Brain injury causes astrocytes to become reactive (astrogliosis). In this study, we compared astrogliosis in acutely injured cortex and striatum of adult FVB/N mice induced by stereotaxic injection of ATP, a component of danger-associated molecular patterns (DAMPs). Interestingly, MR analysis showed that same amount of ATP induced smaller damage in the cortex than in the striatum. However, in histological analysis, thick and dense scar-like astrogliosis was found in the injured cortex near meninges within 2 wk., but not in other regions, including the striatum and even the cortex near the corpus callosum for up to 30 d. There was little regional difference in the number of Ki67(+)-proliferating astrocytes or mRNA expression of inflammatory cytokines. The most prominent difference between regions with and without scar-like astrogliosis was blood vessel formation. Blood vessels highly expressing collagen 1A1 formed densely near meninges, and astrocytes converged on them. In other regions, however, both blood vessels and astrocytes were relatively evenly distributed. Consistent with this, inhibition of blood vessel formation with the vascular endothelial growth factor (VEGF)-blocking antibody, Avastin, attenuated scar-like astrogliosis near meninges. These results indicate that region-specific astrogliosis occurs following brain injury, and that blood vessel formation plays a critical role in scar formation.

中文翻译：

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区域特异性星形胶质细胞增生：不同的血管形成导致皮质和纹状体中星形胶质细胞增生的不同模式。


脑损伤导致星形胶质细胞变得活跃（星形胶质细胞增生）。在这项研究中，我们比较了立体定位注射 ATP（危险相关分子模式 (DAMP) 的一个组成部分）诱导的成年 FVB/N 小鼠急性损伤的皮质和纹状体中的星形胶质细胞增生。有趣的是，MR 分析表明，相同量的 ATP 在皮质中引起的损伤比在纹状体中引起的损伤要小。然而，在组织学分析中，2周内在受伤的脑膜附近的皮质中发现了厚而致密的疤痕样星形胶质细胞增生，而在其他区域，包括纹状体甚至胼胝体附近的皮质中没有发现长达30 d的增生。 Ki67(+)增殖星形胶质细胞数量或炎性细胞因子mRNA表达的区域差异很小。有和没有疤痕样星形胶质细胞增生的区域之间最显着的差异是血管形成。高表达胶原蛋白1A1的血管在脑膜附近密集形成，星形胶质细胞聚集在其上。然而，在其他区域，血管和星形胶质细胞的分布相对均匀。与此相一致的是，用血管内皮生长因子（VEGF）阻断抗体阿瓦斯汀抑制血管形成，可以减轻脑膜附近的疤痕样星形胶质细胞增生。这些结果表明，脑损伤后会发生区域特异性星形胶质细胞增生，并且血管形成在疤痕形成中起着关键作用。