脂氧素受体激动剂BML-111对创伤性脑损伤大鼠NLRP3炎症小体的影响

Effect of lipoxin receptor agonist BML-111 on the NLRP3 inflammasome after traumatic brain injury in rats

目的:探讨脂氧素受体激动剂BML-111对创伤性脑损伤(traumatic brain injury,TBI)大鼠NLRP3炎症小体的影响。方法:60只体重280~340 g雄性SD大鼠,随机分为4组(n=15):假手术组(Sham组)、创伤性脑损伤组(TBI组)、BML-111给药组(BML-111组)、脂氧素受体拮抗剂BOC-2给药组(BOC-2组)。采用颅脑撞击法建立TBI模型,Sham组仅开骨窗但不给予撞击。TBI组、BML-111组和BOC-2组大鼠建立TBI模型,脑创伤前30 min BOC-2组腹腔注射50μg/kg的BOC-2,脑创伤后即刻和24 h BML-111组及BOC-2组腹腔注射1 mg/kg的BML-111。脑创伤后3 d和7 d测量各组大鼠神经损伤评分(NSS),使用Western blot法检测NLRP3、Caspase-1-p20、活化Caspase-3的蛋白表达,使用ELISA法检测脑IL-1β和IL-18蛋白含量,使用TUNEL法检测细胞凋亡。结果:与Sham组比较,TBI组脑含水率及NSS评分明显升高,脑皮层NLRP3、Caspase-1-p20、活化Caspase-3蛋白水平表达、IL-1β和IL-18含量及TUNEL阳性细胞数明显增加(P<0.05);与TBI组比较,BML-111组脑含水率及NSS评分显著降低,脑皮层NLRP3、Caspase-1-p20、活化Caspase-3蛋白表达、IL-1β和IL-18含量及TUNEL阳性细胞数明显减少(P<0.05);与BML-111组比较,BOC-2组脑含水率及NSS评分明显升高,脑皮层NLRP3、Caspase-1-p20、活化Caspase-3蛋白表达、IL-1β和IL-18含量及TUNEL阳性细胞数显著上调(P<0.05)。结论:脂氧素受体激动剂BML-111可通过抑制NLRP3炎症小体的表达缓解大鼠创伤性脑损伤。

Objective:To investigate the effect of lipoxin receptor agonist BML-111 on the NLRP3 inflammasome after traumatic brain injury in rats.Methods:Sixty male Sprague-Dawley rats,weighing 280-340 g,were randomly divided into 4 groups(n=15):the sham operation group(the Sham group),the traumatic brain injury group(the TBI group),the BML-111 treatment group(the BML-111 group),and the BOC-2 treatment group(the BOC-2 group).The TBI model was prepared by craniocerebral collision,while the rats in the Sham group underwent only craniotomy without collision.Acute traumatic brain injury model was prepared in the TBI group,the BML-111 group and the BOC-2 group.The rats in the BOC-2 group were intraperitoneally injected with 50μg/kg of BOC-230 min prior to trauma.Then the rats in the BOC-2 group and the BML-111 group were injected intraperitoneally with 1 mg/kg of BML-111 immediately and 24 h after trauma.The neurological severity scores(NSS)were evaluated at 3 and 7 d after brain trauma.The protein expression levels of NLRP3,Caspase-1-p20 and active Caspase-3 were determined by Western blot.The content of IL-1βand IL-18 was detected by ELISA assays.The apoptotic cells were analyzed by the TUNEL method.Results:Compared with the Sham group,the brain water content and NSS scores in the TBI group were increased,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex were elevated significantly(P<0.05);compared with the TBI group,the brain water content and NSS scores in the BML-111 group were reduced,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex were decreased(P<0.05);Compared with the BML-111 group,the brain water content and NSS scores in the BOC-2 group were increased,and the protein levels of NLRP3,Caspase-1-p20,activated Caspase-3,IL-1βand IL-18 as well as TUNEL-positive cells in the cortex increased(P<0.05).Conclusion:The lipoxin receptor agonist BML-111 might attenuate traumatic brain injury in rats by inhibiting NLRP3 inflammasome activation.