Yen T C, Su J H, King K L, Wei Y H
Department of Biochemistry, National Yang-Ming Medical College, Taipei, Taiwan, Republic of China.
Biochem Biophys Res Commun. 1991 Jul 15;178(1):124-31. doi: 10.1016/0006-291x(91)91788-e.
Using PCR technique and restriction mapping, we analyzed liver mitochondrial DNA (mtDNA) of 2 stillborn babies and 55 Chinese subjects from 27 to 86 years old and blood cell mtDNA from 20 subjects of various ages. An ageing-associated 4,977-bp deletion was detected between nucleotide position 8,469 and 13,447 (or between 8,482 and 13,460) in the liver mtDNA of older subjects. In the region containing the junction fragment, we observed a 13 bp repeat "ACCTCCCTCACCA". Moreover, the incidence of the deleted mtDNA of each of the study subjects was found to increase with age. The deletion was found in 5 out of 8 patients of the 31-40 age group and 9 out of 11 patients of the 41-50 age group, and in all the patients over 50 years old. The deletion was not observed in either the mtDNA of the liver of the stillbirth or the blood cells of subjects of all the age groups. These results support our previous contention that liver mitochondrial respiratory functions decline with age and the hypothesis that continuous accumulation of mitochondrial DNA mutation is an important contributor to ageing process.
我们运用聚合酶链反应（PCR）技术和限制性图谱分析方法，对2例死产儿以及55名年龄在27至86岁之间的中国受试者的肝脏线粒体DNA（mtDNA），还有20名不同年龄段受试者的血细胞mtDNA进行了分析。在老年受试者的肝脏mtDNA中，于核苷酸位置8469至13447（或8482至13460）之间检测到一个与衰老相关的4977碱基对缺失。在包含连接片段的区域，我们观察到一个13碱基对的重复序列“ACCTCCCTCACCA”。此外，发现各研究受试者中缺失型mtDNA的发生率随年龄增长而增加。在31至40岁年龄组的8名患者中有5名、41至50岁年龄组的11名患者中有9名以及所有50岁以上的患者中均发现了该缺失。在死产儿肝脏的mtDNA以及所有年龄组受试者的血细胞中均未观察到该缺失。这些结果支持了我们之前关于肝脏线粒体呼吸功能随年龄下降的观点，以及线粒体DNA突变的持续积累是衰老过程重要因素的假说。
