scholarly journals Bruton's Tyrosine Kinase Is a Toll/Interleukin-1 Receptor Domain-binding Protein That Participates in Nuclear Factor κB Activation by Toll-like Receptor 4

2003 ◽  
Vol 278 (28) ◽  
pp. 26258-26264 ◽  
Author(s):  
Caroline A. Jefferies ◽  
Sarah Doyle ◽  
Cornelia Brunner ◽  
Aisling Dunne ◽  
Elizabeth Brint ◽  
...  
2021 ◽  
Vol 12 ◽  
Author(s):  
Iván Parra-Izquierdo ◽  
Hari Hara Sudhan Lakshmanan ◽  
Alexander R. Melrose ◽  
Jiaqing Pang ◽  
Tony J. Zheng ◽  
...  

Circulating platelets establish a variety of immunological programs and orchestrate inflammatory responses at the endothelium. Platelets express the innate immunity family of Toll-like receptors (TLRs). While TLR2/TLR1 ligands are known to activate platelets, the effects of TLR2/TLR6 ligands on platelet function remain unclear. Here, we aim to determine whether the TLR2/TLR6 agonists Pam2CSK4 and FSL-1 activate human platelets. In addition, human umbilical vein endothelial cells (HUVECs) and platelets were co-cultured to analyze the role of platelet TLR2/TLR6 on inflammation and adhesion to endothelial cells. Pam2CSK4, but not FSL-1, induced platelet granule secretion and integrin αIIbβ3 activation in a concentration-dependent manner. Moreover, Pam2CSK4 promoted platelet aggregation and increased platelet adhesion to collagen-coated surfaces. Mechanistic studies with blocking antibodies and pharmacologic inhibitors demonstrated that the TLR2/Nuclear factor-κB axis, Bruton’s-tyrosine kinase, and a secondary ADP feedback loop are involved in Pam2CSK4-induced platelet functional responses. Interestingly, Pam2CSK4 showed cooperation with immunoreceptor tyrosine-based activation motif (ITAM)-mediated signaling to enhance platelet activation. Finally, the presence of platelets increased inflammatory responses in HUVECs treated with Pam2CSK4, and platelets challenged with Pam2CSK4 showed increased adhesion to HUVECs under static and physiologically relevant flow conditions. Herein, we define a functional role for platelet TLR2-mediated signaling, which may represent a druggable target to dampen excessive platelet activation in thrombo-inflammatory diseases.


2018 ◽  
Vol 499 (2) ◽  
pp. 260-266 ◽  
Author(s):  
Theresa H. Page ◽  
Anna M. Urbaniak ◽  
Ana I. Espirito Santo ◽  
Lynett Danks ◽  
Timothy Smallie ◽  
...  

2020 ◽  
Vol 48 (12) ◽  
pp. 030006052098094
Author(s):  
Shuang Qin ◽  
Li Li ◽  
Jia Liu ◽  
Jinrui Zhang ◽  
Qing Xiao ◽  
...  

Objective The present study aimed to evaluate the effects of cluster of differentiation (CD)4+CD25+ forkhead box p3 (Foxp3)+ regulatory T cells (Tregs) on unexplained recurrent spontaneous abortion (URSA) and the associated mechanisms. Methods The proportion of CD4+CD25+Foxp3+ Tregs and inflammatory cytokine concentrations in the peripheral blood of women with URSA were measured by flow cytometry and enzyme-linked immunosorbent assay, respectively. CBA/JxDBA/2J mating was used to establish an abortion-prone mouse model and the model mice were treated with the Toll-like receptor 4 (TLR4) antagonist E5564 and the TLR4 agonist lipopolysaccharide. Results The proportion of CD4+CD25+Foxp3+ Tregs was decreased and the inflammatory response was increased in women with URSA. In the abortion-prone mouse model, E5564 significantly increased the proportion of CD4+CD25+Foxp3+ Tregs, decreased the inflammatory response, and increased Foxp3 mRNA and protein expression. Lipopolysaccharide had adverse effects on the abortion-prone model. Conclusions These data suggest that CD4+CD25+Foxp3+ Tregs regulate immune homeostasis in URSA via the TLR4/nuclear factor-κB pathway, and that the TLR4 antagonist E5564 may be a novel and potential drug for treating URSA.


2015 ◽  
Vol 93 (4) ◽  
pp. 253-260 ◽  
Author(s):  
Yu Zhang ◽  
Ruhong Yan ◽  
Yae Hu

Oxymatrine (OMT) is the quinolizidine alkaloid extracted from the Chinese herb Sophora flavescens Ait. that has many pharmacological effects and is used for the treatment of some inflammatory diseases. In this study, RAW264.7 cells and THP-1 differentiated macrophages were pretreated with various concentrations of OMT at 2 h prior to treatment with lipopolysaccharide (LPS) (1.0 μg/mL) for different durations. We detected the anti-inflammatory effect of OMT in LPS-stimulated macrophages and investigated the molecular mechanism. We showed that OMT pretreatment significantly inhibited the LPS-induced secretion of nitric oxide (NO), interleukin-1 beta (IL-1β), and tumor necrosis factor-alpha (TNF-α) in supernatant, attenuated the mRNA levels of inducible nitric oxide synthase (iNOS), IL-1β, TNF-α, and Toll-like receptor 4 (TLR4), increased TLR4 and phosphorylation of inhibitor of kappa B-alpha (p-IBα) in cytosol, and decreased the nuclear level of nuclear factor-κB (NF-κB) p65 in macrophages. In conclusion, OMT exerts anti-inflammatory properties in LPS-stimulated macrophages by down-regulating the TLR4/NF-κB pathway.


Sign in / Sign up

Export Citation Format

Share Document