Inhibition of TSH-induced hydrogen peroxide production by TNF-alpha through a sphingomyelinase signaling pathway.

1997 ◽  
Vol 273 (3) ◽  
pp. E638 ◽  
Author(s):  
T Kimura ◽  
F Okajima ◽  
T Kikuchi ◽  
A Kuwabara ◽  
H Tomura ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Thyroid Stimulating Hormone ◽  
Tnf Alpha ◽  
H2o2 Production ◽  
Thyroid Disorder ◽  
Autoimmune Thyroid Diseases ◽  
Necrosis Factor Alpha ◽  
Thyroid Cells ◽  
Hormone Synthesis

Tumor necrosis factor-alpha (TNF-alpha) has been suggested to be related to the pathogenesis of autoimmune thyroid diseases, nonthyroid illness, and other thyroid dysfunctions induced by infectious diseases. In relation to these, in vitro studies demonstrated that TNF-alpha influences growth and/or differentiated functions mediated by thyroid-stimulating hormone (TSH), including 125I organification. In the present study, we found that TNF-alpha inhibits TSH-induced H2O2 production, which is an inevitable process for iodide organification, and hence thyroid hormone synthesis, in FRTL-5 thyroid cells. In the cells, TNF-alpha induced ceramide production and the addition of exogenous ceramide or sphingomyelinase treatment of the cells simulated TNF-alpha actions. Although TSH stimulation of H2O2 production is mediated by the phospholipase C (PLC)-Ca2+ pathway, TNF-alpha and exogenous and endogenous ceramide affected neither TSH-dependent PLC activation and Ca2+ mobilization nor TSH-induced cAMP accumulation but attenuated Ca(2+)-induced H2O2 production. We conclude that TNF-alpha, through a sphingomyelinase-ceramide pathway, regulates TSH-induced H2O2 production at steps beyond the Ca2+ mobilization step in the PLC-Ca2+ signaling pathway coupled to TSH. This suggests participation of TNF-alpha in thyroid disorder in hormone synthesis induced by thyroid disease associated with the activation of immune systems.

scholarly journals Interactions of granulocyte-macrophage colony-stimulating factor (CSF), granulocyte CSF, and tumor necrosis factor alpha in the priming of the neutrophil respiratory burst

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 745-753 ◽  
Author(s):  
A Khwaja ◽  
JE Carver ◽  
DC Linch
Keyword(s):  
Respiratory Burst ◽  
Ex Vivo ◽  
Tnf Alpha ◽  
H2o2 Production ◽  
Colony Stimulating Factor ◽  
Necrosis Factor Alpha ◽  
Gm Csf ◽  
Stimulating Factor

Abstract Exposure of neutrophils to a range of cytokines augments their response to subsequent agonist-induced activation of the respiratory burst. We have examined the effects of several of these factors, both singly and in combination, on the priming of f-met-leu-phe (FMLP) and complement C5a-stimulated neutrophil H2O2 production, using a whole blood flow cytometric assay designed to minimize artefactual activation. Both granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF alpha) produced a similar degree of priming of the FMLP-stimulated burst in vitro (558% +/- 86%, n = 41, and 581% +/- 95%, n = 21, of the response seen with FMLP alone, respectively), but with markedly different kinetics (half-maximal response 20 minutes and 7 minutes, respectively). Preincubation with granulocyte colony- stimulating factor (G-CSF) alone caused only modest priming (202% +/- 39%, n = 14). Priming with cytokine combinations of the FMLP-stimulated burst showed that the combinations of G-CSF and TNF alpha and GM-CSF and TNF alpha are highly synergistic, with recruitment of neutrophils unresponsive to priming by single agents. Priming with the combination of GM-CSF and G-CSF was not significantly different to priming with GM- CSF alone. Similar results were obtained using C5a as the respiratory burst stimulus. Significant priming of the FMLP-stimulated respiratory burst was seen in vivo in patients receiving an infusion of GM-CSF (332% +/- 50% of preinfusion response to FMLP, P less than .005, n = 8). Priming was also seen in patients receiving G-CSF (152% +/- 58%, n = 5), although this did not reach conventional significance levels (.05 less than P less than .1). Although GM-CSF infusion caused priming in vivo, this was 48% less than predicted by preinfusion in vitro responses. This result was not due to inadequate GM-CSF levels as addition of further GM-CSF ex vivo did not correct the response. However, these neutrophils were still able to respond appropriately to ex vivo priming with TNF alpha, with a doubling in H2O2 production.

