Stem cell transplantation for ischemic stroke focusing on timing and lesion specificity

人间充质干细胞在D1期广泛分布于梗死周围和核心，在D4期主要分布于梗死周围。D7上很少观察到细胞。卒中后第7天，D1梗死周围和核心的小胶质细胞激活均明显抑制，D4梗死周围的小胶质细胞激活明显抑制。脑卒中后第21天，脑源性神经营养因子广泛分布于D1和D4梗死周围，伴有许多反应性星形胶质细胞和大量血管生成。D1期运动功能改善早，D4期运动功能改善晚，D7期运动功能无恢复。我们的研究结果表明，动脉内细胞移植通过神经保护、反应性星形胶质细胞增强和血管生成的结合，提供了定时依赖的细胞分布和中风后功能恢复。

Human mesenchymal stem cells were widely distributed both in the peri-infarct and core in D1, and dominantly in the peri-infarct in D4. Very few cells were observed on D7. At day 7 poststroke, microglia activation was significantly suppressed in both the peri-infarct and core in D1, and predominantly in the peri-infarct in D4. At day 21 poststroke, brain-derived neurotrophic factor was widely distributed throughout the peri-infarct in D1 and D4, along with many reactive astrocytes and considerable angiogenesis. Motor function improved earlier in D1 and later in D4, but no recovery was obtained in D7.Our results indicate that intra-arterial cell transplantation provides timing-dependent cell distribution and poststroke functional recovery via a combination of neuroprotection, reactive astrocyte enhancement, and angiogenesis.