Nuclear-recessive mutations of factors involved in mitochondrial translation are responsible for age-related respiration deficiency of human skin fibroblasts
Nuclear-recessive mutations of factors involved in mitochondrial translation are responsible for age-related respiration deficiency of human skin fibroblasts
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DOI：
10.1074/jbc.273.8.4601
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发表时间：
1998-02-20
影响因子：
4.8
通讯作者：
Hayashi, JI
中科院分区：
文献类型：
--
作者：
Isobe, K;Ito, S;Hayashi, JI
我们探讨了人类皮肤成纤维细胞中线粒体和细胞质的翻译活动是否会随着供体年龄的增长而同时下降这一问题，发现与年龄相关的下降仅限于线粒体翻译。然后，为了确定是线粒体基因组还是核基因组导致了这种与年龄相关的、线粒体特异性的下降，我们从无线粒体DNA（mtDNA）的海拉细胞向四种成纤维细胞系进行了纯核移植，其中两种来自老年个体，一种来自胎儿，一种来自心肌病患者，并分离出它们的核杂交克隆。来自胎儿的正常成纤维细胞系和来自患者的呼吸缺陷型成纤维细胞系分别被用作阳性对照和阴性对照。随后，对核杂交克隆的线粒体翻译和呼吸特性进行了比较。一项阴性对照实验表明，该程序可用于分离出甚至整体线粒体呼吸缺陷的核杂交体，然而，无论其mtDNA是完全来自老年供体还是胎儿供体，在任何核杂交体中均未观察到呼吸缺陷。这些观察结果表明，参与线粒体翻译的因子的核隐性突变而非mtDNA突变是人类成纤维细胞与年龄相关的呼吸缺陷的原因。
We addressed the question of whether both mitochondrial and cytoplasmic translation activities decreased simultaneously in human skin fibroblasts with the age of the donors and found that the age-related reduction was limited to mitochondrial translation. Then, to determine which genome, mitochondrial or nuclear, was responsible for this age-related, mitochondria-specific reduction, pure nuclear transfer was carried out from mitochondrial DNA (mtDNA)-less HeLa cells to four fibroblast lines, two from aged subjects, one from a fetus, and one from a patient with cardiomyopathy, and their nuclear hybrid clones were isolated. A normal fibroblast line from the fetus and a respiration-deficient fibroblast line from the patient were used as a positive and a negative control, respectively, Subsequently, the mitochondrial translation and respiration properties of the nuclear hybrid clones were compared, A negative control experiment showed that this procedure could be used to isolate even nuclear hybrids expressing overall mitochondrial respiration deficiency, whereas no respiration deficiencies were observed in any nuclear hybrids irrespective of whether their mtDNAs were exclusively derived from aged or fetal donors. These observations suggest that nuclear recessive mutations of factors involved in mitochondrial translation but not mtDNA mutations are responsible for age-related respiration deficiency of human fibroblasts.