scholarly journals Interactions of granulocyte-macrophage colony-stimulating factor (CSF), granulocyte CSF, and tumor necrosis factor alpha in the priming of the neutrophil respiratory burst

Blood ◽  
1992 ◽  
Vol 79 (3) ◽  
pp. 745-753 ◽  
Author(s):  
A Khwaja ◽  
JE Carver ◽  
DC Linch
Keyword(s):  
Respiratory Burst ◽  
Ex Vivo ◽  
Tnf Alpha ◽  
H2o2 Production ◽  
Colony Stimulating Factor ◽  
Necrosis Factor Alpha ◽  
Gm Csf ◽  
Stimulating Factor

Exposure of neutrophils to a range of cytokines augments their response to subsequent agonist-induced activation of the respiratory burst. We have examined the effects of several of these factors, both singly and in combination, on the priming of f-met-leu-phe (FMLP) and complement C5a-stimulated neutrophil H2O2 production, using a whole blood flow cytometric assay designed to minimize artefactual activation. Both granulocyte-macrophage colony-stimulating factor (GM-CSF) and tumor necrosis factor alpha (TNF alpha) produced a similar degree of priming of the FMLP-stimulated burst in vitro (558% +/- 86%, n = 41, and 581% +/- 95%, n = 21, of the response seen with FMLP alone, respectively), but with markedly different kinetics (half-maximal response 20 minutes and 7 minutes, respectively). Preincubation with granulocyte colony- stimulating factor (G-CSF) alone caused only modest priming (202% +/- 39%, n = 14). Priming with cytokine combinations of the FMLP-stimulated burst showed that the combinations of G-CSF and TNF alpha and GM-CSF and TNF alpha are highly synergistic, with recruitment of neutrophils unresponsive to priming by single agents. Priming with the combination of GM-CSF and G-CSF was not significantly different to priming with GM- CSF alone. Similar results were obtained using C5a as the respiratory burst stimulus. Significant priming of the FMLP-stimulated respiratory burst was seen in vivo in patients receiving an infusion of GM-CSF (332% +/- 50% of preinfusion response to FMLP, P less than .005, n = 8). Priming was also seen in patients receiving G-CSF (152% +/- 58%, n = 5), although this did not reach conventional significance levels (.05 less than P less than .1). Although GM-CSF infusion caused priming in vivo, this was 48% less than predicted by preinfusion in vitro responses. This result was not due to inadequate GM-CSF levels as addition of further GM-CSF ex vivo did not correct the response. However, these neutrophils were still able to respond appropriately to ex vivo priming with TNF alpha, with a doubling in H2O2 production.

scholarly journals Artemisinin Ameliorates Osteoarthritis by Inhibiting the Wnt/β-Catenin Signaling Pathway

2018 ◽  
Vol 51 (6) ◽  
pp. 2575-2590 ◽  
Author(s):  
Gang Zhong ◽  
Ruiming Liang ◽  
Jun Yao ◽  
Jia Li ◽  
Tongmeng Jiang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Cruciate Ligament ◽  
Interleukin 1 ◽  
Cartilage Degradation ◽  
Chondrocyte Apoptosis ◽  
Enzyme Linked Immunosorbent Assay ◽  
Cell Viability Assay ◽  
Necrosis Factor Alpha ◽  
Anti Inflammatory

