Shirotani Keiro, Hatta Daisuke, Wakita Naoki, Watanabe Kaori, Iwata Nobuhisa
Department of Genome-based Drug Discovery, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521, Japan.
Leading Medical Research Core Unit, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki 852-8521, Japan.
J Biochem. 2022 Dec 5;172(6):347-353. doi: 10.1093/jb/mvac073.
Variants of triggering receptor expressed on myeloid cells 2 (TREM2) are associated with an increased incidence of Alzheimer's disease, as well as other neurodegenerative disorders. TREM2 is glycosylated in vitro and in vivo, but the significance of the modification is unknown. We previously established a sensitive and specific reporter cell model involving cultured Jurkat cells stably expressing a luciferase reporter gene and a gene encoding a TREM2DAP12 fusion protein to monitor TREM2-dependent signalling. In the present study, we prepared modified reporter cells to investigate the role of the N-glycans at N20 and N79. We show that the N-glycans at N79 have a requisite role in translocation of TREM2 to the cell surface, while the N-glycans at both N20 and N79 have a critical role in intracellular signal transduction. Our results indicate that structural changes to the TREM2 N-glycans may cause microglial dysfunction that contributes to the pathogenesis of neurodegenerative disorders and that maintaining the integrity of TREM2 N-glycosylation and the responsible glycosyltransferases may be a novel therapeutic strategy to treat these disorders.
髓系细胞触发受体2(TREM2)的变体与阿尔茨海默病以及其他神经退行性疾病的发病率增加有关。TREM2在体外和体内均发生糖基化,但这种修饰的意义尚不清楚。我们之前建立了一个灵敏且特异的报告细胞模型,该模型涉及稳定表达荧光素酶报告基因和编码TREM2-DAP12融合蛋白的基因的培养Jurkat细胞,用于监测TREM2依赖性信号传导。在本研究中,我们制备了修饰的报告细胞,以研究N20和N79处N-聚糖的作用。我们发现,N79处的N-聚糖在TREM2转运至细胞表面过程中起必要作用,而N20和N79处的N-聚糖在细胞内信号转导中均起关键作用。我们的结果表明,TREM2 N-聚糖的结构变化可能导致小胶质细胞功能障碍,进而促成神经退行性疾病的发病机制,并且维持TREM2 N-糖基化及相关糖基转移酶的完整性可能是治疗这些疾病的一种新的治疗策略。