坐骨神经切断后胶质细胞源性神经营养因子mRNA的表达变化

目的探讨大鼠坐骨神经切断后,胶质细胞源性神经营养因子(GDNF)mRNA在两侧断端的表达变化及其意义。方法采用Trizol一步法提取坐骨神经总RNA,取少量作紫外扫描分析和琼脂糖电泳分析,切断SD大鼠左侧坐骨神经,不同时间、半定量RT-PCR方法,观察两侧断端GDNFmRNA的表达变化。结果坐骨神经切断前,GDNFmRNA在两侧坐骨神经微量表达,为(6.5±1.3)%,坐骨神经切断后远断端表达逐渐增加,伤后1d(7.8±1.9)%,伤后7d(10.3±2.1)%,伤后14d(11.9±2.3)%,伤后28d(12.3±2.4)%,近断端表达逐渐减少,伤后1d(5.8±1.3)%,伤后7d(4.0±1.0)%,伤后14d(3.6±1.1)%,伤后28d(3.1±1.0)%。伤后1d与伤前比较(P>0.05,t=1.193,0.879),伤后7,14,28d与伤前比较(P<0.01,t=3.762,3.565,5.059,4.083,5.164,4.905)。结论GDNF在损伤信号的刺激下表达急剧增加,起到修复神经元的作用,为外源性GDNF治疗脊髓损伤提供了理论基础。

The expression changes of glial cell line- derived neurotrophic factor mRNA after sciatic nerve cut in rats

Aim To explore the expression changes of glial cell line- derived neurotrophic factor(GDNF) mRNA in bilateral broken ends after sciatic nerve cut in rats and its significance.Methods The sciatic nerve total RNA was extracted with Trizol one- step method and little of that was given ultraviolet scan analysis and agarose electrophoresis analysis. Others were kept with the temperature of - 80 ℃ .The specimen of sciatic nerve of approximate and distant sides was taken respectively before and after sciatic nerve severed.The level of GDNF mRNA on both cutting sides was observed and compared before and after sciatic nerve cut,using semi- quantitative RT- PCR method with β- actin as a inner consult.Results Much minim expression of GDNF mRNA was found on sciatic nerve before operation ( 6.5± 1.3)% , but it increased ( 7.8± 1.9)% of the expression quantity 24 hours after sciatic nerve cut,( 10.3± 2.1)% 7 d,( 11.9± 2.3)% 14 d and ( 12.3± 2.4)% 28 d,while it decreased ( 5.8± 1.3)% ,( 4.0± 1.0)% , ( 3.6± 1.1)% and ( 3.1± 1.0)% on 1,7,14 and 28 d respectively.1 d after sciatic nerve cut compared with before operation( P >0.05,t=1.193,0.879) ,7,14,28 d after sciatic nerve cut compared with before operation(P< 0.01,t=3.762,3.565,5.059,4.083,5.164,4.905). Conclusion The expression of GDNF increases sharply under the stimulation of injury signals then the neurons can be recovered,which provides theoretical foundations for GDNF to be used in treating spinal cord injury.