Background/Aims: Current drug therapies for osteoarthritis (OA) are not practical because of the cytotoxicity and severe side-effects associated with most of them. Artemisinin (ART), an antimalarial agent, is well known for its safety and selectivity to kill injured cells. Based on its anti-inflammatory activity and role in the inhibition of OA-associated Wnt/β-catenin signaling pathway, which is crucial in the pathogenesis of OA, we hypothesized that ART might have an effect on OA. Methods: The chondro-protective and antiarthritic effects of ART on interleukin-1-beta (IL-1β)-induced and OA patient-derived chondrocytes were investigated in vitro using cell viability assay, glycosaminoglycan secretion, immunofluorescence, quantitative reverse transcription-polymerase chain reaction, and western blotting. We also used OA model rats constructed by anterior cruciate ligament transection and medial meniscus resection (ACLT+MMx) in the joints to investigate the effects of ART on OA by gross observation, morphological staining, immunohistochemistry, and enzyme-linked immunosorbent assay. Results: ART exhibited potent anti-inflammatory effects by inhibiting the expression of proinflammatory chemokines and cytokines, including interleukin (IL)-1β, IL-6, tumor necrosis factor alpha, and matrix metallopeptidase-13. It also showed favorable chondro-protective effect as evidenced by enhanced cell proliferation and viability, increased glycosaminoglycan deposition, prevention of chondrocyte apoptosis, and degeneration of cartilage. Further, ART inhibited OA progression and cartilage degradation via the Wnt/β-catenin signaling pathway, suggesting that it might serve as a Wnt/β-catenin antagonist to reduce inflammation and prevent cartilage degradation. Conclusion: In conclusion, ART alleviates IL-1β-mediated inflammatory response and OA progression by regulating the Wnt/β-catenin signaling pathway. Thereby, it might be developed as a potential therapeutic agent for OA.

scholarly journals Mechanism of KLF4 Protection against Acute Liver Injury via Inhibition of Apelin Signaling

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Weitao Ji ◽  
Hongyun Shi ◽  
Hailin Shen ◽  
Jing Kong ◽  
Jiayi Song ◽  
...  
Keyword(s):  
Liver Injury ◽  
Signaling Pathway ◽  
Acute Liver Injury ◽  
Control Group ◽  
Necrosis Factor Alpha ◽  
Protein Levels ◽  
Klf4 Expression ◽  
Mrna And Protein Expression

Krüppel-like factor 4 (KLF4) is a key transcription factor that regulates genes involved in the proliferation or differentiation in different tissues. Apelin plays roles in cardiovascular functions, metabolic disease, and homeostatic disorder. However, the biological function of apelin in liver disease is still ongoing. In this study, we investigated the mechanism of KLF4-mediated protection against acute liver injury via the inhibition of the apelin signaling pathway. Mice were intraperitoneally injected with carbon tetrachloride (CCl4; 0.2 mL dissolved in 100 mL olive oil, 10 mL/kg) to establish an acute liver injury model. A KLF4 expression plasmid was injected through the tail vein 48 h before CCl4 treatment. In cultured LX-2 cells, pAd-KLF4 or siRNA KLF4 was overexpressed or knockdown, and the mRNA and protein levels of apelin were determined. The results showed that the apelin serum level in the CCl4-injected group was higher than that of control group, and the expression of apelin in the liver tissues was elevated while KLF4 expression was decreased in the CCl4-injected group compared to the KLF4-plasmid-injected group. HE staining revealed serious hepatocellular steatosis in the CCl4-injected mice, and KLF4 alleviated this steatosis in the mice injected with KLF4 plasmid. In vitro experiments showed that tumor necrosis factor-alpha (TNF-α) could downregulate the transcription and translation levels of apelin in LX-2 cells and also upregulate KLF4 mRNA and protein expression. RT-PCR and Western blotting showed that the overexpression of KLF4 markedly decreased basal apelin expression, but knockdown of KLF4 restored apelin expression in TNF-α-treated LX-2 cells. These in vivo and in vitro experiments suggest that KLF4 plays a key role in inhibiting hepatocellular steatosis in acute liver injury, and that its mechanism might be the inhibition of the apelin signaling pathway.

scholarly journals Ability of flt3 ligand to stimulate the in vitro growth of primitive murine hematopoietic progenitors is potently and directly inhibited by transforming growth factor-beta and tumor necrosis factor-alpha

