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In order to investigate the effects of LPS on the TACE gene transcription and expression and its regulating effect on the TM-TNF secretion, in vitro studies were carried out on HL-60 cells stimulated by LPS. TACE, TNF-α mRNA leve...
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In order to investigate the effects of LPS on the TACE gene transcription and expression and its regulating effect on the TM-TNF secretion, in vitro studies were carried out on HL-60 cells stimulated by LPS. TACE, TNF-α mRNA levels were detected by Dot-Elisa and the distribution of membrane molecules determined by flow cytometry assay and indirect immunofluorescence. The results showed that; (1) TACE was detected in or on HL-60 cells and it is predominantly localized on cell surface and to a perinuclear compartment. (2) LPS induced a time dependent increasement of TNF-a mRNA and enhanced TNF conversion with decreasing distribution of TNF in cell surface and increasing secretion of TNF protein. Such conversion could be inhibited by TACE ODN. (3) LPS also induced time-dependently increased expression of TACE gene and activation of its function. On the other hand, TACE protein in cell lysate and on cell surface was decreased. It was suggested that TACE molecular structure might change following its mediating membrane-anchored molecular secretion.
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Since levels of the proinflammatory cytokine tumor necrosis factor alpha (TNFα) are significantly increased in systemic lupus erythematosus (SLE) and may be involved in the disease pathogenesis, we report on the safety and effica...
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Since levels of the proinflammatory cytokine tumor necrosis factor alpha (TNFα) are significantly increased in systemic lupus erythematosus (SLE) and may be involved in the disease pathogenesis, we report on the safety and efficacy of infliximab, a chimeric monoclonal antibody directed against TNFα, given to a patient with difficult-to-treat active nonrenal SLE. This patient, who failed to remit with full doses of glucocorticoids, hydroxychloroquine, methotrexate, and azathioprine, went into sustained remission with the addition of infliximab infusions. Glucocorticoids could be tapered off completely.
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This study investigated the plasma levels of tumor necrosis factor a (INF-alpha) and the expression levels of TNF receptors (TNFRs) in patients with multiple trauma, together with the association between the levels of this cytokin...
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This study investigated the plasma levels of tumor necrosis factor a (INF-alpha) and the expression levels of TNF receptors (TNFRs) in patients with multiple trauma, together with the association between the levels of this cytokine and these cytokine receptors with the severity of traumatic injury. Blood samples were obtained from 60 multiple trauma patients at hospital admission (within 2 h of injury), and 6-8 h and 1-5 days after admission. The plasma levels of TNF-alpha and TNFR1/TNFR2 were detected using enzyme immunoassay. TNFR1 and TNFR2 expression levels on leukocytes, including neutrophils, lymphocytes and monocytes, were determined by flow cytometry. Clinical parameters were determined by injury severity score (ISS). At hospital admission, the plasma TNF-alpha and soluble TNFR levels in the trauma patients were elevated compared with those of healthy controls. Increased expression levels of TNFR1 and TNFR2 were also detected on leukocytes, particularly on lymphocytes and monocytes. The expression levels of the cytokine and the corresponding receptors were correlated with the ISS. TNF-alpha and TNFR expression levels remained significantly elevated for up to the third to fifth day following the traumatic injury. In the trauma patients, increased levels of TNF-alpha and TNFRs were correlated with the severity of traumatic injury in the early post-injury period, supporting the hypothesis that trauma-provoked organ dysfunction may be caused by an overwhelming auto-destructive inflammatory response.
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The aims of the study were to compare the levels of tumor necrosis factor alpha (TNF-α) and its soluble type I (sTNF-R1) and type II (sTNF-R2) receptors detected in intracystic liquid and serum from benign and malignant ovarian n...
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The aims of the study were to compare the levels of tumor necrosis factor alpha (TNF-α) and its soluble type I (sTNF-R1) and type II (sTNF-R2) receptors detected in intracystic liquid and serum from benign and malignant ovarian neoplasms and to relate them to prognostic factors in epithelial ovarian cancer. The patients were divided into benign ovarian neoplasms ( n ?=?46) and malignant ovarian neoplasms ( n ?=?17). The serum and intracystic samples were collected before and during surgery for ovarian cyst, respectively. The levels of TNF-α, sTNF-R1, and sTNF-R2 were measured using ELISA. Results were compared with the Mann–Whitney test. Concentration of sTNF-R2 in the intracystic samples collected from the malignant neoplasia was significantly higher than that of the benign neoplasias ( p? =?0.02). Higher intracystic levels of sTNF-R2 exhibited a significant association with tumor differentiation grades 2 and 3 ( p? =?0.0087). There was no statistical significance in relation to serum levels. Tumor microenvironment levels of sTNF-R2 may represent a factor of poor prognosis in epithelial ovarian cancer.
