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Tissue Explants (tissue + explant)
Selected AbstractsGlucose-induced release of tumour necrosis factor-alpha from human placental and adipose tissues in gestational diabetes mellitusDIABETIC MEDICINE, Issue 11 2001M. T. Coughlan Abstract Aims, The cytokine tumour necrosis factor-alpha (TNF-,) has been implicated in the pathogenesis of insulin resistance in Type 2 diabetes mellitus, but limited data are available in relation to gestational diabetes mellitus (GDM), a disease in which similar biochemical abnormalities exist. We investigated the effect of exogenous glucose on the release of TNF-, from placental and adipose (omental and subcutaneous) tissue obtained from normal pregnant women, and women with GDM. Methods, Human tissue explants were incubated for up to 24 h and TNF-, concentration in the incubation medium quantified by ELISA. The effect of normal (5 mmol/l) and high (15 and 25 mmol/l) glucose concentrations on the release of TNF-, was assessed. Results, In placental and subcutaneous adipose tissues obtained from women with GDM (n = 6), TNF-, release was significantly greater under conditions of high glucose compared with normal glucose (placenta, 25 mmol/l 5915.7 ± 2579.6 and 15 mmol/l 4547.1 ± 2039.1 vs. 5 mmol/l 1897.1 ± 545.5; subcutaneous adipose tissue, 25 mmol/l 423.5 ± 207.0 and 15 mmol/l 278.5 ± 138.7 vs. 5 mmol/l 65.3 ± 28.5 pg/mg protein; P < 0.05). In contrast, there was no stimulatory effect of high glucose on TNF-, release by tissues obtained from normal pregnant women (n = 6) (placenta, 25 mmol/l 1542.1 ± 486.2 and 15 mmol/l 4263.3 ± 2737.7 vs. 5 mmol/l 5422.4 ± 1599.0; subcutaneous adipose tissue, 25 mmol/l 189.8 ± 120.4 and 15 mmol/l 124.5 ± 32.3 vs. 5 mmol/l 217.9 ± 103.5 pg/mg protein). Conclusions, These observations suggest that tissues from patients with GDM release greater amounts of TNF-, in response to high glucose. As TNF-, has been previously implicated in the regulation of glucose and lipid metabolism, and of insulin resistance, these data are consistent with the hypothesis that TNF-, may be involved in the pathogenesis and/or progression of GDM. Diabet. Med. 18, 921,927 (2001) [source] Transgenic mice expressing a dual, CRE-inducible reporter for the analysis of axon guidance and synaptogenesis,GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 6 2007Aurora Badaloni Abstract Improved and modular tools are needed for the neuroanatomical dissection of CNS axonal tracts, and to study the cell-intrinsic and cell-extrinsic cues that govern their assembly and plasticity. Here we describe a general purpose transgenic tracer that can be used to visualize axonal tracts and synaptic terminals in any region of the embryonic neural tube or postnatal CNS, on any wild type or mutant genetic background. The construct permits CRE-inducible expression of a dicistronic axonal marker encoding two surface reporter proteins: a farnesylated GFP and the human Placental Alkaline Phosphatase (PLAP). Both proteins localize alongside the neuronal surface, permitting the concomitant detection of cell body, neurites, and presynaptic and postsynaptic sites in the same neuron. This provides a CRE-inducible dual system for imaging neural circuits in vivo, and to study their assembly and remodeling in cultured neurons, neural stem cells, and tissue explants derived from the reporter line. Unlike existing lines, this reporter does not encode a ubiquitously expressed, floxable LacZ gene, permitting the simultaneous analysis of beta galactosidase activity in mutant lines. genesis 45:405,412, 2007. © 2007 Wiley-Liss, Inc. [source] Increased hepatotoxicity of tumor necrosis factor,related apoptosis-inducing ligand in diseased human liver,HEPATOLOGY, Issue 5 2007Xandra Volkmann Tumor necrosis factor,related apoptosis-inducing ligand (TRAIL) induces apoptosis in tumor cells but not in most normal cells and has therefore been proposed as a promising antitumor agent. Recent experiments suggested that isolated primary human hepatocytes but not monkey liver cells are susceptible to certain TRAIL agonists, raising concerns about the use of TRAIL in cancer treatment. Whether TRAIL indeed exerts hepatotoxicity in vivo and how this is influenced by chemotherapeutic drugs or liver disease are completely unknown. Employing different forms of recombinant TRAIL, we found that the cytokine can induce proapoptotic caspase activity in isolated human hepatocytes. However in marked contrast, these different TRAIL preparations induced little or no cytotoxicity when incubated with tissue explants of fresh healthy liver, an experimental model that may more faithfully mimic the in vivo