scholarly journals Autoantibodies against IL-1-receptor-antagonist in multisystem inflammatory syndrome in children

2021 ◽  
Author(s):  
Jochen Pfeifer ◽  
Bernhard Thurner ◽  
Christoph Kessel ◽  
Natalie Fadle ◽  
Evi Regitz ◽  
...  
Keyword(s):  
Receptor Antagonist ◽  
Plasma Levels ◽  
Case Series ◽  
Reporter Cell ◽  
Western Blots ◽  
Cell Assays ◽  
Concomitant Reduction ◽  
Reporter Assays ◽  
Inflammatory Syndrome

Multisystem inflammatory syndrome in children (MIS-C or PIMS) is a rare but serious complication after an infection with SARS-CoV-2. A possible involvement of pathogenetically relevant autoantibodies has been discussed. Recently neutralizing autoantibodies against anti-inflammatory receptor antagonists progranulin (PGRN) and IL-1-receptor antagonist (IL-1-Ra) were discovered in adult patients with critical COVID-19.Plasma of an index case with severe PIMS/MIS-C was analyzed for autoantibodies against IL-1-Ra and PGRN. The study was extended by a case series of 12 additional patients. In addition to ELISA for of antibodies, IL-1-Ra plasma levels were determined and IL-1-Ra was analyzed by Western-blot and isoelectric focusing. Functional activity of the autoantibodies was examined in vitro with IL-1ß reporter assays.Antibodies against IL-1-Ra could be detected in 10 of 13 (76.9%) patients with PIMS/MIS-C, but not in controls. In contrast to critical COVID-19 in adults, no IL-1-Ra antibodies of the IgM class were detected in PIMS/MIS-C. IL-1-Ra-antibodies exclusively belonged to IgG1. No antibodies directed against PGRN were detected. Western blots and ELISA showed a concomitant reduction of free IL-1-Ra plasma levels in the presence of IL-1-Ra-antibodies. The antibodies inhibited IL-1-Ra function in IL-1ß reporter cell assays. Notably, an additional, hyperphosphorylated, transiently occurring atypical isoform of IL-1-Ra was observed in all IL-1-Ra autoantibody-positive patients.To conclude, IL-1-Ra autoantibodies were observed in high frequency in children with PIMS/MIS-C. They may represent a diagnostic and pathophysiologically relevant marker for PIMS/MIS-C. Their generation is likely to be triggered by an atypical, hyperphosphorylated isoform of IL-1-Ra.

scholarly journals Treatment with the PPARγ agonist rosiglitazone downregulates interleukin-1 receptor antagonist in individuals with metabolic syndrome

2010 ◽  
Vol 162 (2) ◽  
pp. 267-273 ◽  
Author(s):  
Bente Halvorsen ◽  
Eli Heggen ◽  
Thor Ueland ◽  
Camilla Smith ◽  
Wiggo J Sandberg ◽  
...  
Keyword(s):  
Metabolic Syndrome ◽  
Receptor Antagonist ◽  
Plasma Levels ◽  
Controlled Trial ◽  
Interleukin 1 ◽  
Metabolic Markers ◽  
Monocyte Chemoattractant Protein 1 ◽  
Pparγ Agonist ◽  
Anti Inflammatory

