栝楼桂枝颗粒抑制MCAO大鼠神经元凋亡的机制研究

Mechanism of Gualou Guizhi Granule Inhibits Neuronal Cell Apoptosis in MCAO Rats

关键词:  栝楼桂枝颗粒  PI3K/AKT  脑缺血再灌注损伤  大脑中动脉栓塞

Key words:  Gualou Guizhi granule  PI3K/AKT  cerebral ischemia-reperfusion injury  middle cerebral artery occlusion

摘要:

目的 研究栝楼桂枝颗粒（Gualou Guizhi granule，GLGZG）是否通过调控PI3K/AKT通路抑制脑缺血再灌注损伤大鼠神经元凋亡而达到抗脑缺血再灌注损伤的作用。方法 SD大鼠36只，♂，分为假手术组、大脑中动脉栓塞（middle cerebral artery occlusion，MCAO）组、GLGZG组，每组12只。其中MCAO组、GLGZG组采用线栓法致MCAO建立大鼠脑缺血再灌注损伤模型，GLGZG灌胃给药，连续给药7 d。采用改良的神经功能缺损评分法对大鼠神经功能损伤进行评分，MRI观察大鼠脑梗死体积，Real-time PCR检测脑组织中PI3K、Akt mRNA的表达，Western blot法检测大鼠缺血侧脑组织PI3K（p85）、Akt、p-Akt、PDK1、Bcl-2、Bcl-xL、cleaved-caspase-3、Bad、Bax蛋白表达。结果 与MCAO组比较，GLGZG组神经行为学评分降低，第5、7天神经评分显著低于MCAO组（P<0.05）；与MCAO组比较，MRI观察发现GLGZG组大鼠脑梗死体积显著减小（P<0.05）；PI3K（p85）、p-Akt、PDK1、Bcl-2、Bcl-xL蛋白的表达上调（P<0.01），cleaved-caspase-3、Bad、Bax蛋白的表达下调（P<0.01），对Akt的表达没有影响。结论 GLGZG能够提高MCAO大鼠神经功能，抑制神经细胞凋亡，其作用机制可能是通过激活PI3K/AKT信号通路抑制MCAO大鼠神经元凋亡。

Abstract:

OBJECTIVE To investigate the inhibitive effect of Gualou Guizhi granule(GLGZG) on nerve cell apoptosis in cerebral ischemia-reperfusion injury rat through activatig PI3K/nAKT pathway. METHODS Thirty-six male SD rats were divided into sham operation group, middle cerebral artery occlusion(MCAO) model group and GLGZG group, 12 for each group. MCAO model group and GLGZG group subjected to focal cerebral ischemia reperfusion with suture-occluded induced MCAO method. GLGZG was gave by intragastric administration, once daily for 7 d. Neurobehavioral deficit was performed with modified neurological severity score(mNSS) scale. MRI was used to observe the cerebral infarct volume in rats. PI3K, Akt mRNA were detected by qRT-PCR in the infarcted cortex. The protein expression of PI3K(p85), p-Akt, PDK1, Bcl-2, Bcl-xL, cleaved-caspase-3, Bad, Bax were detected by Western blot. RESULTS The mNSS score of GLGZG group was reduced compared with the MACO model group, especially on 5th and 7th day(P<0.05). Compared with MCAO group, the cerebral infarct volume in GLGZG group rats were decreased significantly(P<0.05) and upregulated the proteins expression of PI3K(p85), p-Akt, PDK1, Bcl-2, Bcl-xL(P<0.01), downregulated cleaved-caspase-3, Bad, Bax(P<0.01), however, the protein expression of Akt was not change. CONCLUSION GLGZG can improve the nerve function deficit of MCAO rat and inhibit the apoptosis of neural cell, which may be associated with activating the PI3K/AKT pathway.