视网膜下移植睫状神经营养因子编码基因修饰的细胞保护SD大鼠视神经横断伤后视网膜节细胞变性

目的探讨移植表达睫状神经营养因子(CNTF)的细胞对SD大鼠视神经横断伤后视网膜节细胞的保护作用。方法通过脂质体将CNTF表达质粒转移至人胚肺成纤维细胞,建立稳定、高水平表达CNTF的细胞株。采用双侧背外侧膝状体及上丘核团注射3%荧光金逆行标记视网膜节细胞。将标记后的大鼠分为两组,于标记后7d手术切断眶内段视神经其中一组左眼不做手术作为正常对照组,右眼切断视神经作为手术对照组;另一组双眼均手术切断视神经,左眼注射PBS作为治疗对照组,右眼视网膜下移植表达CNTF的细胞作为实验组。术后5、14、17、21及28d取出眼球,铺片后荧光显微镜观察并计数视网膜内存活的节细胞。结果手术切断眶内段视神经后2周,视网膜内节细胞数减少6744%,视网膜下移植表达CNTF的细胞后第5、17、21d视网膜内存活的节细胞数明显多于治疗对照组(P<005)。结论视网膜下移植高水平表达CNTF的细胞对视网膜节细胞有保护作用。

Protective effects of transplantation of hCNTF-transfected cell line on axotomy-induced degeneration of retinal ganglion cells

Objective To investigate the protective effects of transplantation of cell line stably expressing and secreting human ciliary neurotrophic factor (hCNTF) on the degeneration of retinal ganglion cells (RGCs) after optic nerve transection. Methods Plasmid encoding hCNTF was transfected into human lung fibroblast (HLF) cell line, then the stably transfected clones were selected with methopterin. In adult SD rats, RGCs were labeled with retrograde axonal tracer fluorogold (FG) injected to their targets including dorsal lateral geniculate nuclei (dLGN) and superior colliculi (SC). Seven days later, the optic nerve was transected alone or in combination with transplantation of HLF cells. Five, 14, 17, 21 and 28 days after axotomy, the retinas were mounted and examined under fluorescence microscope to observe the RGCs. Results Compared to the controls, the density of RGC in axotomy group decreased by 67.44 % and 82.73% on the 14 th and 28 th day, respectively. In the eyes with hCNTF-transfected HLF cells transplantation, RGC density was higher than that of the axotomy group on the 5 th, 17 th, 21 st day after axotomy (P<0.05). On the 5th day, the morphology of RGC in the hCNTF group remained the same as the controls, whereas the morphology of RGC in the axotomy alone group began to change. Conclusions~hCNTF administered at the time of optic nerve transection can protect RGC from degeneration, increasing the numbers of surviving RGCs and delaying the death of RGCs.(Chin J Ophthalmol, 2005, 41:119-122 )