MOLECULAR BASIS OF MITOCHONDRIAL RNA PROCESSING SYSTEM IN DEVELOPMENTAL TISSUES AND IN MITOCHONDRIAL MYOPATHY.

发育组织和线粒体肌病中线粒体 RNA 加工系统的分子基础。

基本信息

批准号：
09670856
负责人：
KOGA Yasutoshi
金额：
$ 1.79万
依托单位：
KURUME UNIVERSITY SCHOOL OF MEDICINE
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1998
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-09670856/
关键词：
mitochondrial DNA MELAS mitochondrial RNA processing RNA 19 tissue specificity point mutation respiratory chain enzymes ミトコンドリア DNA RNA 19 ミトコンドリア脳筋症ミトコンドリアtRNA RNAプロセッシング母性遺伝

项目摘要

1)In order to know the steady-state levels of RNA 19 in normal human tissues and the actual levels of it in MELAS patients, we analyzed the total RNA from various human tissues from 8 normal individuals, and biopsied muscles from 4 MELAS patients having MELAS-3243 point mutation. Normal tissues include skeletal muscle, brain, heart, kidney, liver, uterus, and spleen. We also analyzed the percentage of point mutation in RNA 19 fraction in RNAs from muscles, using rTth reverse transcriptase PCR-RFLP methods. We observed significantly increased levels of RNA 19 in muscles from all 4 MELAS patients (5 - 8 times more than that of the control) and from one patient having glycogen storage disease (3 times more than that of the control). The level of RNA 19 in the patient muscles ranged from 20 to 35% of total ND 1 signal is significantly higher than that of the control muscle (less than 4% of total ND I signal), which is well harmonized with the percentage of mutation analysed in their mitoch … More ondrial DNA from muscles. The RNA 19 is also recognized in various human tissues including muscle, heart, brain, kidney, liver, spleen and uterus, ranging 3.5%, 11.6%, 13 6%, 8.4%, 4.2%, 1.7% and 6.5% of their total ND 1 signal, respectively. This accumulation of RNA 19 observed in MELAS-muscle seems to be specific for the tRNALeu(UUR) mutation and related to the pathogenetic mechanism of MELAS.2)Five unrelated patients harboring the A3243G mutation in the mitochondrial DNA (mtDNA) but presenting with different clinical phenotype were studied for their percentage of mutation at the single muscle fiber levels. One patient had a clinically and pathologically defined Leigh syndrome (LS), two showed mitochondrial myopathy, encephalopathy, lactic acidosis and stroke like episodes (MELAS), another showed progressive external ophthalmoplegia (PEO), and the other showed mitochondrial diabetes mellitus (MDM). The mutation load was greater in the muscle from the patient with LS (92%), who showed more than 80% even in the non-ragged red fibers (RRF) and also presented the highest proportion of RRF.The patients with MELAS had lower mutation levels as well as lower proportion of RRF, and these two parameters were even lower in the PEO and MDM patients. These results confirm the concept that differences in the mutation load and in the spatial distribution of the mutation among different cells and tissues are responsible for the differences in phenotypical expression of the disease. Less

1）为了了解正常人体组织中RNA 19的稳态水平及其实际水平的MELAS患者，我们分析了来自8个正常人的各种人体组织的总RNA，以及4例MELAS-3243点突变的MELAS患者的活检肌肉。正常的组织包括骨骼肌，大脑，心脏，肾脏，肝脏，子宫和脾脏。我们还使用RTTH逆转录酶PCR-RFLP方法分析了肌肉中RNA 19中RNA 19中的点突变的百分比。我们观察到来自所有4例MELAS患者的肌肉中RNA 19的水平显着升高（比对照组高5-8倍）和一名患有糖原储存疾病的患者（比对照组高3倍）。患者肌肉中RNA 19的水平范围为ND 1信号的20％至35％，显着高于对照肌肉的水平（少于总ND I信号的4％），这与在其线路中分析的突变百分比相协调…来自肌肉的on Dranial DNA更多。 RNA 19在包括肌肉，心脏，脑，肾脏，肝脏，囊和子宫在内的各种人体组织中也被识别，分别为3.5％，11.6％，13 6％，8.4％，4.2％，4.2％，1.7％，1.7％和6.5％的总ND 1信号。在Melas-Muscle中观察到的RNA 19的积累似乎是特定于Trnaleu（UUR）突变，并且与Melas的致病机制有关。2）五名携带A3243G突变的无关患者在线粒体DNA（MTDNA）（MTDNA）中，但呈现不同的临床现象水平，它们是在单身群体上均在单身群体上进行了研究。一名患者患有临床和病理上定义的Leigh综合征（LS），两名患者显示线粒体肌病，脑病，乳酸性酸中毒和中风（如发作）（Melas），这是另一个显示的渐进性外腹膜外毛虫（PEO），以及其他显示的线粒体糖尿病型糖尿病（PEO）。 LS患者（92％）的肌肉中的突变负荷也更大，即使在非脱落的红色纤维（RRF）中显示超过80％，并且也显示了RRF的最高比例。MELAS患者的突变水平较低，RRF的比例较低，PEO和PEO患者的这两个参数较低。这些结果证实了一个概念，即突变负荷的差异以及不同细胞和组织之间突变的空间分布是疾病表型表达的差异。较少的