表达睫状神经营养因子的人胚肺成纤维细胞视网膜下间隙移植延缓RCS大鼠光感受器变性

目的以遗传性视网膜变性RCS大鼠为模型,探讨视网膜下间隙移植表达睫状神经营养因子(CNTF)的人胚肺(HFL)成纤维细胞治疗视网膜变性的可行性。方法通过脂质体将编码CNTF的表达质粒转入HFL成纤维细胞、MTX及ELISA筛选高水平表达CNTF的细胞克隆。手术显微镜直视下经角膜缘后1mm注射5μl含1×105个高水平表达CNTF的HFL成纤维细胞至4～5周龄RCS大鼠右眼视网膜下间隙,左眼不手术或注射PBS作为对照。分别于移植术后2、4、6、8、10、12及15周随机取1只鼠摘除眼球作光镜观察,随机取2只鼠摘除眼球作电镜观察。结果稳定转染CNTF的HFL成纤维细胞能高水平表达CNTF(91046.15pg/ml),7只经光镜观察的移植眼中的4只,其视网膜外颗粒层明显较对照眼厚,保存的光感受器数量明显较对照眼多(P≤0.002)。14只经电镜观察的移植眼中的10只,视网膜外颗粒层光感受器凋亡明显较对照眼少。在光感受器与视网膜色素上皮间堆积的盘膜碎片亦较少。宿主视网膜色素上皮细胞的形态保存较好,并可见吞噬小体。结论经过CNTF基因修饰的HFL成纤维细胞视网膜下间隙移植能够延缓RCS大鼠视网膜光感受器变性

Subretinal transplantation of human fetal lung fibroblasts expressed ciliary neurotrophic factor gene prevent photoreceptor degeneration in RCS rats

OBJECTIVE: To investigate the efficacy of subretinal transplantation of CNTF gene transfected fibroblasts for preventing photoreceptor degeneration in RCS. METHODS: The human fetal lung fibroblasts with high level expression of CNTF were established by liposome mediated gene transfer and MTX selection. A 5 microl of cell suspension, containing 1 x 10(5) cells, was injected through pars plana of ciliary body into the subretinal space of the right eye at postnatal 4-5 weeks, the left eye was left without injection or injected with PBS as controls. The both eyes were enucleated for histopathological examinations at 2, 4, 6, 8, 10, 12 and 15 weeks following transplantation. RESULTS: The level of CNTF protein (91,046.15 pg/ml) expressed in the transfected cells was determined by sandwich enzyme-linked immunosorbent assay (ELISA). The four of seven eyes examined by light microscopy and the ten of 14 eyes examined by electro microscopy showed rescue effect. The prolonged photoreceptor survival, reduction of apoptotic cells and debris were observed in transplanted eyes in comparison with untreated or sham-injected eyes. CONCLUSION: This study provides the first indication that transplanted human fibroblasts with high level expression of CNTF are able to rescue photoreceptor degeneration in RCS dystrophic rat retina.