ABSTRACT
This work investigated the functional role of nuclear factor-kappaB (NF-kappaB) in respiratory burst activity and in expression of the human phagocyte nicotinamide adenine dinucleotide phosphate (NADPH) oxidase genes CYBB, CYBA, NCF1, and NCF2. U937 cells with a stably transfected repressor of NF-kappaB (IkappaBalpha-S32A/S36A) demonstrated significantly lower superoxide release and lower CYBB and NCF1 gene expression compared with control U937 cells. We further tested Epstein-Barr virus (EBV)-transformed B cells from patients with anhidrotic ectodermal dysplasia with immunodeficiency (EDA-ID), an inherited disorder of NF-kappaB function. Superoxide release and CYBB gene expression by EDA-ID cells were significantly decreased compared with healthy cells and similar to cells from patients with X-linked chronic granulomatous disease (X91(0) CGD). NCF1 gene expression in EDA-ID S32I cells was decreased compared with healthy control cells and similar to that in autosomal recessive (A47(0)) CGD cells. Gel shift assays demonstrated loss of recombinant human p50 binding to a NF-kappaB site 5' to the CYBB gene in U937 cells treated with NF-kappaB inhibitors, repressor-transfected U937 cells, and EDA-ID patients' cells. Zymosan phagocytosis was not affected by transfection of U937 cells with the NF-kappaB repressor. These studies show that NF-kappaB is necessary for CYBB and NCF1 gene expression and activation of the phagocyte NADPH oxidase in this model system.
Subject(s)
Ectodermal Dysplasia/immunology , Leukocytes/metabolism , Membrane Glycoproteins/genetics , NADPH Oxidases/metabolism , NF-kappa B/physiology , Cell Line, Transformed , Cells, Cultured , Gene Expression , Granulomatous Disease, Chronic/pathology , Humans , Leukocytes/pathology , NADPH Oxidase 2 , NADPH Oxidases/genetics , Phagocytes/metabolism , PhagocytosisABSTRACT
O processo inflamatório envolve a expressão de uma ampla série de proteínas inflamatórias, que incluem citocinas, quimiocinas, enzimas que produzem mediadores inflamatórios, receptores para mediadores inflamatórios e moléculas de adesão, cuja expressão gênica de muitos destes elementos é controlada pelo fator nuclear kappa B. Este fator pertence a uma classe de fatores de transcrição gênica que, além de regularem a expressão de múltiplos genes envolvidos na resposta inflamatória, controla também outros genes em outros tipos celulares. Vários fármacos de ação antiinflamatória, tanto hormonais e não-hormonais como os corticóides e salicilatos, possuem ação inibitória sobre o fator nuclear kappa B. Com a finalidade de desenvolver fármacos mais específicos e eficazes, muitos grupos de pesquisa vêm explorando a ação moduladora sobre este fator, com a finalidade de controlar o processo inflamatório. Nesta breve revisão abordaremos os aspectos farmacológicos mais importantes destes inibidores.
