From the Memory Unit (O.D.-I., V.M., S.S., G.L.-P., L.C.-C., M.Q.-V., L.M., O.B., D.A., J.P., R.B., A.L., J.F., J.C.), Neurology Department and Sant Pau Biomedical Research Institute, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona; Network Center for Biomedical Research in Neurodegenerative Diseases (CIBERNED) (O.D.-I., V.M., S.S., G.L.-P., L.C.-C., M.Q.-V., L.M., O.B., D.A., J.P., R.B., A.L., J.F., J.C.), Madrid; Neurological Tissue Bank of the Biobanc-Hospital Clínic-IDIBAPS (L.M.-P.), Barcelona; Alzheimer's Disease and Other Cognitive Disorders Unit, Neurology Department (L.M.-P.), Hospital Clínic, Institut d'Investigacions Biomèdiques August Pi i Sunyer, University of Barcelona; Network Center for Biomedical Research in Rare Diseases (CIBERER) (J.T.-S., R.R.-G.), Madrid; and Neuromuscular Disorders Unit (J.T.-S., R.R.-G.), Department of Neurology, Hospital de la Santa Creu i Sant Pau, Universitat Autònoma de Barcelona, Spain.
Neurol Neuroimmunol Neuroinflamm. 2020 Jul 15;7(5). doi: 10.1212/NXI.0000000000000829. Print 2020 Sep.
To identify transcriptomic changes, neuropathologic correlates, and cellular subpopulations in the motor cortex of sporadic amyotrophic lateral sclerosis (ALS).
We performed massive RNA sequencing of the motor cortex of patients with ALS (n = 11) and healthy controls (HCs; n = 8) and analyzed gene expression alterations, differential isoform usage, and gene coexpression networks. Furthermore, we used cell type deconvolution algorithms with human single-nucleus RNA sequencing data as reference to identify perturbations in cell type composition associated with ALS. We performed immunohistochemical techniques to evaluate neuropathologic changes in this brain region.
We report extensive RNA expression alterations at gene and isoform levels, characterized by the enrichment of neuroinflammatory and synaptic-related pathways. The assembly of gene coexpression modules confirmed the involvement of these 2 major transcriptomic changes, which also showed opposite directions related to the disease. Cell type deconvolution revealed an overrepresentation of microglial cells in ALS compared with HC. Notably, microgliosis was driven by a subcellular population presenting a gene expression signature overlapping with the recently described disease-associated microglia (DAM). Using immunohistochemistry, we further evidenced that this microglial subpopulation is overrepresented in ALS and that the density of pTDP43 aggregates negatively correlates with the proportion of microglial cells.
DAM has a central role in microglia-related neuroinflammatory changes in the motor cortex of patients with ALS, and these alterations are coupled with a reduced expression of postsynaptic transcripts.
鉴定散发性肌萎缩侧索硬化症（ALS）患者运动皮层的转录组变化、神经病理学相关性和细胞亚群。
我们对 11 例 ALS 患者和 8 例健康对照者（HCs）的运动皮层进行了大规模 RNA 测序，并分析了基因表达改变、差异异构体使用和基因共表达网络。此外，我们使用基于人类单细胞 RNA 测序数据的细胞类型去卷积算法来识别与 ALS 相关的细胞类型组成的改变。我们进行了免疫组织化学技术以评估该脑区的神经病理学改变。
我们报告了基因和异构体水平的广泛 RNA 表达改变，其特征是神经炎症和突触相关途径的富集。基因共表达模块的组装证实了这 2 种主要转录组改变的参与，它们与疾病也呈现出相反的方向。细胞类型去卷积显示与 HC 相比，ALS 中存在更多的小胶质细胞。值得注意的是，小胶质细胞增生是由一个具有与最近描述的疾病相关小胶质细胞（DAM）重叠的基因表达特征的亚细胞群驱动的。使用免疫组织化学，我们进一步证明了这种小胶质细胞亚群在 ALS 中过度表达，且 pTDP43 聚集体的密度与小胶质细胞的比例呈负相关。
DAM 在 ALS 患者运动皮层的小胶质细胞相关神经炎症变化中具有核心作用，这些改变与突触后转录物的表达减少有关。
