scholarly journals Interleukin-1 type 1 receptor/Toll-like receptor signalling in epilepsy: the importance of IL-1beta and high-mobility group box 1

2011 ◽  
Vol 270 (4) ◽  
pp. 319-326 ◽  
Author(s):  
M. Maroso ◽  
S. Balosso ◽  
T. Ravizza ◽  
J. Liu ◽  
M. E. Bianchi ◽  
...  
2016 ◽  
Vol 38 (6) ◽  
pp. 2139-2151 ◽  
Author(s):  
Won Seok Yang ◽  
Nam Jeong Han ◽  
Jin Ju Kim ◽  
Mee Jeong Lee ◽  
Su-Kil Park

Background/Aims: Toll-like receptor 4 (TLR4) interacts with endogenous substances as well as lipopolysaccharide. We explored whether TLR4 is implicated in tumor necrosis factor-α (TNF-α) signal transduction in human aortic endothelial cells. Methods: The pathway was evaluated by transfection of siRNAs, immunoprecipitation and Western blot analysis. Results: TNF-α activated spleen tyrosine kinase (Syk) within 10 min, which led to endothelin-1 (ET-1) production. TLR4 was also rapidly activated by TNF-α stimulation, as shown by recruitment of interleukin-1 receptor-associated kinase 1 to TLR4 and its adaptor molecule, myeloid differentiation factor 88 (MyD88). siRNA depletion of TLR4 markedly attenuated TNF-α-induced Syk activation and ET-1 production. TLR4 inhibitor (CLI-095), TLR4-neutralizing antibody and siRNA depletion of MyD88 also attenuated TNF-α-induced Syk activation. Syk was co-immunoprecipitated with TLR4, and TNF-α activated Syk bound to TLR4. High-mobility group box 1 (HMGB1) was rapidly released and associated with TLR4 after TNF-α stimulation with a peak at 5 min, which was prevented by N-acetylcysteine, an antioxidant. Glycyrrhizin (HMGB1 inhibitor), HMGB1-neutralizing antibody and siRNA depletion of HMGB1 all suppressed TNF-α-induced Syk activation and ET-1 production. Conclusion: Upon TNF-α stimulation, TLR4 is activated by HMGB1 that is immediately released after the generation of reactive oxygen species, and plays a crucial role in the signal transduction.


2008 ◽  
Vol 36 (3) ◽  
pp. 449-452 ◽  
Author(s):  
Andrew G. Bowie

TLRs (Toll-like receptors) are an important class of pathogen-sensing proteins, which signal the presence of a pathogen by activating transcription factors, such as NF-κB (nuclear factor κB). The TLR pathway to NF-κB activation involves multiple phosphorylation and ubiquitination events. Notably, TRAF-6 [TNF (tumour necrosis factor)-receptor-associated factor-6] Lys63 polyubiquitination is a critical step in the formation of signalling complexes, which turn on NF-κB. Here, the relative role of different IRAKs [IL-1 (interleukin 1)-receptor-associated kinases] in NF-κB activation is discussed. Further, I demonstrate how understanding one molecular mechanism whereby vaccinia virus inhibits NF-κB activation has led to a revealing of a key role for IRAK-2 in TRAF-6-mediated NF-κB activation.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Angela Simona Montalto ◽  
Alessandra Bitto ◽  
Letteria Minutoli ◽  
Pietro Impellizzeri ◽  
Gaetano Costa ◽  
...  

Laparoscopy (LS) has been shown to decrease the inflammatory sequelae of endotoxemia.β-arrestin 2 plays an important function in signal transduction pathway of TLR4. High mobility group box-1 (HMGB-1) is involved in the delayed systemic inflammatory response. We investigated the effects of CO2insufflation on liver, lung, and kidney expression of bothβ-arrestin 2 and HMGB-1 during sepsis. Cecal ligation and puncture (CLP) was performed in male rats and 6 h later the animals were randomly assigned to receive a CO2pneumoperitoneum or laparotomy. Animals were euthanized; liver, lung, and kidney were removed for the evaluation ofβ-arrestin 2 and HMGB-1 expression. Immunohistochemical detection of myeloperoxidase (MPO) was investigated in lung and liver and bacterial load was determined in the peritoneal fluid. CO2pneumoperitoneum reduced peritoneal bacterial load, increased the expression ofβ-arrestin 2, and blunted the expression of the potent proinflammatory HMGB-1 in liver, lung, and kidney compared with laparotomy. Liver and lung MPO was markedly reduced in rats subjected to LS compared with laparotomy. We believe that CO2exerts an early protective effect by reducing bacterial load and likely toll-like receptor activation which in turn leads to a preservedβ-arrestin 2 expression and a reduced HMGB-1 expression.


2019 ◽  
Vol 32 (2) ◽  
pp. 89-94 ◽  
Author(s):  
Nafise Yaghouti ◽  
Reza Boostani ◽  
Asadollah Mohamamdi ◽  
Zohreh Poursina ◽  
Seyed Abdolrahim Rezaee ◽  
...  

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