图1 外泌体的电镜观测和粒径分析注：A，电镜观测下的外泌体直径约100 nm，呈球状（比例尺为100 nm）；B，外泌体悬液的粒径分析。

Figure 1 Electron microscopic observation and particle size analysis of exosomesNote： A， Exosome observed under electron microscopy has a diameter of approximately 100 nm and is spherical in shape （the scale bar is 100 nm）； B， Particle size analysis of exosome suspension.

图2 MCAO小鼠模型建立过程中MCA血流变化和脑梗死区TTC染色表现注：A，黑色箭头所指为大脑中动脉（MCA），呈Y字型；B，短时间电凝（约2～3 s），血流开始减少；C，继续电凝（累计约5～6 s），血流基本中断；D，充分电凝（累计约8～10 s），血管完全闭塞；E，中动脉闭塞（MCAO）模型组脑切片的2，3，5-三苯基氯化四氮唑（TTC）染色结果，黑色箭头所指白色区域即为梗死区域。A～D图比例尺为3 mm；E图比例尺为5 mm。

Figure 2 MCA blood flow changes during MCAO model establishment and TTC staining of the cerebral infarction areaNote： A， The black arrow indicates the middle cerebral artery （MCA）， which is Y-shaped； B， short-duration electrocoagulation （approximately 2-3 s）， during which blood flow begins to decrease；C， continued electrocoagulation （cumulative approximately 5-6 s）， with blood flow largely interrupted；D， sufficient electrocoagulation （cumulative approximately 8-10 s）， resulting in complete vascular occlusion； E， 2，3，5-triphenyltetrazolium chloride （TTC） staining results of brain sections in the middle cerebral artery occlusion （MCAO） model group， the white area indicated by the black arrow is the infarcted area. The scale bar in A-D indicates 3 mm； The scale bar in E indicates 5 mm.

图3 各组小鼠神经功能缺损评分及脑梗死体积占比分析注：A，各组小鼠神经功能Longa评分；B，各组小鼠脑切片的2，3，5-三苯基氯化四氮唑（TTC）染色结果，每列6张切片为1只小鼠的完整大脑，正常脑组织为红色，梗死区域脑组织为白色；C，各组小鼠脑梗死体积占比。假手术组（Sham）只暴露大脑中动脉，不电凝血管；模型组（MCAO）使用高频手术镊以8 W功率电凝大脑中动脉；模型+生理盐水组（MCAO+NaCl）先通过尾静脉注射100 μL生理盐水，然后进行电凝法造模；模型+外泌体组（MCAO+EXO）先通过尾静脉注射100 μL来自人羊膜间充质干细胞（hAMSCs）培养上清液的外泌体（9.5×1011个/mL），然后进行电凝法造模。每组小鼠各8只，??P＜0.01，???P＜0.001。

Figure 3 Analysis of neurological deficit scores and the percentages of cerebral infarction volume in each group of miceNote： A， Neurological Longa scores of each group of mice； B， 2，3，5-triphenyltetrazolium chloride （TTC） staining results of brain sections in each group of mice， each column contains six slices representing the complete brain of one mouse， normal brain tissue was red， while brain tissue in the infarcted area was white； C， The percentages of brain infarction volume in each group of mice. The sham operation group （Sham） only exposed the middle cerebral artery without electrocoagulation of the vessel； the model group （MCAO） used high-frequency surgical forceps to electrocoagulate the middle cerebral artery at a power of 8 W； the model + normal saline group （MCAO+NaCl） first injected 100 μL of normal saline through the tail vein， and then performed electrocoagulation modeling； the model + exosome group （MCAO+EXO） first injected 100 μL of exosomes （9.5×1011 particles per mL） from the culture supernatant of human amniotic mesenchymal stem cells （hAMSCs） through the tail vein， and then performed electrocoagulation modeling. There were eight mice in each group. ??P＜0.01， ???P＜0.001.

图4 各组小鼠脑组织切片HE染色观察神经细胞形态注：假手术组（Sham）只暴露大脑中动脉，不电凝血管；模型组（MCAO）使用高频手术镊以8 W功率电凝大脑中动脉；模型+生理盐水组（MCAO+NaCl）先通过尾静脉注射100 μL生理盐水，然后进行电凝法造模；模型+外泌体组（MCAO+EXO）先通过尾静脉注射100 μL来自人羊膜间充质干细胞（hAMSCs）培养上清液的外泌体（9.5×1011个/mL），然后进行电凝法造模。图中第1行×40视野比例尺为50 μm，第2行×100视野比例尺为20 μm。黑色箭头所指为细胞质空泡变性区域，蓝色箭头所指为细胞核固缩、碎裂区域。

Figure 4 HE staining of brain tissue sections from each group of mice to observe neuronal morphologyNote： The sham operation group （Sham） only exposed the middle cerebral artery without electrocoagulation of the vessel； the model group （MCAO） used high-frequency surgical forceps to electrocoagulate the middle cerebral artery at a power of 8 W； the model + normal saline group （MCAO+NaCl） first injected 100 μL of normal saline through the tail vein， and then performed electrocoagulation modeling； the model + exosome group （MCAO+EXO） first injected 100 μL of exosomes （9.5×1011 particles per mL） from the culture supernatant of human amniotic mesenchymal stem cells （hAMSCs） through the tail vein， and then performed electrocoagulation modeling. The scale bar of the ×40 field of view in the first row of the figure is 50 μm， and the scale bar of the ×100 field of view in the second row is 20 μm. The area indicated by the black arrow is the region of cytoplasmic vacuolar degeneration， and the area indicated by the blue arrow is the region of nuclear pyknosis and fragmentation.

