Shh mRNA在成年大鼠慢性压迫性脊髓损伤后的表达及其意义

Expression and significance of Shh mRNA in chronic compressive spinal cord injury in adult rats

目的:观察成年大鼠慢性压迫性脊髓损伤后与发育相关的重要分子Shh mRNA的表达,探讨其在神经再生过程中的作用.方法:将30只同龄Wistar大鼠置入后路渐进式压迫装置,制作成慢性压迫性脊髓损伤模型.随机分为对照组(5只)和慢性脊髓损伤组(25只).应用原位杂交检测方法,于脊髓损伤后1,3,7,14,28d对损伤区行Shh mRNA检测.结果:脊髓损伤后7d,Shh mRNA表达水平达到最大值,在损伤区至远端10mm处的灰质和白质中均有表达,这种高水平的表达至少维持到损伤后28d.Shh mRNA在室管膜细胞的表达远远低于在灰质和白质中的表达,其在室管膜区域的表达仅限于损伤区域周围5mm范围内,分布范围远远小于在灰质和白质中的表达.结论:慢性压迫性脊髓损伤可激活Shh mRNA的表达,其表达对脊髓损伤后神经细胞再生的意义值得进一步探讨.

AIM： To explore the expression of Shh mRNA in chronic compressive spinal cord injury （CCSCI） in rats and the role of Shh in the nerve regeneration. METHODS ： Thirty Wistar rats were randomly divided into CCSCI group （n = 25 ） and control group （ n = 5）. The rats of CCSCI group were put into a progressive compression instrument to induce CCSCI. In situ hybridization method was used to observe the changes of Shh mRNA in 1, 3, 7, 14 and 28 d post-operatively in each group. RESULTS： The expression of Shh mRNA was increased in the grey matter and white matter and in the ependyma rostral and candal to the lesion site after injury. Shh mRNA was upregulated 7 d after injury with maximal expression levels in grey and white matter 10 mm distal to the lesion site. This high level of expression was maintained up to at least 28 d after injury. Shh expression was much lower in ependymal cells than in grey or white matter and was restricted to 5 mm distal to the lesion site, and its distribution was narrower than that in grey and white matter. CONCLUSION： CCSCI can induce the expression of Shh mRNA. The role of shh in regulating adult neural cell regeneration in CCSCI is worthy of further investigation.