S-亚硝基化FKBP5经PHLPP-AKT轴抑制缺血性卒中后血管新生
本研究在缺血性卒中小鼠模型和氧糖剥夺/复氧处理的内皮细胞中，通过S-亚硝基化蛋白质组学等方法探讨血管新生的分子机制。结果发现内皮FKBP5半胱氨酸339位点S-亚硝基化增强其与PHLPP结合并抑制AKT信号，从而限制血管新生和功能恢复。内皮靶向表达不可亚硝基化的FKBP5-C339A突变体可促进梗死周围血管新生、改善长期感觉运动恢复。
要点
- FKBP5半胱氨酸339位点S-亚硝基化经PHLPP抑制AKT信号，是缺血性卒中后血管新生的负调控开关。
- 内皮靶向表达FKBP5-C339A突变体可促进梗死周围血管新生和灌注，减少组织损伤并改善慢性感觉运动恢复。
- 诱导型一氧化氮合酶是FKBP5 S-亚硝基化的上游介导因素。
核心结论
- 内皮FKBP5是卒中后血管再生的新调控因子，其半胱氨酸339位点S-亚硝基化通过PHLPP依赖的AKT信号抑制限制血管新生和功能恢复。
- 靶向该修饰可能成为增强缺血性卒中后血管修复的策略。
研究设计与样本
- 采用8周龄雄性小鼠短暂性大脑中动脉闭塞模型及氧糖剥夺/复氧处理的脑微血管内皮细胞进行S-亚硝基化蛋白质组学分析。
- 通过半胱氨酸诱变和生物素开关实验验证候选修饰位点，并比较野生型与C339A突变型FKBP5在内皮血管新生实验中的差异。
- 4周龄雄性小鼠接受编码野生型或C339A突变型FKBP5的内皮靶向腺相关病毒9，4周后行短暂性大脑中动脉闭塞，评估至第28天的血管和神经功能结局。
主要发现
- 缺血性脑组织和氧糖剥夺/复氧处理的内皮细胞中S-亚硝基化FKBP5升高，总FKBP5未升高；诱导型一氧化氮合酶是上游介导因素。
- 质谱和诱变实验确定半胱氨酸339是主要修饰位点；C339A突变可阻止FKBP5 S-亚硝基化，并挽救氧糖剥夺/复氧后的内皮增殖、迁移、出芽和管形成。
- 在小鼠中，内皮靶向表达FKBP5-C339A促进梗死周围血管新生和灌注，减少组织损伤，改善慢性感觉运动恢复。
- 机制上，S-亚硝基化增强FKBP5与PHLPP结合并降低AKT磷酸化；C339A削弱该相互作用并恢复AKT激活。
- 体外用NSC117079抑制PHLPP可增强AKT信号和血管新生反应。
临床怎么用
- 抑制FKBP5半胱氨酸339位点S-亚硝基化或干预FKBP5-PHLPP-AKT信号轴可能是促进缺血性卒中后血管修复和功能恢复的潜在方向。
以上解读依据论文摘要（全文未开放获取或许可不允许翻译转载）。
原文
Stroke, Volume 57, Issue 10, Page 3106-3123, October 1, 2026. BACKGROUND:Angiogenesis contributes to vascular repair and functional recovery after ischemic stroke, yet how nitric oxide–mediated S-nitrosylation shapes this response remains unclear. We investigated the role of S-nitrosylation in postischemic angiogenesis and the underlying molecular mechanism.METHODS:S-nitrosylation proteomics was performed in ischemic brain tissue from 8-week-old male mice subjected to transient middle cerebral artery occlusion and in brain microvascular endothelial cells exposed to oxygen-glucose deprivation/reoxygenation. Candidate modification sites were validated by cysteine mutagenesis and biotin-switch assays. Wild-type and C339A-mutant FKBP5 (FK506-binding protein 5) were compared in endothelial angiogenesis assays. Four-week-old male mice received endothelial-targeted adeno-associated virus 9 encoding wild-type or C339A-mutant FKBP5 and underwent transient middle cerebral artery occlusion 4 weeks later. Vascular and neurological outcomes were assessed through day 28. Protein-interaction and signaling analyses defined the downstream mechanism.RESULTS:S-nitrosylated FKBP5, but not total FKBP5, was increased in ischemic brain tissue and oxygen-glucose deprivation/reoxygenation-treated endothelial cells; inducible nitric oxide synthase was an upstream mediator. Mass spectrometry and mutagenesis identified cysteine 339 as the predominant modification site. C339A prevented FKBP5 S-nitrosylation and rescued endothelial proliferation, migration, sprouting, and tube formation after oxygen-glucose deprivation/reoxygenation. In mice, endothelial-targeted expression of FKBP5-C339A promoted peri-infarct angiogenesis and perfusion, reduced tissue injury, and improved chronic sensorimotor recovery. Mechanistically, S-nitrosylation strengthened FKBP5 binding to PHLPP (PH domain leucine-rich repeat protein phosphatase) and reduced AKT (serine/threonine kinase) phosphorylation. C339A weakened this interaction and restored AKT activation, whereas PHLPP inhibition with NSC117079 enhanced AKT signaling and angiogenic responses in vitro.CONCLUSIONS:We identify endothelial FKBP5 as a previously unrecognized regulator of poststroke vascular regeneration and establish S-nitrosylation at cysteine 339 as a molecular switch that restrains angiogenesis and functional recovery through PHLPP-dependent inhibition of AKT signaling. Targeting this modification may offer a strategy to enhance vascula
引用
- Stroke：S-Nitrosylation of Endothelial FK506-Binding Protein 5 Impairs Angiogenesis via PHLPP-AKT Axis in Ischemic Stroke
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