电针对脊髓损伤模型大鼠热休克蛋白70及其mRNA的影响

Effect of Electroacupuncture on Heat Shock Protein 70 and its mRNA in a Rat Model of Spinal Cord Injury

目的探讨电针对大鼠急性脊髓损伤(ASCI)后热休克蛋白70(Hsp70)及其mRNA(Hsp70mRNA)表达的影响。方法成年雄性SD大鼠,随机分为电针组、模型组和假手术组。采用改良的Allen法建立大鼠急性脊髓损伤模型,电针组动物手术后2h即给予电针处理。分别在1d、2d和3d处死动物,应用实时荧光定量PCR方法检测脊髓损伤部Hsp70mRNA,应用免疫组织化学结合图像定量分析方法检测Hsp70表达。结果手术后1d时模型组和电针组Hsp70mRNA表达量与假手术组比较均明显增高(P<0.05),随后逐渐下降,至3d时已降至假手术组水平。电针组Hsp70mRNA表达下降速率明显较模型组缓慢,Hsp70mRNA表达量在2d时仍明显高于模型组(P<0.05)。模型组和电针组Hsp70蛋白表达也是1d时最高,以后逐渐下降;电针组Hsp70表达在各时间段均明显高于模型组(P<0.05)。结论电针治疗可以增加脊髓损伤大鼠脊髓损伤部Hsp70及其mRNA的表达,减少细胞毒性,从而抑制神经元的凋亡和死亡。

Objective To explore the effect of electroacupuncture on the expressions of heat shock protein 70 （Hsp70） and its mRNA （Hsp70 mRNA） after rat acute spinal cord injury （ASCI） in rats. Methods Adult male SD rats were randomly allocated to electroacupuncture, model and sham operation groups. A rat model of acute spinal cord injury was made using a modified Allen method. The electroacupuncture group of animals were treated at 2 hrs after operation. The animals were sacrificed at 1, 2 and 3 days after operation, respectively. Hsp70 mRNA was detected by real-time quantitative fluorescent PCR. Hsp70 expression in the injured part of the spinal cord was examined using an irnmunohistochemical method and quantitative image analysis. Results In the model and electroacupuncture groups, Hsp70 mRNA expression increased significantly at 1 day after operation compared with the sham operation group （P〈0.05）, and then decreased gradually and reached the level in the sham operation group at 3 days after operation. In the electroacupuncture group, Hsp70 mRNA expression decreased significantly more slowly and was still significantly higher at 2 days after operation compared with the model group （P〈0.05）. In the model and electroacupuncture groups, Hsp70 expression reached the maximum at 1 day after operation and then decreased gradually. Hsp70 expression was significantly higher in different periods in the electroacupuncture group than in the model group （P〈0.05）. Condusion Electroacupuncture can increase the expressions of Hsp70 and its mRNA in the injured part of the spinal cord and reduce the cytotoxicity, and thereby inhibit neuronal apoptosis and death in rats with spinal cord injury.