罗西格列酮对脊髓损伤大鼠神经功能恢复的作用及机制

Effect of rosiglitazone on neurofunction recovery after spinal cord injury in rats

目的:观察罗西格列酮对脊髓损伤(SCI)大鼠后肢运动功能恢复的作用,探讨其作用机制。方法:75只成年SD大鼠,应用Allen改良法制作大鼠T10SCI模型,随机分为A、B、C三组,每组25只,B、C组于损伤后5min、6h、24h腹腔注射罗西格列酮,C组在腹腔注射罗西格列酮前1h给予G3335,A组于相应时间点腹腔注射等体积生理盐水作为对照组。每组取6只大鼠于伤后1d、7d、2w、4w、6w时对后肢运动功能进行BBB评分;伤后3d每组取4只动物脊髓组织行免疫组织化学染色法检测核转录因子κB(nuclear factor kappa-light-chain-enhancer of activated B cells,NF-κB)的表达;伤后1、3、5、7d和2w每组取3只应用Westernblot法检测脊髓组织中凋亡相关蛋白caspase-3和Bcl-2的表达。结果:伤后1d、7d时3组大鼠BBB评分均为0分,伤后2w开始B组BBB评分高于A组和C组,4w和6w时与A、C组比较有显著性差异(P<0.05);伤后3d时三组NF-κB表达均为阳性,但B组平均光密度值明显低于A、C组(P<0.05),B组与C组比较无显著性差异(P>0.05);伤后各时间点B组caspase-3表达量均低于A组和C组(P<0.05),而Bcl-2表达均高于A组和C组(P<0.05),其差异均在伤后5d达到高峰,A组与C组同时间点比较无显著性差异(P>0.05)。结论:罗西格列酮可促进SCI大鼠神经功能恢复,其机制可能与抑制炎症反应及细胞凋亡有关。

Objective：To investigate the effect and mechanism of rosiglitazone on neurofunction recovery after spinal cord injury（SCI） in rats.Method：SCI model at T10 from 75 Sprague Dawley（SD） rats was induced by modified Allen method.All rats were divided into 3 groups：group B（n=25,rosiglitazone were injected at 5min, 6h,24h after SCI）,group C （n=25,rosiglitazone were injected as well as group B and G3335 were injected at 1h before the rosiglitazone were injected）,and group A was sham control group （n =25,the same dose of normal saline were injected）.The BBB scoring system was employed to evaluate the behavioral changes of each group （n=6） at 1d,7d,2w,4w,6w after SCI.The protein expression of nuclear factor kappa-light-chain- enhancer of activated B cells（NF-κB） of each group（n=3） was observed by immunohistochemistry at 3d after SCI,and the total protein of each group was extracted for detection of expression of caspase-3 and Bcl-2 at 1d,3d,5d,7d,2w after SCI （n=3,each group at every time point）.Result：The BBB score of each group was 0 at 1d and 7d,while the BBB scores of group B were higher than that of group A and C at 4w after SCI, which showed significant difference between group B and the other two groups at 4w and 6w after SCI （P 0.05）.The expression of NF-κB protein were positive in every group,but the average optical density（AOD） of NF-κB protein in group B was lower than that of group A and C （P0.05）,which showed no significant difference between group A and C （P0.05）.The expression of caspase-3 in group B was lower than that of group A and C（P0.05）,the expression of Bcl-2 in group B was higher than that of the other two groups（P 0.05）,and the difference reached peak at 5d,there were no significant difference between group A and C ateach time point.Conclusion：Rosiglitazone can promote the neurofunction recovery after spinal cord injury through inhibition of inflammation reaction and process of apoptosis.