Recombinant IκBα-loaded curcumin nanoparticles for improved cancer therapeutics.

The field of recombinant protein therapeutics has been evolving rapidly, making significant impact on clinical applications for several diseases, including cancer. However, the functional aspects of proteins rely exclusively on their structural integrity, in which nanoparticle mediated delivery offers unique advantages over free proteins. In the present work, a novel strategy has been developed where the nanoparticles (NPs) used for the delivery of the recombinant protein could contribute to enhancing the therapeutic efficacy of the recombinant protein. The transcription factor, NFκB, involved in cell growth and its inhibitor, IκBα, regulates its proliferation. Another similar naturally available molecule, which inhibits the function of NFκB, is curcumin. Hence, we have developed a 'green synthesis' method for preparing water-soluble curcumin nanoparticles to stabilize recombinant IκBα protein. The NPs were characterized by UV-vis and fluorescence spectroscopy, transmission electron microscopy (TEM) and dynamic light scattering before administration into human cervical carcinoma (HeLa) and glioblastoma (U87MG) cells. Experimental results demonstrated that this combined module had enhanced therapeutic efficacy, causing apoptotic cell death, which was confirmed by cytotoxicity assay and flowcytometry analyses. The expression of apoptotic genes studied by semi-quantitative reverse transcription PCR delineated the molecular pathways involved in cell death. Thus, our study revealed that the functional delivery of recombinant IκBα-loaded curcumin NPs has promise as a natural-product-based protein therapeutics against cancer cells.

The dichotomy of inhibiting nuclear factor kappa-B in pneumonia.

Activation of nuclear factor kappa-B (NF-κB) results in its translocation from the cytoplasm to the nucleus and binding to the promoters of a large number of genes, including those encoding proinflammatory cytokines and other mediators that can contribute to organ system dysfunction in severe infection. While inhibition of NF-κB activation has been proposed as a therapeutic approach in critical illness, several studies have indicated that such an approach may have deleterious effects in persistent infectious states, such as pneumonia. A new report from Devaney and colleagues shows that while inhibition of NF-κB may be useful in severe pneumonia associated with rapid progression to mortality, it leads to worsened pulmonary injury with increased bacterial numbers in the lungs in a model of prolonged pneumonia. Such data raise concerns about therapeutic approaches targeting NF-κB in critically ill patients with persistent infection.

Inhibition of pulmonary nuclear factor kappa-B decreases the severity of acute Escherichia coli pneumonia but worsens prolonged pneumonia.

INTRODUCTION: Nuclear factor (NF)-κB is central to the pathogenesis of inflammation in acute lung injury, but also to inflammation resolution and repair. We wished to determine whether overexpression of the NF-κB inhibitor IκBα could modulate the severity of acute and prolonged pneumonia-induced lung injury in a series of prospective randomized animal studies. METHODS: Adult male Sprague-Dawley rats were randomized to undergo intratracheal instillation of (a) 5 × 109 adenoassociated virus (AAV) vectors encoding the IκBα transgene (5 × 109 AAV-IκBα); (b) 1 × 10¹° AAV-IκBα; (c) 5 × 10¹° AAV-IκBα; or (d) vehicle alone. After intratracheal inoculation with Escherichia coli, the severity of the lung injury was measured in one series over a 4-hour period (acute pneumonia), and in a second series after 72 hours (prolonged pneumonia). Additional experiments examined the effects of IκBα and null-gene overexpression on E. coli-induced and sham pneumonia. RESULTS: In acute pneumonia, IκBα dose-dependently decreased lung injury, improving arterial oxygenation and lung static compliance, reducing alveolar protein leak and histologic injury, and decreasing alveolar IL-1ß concentrations. Benefit was maximal at the intermediate (1 × 10¹°) IκBα vector dose; however, efficacy was diminished at the higher (5 × 10¹°) IκBα vector dose. In contrast, IκBα worsened prolonged pneumonia-induced lung injury, increased lung bacterial load, decreased lung compliance, and delayed resolution of the acute inflammatory response. CONCLUSIONS: Inhibition of pulmonary NF-κB activity reduces early pneumonia-induced injury, but worsens injury and bacterial load during prolonged pneumonia.

[The experiment study of treatment of infectious acute lung injury by intravenous administration of adenovirus borne inhibitor of nuclear factor-ΚB gene in rat].

