灯盏细辛注射液通过调节JAK2/STAT3信号通路抗脑卒中大鼠神经损伤的研究

Study on the effect of Erigeron Breviscapus Injection on neural injury in stroke rats by regulating the JAK2/STAT3 signaling pathway

关键词:  灯盏细辛注射液  脑卒中  Janus激酶2/信号转导子和转录激活子3  神经保护

Key words:  Erigeron Breviscapus Injection  stroke  janus kinase 2/signal transducer and activator of transcription 3  neuroprotection

摘要:

[目的] 探讨灯盏细辛注射液（EBI）对脑卒中大鼠的神经保护作用及在该过程中对Janus激酶2（JAK2）/信号转导子和转录激活子3（STAT3）信号通路的调节机制。[方法] 通过大脑中动脉闭塞（MCAO）建立缺血性脑卒中大鼠模型，然后将造模成功的大鼠随机分为模型组、尼莫地平组、EBI组、JAK2抑制剂组（AG490组）和EBI+JAK2激动剂组（EBI+CA1组），每组20只，另外选取20只大鼠只暴露颈动脉不进行结扎作为假手术组。利用神经功能缺损评分评估大鼠神经功能；2，3，5-三苯基氯化四氮唑（TTC）染色检测大鼠脑梗死面积；苏木精-伊红（HE）和尼氏（Nissl）染色检测大鼠脑组织的病理性形态；TUNEL染色检测大鼠脑组织中神经细胞凋亡情况；酶联免疫吸附测定（ELISA）检测大鼠脑组织中超氧化物歧化酶（SOD）、谷胱甘肽过氧化物酶（GSH-Px）和丙二醛（MDA）的水平；蛋白免疫印迹法（Western blot）检测大鼠脑组织中Bax、B淋巴细胞瘤-2（Bcl-2）及JAK2、p-JAK2、STAT3、p-STAT3蛋白的表达。[结果] 与假手术组相比，模型组大鼠脑梗死面积增大，神经元细胞凋亡率增加，神经缺损评分、MDA水平、Bax蛋白表达及p-JAK2/JAK2、p-STAT3/STAT3比值均升高（P＜0.05），同时脑组织中神经元退化，神经元数量减少，SOD、GSH-Px活性及Bcl-2蛋白表达降低（P＜0.05）；与模型组相比，EBI组、尼莫地平组和AG490组大鼠脑梗死面积减小，神经元细胞凋亡率减少，神经缺损评分、MDA水平、Bax蛋白表达及p-JAK2/JAK2、p-STAT3/STAT3比值均降低（P＜0.05），同时脑组织中神经元损伤减轻，神经元数量增加，SOD、GSH-Px活性及Bcl-2蛋白表达升高（P＜0.05）；进一步利用JAK2激动剂进行回补实验发现，EBI对大鼠神经损伤的保护作用被逆转（P＜0.05）。[结论] EBI能够通过抑制JAK2/STAT3信号通路减轻脑卒中大鼠的神经损伤。

Abstract:

[Objective] To investigate the neuroprotective effect of Erigeron Breviscapus Injection（EBI） on stroke rats and its regulatory mechanism on the JAK2/STAT3 signaling pathway during this process. [Methods] A rat model of ischemic stroke was established using middle cerebral artery occlusion（MCAO），and the successfully modeled rats were randomly grouped into model group，nimodipine group，EBI group，JAK2 inhibitor group（AG490 group），and EBI+JAK2 agonist group（EBI+CA1 group），with 20 rats in each group. In addition，20 rats were selected as sham surgery group，which only exposed carotid artery without ligation. The neurological deficit score was applied to evaluate the neural function of rats；TTC staining was applied to detect the area of cerebral infarction in rats；HE and Nissl staining were applied to detect the pathological morphology of rat brain tissue；TUNEL staining was applied to detect neuronal apoptosis in rat brain tissue；ELISA was applied to detect the levels of SOD，GSH-Px，and MDA in rat brain tissue；and Western blot was applied to detect the expression of Bax，Bcl-2，and JAK2，p-JAK2，STAT3，and p-STAT3 proteins in rat brain tissue. [Results] Compared with the sham surgery group，the cerebral infarction size of rats in the model group increased，neuronal apoptosis rate increased，nerve defect score，MDA level，Bax protein expression，p-JAK2/JAK2，p-STAT3/STAT3 ratio increased（P＜0.05），meanwhile，neurons in brain tissue degenerated and the number of neurons decreased，the activities of SOD and GSH-Px and the expression of Bcl-2 protein were decreased（P＜0.05）；compared with the model group，the area of cerebral infarction，apoptosis rate of neurons increased，nerve defect score，MDA level，Bax protein，p-JAK2/JAK2 and p-STAT3/STAT3 ratio in the EBI group，nimodipine group，and AG490 group decreased（P＜0.05），meantime，neuronal damage in brain tissue was reduced，and the number of neurons，SOD and GSH-Px activities，Bcl-2 protein expression increased（P＜0.05）；further use of JAK2 agonists for compensatory experiments revealed that the protective effect of EBI on nerve injury in rats was reversed（P＜0.05）. [Conclusion] EBI can reduce nerve damage in stroke rats by inhibiting the JAK2/STAT3 signaling pathway.