Toll-Like Receptors Drive Specific Patterns of Tolerance and Training on Restimulation of Macrophages.

Tolerance is a long-recognized property of macrophages that leads to an altered response to repeated or chronic exposure to endotoxin. The physiological role of tolerance is to limit the potential damage to host tissue that may otherwise result from prolonged production of pro-inflammatory cytokines. Tolerance is induced by all toll-like receptor (TLR) ligands tested to date, however, tolerance induced by the TLR4 ligand lipopolysaccharide (LPS) is by far the best studied.

Measurement of NF-κB transcriptional activity and identification of NF-κB cis-regulatory elements using luciferase assays.

The NF-κB family of transcription factors is activated in response to numerous environmental stimuli and coordinates the transcriptional response to immunoreceptors such as the Toll-like receptors, cytokine receptors, and antigen receptors, growth factors, survival factors, and stress signals such as ultraviolet irradiation and oxidative stress. The transcriptional targets of these various pathways include approximately 500 experimentally indentified genes, and it is highly likely that many others remain to be discovered. A genome-wide analysis of NF-κB-chromatin interactions has revealed a surprisingly large number of NF-κB binding sites across the entire genome, many of which are found in intergenic regions and many more do not appear to be associated with changes in transcription of nearby genes.

Identification of a unique hybrid macrophage-polarization state following recovery from lipopolysaccharide tolerance.

LPS tolerance is an essential immune-homeostatic response to repeated exposure to LPS that prevents excessive inflammatory responses. LPS tolerance induces a state of altered responsiveness in macrophages, resulting in repression of proinflammatory gene expression and increased expression of factors that mediate the resolution of inflammation. In this study, we analyzed the transcriptional plasticity of macrophages following LPS tolerance using genome-wide transcriptional profiling.

Deubiquitination of NF-κB by Ubiquitin-Specific Protease-7 promotes transcription.

NF-κB is the master regulator of the immune response and is responsible for the transcription of hundreds of genes controlling inflammation and immunity. Activation of NF-κB occurs in the cytoplasm through the kinase activity of the IκB kinase complex, which leads to translocation of NF-κB to the nucleus. Once in the nucleus, NF-κB transcriptional activity is regulated by DNA binding-dependent ubiquitin-mediated proteasomal degradation.

Evidence that marine-derived, multi-mineral, Aquamin inhibits the NF-κB signaling pathway in vitro.

It is well established that nuclear factor kappa B (NF-κB) is a central regulator of the immune response and that dysregulation of NF-κB contributes to the pathogenesis of many autoimmune and inflammatory diseases. The food supplement Aquamin is a natural multi-mineral derived from the red algae Lithothamnion corallioides, rich in calcium, magnesium and 72 other trace minerals. This study describes an anti-inflammatory role for Aquamin in inhibiting NF-κB activation through reducing the phosphorylation and degradation of its upstream inhibitor IκBα.