玫瑰花总黄酮对脑缺血/再灌注损伤大鼠PI3K/AKT通路和内质网应激凋亡的影响

Effect of total flavonoids of Rosa rugosa on PI3K/AKT pathway and endoplasmic reticulum stress apoptosis in rats with cerebral ischemia-reperfusion injury

目的研究玫瑰花总黄酮(total flavonoids from Rosa rugosa,TFR)对大鼠脑缺血/再灌注损伤(cerebral ischemia reperfusion injury,CIRI)的影响,探讨TFR是否通过磷脂酰肌醇-3-激酶/蛋白激酶B(phosphoinositide 3-kinase/protein kinase B,PI3K/AKT)信号通路和内质网应激(endoplasmic reticulum stress,ERS)途径调控神经细胞凋亡。方法将SD大鼠随机分成假手术组、模型组、TFR低、中、高剂量组(50、100、200 mg·kg^(-1)·d^(-1))组,灌胃7 d,末次给药1 h后线栓法制备大脑中动脉阻塞/再灌注(middle cerebral artery occlusion/reperfusion,MCAO/R)模型。24 h后检测大鼠神经行为学变化、脑梗死面积、脑组织含水量;HE和尼氏染色观察病理相关指标;TUNEL染色观察神经细胞凋亡情况;Western blot检测Bcl-2、Bax、cleaved Caspase-3、PI3K、p-PI3K、AKT、p-AKT、GRP78、CHOP和Caspase-12的蛋白表达水平。结果与MCAO/R组比,中、高剂量TFR给药组大鼠神经行为学功能改善,脑梗死面积下降,脑水肿程度降低,脑皮质区病理损伤减轻,神经细胞凋亡率明显减少,抗凋亡蛋白Bcl-2表达升高,促凋亡蛋白Bax和cleaved Caspase-3表达降低,p-PI3K/PI3K、p-AKT/AKT表达升高。ERS相关蛋白GRP78、CHOP、Caspase-12表达降低。结论TFR可通过调控PI3K/AKT信号通路和ERS途径抑制神经细胞凋亡,从而发挥对CIRI大鼠的保护作用。

Aim To investigate the effects of total flavonoids from Rosa rugosa(TFR)on cerebral ischemia reperfusion injury(CIRI)in rats,and to investigate whether TFR inhibited neuronal apoptosis by regulating phosphoinositide 3-kinase/protein kinase B(PI3K/AKT)signaling pathway and endoplasmic reticulum stress(ERS)pathways.Methods SD rats were randomly divided into sham operation group,model group,low-dose group(50 mg·kg^(-1)·d^(-1)),medium-does group(100 mg·kg^(-1)·d^(-1)),and high-does group(200 mg·kg^(-1)·d^(-1)).The injury model of middle cerebral artery occlusion/reperfusion(MCAO/R)was prepared following suture method.Neurobehavioral changes,cerebral infarct size and brain tissue water content were detected 24 h after surgery.HE and Nissl staining were performed to observe pathological indicators.TUNEL staining was used to detect the apoptosis of ischemic nerve cells in brain.Western blot was used to detect the protein levels of Bcl-2,Bax,and cleaved Caspase-3,PI3K,p-PI3K,AKT,p-AKT,GRP78,CHOP and Caspase-12.Results Compared with MCAO/R group,the rats in medium-dose group and high-dose group showed improvement in the neurobehavioral function,decrease in the cerebral infarction area and the degree of cerebral edema,and reduction of the pathological damage of cerebral cortex.Moreover,there was a significantly decrease in the apoptosis rate of nerve cells in medium-dose group and high-dose group.The expression of anti-apoptotic protein Bcl-2 increased,and the pro-apoptotic protein Bax and cleaved-Caspase-3 decreased,the expression of p-PI3K/PI3K,p-Akt/AKT increased,and the expression of ERS-related protein GRP78,CHOP,Caspase-12 decreased.Conclusions TFR can inhibit neuronal apoptosis by regulating the PI3K/AKT signaling pathway and ERS pathway,thus playing a protective role in CIRI rats.