胚胎干细胞来源的神经前体细胞移植β-淀粉样蛋白损伤大鼠海马后的靶向迁移与分化

Targeted migration and differentiation of engrafted neural precursor cells in amyloid β-treated hippocampus in rats

目的观察小鼠胚胎干细胞来源的神经前体细胞移植β-淀粉样蛋白(amyloidβpeptide,Aβ)损伤大鼠海马后的靶向迁移及在体分化。方法采用无血清培养法将表达绿色荧光蛋白(enhanced green fluorescent protein,EGFP)的小鼠胚胎干细胞定向诱导为神经前体细胞,移植至Aβ_(1-40)、单侧损伤的大鼠海马;免疫荧光观察移植细胞的迁移距离、迁移方向与分化情况:对移植细胞的平均迁移距离与平均分化率作相关性分析。结果胚胎干细胞经改良的无血.清培养法生长可分化为nestin阳性神经前体细胞。移植后第16周,神经前体细胞平均迁移距离比第4周增长了约5倍。移植细胞中,胶质纤维酸性蛋白(glial fibrillary acidic protein,GFAP)阳性细胞的平均分化率从(30.41±1.45)%增长到(49.25±1_23)%;神经丝蛋白200(neurofilament 200,NF200)细胞的平均分化率从(16.68±0.95)%增长到(27.94±1.21)%;靶向迁移至Aβ斑块同侧的GFAP阳性细胞的比例从60.2%增长到81.3%,靶向迁移至Aβ斑块的NF200阳性细胞的比例从61.3%增至84.1%。相关性分析结果显示平均迁移距离与神经元分化率之间存在显著线性相关(r=0.991),与胶质细胞分化率之间也存在显著线性相关(r=0.953)。结论胚胎干细胞来源的神经前体细胞移植Aβ损伤模型大鼠海马后能够靶向迁移至Aβ损伤区并分化为胶质细胞和神经元。

Objective To observe the migration and differentiation of the neural precursor cells （NPCs） that derived from murine embryonic stem cells （ESCs） when they were transplanted into amyloid β （Aβ）-treated rat hippocampus. Methods MESPU35, a murine ESC cell line that express the enhanced green fluorescent protein （EGFP）, was induced differentiation into nestin-positive NPCs by modified serum-free methods. The Aβ plaques and the differentiation of the grafted cells were observed by immunofluorescent staining. Results Comparing 16 weeks with 4 weeks post-transplantation, the migration distance increased about 5 times; the rate of migratory NPCs differentiating into glial fibrillary acidic protein （GFAP）-positive cells kept rising from （30.41 ± 1.45）% to （49.25± 1.23）%, and the rate of NPCs differentiating into neurofilament 200 （NF200） positive cells increased from （16.68±0.95）% to （27.94± 1.21）%. Meanwhile, the GFAP-positive cells targeting to the ipsilateral side of Aβ plaques increased from 60.2% to 81.3 %, while the NF200-positive cells increased from 61.3% to 84.1%. The migration distance had significant positive linear correlations to the neuronal differentiation rate （r = 0.991） and to the astrocytic differentiation rate （r = 0.953）. Conclusion Engrafted NPCs migrate targetedly to the Aβ injection site and differentiate into neurons and astrocytes.