Blood ◽  
1996 ◽  
Vol 87 (12) ◽  
pp. 5016-5026 ◽  
Author(s):  
SE Jacobsen ◽  
OP Veiby ◽  
J Myklebust ◽  
C Okkenhaug ◽  
SD Lyman
Keyword(s):  
Cell Growth ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Tnf Alpha ◽  
Tgf Beta ◽  
Necrosis Factor Alpha ◽  
Factor Alpha ◽  
Growth Factor Beta ◽  
Necrosis Factor

The recently cloned flt3 ligand (FL) stimulates the growth of primitive hematopoietic progenitor cells through synergistic interactions with multiple other cytokines. The present study is the first demonstrating cytokines capable of inhibiting FL-stimulated hematopoietic cell growth. Tumor necrosis factor-alpha (TNF-alpha) and transforming growth factor-beta 1 (TGF-beta l) potently inhibited the clonal growth of murine Lin-Sca-l+ bone marrow progenitors stimulated by FL alone or in combination with granulocyte colony-stimulating factor (G-CSF), stem cell factor (SCF), interleukin (IL)-3, IL-6, IL-11, or IL-12. TGF-beta 1 inhibited more than 96% of the myeloid colony formation in response to these cytokine combinations, whereas TNF-alpha reduced the number of colonies by 58% to 96% depending on the cytokine by which FL was combined. In addition, both TNF-alpha and TGF-beta 1 inhibited more than 90% of B220+ cell production from B220- bone marrow cells stimulated by FL + IL-7. The effects of TNF-alpha and TGF-beta 1 appeared to be due to a direct effect and on the early progenitors because the inhibition was observed at the single cell level, and because delayed addition of the two inhibitors for only 48 hours dramatically reduced their inhibitory effects. A neutralizing anti-TGF- beta antibody showed the presence of endogenous TGF-beta in the cultures and potently enhanced the ability of FL to stimulate progenitor cell growth in the absence of other cytokines. Agonistic antibodies specifically activating the p75 TNF receptors were more efficient than wild type murine TNF-alpha in signaling growth inhibition of Lin-Sca-l+ progenitor cells, whereas the p55 agonist had less effect than murine TNF-alpha. Finally, TGF-beta increased the number of FL + IL-11-stimulated Lin-Sca-1+ cells in the G1 phase of the cell cycle with 76%, whereas TNF-alpha only had a marginal effect on cell cycle distribution. Thus, TGF-beta, TNF-alpha, and p75 TNF receptor agonists are potent direct inhibitors of FL-stimulated progenitor cell growth in vitro.

scholarly journals Cytokine production by primary bone marrow megakaryocytes

Blood ◽  
1994 ◽  
Vol 84 (12) ◽  
pp. 4151-4156 ◽  
Author(s):  
S Jiang ◽  
JD Levine ◽  
Y Fu ◽  
B Deng ◽  
R London ◽  
...  
Keyword(s):  
Bone Marrow ◽  
Transforming Growth Factor Beta ◽  
Transforming Growth Factor ◽  
Interleukin 1 ◽  
Human Bone ◽  
Human Bone Marrow ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Gm Csf

Primary human bone marrow megakaryocytes were studied for their ability to express and release cytokines potentially relevant to their proliferation and/or differentiation. The purity of the bone marrow megakaryocytes was assessed by morphologic and immunocytochemical criteria. Unstimulated marrow megakaryocytes constitutively expressed genes for interleukin-1 beta (IL-1 beta), IL-6, granulocyte-macrophage colony-stimulating factor (GM-CSF), and tumor necrosis factor-alpha (TNF-alpha), by the polymerase chain reaction (PCR) and Northern blot analysis. At the protein level, megakaryocytes secreted significant amounts of IL-1 beta (53.6 +/- 3.6 pg/mL), IL-6 (57.6 +/- 15.6 pg/mL), and GM-CSF (24 +/- 4 pg/mL) but not TNF-alpha. Exposure of human marrow megakaryocytes to IL-1 beta increased the levels of IL-6 (87.3 +/- 2.3 pg/mL) detected in the culture supernatants. Transforming growth factor- beta was also able to stimulate IL-6, IL-1 beta, and GM-CSF secretion, but was less potent than stimulation with phorbol-12-myristate-13- acetate (PMA). The secreted cytokines acted additively to maintain and increase the number of colony-forming unit-megakaryocytes colonies (approximately 35%). These studies demonstrate the production of multiple cytokines by isolated human bone marrow megakaryocytes constitutively or stimulated in vitro. The capacity of human megakaryocytes to synthesize several cytokines known to modulate hematopoietic cells supports the concept that there may be an autocrine mechanism operative in the regulation of megakaryocytopoiesis.

