RESUMO
The ATP-gated P2X(7) receptor (P2X(7)R) is a promising therapeutic target in chronic inflammatory diseases with highly specific antagonists currently under clinical trials for rheumatoid arthritis. Anti-inflammatory actions of P2X(7)R antagonists are considered to result from inhibition of P2X(7)R-induced release of proinflammatory cytokines from activated macrophages. However, P2X(7)Rs are also expressed in resting macrophages, suggesting that P2X(7)R may also signal via cytokine-independent mechanisms involved in joint disease. In this study, we examined P2X(7)R function in resting human lung macrophages and mouse bone marrow-derived macrophages and found that ATP induced rapid release of the lysosomal cysteine proteases cathepsin B, K, L, and S and that was independent of the presence of the proinflammatory cytokines IL-1beta and IL-18. Cathepsins released into the medium were effective to degrade collagen extracellular matrix. ATP-induced cathepsin release was abolished by P2X(7)R antagonists, absent from P2X(7)R(-/-) mouse macrophages, and not associated with cell death. Our results suggest P2X(7)R activation may play a novel and direct role in tissue damage through release of cathepsins independently of its proinflammatory actions via IL-1 cytokines.
Assuntos
Catepsinas/metabolismo , Citocinas/metabolismo , Artropatias/metabolismo , Macrófagos/metabolismo , Receptores Purinérgicos P2/metabolismo , Trifosfato de Adenosina/farmacologia , Animais , Western Blotting , Catepsina B/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Etanercepte , Humanos , Imunoglobulina G/farmacologia , Imunossupressores/farmacologia , Interleucina-1beta/metabolismo , Artropatias/genética , Células L , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Metotrexato/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Estrutura Molecular , Antagonistas do Receptor Purinérgico P2 , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2X7 , Receptores do Fator de Necrose Tumoral , Tiazóis/química , Tiazóis/farmacologiaRESUMO
The optimisation of a new series of high potency muscarinic M3 antagonists, derived from high throughput screening library hit is described.
Assuntos
Receptor Muscarínico M3/antagonistas & inibidores , Compostos de Espiro/química , Animais , Avaliação Pré-Clínica de Medicamentos , Hepatócitos/metabolismo , Humanos , Microssomos/metabolismo , Ratos , Receptor Muscarínico M3/metabolismo , Compostos de Espiro/síntese química , Compostos de Espiro/farmacologiaRESUMO
A novel series of antagonists of the human P2X7 receptor is described. Modification of substituents enabled identification of compounds selective for the rat P2X7 receptor and provides useful pharmacological tools for evaluation of the role of P2X7 in disease.