Ding Wanqiu, Gao Hongmei, Liu Ruijia, Zhao Hanshu, Liu Sihan, Shen Jinru, Zhao Xinyue, Xu Yuanqi, Zhang Zhongling
Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Department of Neurology, the First Affiliated Hospital of Harbin Medical University, Harbin 150001, China.
Brain Res Bull. 2025 Aug 5;230:111504. doi: 10.1016/j.brainresbull.2025.111504.
Cuproptosis, a consequence of excessively high copper concentrations, is considered a potential therapeutic target for cerebral ischemia-reperfusion injury (IRI). Methyltransferases are key modulators of cuproptosis through N6-methyladenosine (mA) modification on ferredoxin 1 (FDX1) mRNA. This study aims to determine whether methyltransferase-like 14 (METTL14) regulates cuproptosis in cerebral IRI via mA modification on FDX1 mRNA.
The middle cerebral artery occlusion/reperfusion (MCAO/R)-treated mice, and oxygen glucose deprivation/reoxygenation-treated mouse primary hippocampal neurons were used to mimic cerebral IRI in vivo and in vitro, respectively. The functional role of METTL14 in cerebral IRI was determined by examining neurological functions, cerebral infarction, hippocampal CA1 tissue changes, neuronal viability, and cuproptosis using knockdown experiments. The involvement of FDX1 in the METTL14 regulatory pathway was verified by overexpressing FDX1.
METTL14 expression was increased in the hippocampal tissue of mice subjected to MCAO/R. METTL14 knockdown reduced neurological deficits, infarct size, and hippocampal CA1 neuronal cuproptosis in MCAO/R mice. Furthermore, activation of hippocampal CA1 neuronal cuproptosis partly averted the alleviation of cerebral IRI by METTL14 knockdown. These results were reproduced in in vitro studies. Furthermore, mechanistic studies revealed that METTL14 knockdown reduced the stability of FDX1 mRNA through mA modification and consequently limited FDX1 expression. Importantly, FDX1 overexpression could partly reverse the cuproptosis inhibition induced by METTL14 knockdown.
Taken together, this research innovatively demonstrates the neuroprotective effect of METTL14 knockdown on hippocampal CA1 neurons in cerebral IRI via its regulation of FDX1, which might help design new therapies to improve cerebral IRI.
铜死亡是铜浓度过高的结果，被认为是脑缺血再灌注损伤（IRI）的一个潜在治疗靶点。甲基转移酶是通过对铁氧化还原蛋白1（FDX1）mRNA进行N6-甲基腺苷（m6A）修饰来调控铜死亡的关键调节因子。本研究旨在确定类甲基转移酶14（METTL14）是否通过对FDX1 mRNA的m6A修饰来调节脑IRI中的铜死亡。
分别采用大脑中动脉闭塞/再灌注（MCAO/R）处理的小鼠和氧糖剥夺/复氧处理的小鼠原代海马神经元，在体内和体外模拟脑IRI。通过敲低实验检测神经功能、脑梗死、海马CA1组织变化、神经元活力和铜死亡，以确定METTL14在脑IRI中的功能作用。通过过表达FDX1来验证FDX1在METTL14调控途径中的参与情况。
MCAO/R处理的小鼠海马组织中METTL14表达增加。敲低METTL14可减少MCAO/R小鼠的神经功能缺损、梗死面积和海马CA1神经元铜死亡。此外，海马CA1神经元铜死亡的激活部分抵消了敲低METTL14对脑IRI的缓解作用。这些结果在体外研究中得到了重现。此外，机制研究表明，敲低METTL14通过m6A修饰降低了FDX1 mRNA的稳定性，从而限制了FDX1的表达。重要的是，过表达FDX1可部分逆转敲低METTL14诱导的铜死亡抑制作用。
综上所述，本研究创新性地证明了敲低METTL14通过调节FDX1对脑IRI中海马CA1神经元具有神经保护作用，这可能有助于设计新的疗法来改善脑IRI。