scholarly journals Acrylamide does not induce tumorigenesis or major defects in mice in vivo

2008 ◽  
Vol 198 (2) ◽  
pp. 301-307 ◽  
Author(s):  
Ling Jin ◽  
Vanessa Chico-Galdo ◽  
Claude Massart ◽  
Christine Gervy ◽  
Viviane De Maertelaere ◽  
...  
Keyword(s):  
Thyroid Hormone ◽  
Chronic Administration ◽  
Serum Levels ◽  
Human Thyroid ◽  
Thyroid Cell ◽  
Thyroid Cells ◽  
Hormone Synthesis ◽  
Rat Thyroid

Chronic administration of acrylamide has been shown to induce thyroid tumors in rat. In vitro acrylamide also causes DNA damage, as demonstrated by the comet assay, in various types of cells including human thyroid cells and lymphocytes, as well as rat thyroid cell lines. In this work, mice were administered acrylamide in their drinking water in doses comparable with those used in rats, i.e., around 3–4 mg/kg per day for mice treated 2, 6, and 8 months. Some of the mice were also treated with thyroxine (T4) to depress the activity of the thyroid. Others were treated with methimazole that inhibits thyroid hormone synthesis and consequently secretion and thus induces TSH secretion and thyroid activation. These moderate treatments were shown to have their known effect on the thyroid (e.g. thyroid hormone and thyrotropin serum levels, thyroid gland morphology…). Besides, T4 induced an important polydipsia and degenerative hypertrophy of adrenal medulla. Acrylamide exerted various discrete effects and at high doses caused peripheral neuropathy, as demonstrated by hind-leg paralysis. However, it did not induce thyroid tumorigenesis. These results show that the thyroid tumorigenic effects of acrylamide are not observed in another rodent species, the mouse, and suggest the necessity of an epidemiological study in human to conclude on a public health policy.

scholarly journals Liver Growth Factor Induces Glia-Associated Neuroprotection in an In Vitro Model of Parkinson´s Disease

2020 ◽  
Vol 10 (5) ◽  
pp. 315
Author(s):  
Rafael Gonzalo-Gobernado ◽  
Diana Reimers ◽  
María José Casarejos ◽  
Lucía Calatrava Ferreras ◽  
Manuela Vallejo-Muñoz ◽  
...  
Keyword(s):  
Growth Factor ◽  
Neurodegenerative Disorder ◽  
Neuronal Degeneration ◽  
Neuroprotective Effect ◽  
Tnf Alpha ◽  
Sprague Dawley ◽  
Necrosis Factor Alpha ◽  
Liver Growth ◽  
Glial Cultures

Parkinson’s disease is a neurodegenerative disorder characterized by the progressive death of dopaminergic (DA) neurons in the substantia nigra (SN), which leads to a loss of the neurotransmitter dopamine in the basal ganglia. Current treatments relieve the symptoms of the disease, but none stop or delay neuronal degeneration. Liver growth factor (LGF) is an albumin–bilirubin complex that stimulates axonal growth in the striatum and protects DA neurons in the SN of 6-hydroxydopamine-lesioned rats. Our previous results suggested that these effects observed in vivo are mediated by microglia and/or astrocytes. To determine if these cells are LGF targets, E14 (embryos from Sprague Dawley rats of 14 days) rat mesencephalic glial cultures were used. Treatment with 100 pg/mL of LGF up-regulated the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinases 1/2 (ERK1/2) and the cyclic AMP response element binding protein (CREB) phosphorylation in glial cultures, and it increased the microglia marker Iba1 and tumor necrosis factor alpha (TNF-alpha) protein levels. The treatment of E14 midbrain neurons with a glial-conditioned medium from LGF-treated glial cultures (GCM-LGF) prevented the loss of DA neurons caused by 6-hydroxy-dopamine. This neuroprotective effect was not observed when GCM-LGF was applied in the presence of a blocking antibody of TNF-alpha activity. Altogether, our findings strongly suggest the involvement of microglia and TNF-alpha in the neuroprotective action of LGF on DA neurons observed in vitro.