OBJECTIVE: To observe the effects of adenovirus borne IΚB gene, an inhibitor of nuclear factor-ΚB (NF-ΚB), infused via central vein, to treat infectious acute lung injury (ALI) in rats. METHODS: According to random number table method, 30 pathogen-free Sprague-Dawley (SD) rats were randomly divided into three groups: sham group, ALI model group, IΚB gene treatment group, with 10 rats in each group. The rats of IΚB gene treatment group were infused 1 ml adenovirus borne IΚB gene (titre: 1×10(9)pfu ), the rats of sham group and ALI model group were infused 1 ml normal saline through central vein. Subsequently, the rats of ALI model group and the IΚB gene treatment group were given 1 ml lipopolysaccharide (LPS, 5 ml/kg) through tail vein to reproduce model of ALI. On the other hand, the rats of sham group were given 1 ml normal saline through tail vein. Blood gas analysis, the ratio of wet to dry weight (W/D) of lung, plasma contents of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and protein expression of NF-ΚBp65 in lung tissue were determined, the pathobiological changes in lung tissue were microscopically observed and the scores of lung injury were calculated after 7 days. RESULTS: The rats in three groups survived, except 1 rat died in ALI model group.Blood pH and partial pressure of arterial carbon dioxide (PaCO(2)) showed no obviously differences among three groups. Partial pressure of arterial oxygen (PaO(2) ) was highest in sham group and the lowest in ALI model group. The plasma content of TNF-α (µg/L) and IL-6 (ng/L ) in ALI model group were obviously higher than those in sham group (TNF-α: 5.20±1.09 vs. 3.01±0.46; IL-6: 540.28±100.78 vs. 214.45±61.37, both P<0.05). The plasma content of TNF-α and IL-6 in IΚB gene treatment group were obviously lower than those in ALI model group (TNF-α: 3.70±0.96 vs. 5.20±1.09, IL-6: 356.49±60.58 vs. 540.28±100.78, both P<0.05), and TNF-α content had restored to the level observed in sham group. The ratio of W/D of lung was lowest in sham group (4.49±0.36) and highest in ALI model group (5.78±0.43), and that of IΚB gene treatment group (5.33±0.38) was lower than that of ALI group. The score of lung injury was lowest in sham group (0.17±0.41) and highest in ALI model group (2.29±0.76), and that of IΚB gene treatment group (1.57±0.53) was lower than that of ALI group. The scale of NF-ΚBp65 immunohistochemistry was lowest in sham group (1.00±0.89) and highest in ALI model group (9.43±1.13), and that of IΚB gene treatment group (4.00±1.15) was lower than the latter. The differences of all the above parameters in three groups were statistically significant (all P<0.05 ). CONCLUSION: Increased expression of IΚB gene by an infusion of adenovirus borne IΚB gene through central vein can lower the levels of pro-inflammatory factors, such as TNF-α and IL-6, restrain the NF-ΚB activation, reduce lung water, alleviate alveolar collapse and lung consolidation in ALI in rats, thus lung injury is ameliorated.

Reduced infiltration and increased apoptosis of leukocytes at sites of inflammation by systemic administration of a membrane-permeable IkappaBalpha repressor.

OBJECTIVE: NF-kappaB activation is associated with several inflammatory disorders, including rheumatoid arthritis (RA), making this family of transcription factors a good target for the development of antiinflammatory treatments. Although inhibitors of the NF-kappaB pathway are currently available, their specificity has not been adequately determined. IkappaBalpha is a physiologic inhibitor of NF-kappaB and a potent repressor experimentally when expressed in a nondegradable form. We describe here a novel means for specifically regulating NF-kappaB activity in vivo by administering a chimeric molecule comprising the super-repressor IkappaBalpha (srIkappaBalpha) fused to the membrane-transducing domain of the human immunodeficiency virus Tat protein (Tat-srIkappaBalpha). METHODS: The Wistar rat carrageenan-induced pleurisy model was used to assess the effects of in vivo administration of Tat-srIkappaBalpha on leukocyte infiltration and on cytokine and chemokine production. RESULTS: Systemic administration of Tat-srIkappaBalpha diminished infiltration of leukocytes into the site of inflammation. Analysis of the recruited inflammatory cells confirmed uptake of the inhibitor and reduction of the NF-kappaB activity. These cells exhibited elevated caspase activity, suggesting that NF-kappaB is required for the survival of leukocytes at sites of inflammation. Analysis of exudates, while showing decreases in the production of the proinflammatory cytokines tumor necrosis factor alpha and interleukin-1beta, also revealed a significant increase in the production of the neutrophil chemoattractants cytokine-induced neutrophil chemoattractant 1 (CINC-1) and CINC-3 compared with controls. This result could reveal a previously unknown feedback mechanism in which infiltrating leukocytes may down-regulate local production of these chemokines. CONCLUSION: These results provide new insights into the etiology of inflammation and establish a strategy for developing novel therapeutics by regulating the signaling activity of pathways known to function in RA.

Direct inhibition of NF-kappa B blocks bone erosion associated with inflammatory arthritis.

Inflammatory arthritis is associated with devastating joint tissue destruction and periarticular bone erosion. Although secreted products of infiltrating immune cells perpetuate the inflammatory response, the osteolytic component of this disease is a direct result of localized recruitment and activation of osteoclasts. Given that NF-kappaB plays a central role in both processes, the function of this transcription factor was examined. Using a mouse model of autoreactive Ig transfer that engenders inflammatory arthritis, we show numerous osteoclasts in the articular joint tissue associated with progressive periarticular osteolytic lesions. Moreover, cells retrieved from these joints exhibit heightened NF-kappaB activity. Importantly, direct administration of dominant negative*I-kappaB or tyrosine 42-mutated I-kappaB (Y42F*I-kappaB) proteins into mice before induction of the disease attenuates in vivo activation of the transcription factor. More importantly, these I-kappaB mutant forms significantly inhibit in vivo production of TNF and receptor activator of NF-kappaB ligand, and block joint swelling, osteoclast recruitment, and osteolysis. Thus, NF-kappaB appears to be the centerpiece of inflammatory-osteolytic arthritis and direct inhibition of this transcription factor by unique and novel I-kappaB mutant proteins blocks manifestation of the disease.