situation. In healthy liver, TRAIL induced apoptosis only when combined with histone deacetylase inhibitors. Strikingly, however, TRAIL alone triggered massive apoptosis accompanied by caspase activation in tissue explants from patients with liver steatosis or hepatitis C viral infection. This enhanced sensitivity of diseased liver was associated with an increased expression of TRAIL receptors and up-regulation of proapoptotic Bcl-2 proteins. Conclusion: These results suggest that clinical trials should be performed with great caution when TRAIL is combined with chemotherapy or administered to patients with inflammatory liver diseases. (HEPATOLOGY 2007.) [source] Localization of substance P-induced upregulated interleukin-8 expression in human dental pulp explantsINTERNATIONAL ENDODONTIC JOURNAL, Issue 2 2008G. T.-J. Abstract Aim, To localize ex vivo expression of interleukin-8 (IL-8) induced by substance P (SP) in human dental pulps. Methodology, Intact caries-free, freshly extracted third molars (n = 20) were collected from patients (15,25 years old). The teeth were split and pulpal tissue was obtained and stored in Dulbecco's modified Eagle medium. Human dental pulp tissue explants were stimulated with SP. Expression of IL-8 in pulp explants was detected and localized by immunohistochemistry. Results, Moderated IL-8 immunoreactivities were detected mainly in the cell-rich zone in pulp tissues 12 h after tumour necrosis factor alpha (TNF-,) stimulation (positive controls), whereas only weak IL-8 expression was observed in tissues stimulated with SP at the same time interval. These data did not differ from those in negative controls. Increased IL-8 expression in pulp explants after 24 h of SP stimulation was noted compared with negative controls and located in fibroblast-like cells, blood vessel-associated cells and extracellular matrix in the central zone and cell-rich zone of pulp explants. Tissues stimulated with TNF-, for 24 h (positive controls) revealed weak IL-8 immunoreactivities with altered cell morphology. Conclusions, Substance P induces IL-8 expression and was located in fibroblast-like pulp cells, blood vessel-associated cells and extracellular matrix of human dental explants. These data support the hypothesis that neuropeptide (SP) coordinates the modulation of pulpal inflammation via up-regulating chemokine IL-8. [source] A preliminary in vitro study into the use of IL-1Ra gene therapy for the inhibition of intervertebral disc degenerationINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 1 2006Christine L. Le Maitre Summary Conventional therapies for low back pain (LBP) are purely symptomatic and do not target the cause of LBP, which in approximately 40% of cases is caused by degeneration of the intervertebral disc (DIVD). Targeting therapies to inhibit the process of degeneration would be a potentially valuable treatment for LBP. There is increasing evidence for a role for IL-1 in DIVD. A natural inhibitor of IL-1 exists, IL-1Ra, which would be an ideal molecular target for inhibiting IL-1-mediated effects involved in DIVD and LBP. In this study, the feasibility of ex vivo gene transfer of IL-1Ra to the IVD was investigated. Monolayer and alginate cultures of normal and degenerate human intervertebral disc (IVD) cells were infected with an adenoviral vector carrying the IL-1Ra gene (Ad-IL-1Ra) and protein production measured using an enzyme-linked immunosorbent assay. The ability of these infected cells to inhibit the effects of IL-1 was also investigated. In addition, normal and degenerate IVD cells infected with Ad-IL-1Ra were injected into degenerate disc tissue explants and IL-1Ra production in these discs was assessed. This demonstrated that both nucleus pulposus and annulus fibrosus cells infected with Ad-IL-1Ra produced elevated levels of IL-1Ra for prolonged time periods, and these infected cells were resistant to IL-1. When the infected cells were injected into disc explants, IL-1Ra protein expression was increased which was maintained for 2 weeks of investigation. This in vitro study has shown that the use of ex vivo gene transfer to degenerate disc tissue is a feasible therapy for the inhibition of IL-1-mediated events during disc degeneration. [source] Secretion of RANTES (CCL5) and interleukin-10 from mesenteric adipose tissue and from creeping fat in Crohn's disease: Regulation by steroid treatmentJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 9 2006Andreas Schäffler Abstract Background:, Creeping fat represents a characteristic feature of Crohn's disease (CD) and adipose tissue is currently being recognized as a complex compartment secreting highly active molecules. Pro- or