甲强龙预处理对大鼠脊髓损伤后claudin-5表达的影响

The effects of methylprednisolone pretreatment on the claudin-5 expression after spinal cord injury in rats

目的探讨甲强龙(11β,17α,21-三羟基-6α-甲基孕甾-1,4-二烯-3,20二酮-21-琥珀酸钠)对大鼠脊髓损伤(spinal cord injury,SCI)后血-脊髓屏障(blood spinal cord barrier,BSCB)通透性及紧密连接蛋白claudin-5表达的影响。方法参照改良Allen’s法建立大鼠脊髓损伤模型。分为假手术组(n=50)、脊髓损伤组(n=50)、甲强龙预处理组(n=50)。建模后不同时间点(12h、1d、3d、5d、7d)各组随机取5只大鼠检测BSCB通透性,取胸段脊髓损伤区组织经RT-PCR、Western blot方法检测claudin-5表达。结果本实验制模成功率84.0%;脊髓损伤组各时间点EB含量较假手术组显著增高(F=27.732,P均<0.05)。甲强龙预处理组各时间点EB含量较脊髓损伤组显著降低(F=48.149,P均<0.05);脊髓损伤组各时间点claudin-5 m RNA表达较假手术组显著降低(F=12.248,P均<0.05)。甲强龙预处理组各时间点claudin-5 m RNA表达较脊髓损伤组显著升高(F=15.316,P均<0.05);脊髓损伤组各时间点claudin-5表达较假手术组显著降低(F=18.108,P均<0.05)。甲强龙预处理组各时间点claudin-5表达较脊髓损伤组显著升高(F=20.247,P均<0.05)。结论上调claudin-5表达可能是甲强龙改善大鼠脊髓损伤后血-脊髓屏障通透性的途径之一。

Objective To study the effects of methylprednisolone on the permeability of blood-spinal cord barrier （BSCB） and claudin-5 expression after spinal cord injury in rats. Methods The rat model of spinal cord injury was estab？lished using modified Allen method. SD rats were randomly divided into sham-operated group, spinal cord injury group and methylprednisolone pretreatment group. The permeability of BSCB and expression of claudin–5 were assessed at 12 h, 1, 3, 5, and 7 d after the onset of spinal cord injury （five animals per each time point）. RT-PCR and Western blot were used to detect the expression of claudin-5. Results The success rate of the model was 84.0%. EB content was sig？nificantly higher in spinal cord injury group than in sham-operated group at each time point （F value 27.732,P〈0.05）. EB content was lower in methylprednisolone pretreatment group than in spinal cord injury group （F value 48.149,P〈0.05）. The mRNA expression of claudin-5 was lower in spinal cord injury group than sham-operated group at each time point （F value 12.248,P〈0.05）. The mRNA expression of claudin–5 was higher in methylprednisolone pretreatment group than in spinal cord injury group at each time point （Fvalue 15.316,P〈0.05）. The protein expression of claudin-5 was lower in spinal cord injury group than in sham operated group at each time point （Fvalue 18.108,P〈0.05）. The pro？tein expression of Claudin-5 was higher in methylprednisolone pretreatment group than spinal cord injury group at each time point （F value 20.247,P〈0.05）. Conclusions Methylprednisolone improves permeability of BSCB after spinal cord injury probably through enhancing claudin-5 expression in rats. 〈br〉 was lower in spinal cord injury group than in sham operated group at each time point （Fvalue 18.108,P〈0.05）. The pro？tein expression of Claudin-5 was higher in methylprednisolone pretreatment group than spinal cord injury group at each time point （F value 20.247,P〈0.05）. Conclusions Methylprednisolone improves permeability of BSCB after spinal cord injury probably through enhancing claudin-5 expression in rats.