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目的通过动物实验,探讨血管内皮祖细胞移植防治动脉粥样硬化形成的可行性。方法分离、鉴定并培养新西兰大白兔外周磁粒子标记血管内皮祖细胞(EPCs),制备氧化铁(Fe_O_3)-多聚左旋赖氨酸(PLL)并体外标记 EPCs。用2.5 F 球囊扩张并损伤兔右侧颈动脉血管内皮,对损伤血管进行局部 EPCs 移植,A 组8只,移植 Fe_2O_3-PLL 标记的 EPCs;B 组3只,移植荧光标记的 EPCs;C 组5只为空白对照,局部注射生理盐水。细胞移植后4 d,所有实验兔用1.5 T MR 仪进行活体颈动脉扫描,并任意选 A、B、C 组各1只,取受损伤血管做病理组织学检查,并与 MRI 信号变化进行对比分析,其余所有实验兔继续高脂饲料喂养,15周后对损伤血管做 MR 及病理组织学检查。结果 EPCs 的 Fe_2O_3-PLL 标记率>95%,A 组标记细胞移植后4 d,MR T_2~*WI 显示损伤血管壁呈明显低信号区,而 B 组和 C 组无明显异常信号改变;病理学检测显示 A 组损伤血管内膜有普鲁士蓝染色阳性细胞黏附,B 组损伤血管内皮有强荧光表达,C 组损伤血管内皮无表达。15周后,A、B 组动脉粥样硬化形成(3/9)明显低于 C 组(4/4)。结论活体 MR 技术可示踪并检测 EPCs 在损伤血管内皮的黏附及分布;血管内皮祖细胞局部移植可预防动脉粥样硬化的形成。
Objective To investigate the feasibility of transplantation of vascular endothelial progenitor cells to prevent and treat atherosclerosis through animal experiments. Methods Peripheral magnetic particle labeled endothelial progenitor cells (EPCs) of New Zealand white rabbits were isolated, identified, and cultured to produce Fe_O_3 - poly L - lysine (PLL) and labeled EPCs in vitro. EPCs were implanted into the injured vessels by 2.5 F balloon dilatation and injury of the right carotid artery of rabbits. Group A was transplanted with EPCs labeled with Fe_2O_3-PLL; Group B received 3 transplanted EPCs; Group C 5 blank control, local injection of saline. Four days after cell transplantation, all rabbits were scanned by 1.5T MR in vivo carotid artery. One of A, B and C groups were randomly selected. The injured vessels were harvested for histopathological examination and compared with MRI signal changes Analysis, the rest of all experimental rabbits continue to feed high-fat diet, 15 weeks after injury to the blood vessels to do MR and histopathological examination. Results The labeling rate of Fe 2 O 3 -PLL in EPCs was> 95%. The labeled signal of MR T 2 ~ * WI showed a markedly low signal area in the group of A labeled cells at 4 d after transplantation, but no significant changes were observed in group B and C. Pathology The results showed that there was Prussian blue staining positive cell adhesion in the intima of group A, the strong fluorescent expression of vascular endothelial in group B, and no expression of vascular endothelial in group C. After 15 weeks, atherosclerosis (3/9) in group A and B was significantly lower than that in group C (4/4). Conclusion The living MR technique can trace and detect the adhesion and distribution of EPCs in the injured vascular endothelium. Local transplantation of endothelial progenitor cells can prevent the formation of atherosclerosis.