CNTF和Ad-BDNF对视神经夹伤后视网膜神经节细胞存活的影响

目的:观察大鼠视神经夹伤后玻璃体腔内注射睫状神经营养因子(CNTF)和腺病毒介导脑源性神经营养因子(Ad-BDNF)对视神经损伤后视网膜神经节细胞(RGC)存活的影响。方法:制作大鼠视神经定量夹伤模型,玻璃体腔内注射CNTF和Ad-BDNF,经上丘荧光金(FG)逆行标记RGC,计数视网膜铺片上的RGC并行统计学分析。结果:正常SD大鼠视网膜上RGC密度为2155±265个/mm2(n=12),视神经夹伤后RGC在1~2wk内下降速率最快,到3,4wk时RGC细胞数量虽仍有减少但下降速度已经明显减慢。CNTF组在视神经夹伤后1wk时视网膜RGC数显著高于对照组,但2~4wk的结果和对照组比较差异不明显。Ad-BDNF组视神经夹伤后1~4wk视网膜RGC数均显著高于对照组。结论:CNTF治疗组玻璃体腔内一次性注射CNTF可以在损伤早期2wk内为损伤的RGC提供神经营养因子,减少RGC的早期死亡。Ad-BDNF治疗组的这种保护作用可以持续到损伤后4wk,能够为RGC提供长时间地营养支持,但这种作用比较局限,可能与单一营养因子作用有关。

Effects of CNTF and Ad-BDNF on survival of RGC after optic nerve injury

AIM: To investigate the effect of intravitreal injection of CNTF and Ad-BDNF on survival of RGC after optic nerve injury.·METHODS: Optic nerve crush model in rats were established. CNTF and Ad-BDNF were intravitreal injected by retrograde marking the RGC with fluoro-gold (FG). The retrograde labeled RGC were counted under fluorescent microscope.·RESULTS: The number of RGC counted by retrograde labeling of FG was about 2155±265个/mm2 (n=12) after label. Number of RGC decreased quickly after crush 1-2 weeks. In CNTF group, the number of RGC was higher than that of control group (P<0.05). But the number of RGC 2-4 weeks after crush in CNTF group had no difference with that in control group. In Ad-BDNF group, the number of RGC 2-4 weeks after crush were significant difference compared with that of control group at every time point (P<0.05 ).·CONCLUSION: Intravitreal injection of CNTF can protect the RGC in the early time. But these effects can not work for more than 2 weeks. Intravitreal injection of Ad-BDNF can protect the RGC in 4 weeks.·