Treatment of Experimental Septic Shock with Microencapsulated Antisense Oligomers to NF-κB

Pulmonary Administration of Microparticulate Antisense Oligonucleotide (ASO) for the Treatment of Lung Inflammation

Targeted delivery to the lung for controlling lung inflammation is an area that we have explored in this study. The purpose was to use microparticles containing an antisense oligonucleotide (ASO) to NF-κB to inhibit the production of proinflammatory cytokines. Microparticles were prepared using the B-290 Buchi Spray Dryer using albumin as the microparticle matrix. Physicochemical characterization of the microparticles showed the size ranged from 2 to 5 μm, the charge was - 38.4 mV, and they had a sustained release profile over 72 h. Uptake of FITC-labeled ASO-loaded microparticles versus FITC-labeled ASO solution by RAW264.7 murine macrophage cells was 5-10-fold higher. After pulmonary delivery of microparticles to Sprague-Dawley rats, the microparticles were uniformly distributed throughout the lung and were retained in the lungs until 48 h. Serum cytokine (TNF-α and IL-1β) levels of rats after induction of lung inflammation by lipopolysaccharide were measured until 72 h. Animals receiving ASO-loaded microparticles were successful in significantly controlling lung inflammation during this period as compared to animals receiving no treatment. This study was successful in proving that microparticulate ASO therapy was capable of controlling lung inflammation.

Neonatal overfeeding by small-litter rearing sensitises hippocampal microglial responses to immune challenge: Reversal with neonatal repeated injections of saline or minocycline

The early-life period is extremely vulnerable to programming effects from the environment, many of which persist into adulthood. We have previously demonstrated that adult rats overfed as neonates have hypothalamic microglia that are hyper-responsive to an immune challenge, as well as hippocampal microglia that respond less efficiently to learning. We therefore hypothesised that neonatal overfeeding would alter the ability of hippocampal microglia to respond to an immune challenge with lipopolysaccharide (LPS) and that concomitant minocycline, a tetracycline antibiotic that suppresses microglial activity, could restore these responses. We induced neonatal overfeeding by manipulating the litter sizes in which Wistar rat pups were raised, so the pups were suckled in litters of four (neonatally overfed) or 12 (control-fed). We then examined the hippocampal microglial profiles 24 hour after an immune challenge with LPS and found that the neonatally overfed rats had dramatically increased microglial numbers in the hippocampus after immune challenge compared to control-fed rats. Attempts to reverse these effects with minocycline revealed repeated that neonatal injections, whether with minocycline or with saline, markedly suppressed microglial number and density throughout the hippocampus and abolished the difference between the groups in their responses to LPS. These data suggest that neonatal overfeeding not only can have lasting effects on hippocampal immune responses, but also that neonatal exposure to a protocol of repeated injections, irrespective of treatment, has a pronounced long-term impact, highlighting the importance of considering these effects when interpreting experimental data.

The effect of antisense to NF-κB in an albumin microsphere formulation on the progression of left-ventricular remodeling associated with chronic volume overload in rats

BACKGROUND

Increased NF-κB levels play a crucial role in the pathophysiology of heart failure and are known to cause ventricular remodeling. Antisense therapy can be used for blocking the expression of NF-κB and subsequently avoiding heart failure. However, as with most biotechnology products, molecular instability and overall cost are often the major issues and concerns limiting the advancement of most antisense drugs to the market. Therefore, a cost-efficient biodegradable sustained release particle drug delivery system to transport and target NF-kB antisense to its intended site of action would be ideal.

PURPOSE

To evaluate the in vivo performance of a sustained release spray-dried albumin microsphere formulation for effective delivery and treatment of left ventricular remodeling with antisense to NF-κB.

METHODS

Albumin-based microspheres encapsulating antisense to NF-kB were prepared by spray drying and studied in a rat model to treat congestive heart failure.

RESULTS

The NF-κB activation and TNF-α release seen in treated animals were significantly lower than control animals. Ventricular remodeling was controlled in animals with antisense-treated AV fistulas as ΔV0-25 and ΔV0 were significantly lower compared to animals with untreated AV fistulas.

CONCLUSION

This treatment was successful in curbing ventricular remodeling by suppressing NF-κB activation.

