神經毒性小膠質細胞促進前顆粒蛋白缺乏的TDP-43蛋白病
作者:
小柯機器人發布時間:2020/9/2 16:31:15
美國加州大學舊金山分校Eric J. Huang研究小組發現,神經毒性小膠質細胞促進前顆粒蛋白缺乏的TDP-43蛋白病。相關論文於2020年8月31日在線發表於《自然》。
研究人員使用單核RNA測序(snRNA-seq)發現,前顆粒蛋白缺乏會促進小膠質細胞從穩態到疾病特異性狀態的轉變,從而引起溶酶體功能障礙和神經變性。即使在離體培養Grn-/-小膠質細胞時,這些缺陷仍然存在。此外,snRNA-seq揭示了疾病末期興奮性神經元的選擇性丟失,其特徵是突出的核和細胞質TDP-43顆粒以及核孔缺陷。
值得注意的是,來自Grn-/-小膠質細胞的條件培養基足以通過補體激活途徑促進興奮性神經元中TDP-43顆粒的形成、核孔缺陷和細胞死亡。與這些結果一致,敲除C1qa和C3可減輕小膠質細胞毒性,並挽救TDP-43蛋白病和神經變性。這些結果揭示了神經變性期間慢性小膠質細胞毒性對TDP-43蛋白病的新貢獻。
據悉,RNA結合蛋白TDP-43在神經元中的異常聚集是額顳葉變性(由前顆粒蛋白單倍計量不足引起)的標誌。然而,導致TDP-43蛋白病的機制仍不清楚。
附:英文原文
Title: Neurotoxic microglia promote TDP-43 proteinopathy in progranulin deficiency
Author: Jiasheng Zhang, Dmitry Velmeshev, Kei Hashimoto, Yu-Hsin Huang, Jeffrey W. Hofmann, Xiaoyu Shi, Jiapei Chen, Andrew M. Leidal, Julian G. Dishart, Michelle K. Cahill, Kevin W. Kelley, Shane A. Liddelow, William W. Seeley, Bruce L. Miller, Tobias C. Walther, Robert V. Farese, J. Paul Taylor, Erik M. Ullian, Bo Huang, Jayanta Debnath, Torsten Wittmann, Arnold R. Kriegstein, Eric J. Huang
Issue&Volume: 2020-08-31
Abstract: Aberrant aggregation of RNA binding protein TDP-43 in neurons is a hallmark of frontotemporal lobar degeneration caused by progranulin haploinsufficiency1,2. However, the mechanism leading to TDP-43 proteinopathy remains unclear. Here we use single-nucleus RNA-sequencing (snRNA-seq) to show that progranulin deficiency promotes microglial transition from a homeostatic to disease-specific state that causes endolysosomal dysfunction and neurodegeneration. These defects persist even when Grn/ microglia are cultured ex vivo. In addition, snRNA-seq reveals selective loss of excitatory neurons at disease end-stage, characterized by prominent nuclear and cytoplasmic TDP-43 granules and nuclear pore defects. Remarkably, conditioned media from Grn/ microglia is sufficient to promote TDP-43 granule formation, nuclear pore defects and cell death in excitatory neurons via the complement activation pathway. Consistent with these results, deleting C1qa and C3 mitigates microglial toxicity, and rescues TDP-43 proteinopathy and neurodegeneration. These results uncover previously unappreciated contributions of chronic microglial toxicity to TDP-43 proteinopathy during neurodegeneration.
DOI: 10.1038/s41586-020-2709-7
Source: https://www.nature.com/articles/s41586-020-2709-7