Search results for "cell separation"
showing 10 items of 122 documents
Single mechano-gated channels activated by mechanical deformation of acutely isolated cardiac fibroblasts from rats
2010
Aim Mechanosensitive conductances were reported in cardiac fibroblasts, but the properties of single channels mediating their mechanosensitivity remain uncharacterized. The aim of this work was to investigate single mechano-gated channels (MGCs) activated by mechanical deformations of cardiac fibroblasts. Methods Currents through single MGCs and mechanosensitive whole-cell currents were recorded from isolated rat atrial fibroblasts using the cell-attached and whole-cell patch-clamp configurations respectively. Defined mechanical stress was applied via the patch pipette used for the whole-cell recordings. Results Under resting conditions occasional short openings of two types of single MGCs …
Neonatal Livers: A Source for the Isolation of Good-Performing Hepatocytes for Cell Transplantation
2014
Hepatocyte transplantation is an alternative therapy to orthotopic liver transplantation for the treatment of liver diseases. However, the supply of hepatocytes is limited given the shortage of organs available to isolate good-functioning quality cells. Neonatal livers may be a potential source alternative to adult livers to obtain good-performing hepatic cells for hepatocyte transplantation, which has not yet been explored profoundly. High-yield preparations of viable hepatocytes were isolated from 1- to 23-day-old liver donors, cryopreserved, and banked. Cell integrity and functional quality assessment were performed after thawing. Neonatal hepatocytes showed better postthawing recovery …
The gene of hepatocyte growth factor is expressed in fat-storing cells of rat liver and is downregulated during cell growth and by transforming growt…
1992
Hepatocyte growth factor (HGF) has been detected in non-parenchymal cells but not in hepatocytes. We performed Northern blot analysis of total RNA extracted from rat hepatocytes, Kupffer cells, endothelial cells and fat-storing (Ito-) cells. Total RNA was extracted from fat-storing cells at different times after isolation and from cells treated with different amounts of transforming growth factor beta. The RNA was hybridized with HGF, fibronectin-, and alpha-actin-specific cDNA probes, consecutively. We found an abundant amount of HGF mRNA in freshly isolated fat-storing cells, but not in other liver cells. The amount of the HGF transcripts decreases significantly in FSC during the time of …
Steatotic liver: a suitable source for the isolation of hepatic progenitor cells.
2011
Background: Alternative and/or complementary sources of cells such as hepatic progenitor cells (HPC) are under investigation for hepatic cell therapy purposes. Steatotic livers are those most commonly rejected for clinical transplantation and are also unsuitable for good quality hepatocyte isolation. Aim: Taken together these two facts, our aim was to investigate whether they could represent a suitable source for the isolation of progenitor cells. Methods: Rats fed for 7 weeks with methionine–choline deficient diets showing proved steatotic signs (i.e. increase in hepatic lipids; macrovesicular steatosis) and steatotic and normal human liver samples were used to study the expression of HPC …
Structural characterization and primary in vitro cell culture of locust male germline stem cells and their niche
2011
AbstractThe establishment of in vitro culture systems to expand stem cells and to elucidate the niche/stem cell interaction is among the most sought-after culture systems of our time. To further investigate niche/stem cell interactions, we evaluated in vitro cultures of isolated intact male germline–niche complexes (i.e., apical complexes), complexes with empty niche spaces, and completely empty niches (i.e., isolated apical cells) from the testes of Locusta migratoria and the interaction of these complexes with isolated germline stem cells, spermatogonia (of transit-amplifying stages), cyst progenitor cells, cyst progenitor cell-like cells, cyst cells, and follicle envelope cells. The stru…
Epigenetic Control of the foxp3 Locus in Regulatory T Cells
2007
Compelling evidence suggests that the transcription factor Foxp3 acts as a master switch governing the development and function of CD4+ regulatory T cells (Tregs). However, whether transcriptional control of Foxp3 expression itself contributes to the development of a stable Treg lineage has thus far not been investigated. We here identified an evolutionarily conserved region within the foxp3 locus upstream of exon-1 possessing transcriptional activity. Bisulphite sequencing and chromatin immunoprecipitation revealed complete demethylation of CpG motifs as well as histone modifications within the conserved region in ex vivo isolated Foxp3+CD25+CD4+ Tregs, but not in naïve CD25−CD4+ T cells. …
INTACT vs. FANS for Cell-Type-Specific Nuclei Sorting: A Comprehensive Qualitative and Quantitative Comparison
2021
Increasing numbers of studies seek to characterize the different cellular sub-populations present in mammalian tissues. The techniques “Isolation of Nuclei Tagged in Specific Cell Types” (INTACT) or “Fluorescence-Activated Nuclei Sorting” (FANS) are frequently used for isolating nuclei of specific cellular subtypes. These nuclei are then used for molecular characterization of the cellular sub-populations. Despite the increasing popularity of both techniques, little is known about their isolation efficiency, advantages, and disadvantages or downstream molecular effects. In our study, we compared the physical and molecular attributes of sfGFP+ nuclei isolated by the two methods—INTACT and FAN…
The Tick Salivary Protein Sialostatin L Inhibits the Th9-Derived Production of the Asthma-Promoting Cytokine IL-9 and Is Effective in the Prevention …
2012
Abstract Ticks developed a multitude of different immune evasion strategies to obtain a blood meal. Sialostatin L is an immunosuppressive cysteine protease inhibitor present in the saliva of the hard tick Ixodes scapularis. In this study, we demonstrate that sialostatin L strongly inhibits the production of IL-9 by Th9 cells. Because we could show recently that Th9-derived IL-9 is essentially involved in the induction of asthma symptoms, sialostatin L was used for the treatment of experimental asthma. Application of sialostatin L in a model of experimental asthma almost completely abrogated airway hyperresponsiveness and eosinophilia. Our data suggest that sialostatin L can prevent experime…
Specificity of H-2-linked Ir gene control in mice: recognition of the core structure A--L in defined sequence analogues of (T,G,)-A--L.
1979
For further characterization of the processes involved in Ir gene control, the specificity of antibodies and the cross-reaction on the level of helper T cells was studied for a series of polypeptide antigens related to poly-L(Tyr,Glu)-poly-DL-Ala–poly-LLys[(T,G)-A–L] but carrying more defined side chains. Helper cell specificity was assayed in an in vitro secondary anti-dinitrophenyl (DNP) response by cross-stimulation of primed T cells with the various polypeptide carriers. It was established that these polypeptides, although showing the same response pattern, were recognized as distinct entities in the immune response by B and T cells. If this common pattern is due to the effect of the sa…
Freshly isolated mouse 4F7+ splenic dendritic cells process and present exogenous antigens to T cells.
1994
The antibody 4F7 was reported to recognize an epitope expressed on dendritic cells (DC) from various tissues. To study the ability of splenic 4F7+ dendritic cells to process antigen for presentation to CD4+ T cells, DC were enriched using a separation procedure avoiding overnight culture which could lead to an altered phenotype. These DC were used as antigen-presenting cells (APC) in stimulation cultures of major histocompatibility complex class II-restricted T cells. It was found that they induce antigen-dependent lymphokine production by T cells and therefore could present exogenous antigens. These processing takes place intracellularly, because fixation abrogates presentation to T cells.…