摘要目的 观察人脐血干细胞(hUCBSC)移植对视神经部分受损大鼠视网膜神经节细胞(RGC)的保护作用.方法 雄性Sprague-Dawley大鼠48只,随机分为A、B组,每组均为24只.大鼠暴露左眼视神经,在球后2 mm处用40 g力微型视神经夹垂直于视神经水平轴的视神经钳夹30 s建立部分视神经损伤模型.右眼为对照眼.建模后7d,A组大鼠左眼球周注射0.1 ml磷酸盐缓冲液;B组大鼠左眼球周注射0.1 ml hUCBSC悬液.处死大鼠前7d,双上丘注射5％荧光金(FG)逆行标记双眼RGC.FG逆行标记后7、14、21、28 d,两组分别随机选取6只大鼠行视网膜铺片,计数RGC并计算RGC标识率;作视网膜切片进行苏木精-伊红(HE)染色,观察视神经损伤后视网膜形态学变化.结果 随注射时间延长,A、B组大鼠RGC计数均呈下降趋势,B组大鼠损伤眼RGC计数下降幅度明显较A组平缓.A、B组大鼠损伤眼RGC计数均低于对照眼,差异有统计学意义(t=3.24、3.15,P＜0.05).FG逆行标记后7、14、21、28 d,A、B组大鼠损伤眼RGC计数比较,差异均有统计学意义(t=4.78、4.70、3.98、3.27,P＜0.05).FG逆行标记后7、14、21、28 d,A、B组组内大鼠RGC标识率比较,差异均有统计学意义(P＜0.05);B组大鼠标识率较A组明显提高,差异均有统计学意义(t=4.39、4.21、4.36、5.07,P＜0.05).光学显微镜观察发现,大鼠对照眼视网膜组织结构清晰,RGC层细胞排列规整.A、B组大鼠损伤眼视网膜各层变薄,RGC层核固缩、空泡样变性、细胞排列紊乱,RGC数量减少;损伤处视神经肿胀、出血,胶质细胞排列紊乱,空泡样变性,随损伤时间延长而加重.A组较B组病理改变更严重.结论 球周注射hUCBSC可减缓视神经损伤大鼠RGC凋亡,对RGC具有一定的保护作用.

abstractsObjective To observe the protective effect of human umbilical cord blood stem cells (hUCBSC) transplantation on retinal ganglion cells (RGC) after optic nerve injury.Method 48 adult Sprague-Dawley rats were randomly divided into group A and B,therefore 24 rats in each group.Calibrated optic nerve crush injury model was induced in the left eyes,the right eyes served as a control.Medicine was injected at seventh day after optic nerve injury.PBS was injected into the eyes of Group A rats by peribulbar injection.The hUCBSCs were injected into the eyes of Group B rats by peribulbar injection.Seven days before sacrifice,5％ fluorogold was injected into superior colliculi bilaterally.At 7,14,21,28 days after labeled,retinal flat mounts were observed under fluorescence microscope and optical microscope to investigate the morphological and RGC changes in density during retinal degeneration.Results The RGC number showed a tendency to decline gradually along with increases of the time in two groups,but the trend of decrease of Group B was evidently slower than that of Group A.The RGC number of the injury eye were less than the control eye in Group A and B (t=3.24,3.15; P＜0.05).At 7,14,21,28 days after labeled,the RGC number (t=4.78,4.70,3.98,3.27; P＜0.05) and labeled RGC rate (t=4.39,4.21,4.36,5.07; P＜0.05) in group B were more than those in group A.After optic nerve injury,there was karyopycnosis on ganglion cell layer of retina,thinning on each layer of retina,derangement of cell and decrease in RGC.There was different degree of the above change in different time after optic nerve injury.There were the swelling,the hemorrhage,derangement of spongiocyte and the denaturation like vacuole in the spot of optic nerve injury.Moreover,they were aggravating with increases of the time after optic nerve injury.There was no pathological changes in normal eyes.Conclusion The hUCBSC can increase the survival rate of the RGC and can rescue and(or) restore the injujed RGC after transplanted into body of optic nerve crush rat model by peribulbar injection.