米索前列醇抑制内质网应激减轻脊髓损伤小鼠神经细胞凋亡

Misoprostol inhibits endoplasmic reticulum stress and reduces nerve cell apoptosis in mice with spinal cord injury

目的基于内质网应激(ERS)信号通路探究米索前列醇(Mis)减少脊髓损伤(SCI)小鼠损伤处神经细胞凋亡的作用机制。方法将40只SPF级C57BL/6小鼠随机分为假手术组(Sham)、脊髓损伤组(SCI)、SCI+Mis低、中、高剂量组,每组8只。除Sham组外,其他组小鼠采用砸伤法制备SCI模型。进行BMS评分实验和斜板实验检测后肢功能;检测脊髓含水量;HE染色评价脊髓损伤区面积;免疫荧光法检测脊髓损伤区星形胶质细胞和小胶质细胞的表达;TUNEL方法检测脊髓损伤区细胞凋亡;Western blot检测ERS相关蛋白GRP78和CHOP的表达。结果与SCI组相比,不同剂量Mis均显著增强SCI小鼠后肢功能,降低SCI小鼠脊髓含水量和损伤面积,抑制星形胶质细胞和小胶质细胞的活化,减少损伤区细胞凋亡,显著降低Bax/Bcl-2、caspase-3、GRP78和CHOP的蛋白表达,且呈剂量依赖性。结论米索前列醇改善SCI小鼠后肢功能以及损伤处神经细胞的凋亡的作用机制可能与抑制ERS信号通路有关。

Objective To explore the mechanism of misoprostol(Mis)reducing the apoptosis of nerve cells in spinal cord injury(SCI)mice by regulating endoplasmic reticulum stress(ERS)signal pathway.Methods Forty SPFgrade C57BL/6 mice were randomly divided into sham group(Sham),spinal cord injury group(SCI),low,medium and high dose Mis groups,with 8 mice in each group.The SCI model was established by the smashing method.Decimal hindlimb function was detected by BMS scoring and oblique plate experiment.The water content of the spinal cord was measured.The area of spinal cord injury in mice was evaluated by HE staining.The expression of astrocytes and microglia in the spinal cord injury zone was detected by immunofluorescence staining.The apoptosis of nerve cells in the area of spinal cord injury were observed by TUNEL staining.The expressions of ERS-associated proteins GRP78 and CHOP were detected by Western blot.Results Compared with SCI group,Mis significantly enhanced the function of the hind limbs of SCI mice,decreased the water content of the spinal cord and the injured area of SCI mice,inhibited the activation of astrocytes and microglia,reduced the apoptosis of nerve cells in the injured area,and significantly reduced the expressions of Bax/Bcl-2,caspase-3,GRP78 and CHOP protein in a dose-dependent manner.Conclusion The mechanism of Mis in improving the function of hind limbs and the apoptosis of nerve cells in SCI mice may be related to the inhibition of ERS signal pathway.