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Mesangial cells are critical for glomerular filtration. Mesangial cell dysfunction, the hallmark of diabetic nephropathy, results from disordered mesangial growth induced by cytokines, abnormal hemodynamic influence, and metabolic...
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Mesangial cells are critical for glomerular filtration. Mesangial cell dysfunction, the hallmark of diabetic nephropathy, results from disordered mesangial growth induced by cytokines, abnormal hemodynamic influence, and metabolic factors associated with chronic hyperglycemia. Insulin-like growth factors (IGFs) and their high affinity binding proteins (IGFBPs) exert major actions on mesangial cell survival, but their underlying mechanisms remain unclear. In light of emerging IGF-independent roles for IGFBP-3, we investigated IGFBP-3 actions during mesangial cell apoptosis induced by cytokine or high glucose concentration. Quantified by DNA fragmentation ELISA and Annexin V flow cytometry, apoptosis occurred in rat mesangial cells (RMC) exposed to 2 microg/mL IGFBP-3 for 24 h under high ambient or standard glucose. Anti-sense IGFBP-3 oligo at 10 microg/mL significantly inhibited apoptosis induced by 100 ng/mL TNF-alpha, serum-free conditions, or high (25 mM) glucose. Increased IGFBP-3 release associatedwith high ambient glucose or TNF-alpha was inhibited by pre-treatment with anti-sense oligo. Under serum-free conditions, recombinant human IGFBP-3 blocked Akt phosphorylation at threonine 308 (pThr308), whereas anti-sense oligo treatment was associated with enhanced pThr308 activity. In summary, these data support a novel mechanism for TNF-alpha-induced mesangial cell apoptosis mediated by IGFBP-3 and present regulation of pThr308 activity as a novel mechanism underlying IGFBP-3 action.
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Enzyme immunosorbent assays (ELISA) for human tumor necrosis factor-alpha (TNF-alpha) are available from many companies. Although this cytokine is meanwhile well established in scientific work its detection in human blood still le...
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Enzyme immunosorbent assays (ELISA) for human tumor necrosis factor-alpha (TNF-alpha) are available from many companies. Although this cytokine is meanwhile well established in scientific work its detection in human blood still leads often to conflicting results. We studied the analytical performance of three different commercial ELISA (Amersham, Immunotech and Medgenix Diagnostics) in plasma samples of 30 human immunodeficiency virus (HIV) infected individuals. All kits showed significantly different mean concentrations of TNF-alpha in the study population (p < 0.05). Kit A: 30.9 pg/ml +/- 46.6 vs. kit B: 46.9 pg/ml +/- 24.8 vs kit C: 11.8 pg/ml +/- 11.6. Results of assays A and B (r = 0.34) as well as A and C (r = 0.31) were not significantly correlated. A good statistical relation between values was only found for assay B and assay C (r = 0.80. p < 0.001). Three plasma samples were spiked with TNF-alpha standard of the corresponding kit to a final concentration of 200 pg/ml. The detection results ofthese samples were compared with the variation conceded by the manufacturer. Assay A detected two samples above the corresponding coefficient of intra-assay variation (recovery: 81.8% and 89.2%). All three values obtained with assay B were markedly out of its variation range (recovery: 88.7%, 84.6% and 89.0%) while assay C showed again two results above the intra-assay variation (recovery: 92.1% and 89.6%). In our observations we found relevant differences between commercial ELISA kits of different manufacturers, which made interpretation of TNF-alpha in human plasma samples difficult. Additionally, it should be taken into consideration that plasma specimen may contain cytokine-binding proteins or autoantibodies which are capable of blocking epitopes of TNF-alpha. This may lead to the loss of the necessary immunoreactivity which prevents detection antibodies from recognizing these molecules.
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Multicentric reticulohistiocytosis (MRH) is a rare and debilitating systemic disorder characterized by cutaneous nodules and destructive polyarthritis. Due to its unknown etiology, the treatment of MRH varies with different rates ...
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Multicentric reticulohistiocytosis (MRH) is a rare and debilitating systemic disorder characterized by cutaneous nodules and destructive polyarthritis. Due to its unknown etiology, the treatment of MRH varies with different rates of success, which causes treatment options to be rather independent and empirical. In the present study, a case of a 48-year-old woman with a 12-month history of polyarthralgia and skin nodules was reported. Biopsy samples, which were obtained from her skin eruption exhibited dermal infiltration with histiocytes and multinucleated giant cells. Immunohistochemical staining indicated positivity for CD68. The patient was diagnosed with MRH and treated with a combination therapy of infliximab, prednisolone and methotrexate. Her symptoms improved markedly within 2 weeks. Following the results of this case study, a systematic review of 17 cases of MRH treated with tumor necrosis factor (TNF) antagonists was performed, and the efficacy of anti-TNF treatment in MRH was analyzed.
