维生素K_(2)对大鼠创伤性脑损伤的影响及其与NLRP3炎症小体的关系

Effect of vitamin K_(2) on traumatic brain injury and the relationship with NLRP3 inflammasomes in rats

目的评价维生素K2对大鼠创伤性脑损伤的影响及其与NOD样受体热蛋白结构域相关蛋白3(NLRP3)炎症小体的关系。方法SPF级健康雄性SD大鼠36只,体重280~300 g,采用随机数字表法分为3组(n=12):假手术组(Sham组)、创伤性脑损伤组(TBI组)和创伤性脑损伤+维生素K2组(TBI+VK2组)。采用改良Feeney法建立大鼠创伤性脑损伤模型。TBI+VK2组于脑损伤模型制备后30 min时腹腔注射维生素K2400 mg/kg(用DMSO溶解),Sham组和TBI组分别腹腔注射等容量DMSO。于模型制备后24 h时进行改良神经功能缺损评分(mNSS)和旷场实验,行为学测定结束后处死大鼠,取脑,采用干湿重法测定脑含水量,采用TTC法检测脑损伤体积百分比,采用ELISA法检测损伤侧皮层IL-1β、IL-18和caspase-1含量,采用Western blot法检测损伤侧皮层NLRP3、caspase-1和IL-18表达水平。结果与Sham组比较,TBI组大鼠mNSS评分升高,运动总路程和中央区域停留时间减少,脑含水量和脑损伤体积百分比升高,损伤侧皮层IL-1β、IL-18和caspase-1含量升高,NLRP3、caspase-1和IL-18表达上调(P<0.05或0.01);与TBI组比较,TBI+VK2组大鼠mNSS评分降低,运动总路程和中央区域停留时间增加,脑含水量和脑损伤体积百分比降低,损伤侧皮层IL-1β、IL-18和caspase-1含量降低,NLRP3、caspase-1和IL-18表达下调(P<0.05或0.01)。结论维生素K2可减轻大鼠创伤性脑损伤,其机制可能与抑制NLRP3炎症小体激活有关。

Objective To evaluate the effect of vitamin K_(2) on traumatic brain injury(TBI)and the relationship with nucleotide-binding oligomerization domain-like receptor family pyrin domain containing 3(NLRP3)inflammasomes in rats.Methods Thirty-six SPF healthy male Sprague-Dawley rats,weighing 280-300 g,were divided into 3 groups(n=12 each)by a random number table method:sham operation group(group Sham),group TBI and TBI plus vitamin K_(2) group(group TBI+VK_(2)).The TBI model was developed using modified Feeney′s method.In TBI+VK_(2) group,vitamin K_(2)400 mg/kg(dissolved in dimethyl sulfoxide)was intraperitoneally injected at 30 min after developing TBI model.The equal volume of dimethyl sulfoxide was intraperitoneally injected in group Sham and group TBI.The modified neurological severity score(mNSS)was measured and open field tests were performed at 24 h after development of TBI.The rats were sacrificed after the end of behavioral testing,and brains were obtained for measurement of brain water content(by wet-dry weight method),percentage of brain injury volume(by TTC assay),contents of interleukin-1β(IL-1β),IL-18 and caspase-1 in cortex on the injured side(by enzyme-linked immunosorbent assay)and expression of NLRP3,caspase-1 and IL-18 in cortex on the injured side(by Western blot).Results Compared with group Sham,the mNSS score was significantly increased,the total distance travelled was reduced,the time spent in the central zone was shortened,the brain water content and percentage of brain injury volume were increased,the contents of IL-1β,IL-18 and caspase-1 in cortex on the injured side were increased,and the expression of NLRP3,caspase-1 and IL-18 was up-regulated in group TBI(P<0.05 or 0.01).Compared with group TBI,the mNSS score was significantly decreased,the total distance travelled was increased,the time spent in the central zone was prolonged,the brain water content and percentage of brain injury volume were decreased,the contents of IL-1β,IL-18 and caspase-1 in cortex on the injured side were decreased,and the expression of NLRP3,caspase-1 and IL-18 was down-regulated in group TBI+VK_(2)(P<0.05 or 0.01).Conclusions Vitamin K_(2) can reduce TBI,and the mechanism may be related to inhibition of the activation of NLRP3 inflammasomes in rats.