anti-inflammatory adipose tissue-derived secretory products (adipocytokines) might play a role in the pathogenesis of CD. Methods:, Adipose tissue specimens were obtained from creeping fat contiguous to the involved intestine of 10 patients with CD. Mesenteric adipose tissue specimens resected in 13 patients with colon cancer (CC) and in seven patients with diverticulitis (DIV) served as controls. Three fat tissue specimens per well and n = 6,8 wells per patient were incubated ex vivo for 24 h. The release of regulated on activation, T-cell expressed and secreted (RANTES) and interleukin (IL)-10 into the supernatant was measured by ELISA. Results:, Both RANTES and IL-10 secretion could be demonstrated from total adipose tissue explants. The RANTES secretion is increased from creeping fat in CD (3691 ± 597 pg/g fat per 24 h) when compared to mesenteric adipose tissue from patients with CC (1690 ± 191 pg/g fat per 24 h; P < 0.0001) or DIV (1672 ± 336 pg/g fat per 24 h; P < 0.0001). In contrast, IL-10 secretion is downregulated significantly only in patients with DIV (1418 ± 180 pg/g fat per 24 h; P = 0.016) when compared to CC patients (2368 ± 259 pg/g fat per 24 h). Crohn's disease patients receiving steroids had a higher secretion rate of RANTES and IL-10. Conclusions:, Both RANTES and IL-10 secretion can be detected from mesenteric adipose tissue and from creeping fat. The elevated RANTES and IL-10 secretion from creeping fat in CD is not due to a CD-specific effect but caused by steroid treatment. [source] Selective elimination of synovial inflammatory macrophages in rheumatoid arthritis by an Fc, receptor I,directed immunotoxinARTHRITIS & RHEUMATISM, Issue 5 2003Joel A. G. Van Roon Objective To determine whether monocyte/macrophages from rheumatoid arthritis (RA) patients can be selectively eliminated by a toxin-conjugated antibody CD64,ricin A (CD64-RiA) directed toward the high-affinity receptor for IgG (Fc,RI), exploiting the capacity of Fc,RI to efficiently endocytose antibody which it has bound. Methods Mononuclear cells from peripheral blood (PB) and synovial fluid (SF) obtained from RA patients were cultured in the presence of CD64-RiA. Cell death of monocyte/macrophages was measured by phenotypic changes (light-scatter patterns and CD14 and Fc,RI expression) and apoptosis (nuclear DNA fragmentation). We then tested whether CD64-RiA,induced cell death of macrophages affected their capacity to stimulate antigen-induced lymphocyte proliferation and to secrete cytokines. Additionally, the capacity of CD64-RiA to inhibit proinflammatory activity and cartilage degradation by RA synovial tissue explants was evaluated. Results Inflammatory macrophages from RA SF expressed elevated levels of Fc,RI and were selectively eliminated by CD64-RiA via apoptotic cell death. Monocyte/macrophages from RA PB, which had lower levels of Fc,RI expression, were much less affected. Induction of SF macrophage apoptosis was associated with efficient inhibition of antigen-induced lymphocyte proliferation and a reduction in tumor necrosis factor , (TNF,) release. Consistent with these effects on SF macrophages, CD64-RiA also inhibited TNF, production, interleukin-1, production, and cartilage-degrading activity of RA synovial tissue explants. Conclusion Together, these data underscore the crucial role of synovial macrophages in RA joint inflammation and indicate that selective elimination of these cells through Fc,RI-directed immunotoxins could be a novel approach to the treatment of RA. [source] Hypoxia-induced production of stromal cell,derived factor 1 (CXCL12) and vascular endothelial growth factor by synovial fibroblastsARTHRITIS & RHEUMATISM, Issue 10 2002Carol Hitchon Objective Stromal cell,derived factor 1 (SDF-1; or, CXCL12) is a potent chemotactic and angiogenic factor that has been proposed to play a role in the recruitment of lymphocytes into rheumatoid arthritis (RA) synovium. We tested the hypothesis that synovial SDF-1 expression is regulated by cytokine and hypoxic stimulation, the latter being mediated by hypoxia-inducible factor 1, (HIF-1,). These factors regulate the expression of vascular endothelial growth factor (VEGF), itself an important angiogenic mediator. Methods RA and osteoarthritic synovial fibroblasts and whole tissue explants were cultured under normoxic or hypoxic (1% O2) conditions for up to 72 hours in the presence or absence of interleukin-1, (IL-1,), tumor necrosis factor (TNF), or transforming growth factor , (TGF,). Expression of HIF-1,, VEGF, and SDF-1 was detected in synovial tissue and cells by immunohistochemistry and Western blotting. VEGF and SDF-1 expression by cultured synovial fibroblasts was evaluated