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The tumor necrosis factor alpha (TNFA) promoter region exhibits several polymorphisms, which have been hypothesized to influence gene expression, thereby associating positively or negatively with inflammatory conditions. Many stud...
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The tumor necrosis factor alpha (TNFA) promoter region exhibits several polymorphisms, which have been hypothesized to influence gene expression, thereby associating positively or negatively with inflammatory conditions. Many studies have focused on single nucleotide polymorphisms (SNPs) taking not into account additive or inverse effects between different SNPs. We typed 1,021 healthy Caucasian volunteer stem cell donors for their TNFA promoter as well as their HLA-A,-C,-B,-DRB1 loci. Using statistical methods, we reconstructed TNFA promoter alleles and analyzed their frequency and linkage with HLA genes. We show that the number of TNFA promoter alleles frequent enough to be analyzed in clinical studies is limited and that a strong linkage with classical HLA genes is present, especially for the extended HLA-haplotype HLA-A*01:01/HLA-C*07:01/HLA-B*08:01/TNFA promoter allele 3/HLA*DRB1*03:01. Taking into account SNP frequency information, it is possible to quite accurately deduce TNFA promoter alleles by generic Sanger sequencing, obviating the need for elaborating allele-specific sequencing. This information may enable investigators to consider the complete TNFA regulatory region in a phase-separated manner in contrast to previous approaches examining only one or few isolated SNPs.
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Phenotypically different osteoclasts may be generated from different subsets of precursors. To what extent the formation of these osteoclasts is influenced or mediated by the inflammatory cytokine TNF-alpha, is unknown and was inv...
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Phenotypically different osteoclasts may be generated from different subsets of precursors. To what extent the formation of these osteoclasts is influenced or mediated by the inflammatory cytokine TNF-alpha, is unknown and was investigated in this study. The osteoclast precursors early blasts (CD31(hi)Ly-6C(-)), myeloid blasts (CD31(+) Ly-6C(+)), and monocytes (CD31(-)Ly-6C(hi)) were sorted from mouse bone marrow using flow cytometry and cultured with M-CSF and RANKL, with or without TNF-alpha. Surprisingly, TNF-alpha prevented the differentiation of TRAcP+ osteoclasts generated from monocytes on plastic; an effect not seen with early blasts and myeloid blasts. This inhibitory effect could not be prevented by other cytokines such as IL-1 beta or IL-6. When monocytes were pre-cultured with M-CSF and RANKL followed by exposure to TNF-alpha, a stimulatory effect was found. TNF-alpha also stimulated monocytes' osteoclastogenesis when the cells were seeded on bone. Gene expression analysis showed that when TNF-alpha was added to monocytes cultured on plastic, RANK, NFATc1, and TRAcP were significantly down-regulated while TNF-alpha R1 and TNF-aR2 were up-regulated. FACS analysis showed a decreased uptake of fluorescently labeled RANKL in monocyte cultures in the presence of TNF-alpha, indicating an altered ratio of bound-RANK/unbound-RANK. Our findings suggest a diverse role of TNF-alpha on monocytes' osteoclastogenesis: it affects the RANK-signaling pathway therefore inhibits osteoclastogenesis when added at the onset of monocyte culturing. This can be prevented when monocytes were pre-cultured with M-CSFand RANKL, which ensures the binding of RANKL to RANK. This could be a mechanism to prevent unfavorable monocyte-derived osteoclast formation away from the bone.
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In the present study, we investigated the relation between clinical parameters and levels of interleukin (IL) -4 and -5, and tumour necrosis factor-alpha (TNF-alpha) in the leukocyte incubation medium (LIM) obtained from 26 patien...
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In the present study, we investigated the relation between clinical parameters and levels of interleukin (IL) -4 and -5, and tumour necrosis factor-alpha (TNF-alpha) in the leukocyte incubation medium (LIM) obtained from 26 patients with chronic periodontitis (P) and 26 control group subjects (C). The levels of cytokines IL-4 and IL -5 produced by the LIM stimulated with non-opsonised E. coli were determined using the Enzyme-Linked Immunosorbent Assay (ELISA) method and the levels of TNF-alpha were evaluated by applying Enzyme Amplified Sensitivity Immunoassay (EASIA). TNF-alpha levels in stimulated LIM were strongly positively correlated with clinical parameters such as the pocket probing depths (PPD), the clinical attachment level (CAL), the bleeding on probing (BOP) and oral hygiene index (OHI), whereas the IL-4 and IL-5 levels in the analogous medium were strongly negatively correlated with the clinical parameters. IL-4 and IL-5 levels in stimulated LIM of P group patients were significantly lower, whereas TNF-alpha levels were significantly higher than that in analogous medium of C group subjects. These differences were associated with the severity of periodontal disease.
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