图5 各组小鼠脑组织中Fe2+、MDA、total GSH、GSSG和GSH含量的微量比色法分析结果注：A~E，各组小鼠脑组织中亚铁离子（Fe2+）、丙二醛（MDA）、总谷胱甘肽（total GSH）、氧化型谷胱甘肽（GSSG）和还原型谷胱甘肽（GSH，即total GSH和GSSG含量的差值）含量分析。假手术组（Sham）只暴露大脑中动脉，不电凝血管；模型组（MCAO）使用高频手术镊以8 W功率电凝大脑中动脉；模型+生理盐水组（MCAO+NaCl）先通过尾静脉注射100 μL生理盐水，然后进行电凝法造模；模型+外泌体组（MCAO+EXO）先通过尾静脉注射100 μL来自人羊膜间充质干细胞（hAMSCs）培养上清液的外泌体（9.5×1011个/mL），然后进行电凝法造模。每组小鼠各8只，nsP >0.05，??P＜0.01，???P＜0.001，????P＜0.000 1。

Figure 5 Microcolorimetric assays of Fe2+， MDA， total GSH， GSSG and GSH contents in the brains of each group of miceNote： A-E， Contents of Fe2+， malondialdehyde （MDA）， total glutathione （total GSH）， oxidized glutathione （GSSG）， and reduced glutathione （GSH） in the brains of mice from each group. Reduced GSH was calculated as the difference between the contents of total GSH and GSSG. The sham operation group （Sham） only exposed the middle cerebral artery without electrocoagulation of the vessel； the model group （MCAO） used high-frequency surgical forceps to electrocoagulate the middle cerebral artery at a power of 8 W； the model + normal saline group （MCAO+NaCl） first injected 100 μL of normal saline through the tail vein， and then performed electrocoagulation modeling； the model + exosome group （MCAO+EXO） first injected 100 μL of exosomes （9.5×1011 particles per mL） from the culture supernatant of human amniotic mesenchymal stem cells （hAMSCs） through the tail vein， and then performed electrocoagulation modeling. There were eight mice in each group. nsP >0.05， ??P<0.01， ???P<0.001， ????P<0.000 1.

图6 各组小鼠脑组织中NRF2、SLC7A11、GPX4 mRNA及蛋白表达检测分析结果注：A~C，各组小鼠脑组织中核因子-红细胞系2相关因子2（NRF2）、溶质载体家族7成员11（SLC7A11）和谷胱甘肽过氧化物酶4（GPX4）的mRNA转录水平分析；D~F，各组小鼠脑组织中NRF2、SLC7A11和GPX4蛋白相对表达量分析；G，各组小鼠脑组织中NRF2、SLC7A11、GPX4和GAPDH的蛋白质印迹结果图。假手术组（Sham）只暴露大脑中动脉，不电凝血管；模型组（MCAO）使用高频手术镊以8 W功率电凝大脑中动脉；模型+生理盐水组（MCAO+NaCl）先通过尾静脉注射100 μL生理盐水，然后进行电凝法造模；模型+外泌体组（MCAO+EXO）先通过尾静脉注射100 μL来自人羊膜间充质干细胞（hAMSCs）培养上清液的外泌体（9.5×1011个/mL），然后进行电凝法造模。每组小鼠各8只，?P＜0.05，??P＜0.01，???P＜0.001，????P＜0.000 1。

Figure 6 Detection and analysis of mRNA and protein expression of NRF2， SLC7A11 and GPX4 in the brains of each group of miceNote： A-C， mRNA transcription levels of nuclear factor-erythroid 2-related factor 2 （NRF2）， solute carrier family 7 member 11 （SLC7A11）， and glutathione peroxidase 4 （GPX4） in the brains of mice from each group. D-F， Relative protein expression levels of NRF2， SLC7A11， and GPX4 in the brains of mice from each group. G， Western blotting images of NRF2， SLC7A11， GPX4， and GAPDH. The sham operation group （Sham） only exposed the middle cerebral artery without electrocoagulation of the vessel； the model group （MCAO） used high-frequency surgical forceps to electrocoagulate the middle cerebral artery at a power of 8 W； the model + normal saline group （MCAO+NaCl） first injected 100 μL of normal saline through the tail vein， and then performed electrocoagulation modeling； the model + exosome group （MCAO+EXO） first injected 100 μL of exosomes （9.5×1011 particles per mL） from the culture supernatant of human amniotic mesenchymal stem cells （hAMSCs） through the tail vein， and then performed electrocoagulation modeling. There were eight mice in each group. ?P<0.05， ??P<0.01， ???P<0.001， ????P<0.000 1.