脊髓挤压伤后BDNF mRNA表达的RT-PCR研究

The Change of Expression on the BDNF mRNA in Spinal Cord Following cSCI

目的 :探讨实验性脊髓挤压伤后内源性神经营养素BDNFmRNA在不同时段的表达变化 .方法 :采用成年SD大鼠简易脊髓挤压伤模型 .一步法抽提脊髓组织总RNA ,分光光度计测OD2 6 0 ,OD2 80值 .β -actin作内参照 ,RT -PCR技术检测内源性神经营养素BDNFmRNA在不同时段的表达 .结果 :(1)用RT -PCR技术检测到BDNFmRNA在正常大鼠脊髓表达 . (2 )脊髓挤压伤后BDNFmRNA在不同时段表达变化趋势不一 .术后 2 4h组、 5d组、 2 1d组BDNFmRNA的表达水平较正常组显著增高 (P <0 0 5 ) ,而术后 14d组虽高于正常组水平 ,但与正常组及损伤后除 2 4h组外各组相比均无显著性差异 (P >0 0 5 ) .此外 ,除伤后2 4h组与 14d组 ,伤后各组间比较亦均无显著性差异 ,表明脊髓挤压伤后 2 4h ,5dBDNF -mRNA表达明显增加 ,而 14d略有下降 ,2 1d又有回升 .结论 :(1)在正常大鼠脊髓有BDNFmRNA表达 ,提示BDNF可能与脊髓的生理功能有关 . (2 )cSCI后 2 4h ,5d ,2 1dBDNFmRNA表达增高 ,可能有利于BDNF的合成 ,进而BDNF可能参与神经损伤修复 . (3)BDNFmRNA于术后 2 4h ,5d明显升高 ,14d又回复近正常水平 ,而2 1d又明显回升 。

Objective: To explore the change of expression of the BDNF-mRNA in spinal cord in different time following cSCI. Methods: The spinal cord of adult srague-daweley rats at the T13 and L 1 levels was crushed to establish crushed spinal cord model. Total RNA was extracted with TRIzolR reagent, and BDNF gene was amplified by RT-PCR technique. Results: (1) BDNF mRNA is observed in spinal cord of normal animals by RT-PCR. (2) BDNF mRNA is upregulated in spinal cord on 24?h, 5?d, 21?d following SCI(P>0.05), while the level of BDNF mRNA on 14d following SCI keeps no difference compared with control group. The results indicates that the BDNF mRNA expression on 24?h,5?d,21?d following cSCI is different from that seen on 14?d postlesion. Conclusion: The BDNF mRNA is expressed in spinal cord of normal rats and the expression of BDNF mRNA is different in different time following cSCI. The change of BDNF mRNA suggests that BDNF plays an important role in traumatic spinal cord.