Regulation of activity of transcription factor NF-κB by synthetic oligonucleotides

Eukaryotic dimeric nuclear factor-κB (NF-κB) is one of the main transcription factors that activate expression of genes, products of which play the key role in development of cardiovascular pathologies, carcinogenesis, and inflammatory and viral diseases. In this review, the main attention is given to modulation of the transcription factor NF-κB activity by antisense oligonucleotides and oligonucleotide decoys. Also, current concepts about interactions between NF-κB dimers and DNA and general problems that arise in experimental use of synthetic oligonucleotides in vivo are discussed.

Enhanced bioavailability of orally administered antisense oligonucleotide to nuclear factor kappa B mRNA after microencapsulation with albumin

Antisense molecules that pertain to ribonucleic acid (RNA) and complementary to the messenger RNA (mRNA) are produced by transcription of a given gene. Antisense oligonucleotides have emerged as potential gene-specific therapeutic agents that are currently undergoing evaluation in clinical trials for a variety of diseases. When administered orally, antisense oligionucleotides have poor bioavailability as they are rapidly degraded by the acid in the stomach and by the enzymes in the intestine. Therefore, the enhancement of bioavailability after oral administration is highly desirable. This article shows the enhanced bioavailability of antisense oligonucleotides that targets nuclear factor kappa B (NF-κB) mRNA after encapsulating in an inert, biodegradable albumin polymer matrix that was administered via the oral route into a rat model. The bioavailability of the antisense oligonucleotides to NF-κB in microencapsulated form was compared to the solution form of the drug upon oral administration. The solution form had a low bioavailability of 9%, whereas the bioavailability for the microencapsulated form of the drug increased up to 70%. Moreover, the other pharmacokinetic parameters including half-life (t1/2) and volume of distribution (Vd) increased for the microencapsulated form compared to the solution form of the drug.

Microencapsulated drug delivery: a new approach to pro-inflammatory cytokine inhibition

CONTEXT

This article reviews the use of albumin microcapsules 3-4 µm in size containing cytokine inhibiting drugs which include neutralizing antibodies to TNF and IL1, CNI-1493, antisense oligonucleotides to TNF and NF-kappaB, and the antioxidant catalase.

OBJECTIVE

Describe the effects, cellular uptake and distribution of microencapsulated drugs and the effect in both a peritonitis model of infection and a model of adjuvant-induced arthritis.

METHODS

The studies performed by our group are reviewed, the only such studies available.

RESULTS

Microencapsulation of these compounds produced high intracellular drug concentrations due to rapid uptake by phagocytic cells, including endothelial cells, without toxicity. All compounds produced excellent inhibition of TNF and IL1 resulting in improved animal survival in a peritonitis model of septic shock and inflammation in an arthritis model.

CONCLUSION

Albumin microencapsulated pro-inflammatory cytokine inhibiting compounds are superior to equivalent concentration of these compounds administered in solution form.

Synergism in survival to endotoxic shock in rats given microencapsulated CNI-1493 and antisense oligomers to NF-kappaB

The synthesis of TNF may be inhibited at the transcriptional level by antisense to either TNF or NF-kappaB or at the post-transcriptional level by CNI-1493, a guanylhydrazone compound which inhibits p38 MAP kinase activity. Previous studies have demonstrated that targeting macrophages and other phagocytic cells by intracellular drug delivery using albumin microcapsules containing either antisense oligomers to NF-kappaB or CNI-1493 greatly enhances intracellular drug concentration and survival in both endotoxic shock and sepsis models. It is the purpose of this study to determine if microencapsulated drugs acting at different stages in the synthesis of TNF are synergistic. Four groups of 10 rats each were given 15 mg kg(-1) of E.coli endotoxin and treated with (1) CNI-1493 1 mg kg(-1), (2) antisense oligomers to NF-kappaB at 100 mcg, (3) CNI-1493 1 mg kg(-1) plus antisense kappa to NF- at 100 mg kg(-1) and (4) CNI-1493 200 mg kg(-1) plus antisense oligomer to NF-kappaB at 200 mg kg(-1). TNF and IL1 were measured by ELISA at 4, 8, 24 and 48 h. The rats were observed for 5 days. The combination of CNI-1493 and antisense oligomers to NF-kappaB inhibited TNF 41% greater that CNI alone and 51% greater than antisense oligomers to NF-kappaB alone at 4 h after endotoxin administration. Survival at 5 days with CNI alone was 0%, 20% with antisense oligomers to NF-kappaB and 60% with the combination. In conclusion, synergism in survival occurs using microencapsulated drugs acting at different points in the synthesis of TNF was demonstrated using an in-vivo model of endotoxic shock. Both the amount of TNF inhibition and the mortality were significantly improved with combination therapy. Multiple drugs acting at different sites in the synthesis of TNF may be useful in the treatment of disease states characterized by pro-inflammatory cytokine release.

