FUT8 催化的核心岩藻糖基化在阿尔茨海默病淀粉样β寡聚体诱导的人小神经胶质细胞激活中的作用。
The role of FUT8-catalyzed core fucosylation in Alzheimer's amyloid-β oligomer-induced activation of human microglia.
机构信息
Department of Pathology and Laboratory Medicine and M.I.N.D. Institute, University of California Davis Medical Center, Sacramento, California, USA.
Department of Nutrition, University of California, Davis, California, USA.
出版信息
Glia. 2023 May;71(5):1346-1359. doi: 10.1002/glia.24345. Epub 2023 Jan 24.
Fucosylation, especially core fucosylation of N-glycans catalyzed by α1-6 fucosyltransferase (fucosyltransferase 8 or FUT8), plays an important role in regulating the peripheral immune system and inflammation. However, its role in microglial activation is poorly understood. Here we used human induced pluripotent stem cells-derived microglia (hiMG) as a model to study the role of FUT8-catalyzed core fucosylation in amyloid-β oligomer (AβO)-induced microglial activation, in view of its significant relevance to the pathogenesis of Alzheimer's disease (AD). HiMG responded to AβO and lipopolysaccharides (LPS) with a pattern of pro-inflammatory activation as well as enhanced core fucosylation and FUT8 expression within 24 h. Furthermore, we found increased FUT8 expression in both human AD brains and microglia isolated from 5xFAD mice, a model of AD-like cerebral amyloidosis. Inhibition of fucosylation in AβO-stimulated hiMG reduced the induction of pro-inflammatory cytokines, suppressed the activation of p38MAPK, and rectified phagocytic deficits. Specific inhibition of FUT8 by siRNA-mediated knockdown also reduced AβO-induced pro-inflammatory cytokines. We further showed that p53 binds to the two consensus binding sites in the Fut8 promoter, and that p53 knockdown abolished FUT8 overexpression in AβO-activated hiMG. Taken together, our evidence supports that FUT8-catalyzed core fucosylation is a signaling pathway required for AβO-induced microglia activation and that FUT8 is a component of the p53 signaling cascade regulating microglial behavior. Because microglia are a key driver of AD pathogenesis, our results suggest that microglial FUT8 could be an anti-inflammatory therapeutic target for AD.
岩藻糖基化作用,特别是由α1-6 岩藻糖基转移酶(岩藻糖基转移酶 8 或 FUT8)催化的 N-糖基化的核心岩藻糖基化,在调节外周免疫系统和炎症中起着重要作用。然而,其在小胶质细胞激活中的作用知之甚少。在这里,我们使用人诱导多能干细胞衍生的小胶质细胞(hiMG)作为模型,研究 FUT8 催化的核心岩藻糖基化在淀粉样β寡聚体(AβO)诱导的小胶质细胞激活中的作用,因为这与阿尔茨海默病(AD)的发病机制密切相关。hiMG 对 AβO 和脂多糖(LPS)的反应是促炎激活模式,以及在 24 小时内增强核心岩藻糖基化和 FUT8 表达。此外,我们发现在人类 AD 大脑和源自 5xFAD 小鼠的小胶质细胞中,即 AD 样脑淀粉样变性的模型中,FUT8 表达增加。在 AβO 刺激的 hiMG 中抑制岩藻糖基化可减少促炎细胞因子的诱导,抑制 p38MAPK 的激活,并纠正吞噬缺陷。siRNA 介导的敲低特异性抑制 FUT8 也减少了 AβO 诱导的促炎细胞因子。我们进一步表明,p53 结合到 Fut8 启动子中的两个共识结合位点,并且 p53 敲低消除了 AβO 激活的 hiMG 中的 FUT8 过表达。总之,我们的证据表明,FUT8 催化的核心岩藻糖基化是 AβO 诱导的小胶质细胞激活所需的信号通路,并且 FUT8 是调节小胶质细胞行为的 p53 信号级联的组成部分。由于小胶质细胞是 AD 发病机制的关键驱动因素,我们的结果表明,小胶质细胞 FUT8 可能是 AD 的抗炎治疗靶点。