冻存复苏后大鼠视网膜干细胞的增生及分化特性

Proliferation and characters of differentiation of retinal stem cells after cryopreservation and anabiosis in rat

目的研究视网膜干细胞冻存复苏后的成活率及再培养后的增生分化特性。方法对胎龄17d Long Evans的大鼠眼视网膜干细胞进行分离与体外培养。利用无血清培养基短期体外培养大鼠胚胎来源的视网膜干细胞，将传代三代后的视网膜干细胞以冻存液[体积分数为80%的改良基础培养基（DMEM）/F12，10%牛血清白蛋白（BSA），10%二甲基亚砜（DMSO），碱性成纤维细胞生长因子（bFGF）20ng/ml]于液氮中冻存，于1、2、4、8、12、16周分别复苏，计数活细胞比例进行再培养，并进一步诱导分化，采用免疫细胞荧光化学方法检测视网膜干细胞的增生及分化特性。结果不同的冻存时间对冻存后细胞存活率的影响无显著差异（P〉0.05），再培养生长良好，具有视网膜干细胞特异性标志，并可进一步诱导分化为视网膜各种类型的细胞。结论大鼠视网膜干细胞的冻存复苏并不影响其原有的增生及分化特性。

Objective To investigate the viability and the characters of proliferation and differentiation of retinal stem cells （RSCs） after cryopreservation and anabiosis. Methods The RSCs of a Long Evans rat with the embryonic age of 17 days were separated and cultured in vitro. The third-passage RSCs in the cryopreservation liquid consisted of 80% Dulbecco modified Eagle medium （DMEM）/F12,10% bovine serum albumin （BSA）, 10% dimethylsulfoxide （DMSO）,and basic fibroblast growth factor （bFGF） （20 ng/ml）, were stored in liquid nitrogen. After 1, 2, 4, 8, 12, and 16 weeks of freezing period, these cells were thawed. The livability of the cells was counted and the differentiation was induced while the proliferation and characters of differentiation were detected by immunofluorescence. Results The effects of different durations of cryopreservation on the livability of RSCs did not differs much （P〉0.05）. These cells were re-culturd well and presented specific marker of RSCs. In addition, they also could be induced and differentiated into several types of retinal cells. Conclusion Cryopreservation and anabiosis of RSCs does not affect the cellular intrinsic characters of proliferation and differentiation.