丙泊酚通过NLRP3/caspase-1通路对脑缺血大鼠发挥神经保护作用

目的:研究丙泊酚对脑缺血大鼠发挥神经保护作用的过程中对核苷酸结合寡聚化结构域样受体3(NLRP3)/天冬氨酸特异性半胱氨酸蛋白酶1(caspase-1)通路的影响。方法:54只SD大鼠随机分成6组:假手术组、模型组、NLRP3抑制剂组(MCC950,10 mg·kg^-1)、丙泊酚低、中、高剂量组(5,10,15 mg·kg^-1)。除假手术组外,其余各组大鼠均通过结扎大鼠颈内外动脉和向右侧颈内动脉插入线栓阻塞脑中动脉血流构建脑缺血模型。建模成功后NLRP3抑制剂组和丙泊酚各剂量组分别尾静脉注射相应剂量药物,假手术组和模型组给予5%葡萄糖注射液(5 ml·d^-1)。对大鼠进行神经功能评分,测定脑脊液中白细胞介素1β(IL^-1β)和白细胞介素18(IL^-18),2,3,5-氯化三苯基四氮唑(TTC)鉴定脑梗死情况,反转录聚合酶链式反应(RTPCR)和蛋白质免疫印迹(Western blot)分别检测右侧端脑组织中NLRP3、凋亡相关斑点样蛋白(ASC)和caspase-1 mRNA、蛋白表达量。结果:与模型组相比,抑制剂组和丙泊酚各剂量组IL^-1β、IL^-18水平、NLRP3、ASC、caspase-1蛋白水平及caspase-1 mRNA水平、丙泊酚中、高剂量组神经功能评分及NLRP3、ASC mRNA水平、丙泊酚高剂量组脑梗死面积显著降低(P<0.05);与抑制剂组相比,丙泊酚部分剂量组神经功能评分、IL^-1β、IL^-18水平、NLRP3、ASC、caspase-1 mRNA水平、NLRP3、ASC、caspase-1蛋白水平差异有统计学意义(P<0.05)。结论:丙泊酚通过影响脑缺血SD大鼠NLRP3/caspase-1通路,抑制NLRP3炎性小体生成,降低促炎因子水平,从而发挥神经保护作用。

Neuroprotective Effects of Propofol in Cerebral Ischemic Rats through NLRP3 /caspase-1 Pathway

Objective:To study the neuroprotective effect of propofol in cerebral ischemia rats based on nucleotide binding oligomerization domain-like receptor protein 3(NLRP3)/aspartate-specific cysteine protease-1(caspase-1)pathway.Methods:Totally 54 SD rats were divided into 6 groups:the sham operation group,the model group,NLRP3 inhibitor group(MCC950,10 mg·kg^-1)and propofol low,medium and high dose groups(5,10 and 15 mg·kg^-1).Except the sham operation group,the model of cerebral ischemia in the other groups was constructed by ligating the internal and external carotid arteries and inserting a thread into the right internal carotid artery to block the blood flow of middle cerebral artery.After the successful modeling,NLRP3 inhibitor group and propofol dose groups were injected the corresponding dose of drug via tail vein,and the sham operation group and the model group were given 5%glucose injection(5 ml·d^-1).Tha rats were scored for neurological function,the levels of interleukin-1β(IL^-1β)and interleukin-18(IL^-18)in cerebrospinal fluid were measured,2,3,5-triphenyltetrazolium chloride(TTC)was used to identify cerebral infarction,and the expressions of NLRP3,apoptosis-related spot-like protein(ASC)and caspase-1 mRNAs and proteins in right telencephalon tissue were detected by reverse polymerase chain reaction(RT-PCR)and Western blotting of protein(Western blot).Results:Compared with those in the model group,the levels of IL^-1βand IL^-18,the protein levels of NLRP3,ASC and caspase-1,and the mRNA level of caspase-1 in the inhibitor group and propofol three dose groups,the neurological function scores and the mRNA levels of NLRP3 and ASC in propofol medium and high dose groups,and cerebral infarct area in propofol high dose group were all significantly reduced(P<0.05).Compared with the inhibitor group,the differences in the nerve function score,the levels of IL^-1βand IL^-18,the mRNA levels of NLRP3,ASC and caspase-1,and the protein levels of NLRP3,ASC and caspase-1 in propofol partial groups were all statistically significant(P<0.05).Conclusion:Propofol can play a neuroprotective role by affecting NLRP3/caspase-1 pathway,inhibiting NLRP3 inflammatory body formation and reducing the levels of proinflammatory factors in SD rats with cerebral ischemia.