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目的内质网是细胞内重要的细胞器,脑缺血过程中伴随着内质网应激,然而其在脑缺血复灌过程中的作用尚不明确。方法本实验采用小鼠大脑中动脉栓塞(MCAO)模型和大鼠皮质原代神经元氧糖剥夺(OGD)模型,以tunicamy-cin(TM)和thapsigargin(TG)作为内质网应激的激动剂,4-PBA Salt和Salubrinal作为内质网应激抑制剂。MCAO 1 h血流复灌时侧脑室给予不同剂量的TM(3μg,6μg)和TG(0.02μg,0.06μg),对照组注射相同体积人工脑脊液,24 h后分别以TTC染色方法和18氟-脱氧葡萄糖microPET影像学技术检测小鼠脑梗死体积及代谢功能,记录神经行为学症状并评分。在体外培养8 d的大鼠皮质神经元OGD模型中,对神经元OGD 2 h,于复糖复氧时孵育各浓度TM(0.04～1 ng.L-1),TG(0.08～2 nmol·L-1)和4-PBA Salt(6～150 nmol·L-1),Salubrinal(0.2～5 nmol·L-1),复灌24 h后以TUNEL和MTT方法分别检测细胞凋亡和细胞活力。结果与MCAO手术对照组相比,TG,TM可剂量依赖地减少脑梗死体积,缓解脑缺血引起的葡萄糖代谢降低并改善神经行为学症状。神经元OGD复灌模型中,TM(0.2～1 ng.L-1)和TG(0.08～2 nmol·L-1)均可浓度依赖地减少OGD引起的细胞凋亡,而4-PBA Salt(6～150 nmol·L-1)和Salubrinal(1 nmol·L-1)均可显著提高OGD引起的细胞凋亡数及细胞活力降低。结论在脑缺血复灌过程中,内质网应激可能发挥了重要的神经保护作用。
Purpose Endoplasmic reticulum (ER) is an important intracellular organelle. Endoplasmic reticulum (ER) stress is associated with cerebral ischemia. However, its role in cerebral ischemia and reperfusion remains unclear. Methods In this study, MCAO model and OGD model were used to investigate the effects of tunicamy-cin (TM) and thapsigargin (TG) on endoplasmic reticulum stress Agents, 4-PBA Salt and Salubrinal as Endoplasmic Reticulum Stress Inhibitors. The rats in control group were injected with TM (3μg, 6μg) and TG (0.02μg, 0.06μg) at the same time after reperfusion of MCAO for 1 hour. Twenty-four hours later, TTC staining and 18 F- Deoxyglucose microPET imaging technology to detect cerebral infarction volume and metabolic function in mice, neurological behavioral symptoms were recorded and scored. In the OGD model of rat cortical neurons cultured for 8 days in vitro, the concentrations of TM (0.04-1 ng.L-1), TG (0.08-2 nmol · L-1) and Saline (0.2 ~ 5 nmol·L-1) for 4-PBA Salt (6-150 nmol·L-1) and 24 h after reperfusion, respectively. Cell apoptosis and cell viability were detected by TUNEL and MTT . Results Compared with the MCAO surgery group, TG and TM reduced the volume of cerebral infarction dose-dependently, relieved the decrease of glucose metabolism induced by cerebral ischemia and improved the neurobehavioral symptoms. In the model of neuronal OGD reperfusion, TM (0.2-1 ng.L-1) and TG (0.08-2 nmol·L-1) both reduced the apoptosis of cells induced by OGD in a concentration-dependent manner, whereas the 4-PBA Salt 6 ~ 150 nmol·L-1) and Salubrinal (1 nmol·L-1) significantly increased the number of apoptotic cells and cell viability induced by OGD. Conclusion Endoplasmic reticulum stress may play an important neuroprotective role in cerebral ischemia and reperfusion.