Cui X, Liu F, Wang J Q, Zhang W J, Wang J Y, Liu K, Cui S Y, Zhang J, Xu R R
Department of Hematology, Affiliated Hospital, Shandong University of Traditional Chinese Medicine, Jinan, China.
Genet Mol Res. 2012 Aug 6;11(3):2130-7. doi: 10.4238/2012.August.6.16.
This study was primarily undertaken to test the hypothesis that mitochondrial DNA (mtDNA) mutations may be associated with aplastic anemia (AA). We analyzed mtDNA sequences from 15 patients with AA. The samples were obtained from bone marrow, and patients' oral epithelial cells were collected for normal tissue comparison. Total DNA was amplified by PCR after extraction, and these segments were then sent for sequencing. The results were compared with those of oral epithelial tissues as well as mtDNA sequences in the revised Cambridge Reference Sequence (rCRS) database. We detected 61 heteroplasmic mutations in 11 genes, including those encoding NADH dehydrogenase (ND)1-2 and 4-6, tRNA glutamic acid (TRNE), ribosomal RNA (RNR) 1 and 2, cytochrome c oxidase (COX1), cytochrome b (CYTB), and tRNA glycine (TRNG); mutation rates were particularly high in ND2 (34.4%) and ND4 (21.3%) in the patients' mtDNA genomes. The products of these genes are involved in oxidation in the respiratory chain, and a large number of homoplasmic mutations were found. Interestingly, these 162 polymorphisms were mostly in the D-loop DNA structure (54.3%), in which numerous mutations associated with leukemia and myelodysplastic syndromes are found. We conclude that functional impairment of the mitochondrial respiratory chain induced by mutation may be an important reason for hematopoietic failure in AA patients.
本研究主要旨在检验线粒体DNA（mtDNA）突变可能与再生障碍性贫血（AA）相关的假说。我们分析了15例AA患者的mtDNA序列。样本取自骨髓，并收集患者的口腔上皮细胞作为正常组织对照。提取后通过聚合酶链反应（PCR）扩增总DNA，然后将这些片段送去测序。将结果与口腔上皮组织以及修订后的剑桥参考序列（rCRS）数据库中的mtDNA序列进行比较。我们在11个基因中检测到61个异质性突变，包括编码NADH脱氢酶（ND）1 - 2和4 - 6、谷氨酸转运RNA（TRNE）、核糖体RNA（RNR）1和2、细胞色素c氧化酶（COX1）、细胞色素b（CYTB）以及甘氨酸转运RNA（TRNG）的基因；在患者的mtDNA基因组中，ND2（34.4%）和ND4（21.3%）的突变率特别高。这些基因的产物参与呼吸链中的氧化过程，并且发现了大量的同质性突变。有趣的是，这些162个多态性大多位于D环DNA结构中（54.3%），在该结构中发现了许多与白血病和骨髓增生异常综合征相关的突变。我们得出结论，突变诱导的线粒体呼吸链功能障碍可能是AA患者造血功能衰竭的重要原因。
