Exploring RNA interference as a therapeutic strategy for renal disease

Abstract

The short synthetic interfering RNA duplexes (siRNAs) can selectively suppress gene expression in somatic mammalian cells without nonselective toxic effects of double-stranded RNA (dsRNA). However, a selective in vivo delivery of siRNA transfer has not been reported in kidney. Here, we investigated whether injection of synthetic siRNAs via renal artery followed by electroporation could be effective and therapeutic in silencing specific gene in glomerulus. We investigated the effect of siRNA in rat cultured mesangial cells (MCs) and showed that siRNA sequence-specific suppression of transgene expression was over a 1000-fold more potent than that by antisense oligodeoxynucleotide (ASODN). Transfection of siRNA targeting luciferase into rat kidneys significantly inhibited expression of a cotransfected luciferase expression vector in vivo. The delivery of siRNA targeting enhanced green fluorescent protein (EGFP) in the transgenic 'green' rat reduced endogenous EGFP expression, mainly in glomerular MCs. Furthermore, RNAi targeting against TGF-b1 significantly suppressed TGF-b1 mRNA and protein expression, thereby ameliorated the progression of matrix expansion in experimental glomerulonephritis. In addition, vector-based RNAi also inhibited TGF-b1 expression in vitro and in vivo. In conclusion, siRNA-directed TGFb1 silencing may be of therapeutic value in the prevention and treatment of fibrotic diseases. Gene Therapy (2005) 12, 965-973.

In vivo gene silencing in solid tumors by targeted electrically mediated siRNA delivery

“…25 This physical technique has been previously used by different groups including ours to locally deliver siRNAs in various tissues. [29][30][31][32][33][34][35][36] As reported previously we observed that the electrical treatment itself had no detectable effect on tumor growth. Takahashi and coworkers 23 recently found that EP following injection in mouse melanoma tumors slightly improved the uptake of a plasmid encoding luciferase and subsequently attempted this approach for treatment of the tumors with siRNAs or plasmids encoding shRNAs.…”

“…36 However, delivery of large nucleic acids (plasmids) have been found to be poorly efficient in solid tumors. [37][38][39] To assess the relative contribution of electrical treatment to siRNA-mediated endogenous gene silencing in solid tumors we generated B16-F10 mouse melanoma cell lines stably expressing an enhanced green fluorescent protein (EGFP).…”

Ultrasound assisted siRNA delivery using PEG-siPlex loaded microbubbles

“…Strategies that have been considered for in vivo delivery of synthetic siRNA in laboratory animals are hydrodynamic injection of naked siRNA [3] or siRNA conjugates [4], electroporation [5][6][7][8] and the use of cationic carriers [9][10][11][12][13][14]. However, several aspects limit the applicability of these methods in humans.…”

Remedial applications of silencing ribonucleic acids and modalities for its delivery to the kidneys - A review

“…It was observed in GFP-transgenic mice that silencing RNA administration resulted in moderate reduction in renal GFP expression (Kennedy et al, 2004). This effect was observed due to the degradation of silencing RNA by endo-or exonucleases (Takabatake et al, 2005). Cells uptake of silencing RNA other than additional carrier may be possible but is less efficient in comparison to transfection reagents which encapsulate or form complex with silencing RNA ( Polyethylenimine complex with silencing RNA not only enhanced the uptake but also prevented degradation of silencing RNA.…”

“…The effects of silencing RNA were studied in vivo and found that the proteins expression was low due to degradation (Takabatake et al, 2005). Plasmid DNA having sense 21 and antisnse nucleotide are helpful in the formation of short hairpin RNA.…”