Formulation and in vitro characterization of spray-dried antisense oligonucleotide to NF-kappaB encapsulated albumin microspheres

The aim of this study was to formulate and characterize microspheres containing antisense oligonucleotide to NF-kappaB using bovine serum albumin as the polymer matrix. Microspheres were prepared by spray-drying technique with 5, 10 and 15% drug loading. Glutaraldehyde was used as a cross-linking agent. The particle sizes ranged from 3-5 microm. Microspheres were smooth and spherical in shape, as determined by scanning electron microscopy (SEM). The yield of microspheres ranged from 70-75% and the encapsulation efficiencies were found to be in the range of 59-60%, as determined by a novel HPLC method. Zeta potential of the microspheres ranged between -39 to -53 mV, thus indicating good suspension stability in water. In-vitro release studies performed using phosphate buffer saline demonstrated extended drug release up to 72 h. Kinetic model fitting showed high correlation with the Higuchi model, suggesting that the drug release was primarily diffusion controlled.

The effect of intracellular delivery of catalase and antisense oligonucleotides to NF-kappaB using albumin microcapsules in the endotoxic shock model

Microencapsulated (MC) catalase has been shown to inhibit H(2)O(2) and tumor necrosis factor (TNF) in vitro after endotoxin stimulation. It is the purpose of this study to determine whether MC catalase improves pro-inflammatory cytokine inhibition and mortality in an endotoxic shock model in vivo. We also examined whether MC catalase and antisense oligonucleotides (ASO) to nuclear factor kappaB (NF-kappaB) together improved survival by inhibiting pro-inflammatory cytokines using different mechanisms.

METHODS

Albumin microcapsules containing catalase and ASO to NF-kappaB were prepared 2-7 microm in size by using a Büchi spray dryer. Progressively increasing doses of MC catalase, MC ASO to NF-kappaB, and the combination were given to rats before the administration of Escherichia coli endotoxin. Results demonstrated 60% survival in rats given 15 mg/kg MC catalase, 70% survival with 20 mg/kg MC ASO NF-kappaB, and 80% survival with the combination. TNF was inhibited by 53% in the MC catalase group 4 h after endotoxin administration, 43% in the ASO NF-kappaB group, and 78% in the combination group compared to controls. In conclusion, this study demonstrates the effectiveness of MC intracellular delivery of the naturally occurring antioxidant catalase in improving animal survival. The addition of ASO to NF-kappaB improved both cytokine inhibition and animal survival in endotoxic shock.

The effect of intracellular antioxidant delivery (catalase) on hydrogen peroxide and proinflammatory cytokine synthesis: a new therapeutic horizon

Reactive oxygen species synthesized by endothelial cells may be responsible for cell damage and altered physiologic function. After endotoxin stimulation, free radicals including H(2)O(2) are produced. We have developed a method of intracellular drug delivery using albumin microcapsules. Catalase would be an excellent compound to alter H(2)O(2) production. However, the large molecular size of catalase limits cellular penetration. Endothelial cells have been previously shown to readily phagocytoze albumin microcapsules.

METHODS

Catalase was added to an albumin solution to form a 10% solution of catalase. Microspheres from 2 to 7 microm in size were formed using a Bucchi spray dryer. Human endothelial cells were incubated with varying concentrations of microencapsulated catalase. The cells were then exposed to Escherichia coli endotoxin to determine if increased intracellular penetration of catalase would inhibit H(2)O(2), nitrate, and cytokine synthesis.

RESULTS

There was a 7.2-fold increase in endothelial intracellular catalase after 48 h incubation. H(2)O(2) was inhibited by 72%, nitrate 96%, TNF 90%, IL1 21%, IL6 42%.

CONCLUSIONS

These results demonstrate that inhibition of H(2)O(2) as a result of increased intracellular delivery of catalase inhibits proinflammatory cytokine synthesis after endotoxin exposure.

