Analysis of binding site for the novel small-molecule TLR4 signal transduction inhibitor TAK-242 and its therapeutic effect on mouse sepsis model.
Br J Pharmacol
; 157(7): 1250-62, 2009 Aug.
Article
em En
| MEDLINE
| ID: mdl-19563534
ABSTRACT
BACKGROUND AND PURPOSE:
TAK-242, a novel synthetic small-molecule, suppresses production of multiple cytokines by inhibiting Toll-like receptor (TLR) 4 signalling. In this study, we investigated the target molecule of TAK-242 and examined its therapeutic effect in a mouse sepsis model. EXPERIMENTALAPPROACH:
Binding assay with [(3)H]-TAK-242 and nuclear factor-kappaB reporter assay were used to identify the target molecule and binding site of TAK-242. Bacillus calmette guerin (BCG)-primed mouse sepsis model using live Escherichia coli was used to estimate the efficacy of TAK-242 in sepsis. KEYRESULTS:
TAK-242 strongly bound to TLR4, but binding to TLR2, 3, 5, 9, TLR-related adaptor molecules and MD-2 was either not observed or marginal. Mutational analysis using TLR4 mutants indicated that TAK-242 inhibits TLR4 signalling by binding to Cys747 in the intracellular domain of TLR4. TAK-242 inhibited MyD88-independent pathway as well as MyD88-dependent pathway and its inhibitory effect was largely unaffected by lipopolysaccharide (LPS) concentration and types of TLR4 ligands. TAK-242 had no effect on the LPS-induced conformational change of TLR4-MD-2 and TLR4 homodimerization. In mouse sepsis model, although TAK-242 alone did not affect bacterial counts in blood, if co-administered with ceftazidime it inhibited the increases in serum cytokine levels and improved survival of mice. CONCLUSIONS AND IMPLICATIONS TAK-242 suppressed TLR4 signalling by binding directly to a specific amino acid Cys747 in the intracellular domain of TLR4. When co-administered with antibiotics, TAK-242 showed potent therapeutic effects in an E. coli-induced sepsis model using BCG-primed mice. Thus, TAK-242 may be a promising therapeutic agent for sepsis.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Sulfonamidas
/
Sepse
/
Receptor 4 Toll-Like
Tipo de estudo:
Prognostic_studies
Limite:
Animals
/
Humans
Idioma:
En
Ano de publicação:
2009
Tipo de documento:
Article