The Role of Monocytic Cells in Long-Term Post-Stroke Outcome

中风研究中的翻译障碍可能在一定程度上与不同病理机制的相互作用比之前认为的更加复杂有关。特别是，参与脑缺血早期细胞损伤的炎症过程可能会促进后期的恢复。我们的建议验证了这一假设，即脑缺血后，驻留的小胶质细胞与侵袭的单核细胞的致病作用明显不同，并随时间变化。我们将使用骨髓嵌合体、病毒载体和转基因小鼠(例如Ccr2RFP：：Cx3cr1GFP小鼠)来研究小胶质细胞和入侵的单核细胞之间的差异。在双色实验中，我们将追踪红色荧光标记的单核细胞流入表达GFP的小鼠(MacGreen小鼠模型)的缺血脑中。这种方法不仅可以方便地检测小胶质细胞和侵袭的巨噬细胞进行组织学和生理学分析，而且还有助于分离功能分析和转录图谱。然后，我们将使用基因改变的BM(例如，明胶蛋白缺陷的BM导致向缺血脑实质的迁移受损，P-选择素糖蛋白配体-1[PSGL-1]缺陷的BM导致拴系/黏附受损)来干预炎症细胞对脑的入侵。我们将特别关注复杂的终点，包括继发性神经退行性变、细胞可塑性和神经行为结果。

The translational roadblock in stroke research may in part relate to the fact that the interplay of different pathomechanisms is more complex than previously thought. In particular, inflammatory processes which are involved in cellular damage during the early phase of brain ischemia may promote recovery at later stages. Our proposal tests the hypothesis that the pathogenetic role of resident microglia versus invading monocytes diverges markedly and changes time-dependently after brain ischemia. We will use bone-marrow (BM) chimerism, viral vectors, and genetically modified mice (e.g. Ccr2RFP::Cx3cr1GFP mice) to study differences between microglia and invading monocytes. In dual-color experiments, we will trace the influx of red fluorescently labeled monocytes into the ischemic brain of mice harboring microglia expressing GFP (MacGreen mouse model). This approach not only permits convenient detection of microglia and invaded macrophages for histological and physiological analyses, but also facilitates isolation for functional assays and transcriptional profiling. Then, we will interfere with the invasion of inflammatory cells into the brain using genetically altered BM (e.g. gelsolin-deficient BM resulting in impaired migration into ischemic brain parenchyma, P-selectin glycoprotein ligand-1 [PSGL-1] deficient BM resulting in impaired tethering/adhesion). We will specifically focus on complex endpoints including secondary neurodegeneration, cellular plasticity and neurobehavioral outcomes.