RESUMO
Oxidative stress plays a pivotal role in uncontrolled neuro-inflammation leading to many neurological diseases including Alzheimer's. One of the major antioxidant enzymes known to prevent deleterious effects due to oxidative stress is Cu,Zn-superoxide dismutase (SOD). In this study, we examined the regulatory function of SOD on the LPS-induced signaling pathways leading to NF-kappaB activation, expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in BV-2 cells using cell-permeable SOD. Treatment of BV-2 cells with cell-permeable SOD led to a decrease in LPS-induced reactive oxygen species (ROS) generation and significantly inhibited protein and mRNA levels of iNOS and COX-2 upregulated by LPS. Production of NO and PGE2 in LPS stimulated BV-2 cells was significantly abrogated by pretreatment with a cell-permeable SOD fusion protein. Furthermore, cell-permeable SOD inhibited LPS-induced NF-kappaB DNA-binding activity and activation of MAP kinases including ERK, JNK, and p38 in BV-2 cells. These data indicate that SOD has a regulatory function for LPS-induced NF-kappaB activation leading to expression of iNOS and COX-2 in BV-2 cells and suggest that cell-permeable SOD is a feasible therapeutic agent for regulation of ROS-related neurological diseases.
Assuntos
Ciclo-Oxigenase 2/biossíntese , Microglia/enzimologia , Óxido Nítrico Sintase Tipo II/biossíntese , Superóxido Dismutase/fisiologia , Animais , Linhagem Celular/efeitos dos fármacos , Linhagem Celular/enzimologia , Permeabilidade da Membrana Celular , Ciclo-Oxigenase 2/genética , Dinoprostona/biossíntese , Regulação para Baixo/efeitos dos fármacos , Indução Enzimática/efeitos dos fármacos , Regulação da Expressão Gênica/efeitos dos fármacos , HIV-1/genética , Humanos , Lipopolissacarídeos/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Camundongos , Microglia/efeitos dos fármacos , NF-kappa B/metabolismo , Óxido Nítrico/biossíntese , Óxido Nítrico Sintase Tipo II/genética , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/fisiologia , Inibidores de Proteínas Quinases/farmacologia , Proteínas Recombinantes de Fusão/fisiologia , Superóxido Dismutase/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/genética , Produtos do Gene tat do Vírus da Imunodeficiência Humana/fisiologiaRESUMO
Keratinocytes, one of major cell types in the skin, can be induced by TNF-alpha and IFN-gamma to express thymus- and activation-regulated chemokine (TARC/CCL17), which is considered to be a pivotal mediator in the inflammatory responses during the development of inflammatory skin diseases, such as atopic dermatitis (AD). In this study, we examined the effect of 1,2,3,4,6-penta-O-galloyl-beta-d-glucose (PGG), isolated from the barks of Juglans mandshurica, on TNF-alpha/IFN-gamma induced CCL17 expression in the human keratinocyte cell line HaCaT. Pretreatment of HaCaT cells with PGG suppressed TNF-alpha/IFN-gamma-induced protein and mRNA expression of CCL17. PGG significantly inhibited TNF-alpha/IFN-gamma-induced NF-kappaB activation as well as STAT1 activation. Furthermore, pretreatment with PGG resulted in significant reduction in expression of CXCL9, 10, and 11 in the HaCaT cells treated with IFN-gamma. These results suggest that PGG may exert anti-inflammatory responses by suppressing TNF-alpha and/or IFN-gamma-induced activation of NF-kappaB and STAT1 in the keratinocytes and might be a useful tool in therapy of skin inflammatory diseases.
