Gene therapy for progressive kidney diseases using siRNA

背景：我们已经证明，针对转化生长因子-β-1的合成短干扰RNA(SiRNA)可以有效地抑制转化生长因子-β-1在肾小球中的表达，从而改善抗Thy-1肾炎模型的基质扩张进程。然而，将RNAi应用于基因治疗的一个主要问题是体内沉默潜力的长期存在。方法：检测肾脏和肌肉中siRNA的稳定时间，以及siRNase、ERI-1的组织分布。随后，我们检测了西施他丁对进展性肾小球硬化模型的影响。结果：单独将绿色荧光蛋白siRNA(SiEGFP)或其表达载体导入肾脏，仅在2周内使小鼠肾脏中EGFP的表达降低，而将siEGFP导入胫前肌，则意外地使EGFP的表达沉默了90天以上。这些观察结果可以用ERI-1在肾脏和肌肉中的表达差异来解释。另外，在进展性肾小球硬化模型中，转化生长因子-β耐药siSTABLE-1基因可显著减少肾小球基质沉积。结论：对ERI-1具有耐药性的siRNA治疗进展性肾脏疾病可能是一种有效且有前景的策略。

Background ; We previous demonstrated that transfection of synthetic short interfering RNAs (siRNAs) targeting against TGF-β1 could be effective and therapeutic in silencing TGF-β1 expression in glomerulus, thereby ameliorated the progression of matrix expansion in anti-Thy-1 model of glomerulonephritis. However, a major concern in applying RNAi to gene therapy is the prolonged existence of silencing potential in vivo. Method ; We examined the duration of siRNA stability in kidney and muscle, and checked the tissue distribution of siRNase, eri-1. Thereafter, we tested the effect of siSTABLE^<TM> on progressive glomerulosclerosis model. Results ; A single introduction of siRNA for EGFP (siEGFP) or its expression vector into kidney resulted in the reduction of masangial EGFP expression only for up to two weeks, while transfection of siEGFP into the pretibial muscle silenced EGFP expression unexpectedly for more than 90 days. These observations could be explained by the different expression of eri-1 between kidney and muscle. In addition, transfection of ERI-1 resistant siSTABLE^<TM> for TGF-β significantly reducedglomerular matrix deposition in progressive glomerulosclerosis model. Conclusion ; Treatment with siRNA resistant to eri-1 may be effective and promising strategy for progressive renal disease.