RT Journal Article
SR Electronic
T1 TAK-242 (Resatorvid), a Small Molecule Inhibitor of Toll-Like Receptor (TLR) 4 Signaling, Binds Selectively to TLR4 and Interferes with Interactions between TLR4 and Its Adaptor Molecules
JF Molecular Pharmacology
JO Mol Pharmacol
FD American Society for Pharmacology and Experimental Therapeutics
SP mol.110.068064
DO 10.1124/mol.110.068064
A1 Naoko Matsunaga
A1 Noboru Tsuchimori
A1 Tatsumi Matsumoto
A1 Masayuki Ii
YR 2010
UL http://molpharm.aspetjournals.org/content/early/2010/09/29/mol.110.068064.abstract
AB TAK-242 (resatorvid), a small molecule specific inhibitor of Toll-like receptor (TLR) 4 signaling, inhibits the production of lipopolysaccharide-induced inflammatory mediators by binding to the intracellular domain of TLR4. Previously, Cys747 in TLR4 was identified as the binding site of TAK-242. However, the mechanism by which TAK-242 inhibits TLR4 signaling after binding to TLR4 remains unknown. The present study demonstrated, using coimmunoprecipitation, that TAK-242 interferes with protein-protein interactions between TLR4 and its adaptor molecules. Among ten different human TLRs, TAK-242 selectively bound to TLR4. The time course of the inhibitory effect of TAK-242 on inflammatory mediator production corresponded to that of the binding of TAK-242 to TLR4. TAK-242 inhibited the association of TLR4 with TIR domain-containing adaptor protein (TIRAP) or TRIF-related adaptor molecule (TRAM) in HEK293 cells overexpressing TLR4, MD-2 and TIRAP or TRAM, respectively. TAK-242 inhibited the TIRAP-mediated activation of nuclear factor kappa B (NF-kB) and the TRAM-mediated activation of NF-kB and interferon-sensitive response element in HEK293 cells stably expressing TLR4, MD-2 and CD14. The activation of endogenous interleukin-1 receptor-associated kinase in RAW264.7 cells was also inhibited by TAK-242 treatment. These findings suggest that TAK-242 binds selectively to TLR4 and subsequently disrupts the interaction of TLR4 with adaptor molecules, thereby inhibiting TLR4 signal transduction and its downstream signaling events. This work proposes a novel paradigm of a small molecule capable of disrupting protein-protein interactions.