Antisense Inhibition of Silica-induced Tumor Necrosis Factor in Alveolar Macrophages

Abstract

Tumor necrosis factor-␣ (TNF␣) has been shown to play an important role in the pathogenesis of silicotic fibrosis. In this study, antisense oligonucleotides targeted to TNF␣ mRNA were used to inhibit silica-induced TNF␣ gene expression in alveolar macrophages. To achieve macrophage-specific oligonucleotide delivery, a molecular conjugate consisting of mannosylated polylysine that exploits endocytosis via the macrophage mannose receptor was used. Complexes were formed between the mannosylated polylysine and oligonucleotides and added to the cells in the presence of silica. Enzyme-linked immunoadsorbent assay showed that the complex consisting of the conjugate and antisense oligomer effectively inhibited TNF␣ production, whereas the oligomer alone had much less effect. Reverse transcriptase-polymerase chain reaction analysis revealed that the reduction in TNF␣ secretion was associated with specific ablation of targeted TNF␣ mRNA. The conjugate alone or conjugate complexed with inverted or sense sequence oligonucleotide had no effect. The promoting effect of the conjugate on antisense activity was shown to be due to enhanced cellular uptake of the oligomer via mannose receptor-mediated endocytosis. Cells lacking mannose receptors showed no susceptibility to the conjugate treatment. These results indicate that effective and selective inhibition of macrophage TNF␣ expression can be achieved using the antisense mannosylated polylysine system.

Adenovirus-mediated transfer of heme oxygenase-1 cDNA attenuates severe lung injury induced by the influenza virus in mice

“…17 The use of antisense oligonucleotides against pro-inflammatory cytokines, or adhesion molecules important in the development of inflammation (interleukin (IL)-1, IL-1 receptor, TNF-␣, ICAM-1) have also been successful in vivo. [18][19][20] Another strategy to protect lung tissue is based on the fact that high levels of toxic, reactive oxygen species are present in the local milieu where acute inflammation is ongoing. In this regard, the transfer of prostaglandin G/H synthase gene has been effective in an experimental model.…”

JNK Activation Is Required for JB6 Cell Transformation Induced by Tumor Necrosis Factor-α but Not by 12-O-Tetradecanoylphorbol-13-Acetate

“…important role in the pathogenesis of many diseases and elicits a wide range of biological responses, including cell proliferation, differentiation, and apoptosis, depending on the cell type and its state of differentiation (42)(43)(44)(45). We have investigated the tumor promotion activity of TNF-␣ in JB6 Cl 41 cells.…”

Inhibition of TNF-α gene expression and bioactivity by site-specific transcription factor-binding oligonucleotides

“…With regard to ON, it has been reported that ON, due to their polyanionic nature, poorly permeate the cells to reach their intracellular target sites (17,42). Several research groups (3,29,33,40) also observed that in the absence of appropriate delivery systems, ON exhibited weak or no biological activity, whereas in the presence of delivery systems, e.g., liposomes, ON showed strong activity. In agreement with these findings, our results showed that coadministration of the ON with the liposomal agent DOTAP greatly enhanced the inhibitory activities of ON.…”

“…Because TNF-␣ plays an important role in the pathogenesis of a variety of inflammatory and immune diseases, this cytokine has been identified as a key target for pharmacological manipulation (18,33,36,41,45). TNF-␣ is produced principally by macrophages and acts on a variety of immune and nonimmune cells to initiate and amplify inflammatory response (36).…”