RESUMO
Receptor-interacting protein kinase 2 (RIP2 or RICK, herein referred to as RIPK2) is linked to the pathogen pathway that activates nuclear factor κ-light-chain-enhancer of activated B cells (NFκB) and autophagic activation. Using molecular modeling (docking) and chemoinformatics analyses, we used the RIPK2/ponatinib crystal structure and searched in chemical databases for small molecules exerting binding interactions similar to those exerted by ponatinib. The identified RIPK2 inhibitors potently inhibited the proliferation of cancer cells by > 70% and also inhibited NFκB activity. More importantly, in vivo inhibition of intestinal and lung inflammation rodent models suggests effectiveness to resolve inflammation with low toxicity to the animals. Thus, our identified RIPK2 inhibitor may offer possible therapeutic control of inflammation in diseases such as inflammatory bowel disease, asthma, cystic fibrosis, primary sclerosing cholangitis, and pancreatitis.
Assuntos
Descoberta de Drogas , Inibidores de Proteínas Quinases/química , Inibidores de Proteínas Quinases/farmacologia , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/antagonistas & inibidores , Apoptose/efeitos dos fármacos , Domínio Catalítico , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Colite Ulcerativa/tratamento farmacológico , Humanos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Simulação de Acoplamento Molecular , NF-kappa B/metabolismo , Inibidores de Proteínas Quinases/metabolismo , Inibidores de Proteínas Quinases/uso terapêutico , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/química , Proteína Serina-Treonina Quinase 2 de Interação com Receptor/metabolismoRESUMO
Necroptosis is a lytic, inflammatory form of cell death that not only contributes to pathogen clearance but can also lead to disease pathogenesis. Necroptosis is triggered by RIPK3-mediated phosphorylation of MLKL, which is thought to initiate MLKL oligomerisation, membrane translocation and membrane rupture, although the precise mechanism is incompletely understood. Here, we show that K63-linked ubiquitin chains are attached to MLKL during necroptosis and that ubiquitylation of MLKL at K219 significantly contributes to the cytotoxic potential of phosphorylated MLKL. The K219R MLKL mutation protects animals from necroptosis-induced skin damage and renders cells resistant to pathogen-induced necroptosis. Mechanistically, we show that ubiquitylation of MLKL at K219 is required for higher-order assembly of MLKL at membranes, facilitating its rupture and necroptosis. We demonstrate that K219 ubiquitylation licenses MLKL activity to induce lytic cell death, suggesting that necroptotic clearance of pathogens as well as MLKL-dependent pathologies are influenced by the ubiquitin-signalling system.