ObjectivesThiazolidinediones (TZDs) reduce insulin resistance, but also have pleiotropic properties including effects on inflammation. The balance between protective and proatherogenic effects may differ in various patient populations. We studied the effect of rosiglitazone on inflammatory markers in patients with metabolic syndrome (MetSyn).MethodsIn a cross-over randomized controlled trial, 23 subjects with MetSyn were assigned to treatment with rosiglitazone that was uptitrated from 4 mg/day for 6 weeks followed by 8 mg/day for 6 weeks or matching placebo for 12 weeks, and then to the opposite treatment for 12 weeks. Plasma levels of inflammatory and metabolic markers were measured during follow-up.ResultsOur main findings were i) compared to placebo, rosiglitazone significantly decreased the plasma levels of the naturally occurring interleukin (IL)1 inhibitor, IL1 receptor antagonist (IL1Ra; P=0.001), potentially reflecting inflammatory effects on the IL1 system; ii) parallel to this, rosiglitazone decreased plasma levels of IL10 (P=0.029) further suggesting inflammatory effects; iii) rosiglitazone decreased uric acid levels (P=0.001), and monocyte chemoattractant protein-1 (P=0.05) and C-reactive protein (P=0.06) tended to be lower after rosiglitazone than placebo, suggesting potential pro- and anti-inflammatory effects simultaneously and iv) in vitro, rosiglitazone enhanced IL1Ra and decreased IL1β in THP-1 monocytes, illustrating the complex effects of these medications, potentially exhibiting anti-inflammatory effects on the IL1 system in certain tissues or cells at least at certain concentrations.ConclusionOur findings suggest inflammatory effects on the IL1 system during rosiglitazone therapy in MetSyn. However, anti-inflammatory effects were also observed, and the net effect of TZDs in MetSyn should be further investigated.

scholarly journals NF-kB-dependent activation of STAT3 by H. pylori is suppressed by TFF1

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Mohammed Soutto ◽  
Nadeem Bhat ◽  
Shayan Khalafi ◽  
Shoumin Zhu ◽  
Julio Poveda ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Nuclear Localization ◽  
Luciferase Reporter ◽  
Western Blots ◽  
In Vivo Models ◽  
Reporter Assays ◽  
H Pylori ◽  
Trefoil Factor 1

Abstract Background H. pylori infection is the main risk factor for gastric cancer. In this study, we investigated H. pylori-mediated activation of STAT3 and NF-κB in gastric cancer, using in vitro and in vivo models. Methods To investigate the activation of NF-κB and STAT3 by H. pylori strains we used in vitro and in vivo mouse models, western blots, immunofluorescence, ChIP Assay, luciferase and quantitative real-time PCR assays. Results Following infection with H. pylori in vitro, we found an earlier phosphorylation of NF-kB-p65 (S536), followed by STAT3 (Y705). Immunofluorescence, using in vitro and in vivo models, demonstrated nuclear localization of NF-kB and STAT3, following H. pylori infection. NF-kB and STAT3 luciferase reporter assays confirmed earlier activation of NF-kB followed by STAT3. In vitro and in vivo models demonstrated induction of mRNA expression of IL-6 (p < 0.001), VEGF-α (p < 0.05), IL-17 (p < 0.001), and IL-23 (p < 0.001). Using ChIP, we confirmed co-binding of both NF-kB-p65 and STAT3 on the IL6 promoter. The reconstitution of Trefoil Factor 1 (TFF1) suppressed activation of NF-kB with reduction in IL6 levels and STAT3 activity, in response to H. pylori infection. Using pharmacologic (BAY11-7082) and genetic (IκB super repressor (IκBSR)) inhibitors of NF-kB-p65, we confirmed the requirement of NF-kB-p65 for activation of STAT3, as measured by phosphorylation, transcription activity, and nuclear localization of STAT3 in in vitro and in vivo models. Conclusion Our findings suggest the presence of an early autocrine NF-kB-dependent activation of STAT3 in response to H. pylori infection. TFF1 acts as an anti-inflammatory guard against H. pylori-mediated activation of pro-inflammatory networks.

LY53857, a 5HT2 Receptor Antagonist, Delays Occlusion and Inhibits Platelet Aggregation in a Rabbit Model of Carotid Artery Occlusion

1991 ◽  
Vol 66 (03) ◽  
pp. 355-360 ◽  
Author(s):  
Harve C Wilson ◽  
William Coffman ◽  
Anne L Killam ◽  
Marlene L Cohen
Keyword(s):  
Electrical Stimulation ◽  
Platelet Aggregation ◽  
Carotid Artery ◽  
Receptor Antagonist ◽  
Artery Occlusion ◽  
Carotid Artery Occlusion ◽  
Rabbit Platelet ◽  
Rabbit Platelets ◽  
5Ht2 Receptor

