Isolation of transcriptomal changes attributable to LHON mutations and the cybridization process
Isolation of transcriptomal changes attributable to LHON mutations and the cybridization process
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DOI：
10.1093/brain/awh447
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发表时间：
2005-05-01
期刊：
影响因子：
14.5
通讯作者：
Cortopassi, GA
中科院分区：
文献类型：
--
作者：
Danielson, SR;Carelli, V;Cortopassi, GA
Leber遗传性视神经病变（LHON）被认为是由线粒体DNA（mtDNA）点突变引起的最常见的疾病，并且线粒体胞质杂交（cybrid）细胞系是用于理解线粒体疾病的发病机制的最常用的模型。我们已经使用寡核苷酸微阵列和一种新的研究设计的基础上共享的成绩单分配到rho-零依赖，cybridization依赖和LHON依赖的类别在这些细胞中的转录组的变化。分析表明，rho-零过程具有最大的转录组影响，其次是胞质杂交过程，最后是LHON突变。rho-零和胞质杂交过程的转录影响优先并显著影响线粒体区室，导致参与氧化磷酸化的许多转录物上调，推测是响应于在rho-零步骤发生的mtDNA耗尽。骨肉瘤细胞杂交体和携带LHON突变的淋巴母细胞之间共有9种LHON特异性转录改变。值得注意的是，醛糖还原酶转录本在LHON胞质杂交体和淋巴母细胞中过表达。醛糖还原酶在糖尿病视网膜病变中也过表达，导致视神经和视网膜并发症。通过定量逆转录-聚合酶链反应（RT-PCR）证实了转录水平的LHN特异性增加，并且蛋白质印迹证实了突变体线粒体中更高水平的醛糖还原酶。醛糖还原酶的一种产物是山梨糖醇，其与渗透应激、氧化应激和视神经病变有关，并且山梨糖醇水平在LHON胞质杂种中增加。如果这些结果在患者组织中得到证实，醛糖还原酶抑制剂可能对LHON具有一定的治疗价值。
Leber's hereditary optic neuropathy (LHON) is thought to be the most common disease resulting from mitochondrial DNA (mtDNA) point mutations, and transmitochondrial cytoplasmic hybrid (cybrid) cell lines are the most frequently used model for understanding the pathogenesis of mitochondrial disorders. We have used oligonucleotide microarrays and a novel study design based on shared transcripts to allocate transcriptomal changes into rho-zero-dependent, cybridization-dependent and LHON-dependent categories in these cells. The analysis indicates that the rho-zero process has the largest transcriptomal impact, followed by the cybridization process, and finally the LHON mutations. The transcriptomal impacts of the rho-zero and cybridization processes preferentially and significantly affect the mitochondrial compartment, causing upregulation of many transcripts involved in oxidative phosphorylation, presumably in response to the mtDNA depletion that occurs at the rho-zero step. Nine LHON-specific transcriptional alterations were shared among osteosarcoma cybrids and lymphoblasts bearing LHON mutations. Notably, the aldose reductase transcript was overexpressed in LHON cybrids and lymphoblasts. Aldose reductase is also overexpressed in diabetic retinopathy, leading to optic nerve and retinal complications. The LHON-specific increase in transcript level was confirmed by quantitative reverse transcription-polymerase chain reaction (RT-PCR), and a western blot confirmed a higher level of aldose reductase in mutant mitochondria. One product of aldose reductase is sorbitol, which has been linked to osmotic stress, oxidative stress and optic neuropathy, and sorbitol levels were increased in LHON cybrids. If these results are confirmed in patient tissues, aldose reductase inhibitors could have some therapeutic value for LHON.