by reverse transcription,polymerase chain reaction and enzyme-linked immunosorbent assay. Results Immunohistochemistry revealed the presence of HIF-1,, VEGF, and SDF-1 in RA synovium. Patchy expression of HIF-1, was detected primarily in the synovial lining and sublining areas; expression in synovial fibroblasts and in the lining cells of whole synovial tissue explants was markedly augmented by hypoxic culture conditions. Hypoxia enhanced the expression of VEGF and SDF-1 messenger RNA in synovial fibroblasts. The production of VEGF and SDF-1 protein by synovial fibroblasts was augmented by 50% and 132%, respectively, after 24 hours of hypoxia. VEGF production was potently induced by TGF,, and to a lesser extent by IL-1, and TNF, and was further augmented by hypoxia. In contrast, none of the tested cytokines induced SDF-1 production. Conclusion As with VEGF, SDF-1 expression is induced by hypoxia; however, cytokines induce VEGF but not SDF-1. Hypoxic conditions in RA synovium, which are likely to be transient and episodic, may contribute to the persistence of synovitis by inducing VEGF and SDF-1. [source] Novel microfluidic platform for culturing neurons: Culturing and biochemical analysis of neuronal componentsBIOTECHNOLOGY JOURNAL, Issue 11 2009Jeong Won Park Abstract Neurons, one of the most polarized types of cells, are typically composed of cell bodies (soma), dendrites, and axons. Many events such as electric signal transmission, axonal transport, and local protein synthesis occur in the axon, so that a method for isolating axons from somata and dendrites is required for systematically investigating these axonal events. Based on a previously developed neuron culture method for isolating and directing the growth of central nervous system axons without introducing neutrophins, we report three modified microfluidic platforms: (1) for performing biochemical analysis of the pure axonal fraction, (2) for culturing tissue explants, and (3) a design that allows high content assay on same group of cells. The key feature of these newly developed platforms is that the devices incorporate a number of microgrooves for isolating axons from the cell body. They utilize an open cellculture area, unlike the enclosed channels of the previous design. This design has extended the axonal channel so that a sufficient amount of pure axonal fraction can be obtained to perform biochemical analysis. The design also addresses the drawback of the previous neuron culture device, which was not adaptable for culturing thick neuronal tissues such as brain explants, neurospheres, and embryoid bodies, which are essential model tissues in neuroscience research. The design has an open cellculture area in the center and four enclosed channels around open area, and is suitable for multiple drug screening assays. [source] 2333: Cultivation of limbal stem cells-derived corneal epithelium on different biologic materials for clinical transplantationACTA OPHTHALMOLOGICA, Issue 2010G PETROVSKI Purpose To develop simple, reproducible, animal-materials free method for cultivating limbal stem-cells and differentiating them into corneal epithelium on different human biologic materials for clinical transplantation. Methods The limbal tissues (2x2mm) were harvested from cadavers not more than 8 hours after death and proliferated in vitro on cell culture tissue plates, human amniotic membranes (HAM) or human lens capsules in medium containing human AB serum. Cell viability was tested using the MTT assay and annexin-FITC/Propidium Iodide positivity methods. Molecular gene and immunofluorescent marker studies for stemness, proliferation and differentiation were used for the analysis. Results Over a period of one year, 50 limbal tissue explants were cultivated. Emergence of cells at one edge of the explants occurred within 24 hours from culturing and formed monolayer within 14 days. Although the speed of cell growth varied among donors and types of media for growth, inadequate growth at two weeks was never recorded. The viability of the cells at 7 and 14 days of cultivation was higher than 96% except in case of HAM use where viability was below 80%. The growing cells were characterized for their positivity for stemness (P63, ABCG2), proliferation (ki67) and epithelial cell markers CK 3, 8, 12, 14, 18 and 19. Conclusion We demonstrate a simple, animal-materials free technique for generating corneal epithelium from cadavers or alternatively from autologous donors for viable cell growth on different biologic materials for transplantation. The growth of corneal epithelium on lens capsules proved to be superior compared to the other cultivation techiques. [source] | |||||||||||||