compartment of the flask on a weekly basis and replaced with 15 mL of fresh medium supplemented with 10% exosome-depleted FBS. To isolate exosomes, cell debris was firstly removed by centrifugation at 400 × g for 7 min and at 2,000 × g for 15 min at 4°C. The supernatant was filtered through a 0.22 µm filter (Millipore). Exosomes were then isolated by ultracentrifugation onto a sucrose cushion (25% w/w sucrose in D2O, density 1.18–1.20 g/mL) at 100,000 × g for 90 min at 4°C. Upon completion, the sucrose solution layer was collected, washed with PBS, and centrifuged at 100,000 × g for 90 min at 4°C. The final pellet containing exosomes was resuspended in 200 µL sterile PBS and aliquoted before storage at −80°C.