scholarly journals Genistein reduces tumor necrosis factor alpha-induced plasminogen activator inhibitor-1 transcription but not urokinase expression in human endothelial cells

Blood ◽  
1994 ◽  
Vol 84 (9) ◽  
pp. 2984-2991 ◽  
Author(s):  
VW van Hinsbergh ◽  
M Vermeer ◽  
P Koolwijk ◽  
J Grimbergen ◽  
T Kooistra
Keyword(s):  
Endothelial Cells ◽  
Protein Kinase ◽  
Plasminogen Activator ◽  
Kinase Inhibitors ◽  
Protein Kinase Inhibitors ◽  
Tnf Alpha ◽  
Necrosis Factor Alpha ◽  
Tyrosine Protein Kinase ◽  
Pai 1

Abstract The plasminogen activator inhibitor PAI-1 is markedly elevated in vivo and in vitro upon exposure to the inflammatory mediators tumor necrosis factor alpha (TNF alpha), interleukin-1 (IL-1), and bacterial lipopolysaccharide. Here we report that the isoflavone compound genistein prevents the increase in synthesis of PAI-1 induced by these inflammatory mediators in human endothelial cells in vitro, and partially reduces the basal PAI-1 production by these cells. These effects of genistein were accompanied by a decrease in PAI-1 mRNA and in a suppression of the PAI-1 transcription rate as shown by run-on assay. A specific action of genistein, probably by inhibiting a tyrosine protein kinase, is likely, because the structural genistein analogue daidzein, which has a low tyrosine protein kinase inhibitor activity, did not inhibit PAI-1 synthesis. Vanadate, a tyrosine protein phosphatase inhibitor, increased PAI-1 production. The effect of genistein on PAI-1 synthesis was rather selective. Herbimycin A also reduced PAI-1 synthesis, but several other tyrosine protein kinase inhibitors, namely tyrphostin A47, methyl-2,5-dihydroxy-cinnamate, and compound 5, were unable to do so. All these tyrosine protein kinase inhibitors reduced basic fibroblast growth factor (b-FGF)-induced [3H]thymidine incorporation in endothelial cells. This indicates that the effect of genistein on PAI-1 transcription proceeds independently of its effect on mitogenesis. In contrast to TNF-alpha-induced PAI-1 production, the transcription and synthesis of urokinase-type plasminogen activator (u-PA) was not inhibited by genistein. A TNF- alpha-mutant (Trp32Thr86TNF alpha) that specifically recognizes the 55- kD TNF-receptor, mimicked the effects of TNF alpha on both PAI-1 and u- PA. Because genistein affected PAI-1, but not u-PA induced by this mutant, involvement of different TNF-receptors cannot underlie the difference in the effects of genistein on PAI-1 and u-PA synthesis. Because genistein also inhibited PAI-1 induction by thrombin and IL-4, it is likely that genistein does not act on a TNF alpha-receptor- coupled protein kinase but on the signal transduction pathway enhancing PAI-1 transcription. Our results suggest that the TNF alpha-induced signal transduction pathway of PAI-1 transcription involves a genistein- sensitive step that is not involved in the induction of u-PA by TNF alpha. Given the limited sensitivity to several other tyrosine protein kinase inhibitors, this genistein-sensitive step may be a potential target for pharmacologic intervention to reduce elevated plasma PAI-1 levels.

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