A methodology for quantitation and characterization of oligonucleotides in albumin microspheres

A fluorescence assay was developed to quantify oligonucleotides (ODNs) encapsulated in bovine serum albumin (BSA) microspheres using antisense to Nuclear Factor-kappaB (NF-kappaB) as a model ODN and employing Oligreen as the fluorescent dye. Methodologies were optimized for the suspension of the microspheres as well as release of the encapsulated ODN using protease digestion. This was followed by the detection and quantitation of the ODN using the Oligreen dye. The Oligreen fluorescence assay gave a concentration-dependent fluorescent interaction with the ODN. Further characterization of the ODN with respect to their structural integrity in non-irradiated and gamma-irradiated antisense encapsulated in BSA microspheres was performed using HPLC, infrared spectroscopy and polyacrylamide gel electrophoresis. Results showed no structural modification of antisense in the BSA microspheres as determined by HPLC retention times for the pure antisense and microsphere-encapsulated ODN. The migration pattern of the antisense in polyacrylamide gels confirmed the absence of significant alterations as a result of the encapsulation process or due to gamma-irradiation. The infrared spectra of non-irradiated and gamma-irradiated antisense to NF-kappaB microspheres also displayed peaks characteristic of the functional groups. The fluorescence assay could also detect NF-kappaB antisense in the serum of rats administered with encapsulated antisense by oral and intravenous routes. This methodology should be valuable for the analysis of BSA-encapsulated antisense ODN and for pharmacokinetic studies during antisense therapy.

The interaction of nuclear factor-kappa B and cytokines is associated with schizophrenia

BACKGROUND

Many reports suggest that schizophrenia is associated with the inflammatory response mediated by cytokines, and nuclear factor-kappa B (NF-kappaB) regulates the expression of cytokines. However, it remains unclear whether the interaction between NF-kappaB and cytokines is implicated in schizophrenia and whether the effect of neuroleptics treatment for 4 weeks is associated with the alteration of cytokines.

METHODS

Sixty-five healthy subjects and 83 first-episode schizophrenic patients who met DSM-IV criteria and who were never treated with neuroleptics previously were included. Serum levels of cytokines such as interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) were examined by using sandwich enzyme immunoassay (EIA). Peripheral blood mononuclear cell (PBMC) mRNA expressions of cytokines (IL-1beta, TNF-alpha) and NF-kappaB were detected by using semiquantitative reverse transcription polymerase chain reaction (RT-PCR). NF-kappaB activation was examined by using transcription factor assay kits.

RESULTS

Schizophrenic patients showed significantly higher serum levels and PBMC mRNA expressions of IL-1beta and TNF-alpha compared with healthy subjects. However, treatment with the neuroleptic risperidone for 4 weeks significantly decreased serum levels and PBMC mRNA expressions of IL-1beta in schizophrenic patients. NF-kappaB activation and PBMC mRNA expression in patients were significantly higher than those in healthy subjects. Furthermore, PBMC mRNA expressions of IL-1beta and TNF-alpha were positively correlated to NF-kappaB activation in both schizophrenic patients and healthy control subjects.

CONCLUSIONS

Schizophrenic patients showed activation of the cytokine system and immune disturbance. NF-kappaB activation may play a pivotal role in schizophrenia through interaction with cytokines.

Treatment of adjuvant arthritis using microencapsulated antisense NF-κB oligonucleotides

Antisense oligonucleotides are promising new therapeutic agents used to selectively inhibit target genes such as Nuclear Factor Kappa B (NF-κB), an important transcription factor in the pathogenesis of inflammatory disease. The purpose of the present study was to evaluate microencapsulated antisense oligonucleotides specific to NF-κB for in vitro efficacy and treatment of adjuvant-induced arthritis in rats. Oligonucleotide-loaded albumin microspheres were prepared and characterized in terms of size, zeta potential, morphology and release pattern. This study reports significant NF-κB inhibition in vitro after treatment with microencapsulated antisense oligonucleotides. Furthermore, microencapsulated antisense NF-κB oligonucleotides were found to inhibit paw inflammation associated with rat adjuvant-induced arthritis in a dose-dependent manner. Taken together, the results presented in this work described albumin microspheres to be effective delivery vehicles for antisense NF-κB oligonucleotides and a potential treatment for inflammatory diseases.

