Amelioration of Chronic Murine Colitis by Peptide-Mediated Transduction of the IκB Kinase Inhibitor NEMO Binding Domain Peptide

Abstract

The NF-κB family of transcription factors is a central regulator of chronic inflammation. The phosphorylation of IκB proteins by the IκB kinase (IKK) complex (IKKα, IKKβ, and NF-κB essential modulator or NEMO) is a key step in NF-κB activation. Peptides corresponding to the NEMO binding domain (NBD) of IKK blocks NF-κB activation without inhibiting basal NF-κB activity. In this report, we determined the effects of the IKK inhibitor peptide (NBD) in a model of spontaneously occurring chronic murine colitis, the IL-10-deficient (IL-10−/−) mouse. Using a novel cationic peptide transduction domain (PTD) consisting of eight lysine residues (8K), we were able to transduce the NBD peptide into cells and tissues. In a NF-κB reporter system, 8K-NBD dose-dependently inhibits TNF-induced NF-κB activation. Furthermore, 8K-NBD inhibited nuclear translocation of NF-κB family members. In NF-κBEGFP knock-in mice, 8K-NBD inhibited LPS-activated NF-κB (EGFP activity) in the ileum but did not inhibit basal NF-κB in Peyer’s patches. IL-10−/− mice treated systemically with 8K-NBD demonstrate amelioration of established colitis, decreased NF-κB activation in the lamina propria, and a reduction in spontaneous intestinal IL-12 p40, TNF, IFN-γ, and IL-17 production. These results demonstrate that inhibitors of IKK, in particular a PTD-NBD peptide, may be therapeutic in the treatment of inflammatory bowel disease.

Peptide-based inhibition of IκB kinase/nuclear factor-κB pathway protects against diabetes-associated nephropathy and atherosclerosis in a mouse model of type 1 diabetes

“…These findings are consistent with those of previous studies characterising the in vitro NF-κB blocking effect of different NBD peptide sequences in cytokine-stimulated mononuclear cells, osteoclasts and fibroblasts [26,[35][36][37][38]. Remarkably, NBD peptide reversed the cellular responses induced by long-term exposure to HG, but did not influence either NF-κB or cell viability under normoglycaemic conditions.…”

“…Remarkably, NBD peptide reversed the cellular responses induced by long-term exposure to HG, but did not influence either NF-κB or cell viability under normoglycaemic conditions. Hence, the primary role of NF-κB in normal cellular functions is preserved, resulting in less toxicity, which represents an advance over other NF-κB inhibitors [18,19,35]. Our results constitute the first in vivo characterisation of the nephroprotective effect of NBD peptide.…”

Selective Inhibition of NF-kappa-B with NBD Peptide Reduces Tumor- Induced Wasting in a Murine Model of Cancer Cachexia In vivo

“…Recent studies have reported the use of NBD peptide therapy for the treatment of colitis and arthritis in mouse models without any evidence of toxicity [22,61]. Similarly, in the present study, we did not identify any toxicity as a result of treatment of NBD peptide, including any lethality or acute and chronic effects on behavior after daily injection of NBD peptide up to 500 µg per mouse.…”

NF-κB in the regulation of epithelial homeostasis and inflammation

“…NF-κB was found to be activated in mucosal cells of IBD patients [16], while pharmacological inhibition of NF-κB activity ameliorated intestinal inflammation in mouse models of colitis. For instance, administration of antisense oligonucleotides to p65 or a peptide that binds to NEMO and inhibits IKK activation reduced the severity of colon inflammation in both chemical-induced models and in the Il-10 -/-mouse model of colitis [17][18][19]. These studies suggested that excessive NF-κB activation contributes to intestinal inflammation and that NF-κB inhibition could have therapeutic effects in IBD.…”