Modulating mtDNA heteroplasmy by mitochondria-targeted restriction endonucleases in a 'differential multiple cleavage-site' model
Modulating mtDNA heteroplasmy by mitochondria-targeted restriction endonucleases in a 'differential multiple cleavage-site' model
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DOI：
10.1038/sj.gt.3302981
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发表时间：
2007-09-01
期刊：
影响因子：
5.1
通讯作者：
Moraes, C. T.
中科院分区：
文献类型：
--
作者：
Bacman, S. R.;Williams, S. L.;Moraes, C. T.
操纵线粒体DNA （mtDNA）异质性的能力将为治疗线粒体疾病提供有力的工具。最近的研究表明，如果线粒体靶向限制性内切酶识别突变mtDNA中的单个位点，它可以以一种可预测和有效的方式修饰mtDNA异质性。然而，这种模型的适用性仅限于产生新的切割位点的突变，而这种突变不存在于野生型mtDNA中。我们试图将这种方法扩展到“差异多重切割位点”模型，其中mtDNA突变为通常存在于野生型mtDNA中的mtDNA创建了额外的限制位点。利用含有两种mtDNA单倍型（NZB/BALB）的异质小鼠模型，利用腺病毒作为基因载体，将线粒体靶向的尺度限制内切酶传递到不同的小鼠组织中。scale在NZB mtDNA中识别出5个位点，但在BALB mtDNA中只识别出3个位点。我们的研究结果表明，线粒体靶向的ScaI在静脉注射后的肝脏和肌肉注射后的骨骼肌中的表达都发生了mtDNA异质性的变化。虽然mtDNA缺失是一种不良的副作用，但我们的数据表明，在调节表达系统下，mtDNA缺失可以最小化，并且识别多个位点的限制性内切酶可能具有治疗用途的潜力。
The ability to manipulate mitochondrial DNA ( mtDNA) heteroplasmy would provide a powerful tool to treat mitochondrial diseases. Recent studies showed that mitochondria-targeted restriction endonucleases can modify mtDNA heteroplasmy in a predictable and efficient manner if it recognizes a single site in the mutant mtDNA. However, the applicability of such model is limited to mutations that create a novel cleavage site, not present in the wild-type mtDNA. We attempted to extend this approach to a 'differential multiple cleavage site' model, where an mtDNA mutation creates an extra restriction site to the ones normally present in the wild-type mtDNA. Taking advantage of a heteroplasmic mouse model harboring two haplotypes of mtDNA (NZB/BALB) and using adenovirus as a gene vector, we delivered a mitochondria-targeted Scal restriction endonuclease to different mouse tissues. Scal recognizes five sites in the NZB mtDNA but only three in BALB mtDNA. Our results showed that changes in mtDNA heteroplasmy were obtained by the expression of mitochondria-targeted ScaI in both liver, after intravenous injection, and in skeletal muscle, after intramuscular injection. Although mtDNA depletion was an undesirable side effect, our data suggest that under a regulated expression system, mtDNA depletion could be minimized and restriction endonucleases recognizing multiple sites could have a potential for therapeutic use.