SummaryThe present study was designed to evaluate the effectiveness of the ergoline 5HT2 receptor antagonist, LY53857 in a rabbit model of vascular arterial occlusion. LY53857 (1 and 10 εM) inhibited serotonin amplified platelet aggregation responses to threshold concentrations of ADP in rabbit platelets in vitro. LY53857 (1 εM) not only inhibited the serotonin component of rabbit platelet aggregation, but also inhibited in vitro aggregation induced by ADP (48.7 ± 16.7% inhibition), collagen (76.1 ± 15.9% inhibition) and U46619 (65.2 ± 12.3% inhibition). The effectiveness of this ergoline 5HT2 receptor antagonist in blocking aggregation to ADP, collagen and U46619 may be related to its ability to inhibit a serotonin component of platelet aggregation since rabbit platelets possess high concentrations of serotonin that may be released during aggregation produced by other agents. Based on the effectiveness of LY53857 to inhibit rabbit platelet aggregation, we explored the ability of LY53857 to extend the time to carotid artery occlusion in rabbits following electrical stimulation of the artery. Reproducible carotid artery occlusion was induced in rabbits by moderate stenosis coupled to arterial cross clamping, followed by electrical stimulation. With this procedure, occlusion occurred at 47.0 ± 7 min (n = 30) after initiation of the electrical stimulation. Animals pretreated with LY53857 (50 to 500 εg/kg i.v.) showed a delay in the time to carotid artery occlusion (at 100 εg/kg i.v. occlusion time extended to 164 ± 16 min). Furthermore, ex vivo platelet aggregation from animals treated with LY53857 (300 εg/kg i.v.) resulted in 40.5% inhibition of platelet aggregation in response to the combination of ADP (1 εM) and serotonin (1 εM). These studies document the ability to obtain reproducible arterial occlusion in the rabbit and showed that intravenously administered LY53857 prolonged the time to carotid artery occlusion. Prolongation of carotid artery occlusion time was accompanied by inhibition of serotonin-amplified ADP-induced aggregation in rabbit platelets, an effect observed both in vitro and ex vivo. Thus, the rabbit is a useful model for studying the effectiveness of 5HT2 receptor antagonists in prolonging vascular occlusion induced by insult of the carotid artery.

The d-Enantiomer Form of Indobufen Totally Accounts for the Anti-Cyclooxygenase and Antiplatelet Activity Ex Vivo and for the Increase in Bleeding Time by Indobufen in Man

1992 ◽  
Vol 67 (02) ◽  
pp. 258-263 ◽  
Author(s):  
Raffaele De Caterina ◽  
Rosa Sicari ◽  
An Yan ◽  
Walter Bernini ◽  
Daniela Giannessi ◽  
...  
Keyword(s):  
Arachidonic Acid ◽  
Platelet Aggregation ◽  
Plasma Levels ◽  
Bleeding Time ◽  
Ex Vivo ◽  
Random Sequence ◽  
Antiplatelet Agent ◽  
Antiplatelet Drug ◽  
Double Blind

