神经干细胞移植对视网膜节细胞再生的影响

Effect of neural stem cells transplantation on the regeneration of retinal ganglion cells

目的探讨神经干细胞（NSCs）在视神经损伤后对视网膜节细胞轴突再生的作用及其在视神经内迁移和分化。方法实验动物分对照组（PBS组），实验组（NSCs组）；成年SD大鼠在眼球后1min处切断视神经。移植NSCs或PBS至视神经断端；4周后以霍乱毒素B亚基顺行标记观察轴突再生情况，并观察NSCs在视神经内的迁移及免疫组织化学法检测移植后的细胞表达神经丝蛋白（NF）、2，3-环核苷酸磷酸二酯酶（CNP）、胶质纤维酸性蛋白（GFAP）的情况。结果4周后视网膜节细胞再生轴突穿过视神经断端到达远端，移植的NSCs分化为星形胶质细胞并在视神经内迁移0．5～1min。免疫组织化学法检测NSCs部分呈GFAP阳性，未见NF、CNP表达。结论NSCs移植可促进视网膜节细胞轴突再生，能在视神经内迁移并在视神经周围分化为星形胶质细胞。

Objective To investigate the effect of neural stem cells （NSCs） on the regeneration of retinal ganglion cells after optic nerve （ON） cut and its differentiation and migration in the injured ON. Methods Animals were separated into control group （PBS group） and experimental group （NSCs group）. Gelatin sponge soaked with 1 μL 1×10^7/μL NSCs or 1μL 0.1 mol/L PBS was inserted into the broken end after ON cut in adult SD rats. Animals in each group were allowed to survive for 4 weeks respectively, then observed for the regenerating axons of retinal ganglion cells labeled anterogradely with choleratoxin B, for the migration of NSCs and the expressions of neurofilament protein （NF）, 2, 3-cyclic nucleotide phosphodiesterase （CNP）, glial fibrillary acidic protein （GFAP） in the injured ON. Results The regenerating axons crossed the broken end to distance; NSCs expressed immunoreactivity for GFAP at 4 weeks and migrated into ON for 0.5-1 mm. GFAP positive was detected partially in NSCs by staining, but no NF or CNP expression was detected. Condusion NSCs can enhance the regeneration of retinal ganglion cells and migrate alter ON cut and differentiate into astrocytes around the ON.