Increases of Mitochondrial Mass and Mitochondrial Genome in Association with Enhanced Oxidative Stress in Human Cells Harboring 4,977 BP‐Deleted Mitochondrial DNA
Increases of Mitochondrial Mass and Mitochondrial Genome in Association with Enhanced Oxidative Stress in Human Cells Harboring 4,977 BP‐Deleted Mitochondrial DNA
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DOI：
10.1111/j.1749-6632.2001.tb05640.x
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发表时间：
2001-04
影响因子：
5.2
通讯作者：
Yau-Huei Wei;Cheng‐Feng Lee;Hsin-Chen Lee;Yi‐Shing Ma;Chia‐Wen Wang;Ching‐You Lu;C. Pang
中科院分区：
文献类型：
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作者：
Yau-Huei Wei;Cheng‐Feng Lee;Hsin-Chen Lee;Yi‐Shing Ma;Chia‐Wen Wang;Ching‐You Lu;C. Pang
摘要：为了研究衰老和疾病相关的mtDNA缺失对细胞功能的影响，我们使用细胞质融合从慢性进行性眼外肌麻痹患者的皮肤成纤维细胞中构建了一系列含有不同比例mtDNA的细胞质杂种，其中缺失了4，977 bp。胞质杂交体在补充有5%胎牛血清、100 μg/ml丙酮酸和50 μg/ml尿苷的Dulbecco改良Eagle培养基中生长。对于含有较高比例的4，977 bp缺失mtDNA的胞质杂种，群体倍增时间更长。此外，我们发现胞质杂种的呼吸功能随着mtDNA 4，977 bp缺失的增加而降低。由于线粒体呼吸系统的损伤增加了呼吸链的电子泄漏，我们进一步确定了这些胞质杂种的氧化应激。结果表明，与未检测到突变mtDNA的胞质杂交体相比，含有> 65%的4, 977 bp缺失mtDNA的胞质杂交体的8-羟基2′-脱氧鸟苷和脂质过氧化物的比含量显著增加。另一方面，我们发现携带4，977 bp缺失mtDNA的胞质杂种的线粒体质量和线粒体基因组的相对含量高于仅包含野生型mtDNA的胞质杂种。在含有17%和56%的4, 977 bp缺失的胞质杂种中，mtDNA的相对含量分别增加了17%和30%。此外，180 μM的过氧化氢处理的胞质杂种的线粒体质量和mtDNA含量同时增加。综合这些发现，我们得出结论，线粒体质量和mtDNA的增加是与线粒体DNA缺失引起的呼吸功能受损的人类细胞中氧化应激增强相关的分子事件。
Abstract: In order to investigate the effect of aging‐ and disease‐associated deletion of mtDNA on cellular functions, we used cytoplasm fusion to construct a series of the cybrids harboring varying proportions of mtDNA with 4,977 bp deletion from skin fibroblasts of a patient with chronic progressive external ophthalmoplegia. The cybrids were grown in the Dulbecco's modified Eagle medium supplemented with 5% fetal bovine serum, 100 μg/ml pyruvate and 50 μg/ml uridine. The population doubling time was longer for the cybrids containing higher proportions of 4,977 bp‐deleted mtDNA. In addition, we found that the respiratory function was decreased with the increase of mtDNA with 4,977 bp deletion in the cybrids. Since impairment of the respiratory system of mitochondria increases the electron leak of the respiratory chain, we further determined the oxidative stress in these cybrids. The results showed that the specific contents of 8‐hydroxy 2′‐deoxyguanosine and lipid peroxides of the cybrids harboring > 65% of the 4,977 bp‐deleted mtDNA were significantly increased as compared with those of the cybrids containing undetectable mutant mtDNA. On the other hand, we found that the mitochondrial mass and the relative content of the mitochondrial genome in the cybrids harboring 4,977 bp‐deleted mtDNA were higher than those of the cybrids containing only wild type mtDNA. The relative content of mtDNA was increased 17% and 30%, respectively, in the cybrids harboring 17% and 56% of mtDNA with 4,977 bp deletion. Moreover, both mitochondrial mass and mtDNA content were concurrently increased by treatment of the cybrids with 180 μM of hydrogen peroxide. Taken these findings together, we conclude that increase of mitochondrial mass and mtDNA are the molecular events associated with enhanced oxidative stress in human cells with impaired respiratory function caused by mtDNA deletion.