Immunomodulatory effects of diclofenac in leukocytes through the targeting of Kv1.3 voltage-dependent potassium channels

Kv1.3 plays a crucial role in the activation and proliferation of T-lymphocytes and macrophages. While Kv1.3 is responsible for the voltage-dependent potassium current in T-cells, in macrophages this K+ current is generated by the association of Kv1.3 and Kv1.5. Patients with autoimmune diseases show a high number of effector memory T cells that are characterized by a high expression of Kv1.3 and Kv1.3 antagonists ameliorate autoimmune disorders in vivo. Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) used in patients who suffer from painful autoimmune diseases such as rheumatoid arthritis. In this study, we show that diclofenac impairs immune response via a mechanism that involves Kv1.3. While diclofenac inhibited Kv1.3 expression in activated macrophages and T-lymphocytes, Kv1.5 remained unaffected. Diclofenac also decreased iNOS levels in Raw 264.7 cells, impairing their activation in response to lipopolysaccharide (LPS). LPS-induced macrophage migration and IL-2 production in stimulated Jurkat T-cells were also blocked by pharmacological doses of diclofenac. These effects were mimicked by Margatoxin, a specific Kv1.3 inhibitor, and Charybdotoxin, which blocks both Kv1.3 and Ca2+-activated K+ channels (KCa3.1). Because Kv1.3 is a very good target for autoimmune therapies, the effects of diclofenac on Kv1.3 are of high pharmacological relevance. © 2010 Elsevier Inc.This work was supported by the Ministerio Ciencia e Innovación (MICINN), Spain (BFU2008-00431 and CSD2008-00005 to AF, SAF2007-65868 and FIS D06/0014/0006 to CV, and BFU2009-07501 to CS). NV and JB held a fellowship from the Ministerio Ciencia e Innovación (MICINN). MD held a FIS RD06/0014/0006 contract. NC and TG were supported by the Juan de la Cierva program (MICINN).Peer Reviewe

Immunomodulatory effects of diclofenac in leukocytes through the targeting of Kv1.3 voltage-dependent potassium channels

Kv1.3 plays a crucial role in the activation and proliferation of T-lymphocytes and macrophages. While Kv1.3 is responsible for the voltage-dependent potassium current in T-cells, in macrophages this K+ current is generated by the association of Kv1.3 and Kv1.5. Patients with autoimmune diseases show a high number of effector memory T cells that are characterized by a high expression of Kv1.3 and Kv1.3 antagonists ameliorate autoimmune disorders in vivo. Diclofenac is a non-steroidal anti-inflammatory drug (NSAID) used in patients who suffer from painful autoimmune diseases such as rheumatoid arthritis. In this study, we show that diclofenac impairs immune response via a mechanism that involves Kv1.3. While diclofenac inhibited Kv1.3 expression in activated macrophages and T-lymphocytes, Kv1.5 remained unaffected. Diclofenac also decreased iNOS levels in Raw 264.7 cells, impairing their activation in response to lipopolysaccharide (LPS). LPS-induced macrophage migration and IL-2 production in stimulated Jurkat T-cells were also blocked by pharmacological doses of diclofenac. These effects were mimicked by Margatoxin, a specific Kv1.3 inhibitor, and Charybdotoxin, which blocks both Kv1.3 and Ca2+-activated K+ channels (KCa3.1). Because Kv1.3 is a very good target for autoimmune therapies, the effects of diclofenac on Kv1.3 are of high pharmacological relevance. © 2010 Elsevier Inc.This work was supported by the Ministerio Ciencia e Innovación (MICINN), Spain (BFU2008-00431 and CSD2008-00005 to AF, SAF2007-65868 and FIS D06/0014/0006 to CV, and BFU2009-07501 to CS). NV and JB held a fellowship from the Ministerio Ciencia e Innovación (MICINN). MD held a FIS RD06/0014/0006 contract. NC and TG were supported by the Juan de la Cierva program (MICINN).Peer Reviewe