SummaryIndobufen is an antiplatelet drug able to inhibit thromboxane production and cyclooxygenase-dependent platelet aggregation by a reversible inhibition of cyclooxygenase. Indobufen exists in two enantiomeric forms, of which only d-indobufen is active in vitro in inhibiting cyclooxygenase. In order to verify that also inhibition of platelet function is totally accounted for by d-indobufen, ten patients with proven coronary artery disease (8 male, 2 female, age, mean ± S.D., 58.7 ± 7.5 years) were given, in random sequence, both 100 mg d-indobufen and 200 mg dl-indobufen as single administrations in a double-blind crossover design study with a washout period between treatments of 72 h. In all patients thromboxane (TX) B2 generation after spontaneous clotting (at 0, 1, 2, 4, 6, 8, 12, 24 h), drug plasma levels (at the same times), platelet aggregation in response to ADP, adrenaline, arachidonic acid, collagen, PAF, and bleeding time (at 0, 2, 12 h) were evaluated after each treatment. Both treatments determined peak inhibition of TXB2 production at 2 h from administration, with no statistical difference between the two treatments (97 ±3% for both treatments). At 12 h inhibition was 87 ± 6% for d-indobufen and 88 ± 6% for dl-indobufen (p = NS). Inhibition of TXB2 production correlated significantly with plasma levels of the drugs. Maximum inhibitory effect on aggregation was seen in response to collagen 1.5 pg/ml (63 ± 44% for d-indobufen and 81 ± 22% for dl-indobufen) and arachidonic acid 0.5-2 mM (78 ± 34% for d-indobufen and 88 ± 24% for dl-indobufen) at 2 h after each administration. An effect of both treatments on platelet aggregation after 12 h was present only for adrenaline 2 μM (55 ± 41% for d-indobufen and 37 ± 54% for dl-indobufen), collagen 1.5 pg/ml (69 ± 30% for d-indobufen and 51 ± 61% for dl-indobufen), arachidonic acid 0.5-2 mM (56 ± 48% for d-indobufen and 35 ± 49% for dl-indobufen). The extent of inhibition of TX production and the extent of residual platelet aggregation were never significantly different between treatments. Bleeding time prolongation was similar in the two treatment groups without showing a pronounced and long lasting effect (from 7.0 ± 2.0 min to 10.0 ± 3.0 min at 2 h and 8.0 ± 2.0 min at 12 h for d-indobufen; from 6.0 ±1.0 min to 8.5 ± 2.0 min at 2 h and 8.0 ± 1.0 min at 12 h for dl-indobufen). These results demonstrate that the biological activity of dl-indobufen as an antiplatelet agent in vivo is totally accounted for by d-indobufen.

Effects of Ticlopidine of Platelet Function in Men with Stable Angina Pectoris

1985 ◽  
Vol 54 (04) ◽  
pp. 808-812 ◽  
Author(s):  
Ulf Berglund ◽  
Henning von Schenck ◽  
Lars Wallentin
Keyword(s):  
Platelet Aggregation ◽  
Angina Pectoris ◽  
Platelet Function ◽  
Plasma Levels ◽  
Platelet Reactivity ◽  
Inhibitory Effect ◽  
Controlled Study ◽  
Double Blind ◽  
Platelet Factor

SummaryThe effects of ticlopidine (T) (500 mg daily) on platelet function were investigated in a double-blind placebo-controlled study in 38 middle-aged men with stable incapacitating angina pectoris. The in vitro platelet reactivity to aggregating agents, the platelet sensitivity to prostacyclin and the plasma levels of platelet specific proteins and fibrinogen were determined before and after 4 and 8 weeks of treatment. T exerted a potent inhibitory effect on ADP- and collagen-induced platelet aggregation. The effect of T was proportional to the pretreatment reactivity to ADP and collagen. The inhibitory effect of T on the epinephrine response was less pronounced. The plasma levels of beta-thromboglobulin, platelet factor 4 and fibrinogen were not influenced by T. The platelet inhibition of prostacyclin was potentiated by T, and it was demonstrated that T and prostacyclin had synergistic inhibitory effects on platelet aggregation.

The Involvement of Platelets and the Coronary Vasculature in Collagen-Induced Sudden Death in Rabbits

1985 ◽  
Vol 53 (01) ◽  
pp. 070-074 ◽  
Author(s):  
G Mallarkey ◽  
G M Smith
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Platelet Count ◽  
Sudden Death ◽  
Myocardial Ischaemia ◽  
Plasma Levels ◽  
Sodium Citrate ◽  
Plasma Samples ◽  
Calcium Entry Blockers

