Nuclear Factor-kB (NF-kB), is a transcription factor composed of dimeric complexes of p50 (NF-kB1) or p52 (NF-kB2) usually associated with members of the Rel family (p65, c-Rel, Rel B) which have potent transactivation domains. Different combinations of NF-kB/Rel proteins bind distinct kB sites to regulate the transcription of different genes. In resting cells NF-kB resides in the cytoplasm in inactive form, complexed to members of a family of inhibitory proteins referred to as IkB. The bound IkB masks the NF-kB nuclear localization signal and thereby inhibits its nuclear transport. NF-kB can be activated by a variety of signals relevant to pathophysiology including inflammatory cytokines and bacterial lipopolysaccharides (LPS) as well as oxidative and fluid mechanical stress. Upon activation by these stimuli, IkB is phosphorylated and subsequently degraded. Phosphorylation targets IkB for ubiquitination and degradation by the 26S proteasome thus leading to NF-kB nuclear translocation. The same proteolytic pathway is involved in the processing of the p105 and p100 precursors to generate mature p50 and p52 subunits, respectively. Once in the nucleus, NF-kB is able to regulate the expression of many genes involved in the immune and inflammatory responses (i.e. inflammatory cytokines and adhesion molecules). Thus, new approaches to modulating NF-kB activation, and as a consequence inflammatory or metastatic processes, may take advantage of the selectivity of the ubiquitination and ATP-dependent proteolytic processes leading to IkB turnover. This review will analyze the current strategies aimed at interfering with NF-kB activation and will consider the ubiquitination system as a new selective target for the development of new anti-inflammatory therapies.

Transfection of cis-element double-stranded oligonucleotides, referred to as decoy ODNs, has been reported to be a powerful tool that provides a new class of antigene strategies for gene therapy. However, one of the major limitations of the decoy approach is the rapid degradation of phosphodiester oligonucleotides by intracellular nucleases. To date, several DNA analogs have been employed to overcome this issue, but insufficient efficacy and/or specificity have limited their in vivo usefulness. In this paper we have investigated the use of conformationally restricted nucleotides in the design of decoy molecules for nuclear transcription factor κB (NF-κB). Starting from a synthetic double-stranded oligonucleotide, containing the κB consensus binding sequence, we designed a panel of decoy molecules modified to various extents and at various positions with locked nucleic acids (LNAs). Our results indicate that the addition of terminal LNA bases, outside the κB sequence, to generate LNA–DNA–LNA co-polymers was sufficient to confer appreciable protection towards nuclease digestion, without interfering with transcription factor binding. Conversely, insertion of LNA substitutions in the context of the κB-binding site resulted in further increased stability, but caused a loss of affinity of NF-κB for the target sequence. However, our results also indicate that this latter effect was apparently dependent not only on the extent but also on strand positioning of the internal LNA substitutions. This observation is of great importance since it provides evidence for the possibility of tuning DNA–LNA duplexes with internal LNAs into decoy agents with improved features in terms of biological stability and inhibitory effect.

Oxysterols are bioactive lipids that act as regulators of lipid metabolism, inflammation, cell viability and are involved in several diseases, including atherosclerosis. Mounting evidence linked the atherosclerosis to endothelium dysfunction; in fact, the endothelium regulates the vascular system with roles in processes such as hemostasis, cell cholesterol, hormone trafficking, signal transduction and inflammation. Several papers shed light the ability of oxysterols to induce apoptosis in different cell lines including endothelial cells. Apoptotic endothelial cell and endothelial denudation may constitute a critical step in the transition to plaque erosion and vessel thrombosis, so preventing the endothelial damaged has garnered considerable attention as a novel means of treating atherosclerosis. Endoplasmic reticulum (ER) is the site where the proteins are synthetized and folded and is necessary for most cellular activity; perturbations of ER homeostasis leads to a condition known as endoplasmic reticulum stress. This condition evokes the unfolded protein response (UPR) an adaptive pathway that aims to restore ER homeostasis. Mounting evidence suggests that chronic activation of UPR leads to cell dysfunction and death and recently has been implicated in pathogenesis of endothelial dysfunction. Autophagy is an essential catabolic mechanism that delivers misfolded proteins and damaged organelles to the lysosome for degradation, maintaining basal levels of autophagic activity it is critical for cell survival. Several evidence suggests that persistent ER stress often results in stimulation of autophagic activities, likely as a compensatory mechanism to relieve ER stress and consequently cell death. In this review, we summarize evidence for the effect of oxysterols on endothelial cells, especially focusing on oxysterols-mediated induction of endoplasmic reticulum stress.