伊泽替米贝对脊髓损伤大鼠运动功能的作用

Role of ezetimibe in the motor function of rats with spinal cord injury

目的探讨伊泽替米贝对脊髓损伤(spinal cord injury, SCI)大鼠运动功能的保护作用及可能机制。方法 SD大鼠15只,随机分为假手术组、模型组、实验组,每组各5只。模型组、实验组大鼠采用失重法建立SCI大鼠模型,实验组建模后1 h,给予伊泽替米贝20 mg/kg灌胃治疗,假手术组和模型组给予等体积生理盐水灌胃,1次/d,连续21 d。建模21 d后,采用脊髓损伤行为学评分(Basso-Beattie-Bresnahan, BBB)评估3组大鼠后肢各关节运动功能,采用ELISA法检测3组大鼠血清白细胞介素(interleukin, IL)-1β、IL-6和肿瘤坏死因子-α水平,3组大鼠脊髓组织采用WST-8法检测超氧化物歧化酶活性,采用NADPH法检测谷胱甘肽过氧化物酶活性,采用TBA法检测丙二醛水平,采用Griess法检测一氧化氮水平;采用Western blot法检测3组大鼠脊髓组织诱导型一氧化氮合酶、IL-1β前体、caspase-1前体、NLRP3蛋白相对表达量。结果建模21 d后,假手术组大鼠BBB评分[(20.60±0.49)分]高于模型组[(8.80±0.75)分]、实验组[(17.80±1.17)分](P<0.05),实验组高于模型组(P<0.05);假手术组大鼠血清IL-1β[(32.05±6.87)ng/L]、IL-6[(55.07±6.46)ng/L]、肿瘤坏死因子-α[(60.88±13.31)ng/L]水平均低于模型组[(279.40±13.43)、(161.95±14.41)、(174.20±13.20)ng/L]、实验组[(172.25±13.41)、(107.45±14.25)、(119.86±11.69)ng/L](P<0.05),实验组均低于模型组(P<0.05);假手术组大鼠脊髓组织超氧化物歧化酶、谷胱甘肽过氧化物酶活性均高于模型组、实验组(P<0.05),实验组均高于模型组(P<0.05);假手术组大鼠脊髓组织丙二醛、一氧化氮水平及诱导型一氧化氮合酶、IL-1β前体、caspase-1前体、NLRP3蛋白相对表达量均低于模型组、实验组(P<0.05),实验组均低于模型组(P<0.05)。结论伊泽替米贝对SCI大鼠运动功能具有保护作用,可能与抑制NLRP3炎性小体介导的炎性反应有关。

Objective To investigate the protective role and mechanism of ezetimibe in the motor function of rats with spinal cord injury(SCI). Methods Fifteen SD rats were randomly divided into sham operation group, model group and experimental group, with 5 rats in each group. Model group and experimental group were established SCI models by weight loss method. Experimental group was given gavage with ezetimibe 20 mg/kg 1 h after operation, while sham operation group and model group were given gavage with equal volume of normal saline, once a day, totally for 21 days. After 21 days of modeling, Basso-Beattie-Bresnahan(BBB) score was used to evaluate the joint motor function of the hind limbs. ELISA method was used to detect the serum interleukin(IL)-1β, IL-6 and tumor necrosis factor-α levels. WST-8 method was used to detect the activity of superoxide dismutase, and NADPH method was used to detect glutathione peroxidase in spinal cord tissue. TBA was used to detect malondialdehyde level. Griess methods was used to detect nitric oxide level. Western blot was used to detect the relative expressions of inducible nitric oxide synthase, pro-IL-1β, pro-caspase-1 and NLRP3 protein in spinal cord tissue. Results After 21 days of modeling, the BBB score was higher in sham operation group(20.60±0.49) than that in model group(8.80±0.75) and experimental group(17.80±1.17)(P<0.05), and higher in experimental group than that in model group(P<0.05). The levels of IL-1β, IL-6 and tumor necrosis factor-α were lower in sham operation group [(32.05±6.87),(55.07±6.46),(60.88±13.31) ng/L] than those in model group [(279.40±13.43),(161.95±14.41),(174.20±13.20) ng/L] and experimental group [(172.25±13.41),(107.45±14.25),(119.86±11.69) ng/L](P<0.05), and lower in experimental group than those in model group(P<0.05). The superoxide dismutase and glutathione peroxidase activities were higher in sham operation group than those in model group and experimental group(P<0.05), and higher in experimental group than those in model group(P<0.05). The levels of malondialdehyde and nitric oxide as well as the relative expressions of inducible nitric oxide synthase, pro-IL-1β, pro-caspase-1 and NLRP3 proteins were lower in sham operation group than those in model group and experimental group(P<0.05), and lower in experimental group than those in model group(P<0.05). Conclusion Ezetimibe has a protective role in the motor function of SCI rats, probably by inhibiting the inflammatory response mediated by the NLRP3 inflammasome.