SummaryThe mechanism of collagen-induced sudden death in rabbits was studied by measuring blood pressure (BP), heart rate, ECG, the continuous platelet count and the plasma levels of thromboxane B2 (TxB2) and 6-keto prostaglandin Fia (6-keto PGF1α). Death was preceded by myocardial ischaemia and a sharp fall in BP which occurred before any fall in platelet count was observed. The calcium entry blockers (CEBs), verapamil, nifedipine and PY 108-068 protected the rabbits from sudden death without any significant effect on the decrease in the platelet count or increase in plasma TxB2 levels. 6-keto PGF1α could not be detected in any plasma samples. Indomethacin and tri-sodium citrate also protected the rabbits but significantly reduced the fall in platelet count and plasma TxB2. In vitro studies on isolated aortae indicated that verapamil non-specifically inhibited vasoconstriction induced by KC1, adrenaline and U46619 (a thromboxane agonist). It is concluded that CEBs physiologically antagonize the vasoconstricting actions of platelet-derived substances and that it is coronary vasoconstriction that is primarily the cause of death.

Rapid, Refined, and Robust Method for Expression, Purification, and Characterization of Recombinant Human Amyloid-beta M1-42

2019 ◽  
Author(s):  
Priya Prakash ◽  
Travis Lantz ◽  
Krupal P. Jethava ◽  
Gaurav Chopra
Keyword(s):  
Amyloid Beta ◽  
Western Blots ◽  
Force Microscopy ◽  
E Coli ◽  
Atomic Force ◽  
Set Up ◽  
Short Time

Amyloid plaques found in the brains of Alzheimer’s disease (AD) patients primarily consists of amyloid beta 1-42 (Ab42). Commercially, Ab42 is synthetized using peptide synthesizers. We describe a robust methodology for expression of recombinant human Ab(M1-42) in Rosetta(DE3)pLysS and BL21(DE3)pLysS competent E. coli with refined and rapid analytical purification techniques. The peptide is isolated and purified from the transformed cells using an optimized set-up for reverse-phase HPLC protocol, using commonly available C18 columns, yielding high amounts of peptide (~15-20 mg per 1 L culture) in a short time. The recombinant Ab(M1-42) forms characteristic aggregates similar to synthetic Ab42 aggregates as verified by western blots and atomic force microscopy to warrant future biological use. Our rapid, refined, and robust technique to purify human Ab(M1-42) can be used to synthesize chemical probes for several downstream in vitro and in vivo assays to facilitate AD research.

In vitro Cytotoxicity and Genotoxicity Analysis of Ten Tannery Chemicals Using SOS/umu Tests and High-content In vitro Micronucleus Tests

2018 ◽  
Vol 21 (4) ◽  
pp. 262-270 ◽  
Author(s):  
Zehao Huang ◽  
Na Li ◽  
Kaifeng Rao ◽  
Cuiting Liu ◽  
Zijian Wang ◽  
...  
Keyword(s):  
Micronucleus Test ◽  
A549 Cells ◽  
Quantitative Structure Activity Relationship ◽  
In Vitro Cytotoxicity ◽  
Cytotoxic Effects ◽  
Qsar Analysis ◽  
Cell Assays ◽  
Micronucleus Tests ◽  
Damaging Effects

Background: More than 2,000 chemicals have been used in the tannery industry. Although some tannery chemicals have been reported to have harmful effects on both human health and the environment, only a few have been subjected to genotoxicity and cytotoxicity evaluations. Objective: This study focused on cytotoxicity and genotoxicity of ten tannery chemicals widely used in China. Materials and Methods: DNA-damaging effects were measured using the SOS/umu test with Salmonella typhimurium TA1535/pSK1002. Chromosome-damaging and cytotoxic effects were determined with the high-content in vitro Micronucleus test (MN test) using the human-derived cell lines MGC-803 and A549. Conclusion: The cytotoxicity of the ten tannery chemicals differed somewhat between the two cell assays, with A549 cells being more sensitive than MGC-803 cells. None of the chemicals induced DNA damage before metabolism, but one was found to have DNA-damaging effects on metabolism. Four of the chemicals, DY64, SB1, DB71 and RR120, were found to have chromosome-damaging effects. A Quantitative Structure-Activity Relationship (QSAR) analysis indicated that one structural feature favouring chemical genotoxicity, Hacceptor-path3-Hacceptor, may contribute to the chromosome-damaging effects of the four MN-test-positive chemicals.

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