依达拉奉右莰醇抑制TLR4/NF-κB通路减轻大鼠液压冲击脑损伤

Edaravone dexbornol attenuate hydraulic shock brain injury in rats by inhibiting TLR4/NF-kB pathway

目的 探讨依达拉奉右莰醇(ED)对大鼠液压冲击脑损伤的影响及机制。方法 取96只SD大鼠随机分为假手术组、模型组、ED组和ED+脂多糖(LPS,TLR4激活剂)组,每组24只;采用液压冲击法制备脑损伤大鼠模型。ED组腹腔注射(ip)给予5.6 mg·kg^(-1)依达拉奉+1.4 mg·kg^(-1)右莰醇,ED+LPS组ip给予5.6 mg·kg^(-1)依达拉奉+1.4 mg·kg^(-1)右莰醇+0.4 mg·kg^(-1)LPS,假手术组和模型组ip给予生理盐水,均1次·d^(-1)连续14 d。通过mNSS评分评价大鼠神经功能缺损状况,干湿重法检测脑组织含水量(BWC),苏木精-伊红染色法、TUNEL染色法观察脑组织病理变化和神经元凋亡状况,ELISA法检测炎症因子水平,Western blot检测Toll样受体4(TLR4)/核因子-κB p65(NF-κB p65)通路相关蛋白表达。结果 治疗后,ED组大鼠mNSS评分和BWC均明显低于模型组(P<0.05);模型组脑组织呈现结构疏松、神经元间隙增大、空泡变性、炎细胞浸润等病理变化及大量神经元凋亡,ED组脑组织病理学变化及神经元凋亡状况较模型组明显改善、凋亡指数明显降低(P<0.05);ED组脑组织肿瘤坏死因子-α(TNF-α)、白细胞介素-1 β (IL-1β)水平和TLR4表达量及p-NF-κB p65/NF-κB p65、p-IκBα/IκBα表达比值较模型组均明显降低(P<0.05)。LPS能够明显逆转ED对液压冲击脑损伤大鼠上述各指标的调控作用(P<0.05)。结论 ED可抑制液压冲击脑损伤大鼠炎症反应、减轻脑损伤,其作用机制可能与抑制TLR4/NF-κB通路活化有关。

Objective To explore the effect and mechanism of edaravone dexborneol(ED)on brain injury induced by hydraulic shock in rats.Methods 96 SD rats were randomly divided into sham operation group,model group,ED group and ED+LPS(TLR4 activator)group,n=24;the hydraulic impact method was used to preparate the brain injury rat model.The rats in ED group was given 5.6 mg·kg^(-1)edaravone+1.4 mg·kg^(-1)dextrose by intraperitoneal injection(ip);and rats in ED+TAK242 group was given 5.6 mg kg^(-1)edaravone+1.4 mg·kg^(-1)dextrose+5 mg·kg^(-1)LPS by ip;the rats in sham operation group and model group were given normal saline by ip,once a day for 14 days.The neurological deficit of rats was evaluated by modified neureological severity scores(mNSS),the water content of brain tissue(BWC)was detected by dry-wet weight method,the pathological changes of brain tissue and neuronal apoptosis were observed by HE staining and TUNEL staining,the level of inflammatory factors were detected by ELISA,the expression of proteins related to Toll-like receptor 4(TLR4)/nuclear factor-k B p65(NFk B p65)pathway were detected by Western blot.Results After treatment,the mNSS score and BWC of the rats in the ED group were significantly lower than those in the model group(P<0.05).The brain tissue of the rats in model group showed pathological changes such as loose structure,increased neuronal gap,vacuolar degeneration,inflammatory cell infiltration,and a large number of neuronal apoptosis.Compared with the model group,the pathological changes of brain tissue and neuronal apoptosis in the ED group were significantly improved,and the apoptosis index was significantly decreased(P<0.05);the tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)levels,TLR4 expression and p-NF-k B p65/NF-k B p65,p-I k Bα/l k Bαexpression ratios in brain tissue were significantly devreased(P<0.05).LPS could significantly reverse the regulatory effect of ED on the above indexes in rats with hydraulic shock brain injury(P<0.05).Conclusion ED can inhibit the inflammatory response and reduce brain injury in rats with hydraulic shock brain injury,which mechanism may be related to the inhibition of TLR4/NF-k B pathway activation.