Department of Clinical and Biomedical Sciences, Faculty of Health and Life Sciences, University of Exeter, Exeter, United Kingdom.
Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, United Kingdom.
Front Endocrinol (Lausanne). 2023 Jan 16;13:1059120. doi: 10.3389/fendo.2022.1059120. eCollection 2022.
There is growing interest in the role of DNA methylation in regulating the transcription of mitochondrial genes, particularly in brain disorders characterized by mitochondrial dysfunction. Here, we present a novel approach to interrogate the mitochondrial DNA methylome at single base resolution using targeted bisulfite sequencing. We applied this method to investigate mitochondrial DNA methylation patterns in post-mortem superior temporal gyrus and cerebellum brain tissue from seven human donors.
We show that mitochondrial DNA methylation patterns are relatively low but conserved, with peaks in DNA methylation at several sites, such as within the and the genes , , , and , predominantly in a non-CpG context. The elevated DNA methylation we observe in the we validate using pyrosequencing. We identify loci that show differential DNA methylation patterns associated with age, sex and brain region. Finally, we replicate previously reported differentially methylated regions between brain regions from a methylated DNA immunoprecipitation sequencing study.
We have annotated patterns of DNA methylation at single base resolution across the mitochondrial genome in human brain samples. Looking to the future this approach could be utilized to investigate the role of mitochondrial epigenetic mechanisms in disorders that display mitochondrial dysfunction.
人们对 DNA 甲基化在调节线粒体基因转录中的作用越来越感兴趣，特别是在以线粒体功能障碍为特征的脑部疾病中。在这里，我们提出了一种新的方法，使用靶向亚硫酸氢盐测序来检测线粒体 DNA 甲基组，达到单碱基分辨率。我们应用这种方法研究了来自七个人类供体的死后颞上回和小脑脑组织中的线粒体 DNA 甲基化模式。
我们表明，线粒体 DNA 甲基化模式相对较低但保守，在几个位点存在 DNA 甲基化峰，例如 和 基因 、 、 、 ，主要是非 CpG 背景下。我们通过焦磷酸测序验证了在 中观察到的升高的 DNA 甲基化。我们确定了与年龄、性别和大脑区域相关的具有不同 DNA 甲基化模式的基因座。最后，我们复制了先前报道的在甲基化 DNA 免疫沉淀测序研究中大脑区域之间的差异甲基化区域。
我们已经在人类脑组织样本中注释了线粒体基因组中单碱基分辨率的 DNA 甲基化模式。展望未来，这种方法可用于研究在表现出线粒体功能障碍的疾病中，线粒体表观遗传机制的作用。
