RESUMO
Toll-like receptor 4 (TLR4) recognizes lipopolysaccharide (LPS) and triggers the activation of myeloid differention factor 88 (MyD88) and the Toll/interleukin-1 receptor domain-containing adapter, inducing interferon-ß (TRIF)-dependent major downstream signaling pathways. To evaluate the therapeutic potential of 1-[5-methoxy-2-(2-nitrovinyl)phenyl]pyrrolidine (MNP), previously synthesized in our laboratory, its effect on signal transduction via the TLR signaling pathways was examined. Here, we investigated whether MNP modulates the TLR4 signaling pathways and which anti-inflammatory target in TLR4 signaling is regulated by MNP. MNP inhibited the activation of nuclear factor-κB (NF-κB) induced by LPS (TLR4 agonist), and it also inhibited the expression of cyclooxygenase-2 and inducible nitric oxide synthase. MNP inhibited LPS-induced NF-κB activation by targeting TLR4 dimerization in addition to IKKß. These results suggest that MNP can modulate the TLR4 signaling pathway at the receptor level to decrease inflammatory gene expression.
Assuntos
Nitrocompostos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Pirrolidinas/farmacologia , Receptor 4 Toll-Like/metabolismo , Animais , Anti-Inflamatórios/farmacologia , Células Cultivadas , Ciclo-Oxigenase 2/biossíntese , Relação Dose-Resposta a Droga , Quinase I-kappa B/antagonistas & inibidores , Lipopolissacarídeos , Camundongos , NF-kappa B/biossíntese , Óxido Nítrico Sintase Tipo II/biossíntese , Transdução de Sinais/efeitos dos fármacosRESUMO
Toll-like receptors (TLRs) play significant roles in recognizing the pathogen-associated molecular patterns that induce innate immunity, and subsequently, acquired immunity. In general, TLRs have two downstream signaling pathways, the myeloid differential factor 88 (MyD88)-dependent and toll-interleukin-1 receptor domain-containing adapter-inducing interferon-ß (TRIF)-dependent pathways, which lead to the activation of nuclear factor-kappa B (NF-κB) and interferon regulatory factor 3 (IRF3). 1-[5-methoxy-2-(2-nitrovinyl)phenyl]pyrrolidine (MNP) has been previously synthesized in our laboratory. To evaluate the therapeutic potential of MNP, its effect on signal transduction via the TLR signaling pathways was examined. MNP was shown to inhibit the activation of NF-κB and IRF3 induced by TLR agonists, as well as to inhibit the expression of cyclooxygenase-2, inducible nitric oxide synthase, and interferon inducible protein-10. MNP also inhibited the activation of NF-κB and IRF3 induced by the overexpression of downstream signaling components of the MyD88- or TRIF-dependent signaling pathways. These results suggest that MNP can modulate MyD88- and TRIF-dependent signaling pathways of TLRs, leading to decreased inflammatory gene expression.
Assuntos
Nitrocompostos/farmacologia , Pirrolidinas/farmacologia , Receptores Toll-Like/agonistas , Proteínas Adaptadoras de Transporte Vesicular/metabolismo , Animais , Quimiocina CXCL10/metabolismo , Ciclo-Oxigenase 2/metabolismo , Células HEK293 , Humanos , Imunidade Inata , Fator Regulador 3 de Interferon/genética , Fator Regulador 3 de Interferon/metabolismo , Camundongos , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/metabolismo , Óxido Nítrico Sintase Tipo II/metabolismo , Nitrocompostos/química , Pirrolidinas/química , Células RAW 264.7 , Transdução de Sinais/efeitos dos fármacosRESUMO
Toll-like receptor 4 (TLR4) recognizes LPS and triggers the activation of the myeloid differential factor 88 (MyD88)- and toll-interleukin-1 receptor domain-containing adapter, inducing interferon-ß (TRIF)-dependent major downstream signaling pathways. Previously, we presented biochemical evidence that 1-[4-Fluoro-2-(2-nitrovinyl)phenyl]pyrrolidine (FPP), which was synthesized in our laboratory, inhibits NF-κB activation induced by LPS. Here, we investigated whether FPP modulates the TLR4 downstream signaling pathways and what anti-inflammatory target in TLR4 signaling is regulated by FPP. FPP inhibited LPS-induced NF-κB activation by targeting TLR4 dimerization. These results suggest that FPP can modulate the TLR4 signaling pathway at the receptor level to decrease inflammatory gene expression.
Assuntos
Lipopolissacarídeos/farmacologia , Multimerização Proteica/efeitos dos fármacos , Pirrolidinas/farmacologia , Receptor 4 Toll-Like/metabolismo , Compostos de Vinila/farmacologia , Animais , Células Cultivadas , Células HEK293 , Humanos , Camundongos , Estrutura Molecular , NF-kappa B/metabolismo , Ligação Proteica/efeitos dos fármacos , Receptor 4 Toll-Like/químicaRESUMO
When various pathogens invade a host, toll-like receptors (TLRs) play a significant role in recognizing the pathogen-associated molecular patterns carried by the pathogens to induce innate immune reaction, followed by acquired immunity reaction. TLRs have two downstream signaling pathways, the myeloid differential factor 88 (MyD88)-dependent and toll-interleukin-1 receptor domain-containing adapter inducing interferon-ß (TRIF)-dependent pathways. To evaluate the therapeutic potential of 1-[4-fluoro-2-(2-nitrovinyl)phenyl]pyrrolidine (FPP), previously synthesized in our laboratory, its effect on signal transduction via the TLR signaling pathways was examined. FPP inhibited the activation of nuclear factor-κB (NF-κB) and interferon regulatory factor 3 (IRF3) induced by TLR agonists, as well as inhibited the expression of cyclooxygenase-2, inducible nitric oxide synthase, and interferon inducible protein-10. FPP also inhibited the activation of NF-κB and IRF3 when induced by the overexpression of downstream signaling components of the TLRs. As a result, FPP has potential to become a new therapeutic drug for many inflammatory diseases.
