Reduction of liver tumor necrosis factor‐α expression by targeting delivery of antisense oligonucleotides into Kupffer cells protects rats from fulminant hepatitis

Background

Fulminant liver failure can cause extreme mortality due to the lack of effective and targeting therapeutics for the disease. Novel therapeutics using antisense technology require an efficient and safe delivery system with Kupffer cell targeting ability.

Methods

We explored the capacity of galactosylated low molecular weight chitosan (GLC) to efficiently mediate the antisense oligonucleotide (ASO) TJU‐2755 into Kupffer cells, enhance the effect of the oligonucleotides on the suppression of tumor necrosis factor (TNF)‐α and prolong the active time of the antisense drug in vivo. The protective and therapeutic effect of ASO/GLC in the animal model of D ‐galactosamine/lipopolysaccharide‐induced fulminant hepatitis was tested.

Results

ASOs delivered by GLC were concentrated in Kupffer cells and more potent in reducing the expression of TNF‐α mRNA, as well as reducing serum TNF‐α levels. Furthermore, the ASO/GLC complex successfully rescued animals from fulminant hepatitis and mortality. Compared to naked ASO, the complex notably reduced the dose administrated in animals and prolonged its effectiveness. A single dose of 5 mg ASO per kg body weight achieved a satisfactory effect after 5 days, and 20 mg ASO per kg body weight preserved 70% of the effect after more than 2 weeks. Its efficacy was affirmed through both pretreatment and therapeutic use after liver damage had begun.

Conclusions

Inhibiting TNF‐α expression in the liver by this strategy represents a novel therapeutic approach that may be valuable for the treatment of some inflammation‐related liver diseases. Copyright © 2009 John Wiley & Sons, Ltd.