桔皮素调控Nrf2/NQO1通路减轻脊髓损伤大鼠炎症与氧化应激损伤

Tangeretin attenuating inflammatory and oxidative stress injury via Nrf2/NQO1 pathway in rats with spinal cord injury

目的研究桔皮素对脊髓损伤大鼠的修复作用及其机制。方法将大鼠按随机数字表法分为假手术组、模型组、桔皮素组,每组8只。除假手术组外,其余各组采用Allen打击法制作脊髓损伤大鼠模型。造模成功后,桔皮素组灌胃桔皮素50 mg/kg,假手术组及模型组灌胃等体积的生理盐水,1次/d,连续干预14 d。分别于造模后第0、3、7、14天,采用Basso-Beattie-Bresnahan(BBB)评分评估大鼠运动功能恢复情况;采用HE染色及Nissl染色观察脊髓组织形态学变化,使用ELISA法检测各组大鼠脊髓组织SOD、GSH活性和MDA、IL-1β、TNF-α、IL-10水平,免疫荧光法检测脊髓组织胶质纤维酸性蛋白(GFAP)和神经元核抗原(Neun)表达,Western blot法检测脊髓组织IL-1β、TNF-α、IL-10、核因子E2相关因子2(Nrf-2)和NAD(P)H-醌氧化还原酶1(NQO-1)表达。结果与模型组比较,桔皮素组大鼠BBB评分升高(P<0.05),HE染色评分降低(P<0.05),Nissl染色尼氏小体数增加(P<0.05);脊髓组织SOD、GSH活性及IL-10水平升高(P<0.05),MDA、IL-1β、TNF-α水平降低(P<0.05);GFAP荧光强度减弱(P<0.05),Neun荧光强度增强(P<0.05);IL-1β、TNF-α蛋白相对表达降低(P<0.05),IL-10、Nrf-2、NQO-1蛋白相对表达升高(P<0.05)。结论桔皮素可能通过Nrf2/NQO1信号通路发挥抗炎、抗氧化应激的作用,缓解大鼠早期的脊髓损伤;另一方面可能通过减少胶质瘢痕,促进神经细胞生成,从而促进脊髓损伤的恢复。

Objective To explore the repairing effect and mechanism of tangeretin in rats with spinal cord injury.Methods The rats were divided into sham-operation group,model group and tangeretin group according to random number table,with 8 rats in each group.Except for the sham-operation group,Allen hit method was used to make rat models in the other groups.After the model was successfully established,the tangeretin group was intragastrically administered with tangeretin 50 mg/kg,and the sham-operation group and the model group were intragastrically administered with an equal volume of normal saline once a day for 14 days.On days 0,3,7,and 14 after modeling,the motor function recovery of rats was assessed using the Basso-Beattie-Bresnahan(BBB)score;the morphological changes of the spinal cord tissues were observed using HE staining and Nissl staining;the SOD and GSH activities and MDA,IL-1β,TNF-α,and IL-10 levels in the spinal cord tissues of rats in each group were measured using ELISA kit detection;the GFAP and Neun expressions in the spinal cord tissues were detected by immunofluorescence;the IL-1β,TNF-α,IL-10,nuclear factor E2-related factor 2(Nrf-2),and NAD(P)H-quinone oxidoreductase 1(NQO-1)expressions in the spinal cord tissues were detected by Western blot.Results Compared with the model group,the BBB score increased in the tangeretin group(P<0.05),HE staining score decreased(P<0.05),and the number of Nissl bodies increased(P<0.05);the level of IL-10,SOD and GSH activities increased(P<0.05),and IL-1β,TNF-αand MDA levels decreased in the spinal cord tissue(P<0.05);GFAP fluorescence intensity decreased(P<0.05)and NeuN fluorescence intensity increased(P<0.05);the relative expression of IL-1βand TNF-αdecreased(P<0.05),and the relative expressions of IL-10,Nrf-2 and NQO-1 protein increased(P<0.05).Conclusions Tangeretin can exert anti-inflammatory and anti-oxidative stress effects through the Nrf2/NQO1 signaling pathway and alleviate early spinal cord injury in rats.On the other hand,it may promote the recovery of spinal cord injury by reducing glial scar generation and promoting neural cellogenesis.