|
KMID : 0578320080250020253
|
|
Molecules and Cells
2008 Volume.25 No. 2 p.253 ~ p.257
|
|
|
Acrolein with an alpha, beta-unsaturated Carbonyl Group Inhibits LPS-induced Homodimerization of Toll-like Receptor 4
|
|
Lee Jeon-Soo
Youn Hyung-Sun
Lee Mi-Young
Lee Joo-Young
Hwang Daniel H.
|
|
|
Abstract
|
|
|
|
Acrolein is a highly electrophilic alpha,beta-unsaturated aldehyde present in a number of environmental sources, especially cigarette smoke. It reacts strongly with the thiol groups of cysteine residues by Michael addition and has been reported to inhibit nuclear factor-kB (NF-kB) activation by lipopolysaccharide (LPS). The mechanism by which it inhibits NF-?B is not clear. Toll-like receptors (TLRs) play a key role in sensing microbial components and inducing innate immune responses, and LPS-induced dimerization of TLR4 is required for activation of downstream signaling pathways. Thus, dimerization of TLR4 may be one of the first events involved in activating TLR4-mediated signaling pathways. Stimulation of TLR4 by LPS activates both myeloid differential factor 88 (MyD88)- and TIR domain-containing adapter inducing IFNbeta(TRIF)-dependent signaling pathways leading to activation of NF-kB and IFN-regulatory factor 3 (IRF3). Acrolein inhibited NF-kB and IRF3 activation by LPS, but it did not inhibit NF-kB or IRF3 activation by MyD88, inhibitor kB kinase (IKK)beta, TRIF, or TNF-receptor-associated factor family member-associated NF-kB activator (TANK)-binding kinase 1 (TBK1). Acrolein inhibited LPS-induced dimerization of TLR4, which resulted in the down-regulation of NF-kB and IRF3 activation. These results suggest that activation of TLRs and subsequent immune/inflammatory responses induced by endogenous molecules or chronic infection can be modulated by certain chemicals with a structural motif that enables Michael addition.
|
|
|
KEYWORD
|
|
|
Acrolein, Dimerization, LPS, Michael Addition, NF-κB, IRF3, Toll-like Receptor
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
  
|
|