Intracellular distribution of NFκB decoy and its inhibitory effect on TNFα production by LPS stimulated RAW 264.7 cells

Potential use of fucose-appended dendrimer/α-cyclodextrin conjugates as NF-κB decoy carriers for the treatment of lipopolysaccharide-induced fulminant hepatitis in mice

The purpose of the present study is to treat lipopolysaccharide (LPS)-induced fulminant hepatitis by NF-κB decoy complex with fucose-appended dendrimer (generation 2; G2) conjugate with α-cyclodextrin (Fuc-S-α-CDE (G2)). Fuc-S-α-CDE (G2, average degree of substitution of fucose (DSF2))/NF-κB decoy complex significantly suppressed nitric oxide and tumor necrosis factor-α (TNF-α) production from LPS-stimulated NR8383 cells, a rat alveolar macrophage cell line, by adequate physicochemical properties and fucose receptor-mediated cellular uptake. Intravenous injection of Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex extended the survival of LPS-induced fulminant hepatitis model mice. In addition, Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex administered intravenously highly accumulated in the liver, compared to naked NF-κB decoy alone. Furthermore, the liver accumulation of Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex was inhibited by the pretreatment with GdCl3, a specific inhibitor of Kupffer cell uptake. Also, the serum aspartate aminotransferase, alanine aminotransferase and TNF-α levels in LPS-induced fulminant hepatitis model mice were significantly attenuated by the treatment with Fuc-S-α-CDE (G2, DSF2)/NF-κB decoy complex, compared with naked NF-κB decoy alone. Taken together, these results suggest that Fuc-S-α-CDE (G2, DSF2) has the potential for a novel Kupffer cell-selective NF-κB decoy carrier for the treatment of LPS-induced fulminant hepatitis in mice.

Effect of NF-κB decoy oligodeoxynucleotide on LPS/high-fat diet-induced atherosclerosis in an animal model

Atherosclerosis is a chronic inflammatory process occurring in the walls of arteries, in large part due to the accumulation of inflammatory cells. This study was conducted to determine the effect of nuclear factor (NF)-κB decoy oligodeoxynucleotide (ODN) in an atherosclerosis animal model. The mice received i.p. injections of lipopolysaccharide (LPS, 2 mg/kg) three times a week to induce atherosclerotic change, and fed an atherogenic diet for 12 weeks. NF-κB decoy ODN (0.4 mg/kg) was injected into the tail vein. Treatment with NF-κB decoy ODN decreased pro-inflammatory cytokines, tumour necrosis factor (TNF)-α and interleukin (IL)-1β and inflammatory markers, vascular adhesion molecule (VCAM)-1 and intercellular adhesion molecule (ICAM)-1, in the LPS/Fat-induced mice. In addition, the expression of proteins related to fibrosis, transforming growth factor (TGF)-β1 and fibronectin were markedly decreased in the mice treated with NF-κB decoy ODN compared with the LPS/Fat-induced mice without decoy ODN treatment. These data suggest that NF-κB decoy ODN may exert an inhibitory effect on the expression levels of pro-inflammatory cytokines and cell adhesion molecules in atherosclerotic mice.

Oxidized ultrashort nanotubes as carbon scaffolds for the construction of cell-penetrating NF-kappaB decoy molecules

Oligonucleotide (ODN) decoys are synthetic ODNs containing the DNA binding sequence of a transcription factor. When delivered to cells, these molecules can compete with endogenous sequences for binding the transcription factor, thus inhibiting its ability to activate the expression of target genes. Modulation of gene expression by decoy ODNs against nuclear factor-kappaB (NF-kappaB), a transcription factor regulating many genes involved in immunity, has been achieved in a variety of immune/inflammatory disorders. However, the successful use of transcription factor decoys depends on an efficient means to bring the synthetic DNA to target cells. It is known that single-walled carbon nanotubes (SWCNTs), under certain conditions, are able to cross the cell membrane. Thus, we have evaluated the possibility to functionalize SWCNTs with decoy ODNs against NF-kappaB in order to improve their intracellular delivery. To couple ODNs to CNTs, we have exploited the carbodiimide chemistry which allows covalent binding of amino-modified ODNs to carboxyl groups introduced onto SWCNTs through oxidation. The effective binding of ODNs to nanotubes has been demonstrated by a combination of microscopic, spectroscopic, and electrophoretic techniques. The uptake and subcellular distribution of ODN decoys bound to SWCNTs was analyzed by fluorescence microscopy. ODNs were internalized into macrophages and accumulated in the cytosol. Moreover, no cytotoxicity associated with SWCNT administration was observed. Finally, NF-kappaB-dependent gene expression was significantly reduced in cells receiving nanomolar concentrations of SWCNT-NF-kappaB decoys compared to cells receiving SWCNTs or SWCNTs functionalized with a nonspecific ODN sequence, demonstrating both efficacy and specificity of the approach.

