PDF(Pubmed)
Abstract：
BACKGROUND: Ischemic stroke elicits a complex and sustained immune response in the brain. Immunomodulatory treatments have long held promise for improving stroke outcomes, yet none have succeeded in the clinical setting. This lack of success is largely due to our incomplete understanding of how immune cells respond to stroke. The objective of the current study was to dissect the effect of permanent stroke on microglia, the resident immune cells within the brain parenchyma.
METHODS: A permanent middle cerebral artery occlusion (pMCAO) model was used to induce ischemic stroke in young male and female mice. Microglia were sorted from fluorescence reporter mice after pMCAO or sham surgery and then subjected to single-cell RNA sequencing analysis. Various methods, including flow cytometry, RNA in situ hybridization, immunohistochemistry, whole-brain imaging, and bone marrow transplantation, were also employed to dissect the microglial response to stroke. Stroke outcomes were evaluated by infarct size and behavioral tests.
RESULTS: First, we showed the morphologic and spatial changes in microglia after stroke. We then performed single-cell RNA sequencing analysis on microglia isolated from sham and stroke mice of both sexes. The data indicate no major sexual dimorphism in the microglial response to permanent stroke. Notably, we identified seven potential stroke-associated microglial clusters, including four major clusters characterized by a disease-associated microglia-like signature, a highly proliferative state, a macrophage-like profile, and an interferon (IFN) response signature, respectively. Importantly, we provided evidence that the macrophage-like cluster may represent the long-sought stroke-induced microglia subpopulation with increased CD45 expression. Lastly, given that the IFN-responsive subset constitutes the most prominent microglial population in the stroke brain, we used fludarabine to pharmacologically target STAT1 signaling and found that fludarabine treatment improved long-term stroke outcome.
CONCLUSIONS: Our findings shed new light on microglia heterogeneity in stroke pathology and underscore the potential of targeting specific microglial populations for effective stroke therapies.
METHODS: A permanent middle cerebral artery occlusion (pMCAO) model was used to induce ischemic stroke in young male and female mice. Microglia were sorted from fluorescence reporter mice after pMCAO or sham surgery and then subjected to single-cell RNA sequencing analysis. Various methods, including flow cytometry, RNA in situ hybridization, immunohistochemistry, whole-brain imaging, and bone marrow transplantation, were also employed to dissect the microglial response to stroke. Stroke outcomes were evaluated by infarct size and behavioral tests.
RESULTS: First, we showed the morphologic and spatial changes in microglia after stroke. We then performed single-cell RNA sequencing analysis on microglia isolated from sham and stroke mice of both sexes. The data indicate no major sexual dimorphism in the microglial response to permanent stroke. Notably, we identified seven potential stroke-associated microglial clusters, including four major clusters characterized by a disease-associated microglia-like signature, a highly proliferative state, a macrophage-like profile, and an interferon (IFN) response signature, respectively. Importantly, we provided evidence that the macrophage-like cluster may represent the long-sought stroke-induced microglia subpopulation with increased CD45 expression. Lastly, given that the IFN-responsive subset constitutes the most prominent microglial population in the stroke brain, we used fludarabine to pharmacologically target STAT1 signaling and found that fludarabine treatment improved long-term stroke outcome.
CONCLUSIONS: Our findings shed new light on microglia heterogeneity in stroke pathology and underscore the potential of targeting specific microglial populations for effective stroke therapies.
摘要：
背景：缺血性卒中在大脑中引起复杂且持续的免疫应答。免疫调节治疗长期以来一直有望改善卒中结局，然而，没有一个在临床上成功。这种缺乏成功的主要原因是我们对免疫细胞如何应对中风的理解不完全。本研究的目的是剖析永久性中风对小胶质细胞的影响，大脑实质内的固有免疫细胞。
方法：采用永久性大脑中动脉闭塞（pMCAO）模型在幼年雄性和雌性小鼠中诱发缺血性中风。pMCAO或假手术后，从荧光报告小鼠中分选小胶质细胞，然后进行单细胞RNA测序分析。各种方法,包括流式细胞术,RNA原位杂交,免疫组织化学，全脑成像,骨髓移植，还用于解剖小胶质细胞对中风的反应。通过梗死面积和行为测试评估卒中结果。
结果：首先，我们显示了卒中后小胶质细胞的形态和空间变化。然后，我们对从两种性别的假手术和中风小鼠中分离的小胶质细胞进行了单细胞RNA测序分析。数据表明，对永久性中风的小胶质细胞反应中没有主要的性二态性。值得注意的是,我们确定了七个潜在的卒中相关小胶质细胞簇,包括以疾病相关的小胶质细胞样特征为特征的四个主要簇，一种高度增殖的状态,巨噬细胞样的轮廓，和干扰素（IFN）应答签名，分别。重要的是,我们提供的证据表明,巨噬细胞样簇可能代表长期寻找的卒中诱导的小胶质细胞亚群,CD45表达增加.最后,鉴于IFN反应性子集构成了中风大脑中最突出的小胶质细胞群体，我们使用氟达拉滨在药理学上靶向STAT1信号,发现氟达拉滨治疗可改善长期卒中结局.
结论：我们的研究结果为小胶质细胞在卒中病理学中的异质性提供了新的启示，并强调了针对特定小胶质细胞群体进行有效卒中治疗的潜力。
方法：采用永久性大脑中动脉闭塞（pMCAO）模型在幼年雄性和雌性小鼠中诱发缺血性中风。pMCAO或假手术后，从荧光报告小鼠中分选小胶质细胞，然后进行单细胞RNA测序分析。各种方法,包括流式细胞术,RNA原位杂交,免疫组织化学，全脑成像,骨髓移植，还用于解剖小胶质细胞对中风的反应。通过梗死面积和行为测试评估卒中结果。
结果：首先，我们显示了卒中后小胶质细胞的形态和空间变化。然后，我们对从两种性别的假手术和中风小鼠中分离的小胶质细胞进行了单细胞RNA测序分析。数据表明，对永久性中风的小胶质细胞反应中没有主要的性二态性。值得注意的是,我们确定了七个潜在的卒中相关小胶质细胞簇,包括以疾病相关的小胶质细胞样特征为特征的四个主要簇，一种高度增殖的状态,巨噬细胞样的轮廓，和干扰素（IFN）应答签名，分别。重要的是,我们提供的证据表明,巨噬细胞样簇可能代表长期寻找的卒中诱导的小胶质细胞亚群,CD45表达增加.最后,鉴于IFN反应性子集构成了中风大脑中最突出的小胶质细胞群体，我们使用氟达拉滨在药理学上靶向STAT1信号,发现氟达拉滨治疗可改善长期卒中结局.
结论：我们的研究结果为小胶质细胞在卒中病理学中的异质性提供了新的启示，并强调了针对特定小胶质细胞群体进行有效卒中治疗的潜力。