Reversal of LPS induced endothelial cell TNF synthesis and increased permeability with microencapsulated antisense oligomers to NF-kappaB

Endothelial cells form the barrier between the circulation and interstitial space. Changes in permeability of endothelial cells allow penetration of inflammatory cells such as polymorphonuclear cells and macrophages to respond to infections and other inflammatory stimuli. Endothelial cells have also been shown to be phagocytic and produce pro-inflammatory cytokines such as TNF. It is the purpose of this study to evaluate endothelial cell phagocytosis of albumin microspheres containing antisense oligonucluetide to NF-kappaB (MASO), the effect of MASO on TNF synthesis after LPS stimulation and the effect of TNF inhibition on the permeability of endothelial cells in vitro. Results were (1) endothelial cells avidly phagocytozed albumin miocrospheres 1.0 and 1.7 microm in size, (2) phagocytosis of microspheres was potentiated by LPS, (3) TNF is synthesized by endothelial cells in cell culture with the peak concentrations occurring 4 h after stimulation with LPS, (4) MASO results in high intracellular concentration of oligomer, (5) MASO inhibits TNF synthesis to a greater extent than equivalent amounts of NF-kappaB antisense in solution and (6) the inhibition of TNF by MASO significantly decreases the permeability of albumin through endothelial cells in vitro.

Pro-inflammatory cytokine inhibition in the primate using microencapsulated antisense oligomers to NF-kappaB

PRIMARY OBJECTIVE

Antisense oligomers to NF-kappaB (ASO) were incorporated into albumin microspheres to determine if microcapsules containing ASO inhibit pro-inflammatory cytokines to a greater extent than comparable doses of ASO in solution. Phagocytosis of microcapsules and intracellular release of ASO in macrophages was evaluated.

RESEARCH DESIGN

Comparable doses of microencapsulated ASO and ASO in solution were evaluated in non-human primates.

METHODS

Blood was sampled and stimulated with Escherichia coli endotoxin ex vivo. TNF, IL-1 and IL-6 concentrations were compared for 72 hrs. The intracellular concentration of ASO was measured in macrophages in vitro to evaluate the difference in intracellular penetration of microencapsulated ASO.

RESULTS

Microencapsulated ASO produced significantly greater cytokine inhibition at all time points compared to ASO in solution. There were no side effects to ASO in the baboons. Intracellular ASO concentration was 10 fold greater in macrophages using microencapsulation.

CONCLUSIONS

Microencapsulated ASO to NF-kappaB is more effective than ASO in solution in pro-inflammatory cytokine inhibition in non-human primates.

Targeting mechanisms of Pseudomonas aeruginosa pathogenesis

Pseudomonas aeruginosa is an opportunistic pathogen responsible for ventilator-acquired pneumonia, acute lower respiratory tract infections in immunocompromised patients and chronic respiratory infections in cystic fibrosis patients. High incidence, infection severity and increasing resistance characterize P. aeruginosa infections, highlighting the need for new therapeutic options. One such option is to target the many pathogenic mechanisms conferred to P. aeruginosa by its large genome encoding many different virulence factors. This article reviews the pathogenic mechanisms and potential therapies targeting these mechanisms in P. aeruginosa respiratory infections.

Cytokines and Escherichia coli Sepsis

This review reviews the critical role played by cytokines in the pathogenesis of Escherichia coli sepsis. It focuses on prototypic pro-inflammatory and anti-inflammatory cytokines and their influence on mortality in experimental animal models of E. coli endotoxemia and of live E. coli sepsis. The review reviews the results of clinical trials on anticytokine therapy in patients with severe sepsis or septic shock. The recognition of the critical role played by tumor necrosis factor (TNF), a secreted 17kDa cytokine, in endotoxic and gram-negative shock has been a major step forward in our understanding of the pathogenesis of sepsis. The review describes the role of TNF, IL1, and IL6 in animal models of E. coli endotoxemia and sepsis. Given the pivotal role played by TNF in experimental sepsis and the fact that elevated concentrations of TNF were detected in the circulation of patients with sepsis, anti-TNF treatment strategies were investigated as adjunctive therapy for severe sepsis and septic shock. Several studies demonstrated that high levels of interleukin-6 (IL-6) are associated with an increased risk for fatal outcome. Gamma interferon (IFN-γ), IL-12, and IL-18 are functionally related cytokines. A recent study has indicated that transgenic mice overexpressing IL-15 are resistant to an otherwise lethal intraperitoneal E. coli challenge. IL4, IL10, and IL13are prototypic anti-inflammatory cytokines. Their classification as anti-inflammatory cytokines is based on the observation that these molecules inhibit the production of proinflammatory cytokines (primarily TNF and IL1) and toxic oxygen and reactive nitrogen species by myeloid cells.