背景:脑出血(ICH)是一种导致严重神经功能缺损的破坏性疾病。小胶质细胞是大脑的第一道防线,在脑出血后的神经功能恢复中起着至关重要的作用,其活动主要由葡萄糖代谢驱动。然而,关于小胶质细胞葡萄糖代谢的状态及其与ICH后炎症反应的相互作用知之甚少.
目的:本研究探讨了小胶质细胞糖酵解及其对ICH后小胶质细胞炎症的作用机制。
方法:我们通过2-脱氧-[18F]氟-D-葡萄糖正电子发射断层扫描(FDG-PET)分析和γ发射,探索了同侧区域和荧光激活细胞分选分离(FACS分离)小胶质细胞中葡萄糖代谢的状态,分别。能量相关的靶向代谢组学,随着13C-葡萄糖同位素示踪,用于分析小胶质细胞中的糖酵解产物。通过流式细胞术评估线粒体膜电位和线粒体活性氧(MitoROS)积累。行为,西方印迹,基因调控,和酶活性分析的重点是小胶质细胞。
结果:神经功能障碍与血肿周围区域FDG-PET信号降低密切相关,其中小胶质细胞对FDG的摄取减少。小胶质细胞中葡萄糖-6-磷酸(G-6-P)的减少归因于葡萄糖转运蛋白1(GLUT1)和己糖激酶2(HK2)的下调。增强的炎症反应是由HK2抑制通过降低线粒体膜电位驱动的,可以由Mitoros拾荒者拯救。HK抑制剂通过抑制FDG摄取和增强ICH小鼠小胶质细胞炎症而加重神经损伤。
结论:这些研究结果表明ICH后促炎性小胶质细胞出现了意想不到的代谢状态,由GLUT1和HK2下调引起的糖酵解损害组成。此外,HK2抑制通过破坏线粒体功能促进炎症反应,深入了解ICH后可能促进炎症的机制,并表明代谢酶是ICH治疗的潜在靶点.
BACKGROUND: Intracerebral haemorrhage (ICH) is a devastating disease that leads to severe neurological deficits. Microglia are the first line of defence in the brain and play a crucial role in neurological recovery after ICH, whose activities are primarily driven by glucose metabolism. However, little is known regarding the status of glucose metabolism in microglia and its interactions with inflammatory responses after ICH.
OBJECTIVE: This study investigated microglial glycolysis and its mechanistic effects on microglial inflammation after ICH.
METHODS: We explored the status of glucose metabolism in the ipsilateral region and in fluorescence-activated-cell-sorting-isolated (FACS-isolated) microglia via 2-deoxy-[18F]fluoro-D-glucose positron emission tomography (FDG-PET) analyses and gamma emission, respectively. Energy-related targeted metabolomics, along with 13C-glucose isotope tracing, was utilised to analyse glycolytic products in microglia. Mitochondrial membrane potential and mitochondrial reactive oxygen species (MitoROS) accumulation was assessed by flow cytometry. Behavioural, western blotting, gene regulation, and enzymatic activity analyses were conducted with a focus on microglia.
RESULTS: Neurological dysfunction was strongly correlated with decreased FDG-PET signals in the perihaematomal region, where microglial uptake of FDG was reduced. The decreased quantity of glucose-6-phosphate (G-6-P) in microglia was attributed to the downregulation of glucose transporter 1 (GLUT1) and hexokinase 2 (HK2). Enhanced inflammatory responses were driven by HK2 suppression via decreased mitochondrial membrane potential, which could be rescued by MitoROS scavengers. HK inhibitors aggravated neurological injury by suppressing FDG uptake and enhancing microglial inflammation in ICH mice.
CONCLUSIONS: These findings indicate an unexpected metabolic status in pro-inflammatory microglia after ICH, consisting of glycolysis impairment caused by the downregulation of GLUT1 and HK2. Additionally, HK2 suppression promotes inflammatory responses by disrupting mitochondrial function, providing insight into the mechanisms by which inflammation may be facilitated after ICH and indicating that metabolic enzymes as potential targets for ICH treatment.