黄芩素对创伤性脑损伤大鼠血脑屏障和神经元焦亡及NLRP3/Caspase-1信号通路的影响

Impacts of baicalein on blood-brain barrier,neuronal pyroptosis and NLRP3/Caspase-1 signaling pathway in rats with traumatic brain injury

目的探究黄芩素对创伤性脑损伤大鼠血脑屏障和神经元焦亡的影响及对NOD样受体热蛋白结构域3(NLRP3)/半胱天冬酶-1(Caspase-1)信号通路的影响。方法将大鼠随机分为对照组、模型组、黄芩素(2.5、5.0、10.0 mg/kg)组,每组12只。黄芩素组分别按2.5、5.0、10.0 mg/kg剂量ip黄芩素。ELISA法测定大鼠血清肿瘤坏死因子-α(TNF-α)、白细胞介素(IL)-6、谷胱甘肽过氧化物酶(GSH-Px)、超氧化物歧化酶(SOD)、丙二醛(MDA)水平;伊文思蓝(EB)染料的超流体测量血脑屏障的通透性;TUNEL和Caspase-1双染法检测细胞焦亡情况;荧光定量PCR(RT-qPCR)测定大鼠脑海马组织中闭锁小带蛋白1(ZO-1)、紧密连接蛋白1(Claudin-1)、闭合蛋白(Occludin)的mRNA表达量;Western blotting法检测脑海马组织中NLRP3/Caspase-1通路相关蛋白表达。结果与模型组相比,黄芩素各剂量组大鼠病变半球EB含量显著降低,血脑屏障通透性显著改善,ZO-1、Claudin-1、Occludin mRNA及SOD、GSH-Px水平显著上升(P<0.05),海马组织细胞焦亡率及MDA、IL-6、TNF-α、NLRP3、Caspase-1、GSDMD-N、IL-1β和IL-18水平显著下降(P<0.05)。结论黄芩素可抑制NLRP3/Caspase-1信号通路,减轻炎症反应和氧化应激反应,改善创伤性脑损伤大鼠血脑屏障和神经元焦亡。

Objective To investigate the impacts of baicalein on the blood-brain barrier and neuronal pyroptosis in rats with traumatic brain injury,and its impact on the NLRP3/Caspase-1 signaling pathway.Methods Rats were assigned into control group,model group,baicalein(2.5,5.0,and 10.0 mg/kg)group,with 12 rats in each group.Baicalein groups were intraperitoneally injected with baicalein at doses of 2.5,5.0,and 10.0 mg/kg,respectively.The serum TNF-α,IL-6,GSH-Px,SOD,and MDA were determined by ELISA method.The superfluid of Evans blue(EB)dye was used to measure the permeability of the blood-brain barrier.TUNEL and Caspase-1 double staining method was applied to detect cell apoptosis.RT-qPCR was applied to measure the mRNA expression levels of ZO-1,Claudin-1,and Occludin in hippocampal tissue.The expression of NLRP3/Caspase-1 pathway related proteins in hippocampal tissue were detected by Western blotting.Results Compared with the model group,the EB content in the affected hemisphere of rats in the baicalein groups were greatly reduced,and the permeability of the blood-brain barrier was greatly improved,the levels of ZO-1,Claudin-1,Occludin mRNA,and SOD and GSH-Px were greatly increased(P<0.05),the cell apoptosis rate and the levels of MDA,IL-6,TNF-α,NLRP3,Caspase-1,GSDMD-N,IL-1β,and IL-18 were greatly decreased(P<0.05).Conclusion Baicalein can inhibit the NLRP3/Caspase-1 signaling pathway,alleviate inflammatory and oxidative stress responses,and improve the blood-brain barrier and neuronal pyroptosis in traumatic brain injury rats.