Effects of treatment with small interfering RNA on joint inflammation in mice with collagen-induced arthritis
Raymond M Schiffelers1, Jun Xu, Gert Storm
1Intradigm Co., Rockville, Maryland, USA. R.M.Schiffelers@pharm.uu.nl
Objective:
RNA interference is a process in which genes can be silenced sequence-specifically. In mammals, RNA interference can be invoked by introduction of small (19-21-nucleotide) double-stranded RNA molecules known as small interfering RNA (siRNA) into cells. Thereby, siRNA offers promise as a novel therapeutic modality. However, siRNA is a relatively large, highly charged molecule and does not readily enter cells. This study was undertaken to investigate the use of electroporation for in vivo transfection of siRNA into joint tissue in arthritic mice to achieve local RNA interference.
Methods:
Proof of principle that siRNA is able to inhibit gene expression in vivo in the mouse joint was studied by local injection and electroporation of siRNA designed to silence reporter genes. In mice with collagen-induced arthritis (CIA), the disease-modulating activity of siRNA designed to silence tumor necrosis factor alpha (TNFalpha) was investigated.
Results:
Luciferase activity could be reduced by >90% with luciferase-specific siRNA as compared with the activity measured after electroporation without siRNA or with irrelevant siRNA. The effect was observed only locally. In mice with CIA, electroporation of siRNA designed to inhibit TNFalpha strongly inhibited joint inflammation, whereas electroporation of irrelevant siRNA or injection of siRNA against TNFalpha without electroporation failed to produce therapeutic effects.
Conclusion:
Local electroporation of siRNA in joint tissue can inhibit CIA in mice. These results offer promise for the use of siRNA as a new strategy for therapeutic intervention in rheumatoid arthritis and may serve as a tool to study arthritis disease pathways through loss-of-function phenotypes.
Insights
Electroporation effectively delivers small interfering RNA (siRNA) into joint tissues, silencing target genes and reducing inflammation in arthritic mice. This method shows promise for treating rheumatoid arthritis by enabling local RNA interference.
Area of Science:
- Molecular Biology
- Immunology
- Biotechnology
Background:
- RNA interference (RNAi) is a gene-silencing mechanism.
- Small interfering RNA (siRNA) can be used therapeutically but faces delivery challenges due to its molecular properties.
- In vivo delivery of siRNA to specific tissues like joints is crucial for therapeutic applications.
Purpose of the Study:
- To investigate electroporation as a method for in vivo siRNA delivery into joint tissue.
- To assess the efficacy of local RNA interference in arthritic mouse models.
- To evaluate siRNA targeting of tumor necrosis factor alpha (TNFalpha) for treating collagen-induced arthritis (CIA).
Main Methods:
- Proof-of-concept studies involved electroporation of siRNA targeting reporter genes in mouse joints.
- Studies in collagen-induced arthritis (CIA) models utilized siRNA designed to silence TNFalpha.
- Control groups received irrelevant siRNA or no electroporation.
Main Results:
- Electroporation with luciferase-specific siRNA reduced luciferase activity by over 90% locally.
- Electroporation of TNFalpha-specific siRNA significantly inhibited joint inflammation in CIA mice.
- Non-electroporated siRNA or irrelevant siRNA showed no therapeutic effect.
Conclusions:
- Local electroporation of siRNA into joint tissue is an effective method for gene silencing in vivo.
- This technique successfully inhibited collagen-induced arthritis in a mouse model.
- Electroporation-mediated siRNA delivery offers a promising therapeutic strategy for rheumatoid arthritis and a tool for studying disease pathways.
