Capulli Mattia, Maurizi Antonio, Ventura Luca, Rucci Nadia, Teti Anna
Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, L'Aquila, Italy.
Department of Pathology, San Salvatore Hospital, L'Aquila, Italy.
Mol Ther Nucleic Acids. 2015 Sep 1;4(9):e248. doi: 10.1038/mtna.2015.21.
In about 70% of patients affected by autosomal dominant osteopetrosis type 2 (ADO2), osteoclast activity is reduced by heterozygous mutations of the CLCN7 gene, encoding the ClC-7 chloride/hydrogen antiporter. CLCN7(G215R)-, CLCN7(R767W)-, and CLCN7(R286W)-specific siRNAs silenced transfected mutant mRNA/EGFP in HEK293 cells, in RAW264.7 cells and in human osteoclasts, with no change of CLCN7(WT) mRNA and no effect of scrambled siRNA on the mutant transcripts. Osteoclasts from Clcn7(G213R) ADO2 mice showed reduced bone resorption, a condition rescued by Clcn7(G213R)-specific siRNA. Treatment of ADO2 mice with Clcn7(G213R)-specific siRNA induced increase of bone resorption variables and decrease of trabecular bone mass, leading to an overall improvement of the osteopetrotic bone phenotype. Treatment did not induce overt adverse effects and was effective also with siRNAs specific for other mutants. These results demonstrate that a siRNA-based experimental treatment of ADO2 is feasible, and underscore a translational impact for future strategy to cure this therapeutically neglected form of osteopetrosis.
在约70%受常染色体显性2型骨硬化症（ADO2）影响的患者中，破骨细胞活性因编码ClC - 7氯/氢反向转运体的CLCN7基因的杂合突变而降低。CLCN7（G215R）特异性、CLCN7（R767W）特异性和CLCN7（R286W）特异性小干扰RNA（siRNA）在HEK293细胞、RAW264.7细胞和人破骨细胞中沉默了转染的突变体mRNA/增强绿色荧光蛋白（EGFP），而CLCN7（野生型）mRNA无变化，且乱序siRNA对突变体转录本无影响。来自Clcn7（G213R）ADO2小鼠的破骨细胞显示骨吸收减少，而Clcn7（G213R）特异性siRNA可挽救这种情况。用Clcn7（G213R）特异性siRNA治疗ADO2小鼠可诱导骨吸收变量增加和骨小梁骨量减少，从而使骨硬化骨表型总体得到改善。该治疗未诱导明显的不良反应，对其他突变体特异性的siRNA也有效。这些结果表明，基于siRNA的ADO2实验性治疗是可行的，并强调了对未来治疗这种被忽视型骨硬化症策略的转化影响。
