Li Xing, Shang Jinyao, Li Shuang, Wang Yue
Department of Endocrinology, Ordos Center Hospital, Ordos, Inner Mongolian, 017010, People's Republic of China.
Pharmgenomics Pers Med. 2024 Apr 17;17:149-161. doi: 10.2147/PGPM.S438978. eCollection 2024.
Mutations in mitochondrial tRNA (mt-tRNA) could be the origin of some type 2 diabetes mellitus (T2DM) cases, but the mechanism remained largely unknown.
The aim of this study was to assess the impact of a novel mitochondrial tRNA/tRNA A5826G mutation on the development and progression of T2DM.
A four-generation Han Chinese family with maternally inherited diabetes underwent clinical, genetic and biochemical analyses. The mitochondrial DNA (mtDNA) mutations of three matrilineal relatives were screened by PCR-Sanger sequencing. Furthermore, to see whether m.A5826G mutations affected mitochondrial functions, the cybrid cell lines were derived from three subjects with m.A5826G mutation and three controls without this mutation. ATP was evaluated by luminescent cell viability assay, mitochondrial membrane potential (MMP), and reactive oxygen species (ROS) were determined by flow cytometry. The student's two-tailed, unpaired -test was used to assess the statistical significance between the control and mutant results.
The age at onset of diabetes in this pedigree varied from 40 to 63 years, with an average of 54 years. Mutational analysis of mitochondrial genomes revealed the presence of a novel m.A5826G mutation. Interestingly, the m.A5826G mutation occurred at the conjunction between tRNA and tRNA, a very conserved position that was critical for tRNAs processing and functions. Using trans-mitochondrial cybrid cells, we found that mutant cells carrying the m.A5826G showed approximately 36.5% and 22.4% reductions in ATP and MMP, respectively. By contrast, mitochondrial ROS levels increased approximately 33.3%, as compared with the wild type cells.
A novel m.A5826G mutation was identified in a pedigree with T2DM, and this mutation would lead to mitochondrial dysfunction. Thus, the genetic spectrum of mitochondrial diabetes was expanded by including m.A5826G mutation in tRNA/tRNA, our study provided novel insight into the molecular pathogenesis, early diagnosis, prevention and clinical treatment for mitochondrial diabetes.
线粒体转运RNA(mt-tRNA)突变可能是某些2型糖尿病(T2DM)病例的病因,但机制仍不清楚。
本研究旨在评估一种新的线粒体tRNA/tRNA A5826G突变对T2DM发生发展的影响。
对一个患有母系遗传糖尿病的四代汉族家庭进行临床、遗传和生化分析。通过PCR-Sanger测序筛查三位母系亲属的线粒体DNA(mtDNA)突变。此外,为了观察m.A5826G突变是否影响线粒体功能,构建了来自三位携带m.A5826G突变的受试者和三位未携带该突变的对照的细胞杂交系。通过发光细胞活力测定评估ATP,通过流式细胞术测定线粒体膜电位(MMP)和活性氧(ROS)。采用学生双尾、非配对t检验评估对照与突变结果之间的统计学意义。
该家系糖尿病发病年龄在40至63岁之间,平均54岁。线粒体基因组的突变分析显示存在一种新的m.A5826G突变。有趣的是,m.A5826G突变发生在tRNA与tRNA的连接处,这是一个非常保守的位置,对tRNA的加工和功能至关重要。利用线粒体杂交细胞,我们发现携带m.A5826G的突变细胞的ATP和MMP分别降低了约36.5%和22.4%。相比之下,与野生型细胞相比,线粒体ROS水平增加了约33.3%。
在一个T2DM家系中鉴定出一种新的m.A5826G突变,该突变会导致线粒体功能障碍。因此,通过将tRNA/tRNA中的m.A5826G突变纳入线粒体糖尿病的遗传谱中,我们的研究为线粒体糖尿病的分子发病机制、早期诊断、预防和临床治疗提供了新的见解。