Wang Shuo, Qi Chuangye, Rajpurohit Chetan, Ghosh Baijayanti, Xiong Wen, Wang Baiping, Qi Yanyan, Hwang Sung Hee, Hammock Bruce D, Li Hongjie, Gan Li, Zheng Hui
Huffington Center on Aging, Baylor College of Medicine, Houston, TX.
Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX.
Res Sq. 2025 Feb 24:rs.3.rs-6038641. doi: 10.21203/rs.3.rs-6038641/v1.
The epoxyeicosatrienoic acids (EETs) are derivatives of the arachidonic acid metabolism with anti-inflammatory activities. However, their efficacy is limited due to the rapid hydrolasis by the soluble epoxide hydrolase (sEH). Accordingly, inhibition of sEH has been shown to stabilize the EETs and dampen neuroinflammation in Aβ mouse models of Alzheimer's disease (AD). However, the role of the sEH-EET signaling pathway in other cell types of the CNS and in other neurodegenerative conditions are less understood.
Here we examined the mechanisms and the functional role of the sEH-EET axis in tauopathy by treating the PS19 mice with a small molecule sEH inhibitor TPPU and by crossing the PS19 mice with (gene encoding sEH) knockout mice, followed by single-nucleus RNA-sequencing (snRNA-seq), biochemical and immunohistochemical characterization, and behavioral analysis. We also tested the effect of the sEH-EET pathway in primary microglia cultures and human induced pluripotent stem cell (iPSC)-derived neurons that develop seeding-induced Tau inclusions.
We show that sEH inhibition improved cognitive function, rescued neuronal cell loss, and reduced Tau pathology and microglia reactivity. snRNA-seq revealed that TPPU treatment resulted in the upregulation of actin cytoskeleton and excitatory synaptic pathway genes. Treating the human iPSC-derived neurons with TPPU led to enhanced synaptic density without affecting Tau accumulation, indicating a cell-autonomous effect of sEH blockade in neuroprotection. Further, sEH inhibition reversed disease-associated and interferon-response microglia states in PS19 mice and EET supplementation enhanced Tau phagocytosis and clearance in primary microglia cultures.
These findings demonstrate that sEH blockade or EET augmentation confer therapeutic benefit against neurodegenerative tauopathies through parallel targeting of neuronal and microglial pathways.
环氧二十碳三烯酸（EETs）是具有抗炎活性的花生四烯酸代谢衍生物。然而，由于其可被可溶性环氧化物水解酶（sEH）快速水解，其功效受到限制。因此，在阿尔茨海默病（AD）的Aβ小鼠模型中，抑制sEH已被证明可稳定EETs并减轻神经炎症。然而，sEH-EET信号通路在中枢神经系统的其他细胞类型以及其他神经退行性疾病中的作用尚不清楚。
在这里，我们通过用小分子sEH抑制剂TPPU处理PS19小鼠，并将PS19小鼠与（编码sEH的基因）敲除小鼠杂交，然后进行单核RNA测序（snRNA-seq）、生化和免疫组织化学表征以及行为分析，研究了sEH-EET轴在tau蛋白病中的机制和功能作用。我们还测试了sEH-EET通路在原代小胶质细胞培养物和人类诱导多能干细胞（iPSC）衍生的神经元中的作用，这些神经元会形成种子诱导的Tau包涵体。
我们发现抑制sEH可改善认知功能、挽救神经元细胞损失并减少Tau病理和小胶质细胞反应性。snRNA-seq显示，TPPU处理导致肌动蛋白细胞骨架和兴奋性突触通路基因上调。用TPPU处理人类iPSC衍生的神经元可增加突触密度，而不影响Tau积累，表明sEH阻断在神经保护中具有细胞自主效应。此外，抑制sEH可逆转PS19小鼠中与疾病相关的和干扰素反应性小胶质细胞状态，补充EET可增强原代小胶质细胞培养物中Tau的吞噬作用和清除。
这些发现表明，阻断sEH或增加EET通过平行靶向神经元和小胶质细胞通路，对神经退行性tau蛋白病具有治疗益处。