[Development of cell-selective targeting systems of NFkappaB decoy for inflammation therapy]

NFkappaB regulate several inflammatory related molecules and evoke immune and inflammatory response by several stimuli, therefore inhibition of NFkappaB activation would be a novel therapeutic strategy. To date, there are many conventional drugs including nonsteroldal or steroldal anti-inflammatory drugs or immune suppressors etc. were known to inhibit NFkappaB activation, however, several side effects were also reported. Recently, double stranded oligonucleotide including NFkappaB binding sequence, called NFkappaB decoy, was developed to prevent NFkappaB activation, which is powerful tool in a new class of anti-gene strategy for molecular therapy with low side effect. However, NFkappaB decoy is easily degraded by nuclease and rapidly excreted to urine, therefore it is necessary to develop carrier for NFkappaB decoy therapy. Here, we shall review delivery system for NFkappaB decoy and introduce our cell-selective delivery system for NFkappaB decoy using sugar decorated cationic liposomes.

Innate immune response induced by gene delivery vectors

Gene therapy is a clinical strategy that has the potential to treat an array of genetic and nongenetic diseases. Vectors for gene transfer are the essential tools of gene therapy. For gene therapy to be successful, an appropriate amount of the therapeutic gene must be delivered into the target cells without substantial toxicity. A major limitation of the use of gene therapy vectors is the innate immune responses triggered by systemic administration of such vectors. It is essential to overcome vector-mediated innate immune responses, such as production of inflammatory cytokines, the maturation of antigen-presenting cells and tissue damage, because the induction of these responses not only shortens the period of gene expression but also leads to serious side effects. Viral vectors (for example, adenovirus (Ad) vectors) have been assumed to be more potent in inducing innate immune responses in spite of their high transduction efficiency since they contain pathogenic proteins. However, recent studies have demonstrated that not only viral vectors but also nonviral vectors, such as lipoplex (liposome/plasmid DNA complex), can induce innate immune responses. Indeed, nonviral vectors including lipoplex induce comparable or larger levels of innate immune response than viral vectors. In this review, we present an overview of the innate immune responses induced by Ad vector and lipoplex, which are used primarily for in vivo gene transfer.

The potential role of fucosylated cationic liposome/NFkappaB decoy complexes in the treatment of cytokine-related liver disease

Cytokine production by Kupffer cells, which is regulated by NFkappaB, causes severe liver injury in endotoxin syndrome. NFkappaB decoy has been reported to inhibit NFkappaB-mediated transcription. The purpose of this study is to inhibit LPS-induced cytokine production by Kupffer cell-targeted delivery of NFkappaB decoy using fucosylated cationic liposomes (Fuc-liposomes). Cholesten-5-yloxy-N-{4-[(1-imino-2-L-thiofucosyl-ethyl)-amino] butyl-}formamide (Fuc-C4-Chol) was synthesized to prepare Fuc-liposomes. Tissue accumulation, intrahepatic distribution and serum cytokine concentrations were investigated after intravenous injection of Fuc-liposomes/NFkappaB decoy complexes. Intravenously injected Fuc-liposome complexes rapidly and highly accumulated in the liver while little naked NFkappaB decoy accumulated in the liver. An intrahepatic distribution study showed that Fuc-liposome complexes are mainly taken up by non-parenchymal cells. The liver accumulation of Fuc-liposome complexes was inhibited by GdCl(3) pretreatment, which selectively inhibited Kupffer cell uptake. This result suggested that Kupffer cells contribute to liver accumulation. TNFalpha, IFNgamma, ALT and AST serum levels in LPS-infected mice were significantly attenuated by treatment with Fuc-liposome complexes compared with naked NFkappaB decoy. Fuc-liposome complexes also reduced the amount of activated NFkappaB in the liver nuclei. Fuc-liposomes would be a useful carrier for Kupffer cell-selective delivery of NFkappaB decoy by intravenous injection.

Folate-linked lipid-based nanoparticles deliver a NFkappaB decoy into activated murine macrophage-like RAW264.7 cells

Activated macrophages are the key effector cells in rheumatoid arthritis (RA) and secrete multiple mediators of inflammation including proinflammatory cytokines. We investigated delivery of a nuclear factor kappa B (NFkappaB) decoy by folate-linked lipid-based nanoparticles (NP-F) into murine macrophages. The expression of folate receptor (FR) in RAW264.7 cells activated by lipopolysaccaride was confirmed by strong expression of FR mRNA, and association of FITC-labeled folate-BSA conjugate. When transfected via NP-F, the NFkappaB decoy was strongly detected in the cytoplasm, and an inhibitory effect on the translocation of NFkappaB into the nucleus was observed at 0.03 microM of the decoy, suggesting that NP-F effectively delivered the NFkappaB decoy into the cytoplasm. This information is of value for the design of NFkappaB decoy carrier systems targeting FR in activated macrophages in gene therapy for autoimmune diseases such as RA.