Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA.
Department of Neurological Surgery, University of Wisconsin, Madison, WI, USA; William S. Middleton Memorial Veteran Administration Hospital, Madison, WI, USA.
Neurochem Int. 2024 Sep;178:105802. doi: 10.1016/j.neuint.2024.105802. Epub 2024 Jul 5.
We previously showed that stroke alters circular RNA (circRNA) expression profiles. Many circRNAs undergo epitranscriptomic modifications, particularly methylation of adenosine to form N-methyladenosine (mA). This modification significantly influences the circRNA metabolism and functionality. Hence, we currently evaluated if transient focal ischemia in adult C57BL/6J mice alters the mA methylation of circRNAs. Changes in mA were profiled in the peri-infarct cortex following immunoprecipitation coupled with microarrays. Correlation and gene ontology analyses were performed to understand the association of mA changes with circRNA regulation and functional implications after stroke. Many circRNAs showed differential regulation (up or down) after stroke, and this change was highest at 24h of reperfusion. Notably, most circRNAs differentially regulated after stroke also exhibited temporal changes in mA modification patterns. The majority of circRNAs that showed post-stroke differential mA modifications were derived from protein-coding genes. Hyper-than hypomethylation of circRNAs was most prevalent after stroke. Gene ontology analysis of the host genes suggested that mA-modified circRNAs might regulate functions such as synapse-related processes, indicating that mA epitranscriptomic modification in circRNAs could potentially influence post-stroke synaptic pathophysiology.
我们之前的研究表明，中风会改变环状 RNA（circRNA）的表达谱。许多 circRNA 会发生表转录组修饰，特别是腺苷的甲基化形成 N6-甲基腺苷（m6A）。这种修饰显著影响 circRNA 的代谢和功能。因此，我们目前评估了成年 C57BL/6J 小鼠短暂局灶性缺血是否会改变 circRNA 的 m6A 甲基化。在免疫沉淀后，通过微阵列对梗死周边皮层中的 m6A 变化进行了分析。进行了相关性和基因本体分析，以了解 m6A 变化与中风后 circRNA 调控和功能意义的关联。中风后许多 circRNA 表现出差异调节（上调或下调），这种变化在再灌注 24 小时时最高。值得注意的是，中风后差异调节的大多数 circRNA 也表现出 m6A 修饰模式的时间变化。大多数表现出中风后差异 m6A 修饰的 circRNA 来自蛋白质编码基因。中风后 circRNA 的 m6A 修饰主要表现为过度修饰（高甲基化）而非低甲基化。宿主基因的基因本体分析表明，m6A 修饰的 circRNA 可能调节与突触相关的过程等功能，这表明 circRNA 中的 m6A 表转录组修饰可能会影响中风后的突触病理生理学。
