Effects of axotomy and intraocular administration of NT-4, NT-3, and brain-derived neurotrophic factor on the survival of adult rat retinal ganglion cells. A quantitative in vivo study.
Effects of axotomy and intraocular administration of NT-4, NT-3, and brain-derived neurotrophic factor on the survival of adult rat retinal ganglion cells. A quantitative in vivo study.
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发表时间：
1996-03
影响因子：
4.4
通讯作者：
P. Peinado-Ramon;M. Salvador;M. Villegas-Pérez;M. Vidal-Sanz
中科院分区：
文献类型：
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作者：
P. Peinado-Ramon;M. Salvador;M. Villegas-Pérez;M. Vidal-Sanz
目的研究视神经切断后4 ~ 14天视网膜神经节细胞（retinal ganglion cells，RGC）的存活情况，以及联合眼内注射神经营养因子4（neurotrophin-4，NT-3）、脑源性神经营养因子（brain-derived neurotrophin factor，BDNF）对RGC存活的影响。方法用荧光金（FG）标记成年大鼠视网膜节细胞（RGCs）的主要靶点。7天后，眶内切断左侧ON，在几组动物中，左眼接受假注射或单独注射5微升1%牛血清白蛋白磷酸盐缓冲盐水或含有5微克NT-4、NT-3或BDNF。ON切断后4、5、7、9、12和14天，在荧光显微镜下检查视网膜以估计RGC存活。结果在对照视网膜中，FG标记的RGCs的平均密度（细胞/mm 2 +/-SEM）为2421+/-55（n=20）。轴突切断后4天，RGCs的密度与对照视网膜中观察到的相似，但轴突切断后5天和7天，平均密度分别降低至2028+/-63（n=6）和1568+/-50（n=6）。在用假注射、仅用媒介物或用NT-3的视网膜组中，RGC密度也在7天内分别降低至1261+/-71（n=5）、1506+/-98（n=10）和1474+/-125（n=4）。然而，在用NT-4（2505+/-91; n=7）或BDNF（2380+/-74; n=7）处理的视网膜组中，在ON横切后7天观察到与对照视网膜中观察到的密度相似的密度。轴突切断后14天，RGC密度降至521+/-39（n=10）。在经历轴突切开术和假注射（533+/-51; n=5）、注射载体（588+/-19; n=10）或NT-3治疗（634+/-62; n=6）的组中发现了相当的密度。然而，此时，在用NT-4 839+/-39（n=8）或BDNF 1321+/-120（n=7）处理的组中观察到更高的密度。结论：轴突切断诱导的RGC死亡首先出现在第5天，到第12天达到80%的原始RGC群体。在轴突切断术时眼内给予NT-4和BDNF对轴突切断术诱导的RGC死亡发挥神经保护作用，从而增加存活的RGC的群体，并将轴突切断术诱导的RGC死亡的RGC发作延迟约3天。眼内给予NT-3并没有改变损伤后RGCs的存活。
PURPOSE To investigate in vivo the survival of retinal ganglion cells (RGC) 4 to 14 days after optic nerve (ON) transection alone or in combination wih a single intraocular injection of neurotrophin-4 (NT-4), neurotrophin-3 (NT-3), or brain-derived neurotrophic factor (BDNF). METHODS In adult rats, RGCs were labeled with fluorogold (FG) applied to their main targets in the brain. Seven days later, the left ON was intraorbitally transected, and, in several groups of animals, the left eye received a sham injection or was injected with 5 microliters of 1% bovine serum albumin-phosphate-buffered saline alone or containing 5 micrograms of NT-4, NT-3, or BDNF. Four, 5, 7, 9, 12 and 14 days after ON transection, the retinas were examined under fluorescence microscopy to estimate RGC survival. RESULTS In control retinas, the mean densities (cells/mm2+/-SEM) of FG-labeled RGCs were 2421+/-55 (n=20). Four days after axotomy, the densities of RGCs were similar to those observed in control retinas, but 5 and 7 days after axotomy, the mean densities had decreased to 2028+/-63 (n=6) and 1568+/-50 (n=6) respectively. In the group of retinas with sham injection, with vehicle alone or with NT-3, RGC densities also decreased by 7 days to 1261+/-71 (n=5), 1506+/-98 (n=10), and 1474+/-125 (n=4), respectively. However, similar densities to those observed in control retinas were observed 7 days after ON transection in the groups of retinas treated with NT-4 (2505+/-91; n=7) or BDNF (2380+/-74; n=7). Fourteen days after axotomy, RGC densities decreased to 521+/-39 (n=10). Comparable densities were found in groups that underwent axotomy and either sham injection (533+/-51; n=5), injection of vehicle (588+/-19; n=10), or NT-3 treatment (634+/-62; n=6). However, at this time, higher densities were observed in the groups treated with NT-4 839+/-39 (n=8) or BDNF 1321+/-120 (n=7). CONCLUSIONS Axotomy-induced RGC death first appears by day 5 and reaches 80% of the original RGC population by day 12. NT-4 and BDNF administered intraocularly at the time of axotomy exert a neuroprotective effect on axotomy-induced RGC death, thus increasing the population of surviving RGCs and delaying the onset of RGC of axotomy-induced RGC death by approximately 3 days. Intraocular administration of NT-3 did not modify the survival of RGCs after injury.