laminaran and Shock--Septic

Growing evidence supports the role of transcription factor activation in the pathophysiology of inflammatory disorders, sepsis, ARDS, SIRS, and shock. Kinase mediated phosphorylation of IkappaBalpha is a crucial step in the NFkappaB activation pathway. We investigated IKBalpha phosphorylation in murine liver and lung extracts after cecal ligation and puncture (CLP) in the presence and absence of a glucan ligand. ICR mice were subjected to CLP. Unoperated and sham-operated mice served as the controls. Glucan phosphate (50 mg/kg) was administered 1 h before or 15 min after CLP. CLP increased hepatic and pulmonary levels of phospho-IkappaBalpha by 48-192%. Pre- or post-treatment with glucan phosphate decreased (P < 0.05) tissue phospho-IkappaBalpha levels in CLP mice. Phospho-IkappaBalpha in the glucan-CLP group were not significantly different from the unoperated controls. To investigate mechanisms we examined IKKbeta kinase activity, IkappaBalpha phosphorylation and degradation, and NFkappaB activity in a murine macrophage cell line, J774a.1, treated with LPS (1 microg/mL) and/or glucan phosphate (1 microg/mL) for up to 120 min. The glucan ligand blunted LPS-induced IKKbeta kinase activity, phosphorylation and degradation of IkappaBalpha, and NFkappaB nuclear binding activity. The data indicate that one mechanism by which (1-->3)-beta-D-glucan may alter the response to endotoxin or polymicrobial sepsis involves modulation of IKK3 kinase activity with subsequent decreases in IkappaBalpha phosphorylation and NFkappaB activation.

Topics: Animals; beta-Glucans; Cell Line; Cell Nucleus; Cells, Cultured; Cytosol; DNA-Binding Proteins; Gene Expression Regulation; Glucans; I-kappa B Kinase; I-kappa B Proteins; Intestinal Perforation; Ligands; Lipopolysaccharides; Liver; Lung; Macrophages; Male; Mice; Mice, Inbred ICR; NF-kappa B; NF-KappaB Inhibitor alpha; Phosphorylation; Protein Processing, Post-Translational; Protein Serine-Threonine Kinases; Sepsis; Shock, Septic