Lipidomic analysis identifies long-chain acylcarnitine as a target for ischemic stroke
Lipidomic analysis identifies long-chain acylcarnitine as a target for ischemic stroke
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DOI：
10.1016/j.jare.2023.08.007
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发表时间：
2024-06-22
影响因子：
10.7
通讯作者：
Sun，Xiu-Lan
中科院分区：
文献类型：
--
作者：
Huang，Xin-Xin;Li，Lei;Sun，Xiu-Lan
脂代谢异常广泛参与急性缺血性卒中(AIS)的病理过程。神经元和星形胶质细胞之间的脂代谢协调具有重要意义。然而，AIS过程中脂质动态变化的全部范围和关键脂类的功能仍不清楚。因此，识别脂质改变并确定其在AIS中的关键作用是非常重要的。方法采用非靶向和靶向的脂质组学分析方法，对短暂性大脑中动脉闭塞(TMCAO)小鼠的缺血半暗带和外周血以及AIS患者的外周血中的脂质变化进行分析。TMCAO后评估脑梗塞体积和神经功能缺损程度。CCK8比色法和Sholl法检测原代神经元的细胞活性和树突复杂性。用海马、MitoTracker Green、四甲基罗丹明甲酯(TMRM)、2‘，7’-二氯二氢荧光素二乙酸酯(DCFH-DA)和MitoSOX作为线粒体健康的标志物。结果长链酰肉碱(LCACs)是tMCAO小鼠缺血半影区和外周血中变化最显著的脂类。AIS患者入院时LCAC显著升高，且与AIS患者不良预后相关。通过推注棕榈酰肉碱增加LCACs增加卒中损伤，而通过过表达肉碱棕榈酰基转移酶2(CPT2)减少LCACs可改善卒中损伤。棕榈酰卡尼汀加重OGD/R后星形胶质细胞线粒体的损伤，而CPT2在星形胶质细胞中的过表达可改善共培养神经元的活力。进一步研究发现，在OGD/R刺激下，星形胶质细胞从脂滴中释放游离脂肪酸进入线粒体，形成LCACs，导致线粒体损伤，降低星形胶质细胞代谢支持，从而加重神经元损伤。结论LCACs可通过诱导AIS星形胶质细胞线粒体功能障碍而积聚和损伤神经元。LCACs在AIS的病理过程中起着至关重要的作用，是一种新的、有前景的AIS诊断和预后生物标志物。
IntroductionLipid metabolism dysfunction is widely involved in the pathological process of acute ischemic stroke (AIS). The coordination of lipid metabolism between neurons and astrocytes is of great significance. However, the full scope of lipid dynamic changes and the function of key lipids during AIS remain unknown. Hence, identifying lipid alterations and characterizing their key roles in AIS is of great importance.MethodsUntargeted and targeted lipidomic analyses were applied to profile lipid changes in the ischemic penumbra and peripheral blood of transient middle cerebral artery occlusion (tMCAO) mice as well as the peripheral blood of AIS patients. Infarct volume and neurological deficits were assessed after tMCAO. The cell viability and dendritic complexity of primary neurons were evaluated by CCK8 assay and Sholl analysis. Seahorse, MitoTracker Green, tetramethyl rhodamine methyl ester (TMRM), 2′,7′-dichlorodihydrofluorescein diacetate (DCFH-DA) and MitoSOX were used as markers of mitochondrial health. Fluorescent and isotopic free fatty acid (FFA) pulse-chase assays were used to track FFA flux in astrocytes.ResultsLong-chain acylcarnitines (LCACs) were the lipids with the most dramatic changes in the ischemic penumbra and peripheral blood of tMCAO mice. LCACs were significantly elevated on admission in AIS patients and associated with poor outcomes in AIS patients. Increasing LCACs through a bolus administration of palmitoylcarnitine amplified stroke injury, while decreasing LCACs by overexpressing carnitine palmitoyltransferase 2 (CPT2) ameliorated stroke injury. Palmitoylcarnitine aggravated astrocytic mitochondrial damage after OGD/R, while CPT2 overexpression in astrocytes ameliorated cocultured neuron viability. Further study revealed that astrocytes stimulated by OGD/R liberated FFAs from lipid droplets into mitochondria to form LCACs, resulting in mitochondrial damage and lowered astrocytic metabolic support and thereby aggravated neuronal damage.ConclusionLCACs could accumulate and damage neurons by inducing astrocytic mitochondrial dysfunction in AIS. LCACs play a crucial role in the pathology of AIS and are novel promising diagnostic and prognostic biomarkers for AIS.