A coronary artery disease-associated tRNAThr mutation altered mitochondrial function, apoptosis and angiogenesis
A coronary artery disease-associated tRNAThr mutation altered mitochondrial function, apoptosis and angiogenesis
复制标题
冠状动脉疾病相关的 tRNAThr 突变改变线粒体功能、细胞凋亡和血管生成
DOI：
10.1093/nar/gky1241
复制
发表时间：
2019-02-28
影响因子：
14.9
通讯作者：
Guan, Min-Xin
中科院分区：
文献类型：
--
作者：
Jia, Zidong;Zhang, Ye;Guan, Min-Xin
摘要线粒体tRNA突变的组织特异性在很大程度上仍然难以捉摸。在这项研究中，我们证明了tRNAThr 15927 G>A突变的有害作用，有助于冠状动脉疾病的发病机制。m.15927G>A突变消除了tRNAThr反密码子茎的高度保守的碱基配对（28 C-42 G）。使用分子动力学模拟，我们表明m.15927G>A突变导致不稳定的tRNAThr结构，这得到了突变tRNA的解链温度降低和电泳迁移率降低的支持。使用通过将来自携带m.15927G>A突变的中国家庭的线粒体和对照转移到线粒体DNA（mtDNA）较少的人脐静脉内皮细胞中而构建的胞质杂交体，我们证明了m.15927G>A突变导致氨酰化效率和稳态tRNAThr水平显著降低。异常的tRNAThr代谢导致mtDNA编码的多肽的可变减少、呼吸缺陷、膜电位降低和活性氧的产生增加。m.15927G>A突变促进了细胞凋亡，细胞色素c释放到胞质溶胶中的升高和细胞凋亡激活蛋白（半胱天冬酶3、7、9和PARP）水平的增加证明了这一点。此外，在突变胞质杂交体中观察到较低的伤口愈合细胞和扰动的管形成，表明改变的血管生成。我们的研究结果为冠状动脉疾病的病理生理学提供了新的见解，这是由tRNAThr突变诱导的改变所表现的。
Abstract The tissue specificity of mitochondrial tRNA mutations remains largely elusive. In this study, we demonstrated the deleterious effects of tRNAThr 15927G>A mutation that contributed to pathogenesis of coronary artery disease. The m.15927G>A mutation abolished the highly conserved base-pairing (28C-42G) of anticodon stem of tRNAThr. Using molecular dynamics simulations, we showed that the m.15927G>A mutation caused unstable tRNAThr structure, supported by decreased melting temperature and slower electrophoretic mobility of mutated tRNA. Using cybrids constructed by transferring mitochondria from a Chinese family carrying the m.15927G>A mutation and a control into mitochondrial DNA (mtDNA)-less human umbilical vein endothelial cells, we demonstrated that the m.15927G>A mutation caused significantly decreased efficiency in aminoacylation and steady-state levels of tRNAThr. The aberrant tRNAThr metabolism yielded variable decreases in mtDNA-encoded polypeptides, respiratory deficiency, diminished membrane potential and increased the production of reactive oxygen species. The m.15927G>A mutation promoted the apoptosis, evidenced by elevated release of cytochrome c into cytosol and increased levels of apoptosis-activated proteins: caspases 3, 7, 9 and PARP. Moreover, the lower wound healing cells and perturbed tube formation were observed in mutant cybrids, indicating altered angiogenesis. Our findings provide new insights into the pathophysiology of coronary artery disease, which is manifested by tRNAThr mutation-induced alterations.