目的:探究乌司他丁在脑缺血再灌注损伤中的脑保护作用机制。方法:原代分离培养雄性SD大鼠脑皮质细胞,部分细胞经siRNA沉默HSP70基因。细胞先以无糖培养基在低氧条件下培养,12 h后复糖复氧模拟体外缺血再灌注损伤,并实施乌司他丁预处理干预,流式细胞术检测各组细胞的凋亡率,western-blotting检测Bcl-2,Bax,HSP70,JNK和p-JNK蛋白的表达。结果:与对照组比较,模型组脑组织细胞凋亡率明显增多(P<0.05)、Bcl-2和Bax的表达量均有上调,Bcl-2/Bax的比值显著降低(P<0.01)、HSP70的表达无显著变化;与模型组比较,乌司他丁处理组脑组织细胞凋亡率明显降低(P<0.05)、Bax的表达量显著下调(P<0.05),Bcl-2/Bax的比值显著上调(P<0.05),HSP70的表达显著上调(P<0.05),JNK的表达无显著变化、p-JNK则显著下调(P<0.05)。HSP70沉默后乌司他丁的脑保护作用消失,对以上蛋白的表达无显著影响。结论:乌司他丁可能是通过上调HSP70表达进而抑制JNK信号转导通路对缺血再灌注引起的脑损伤起保护作用。 Objective: To investigate the protective effect of ulinastatin on cerebral ischemia-reperfusion injury. Methods: Primary cortex cells of male Sprague-Dawley rats were isolated and cultured, and some cells were silenced HSP70 by siRNA. Cells were cultured in glucose-free medium under hypoxic conditions. After 12 h, reoxygenation was simulated to induce ischemia-reperfusion injury and ulinastatin preconditioning. Flow cytometry was used to detect the apoptosis in each group The expressions of Bcl-2, Bax, HSP70, JNK and p-JNK protein were detected by Western blotting and Western blotting. Results: Compared with the control group, the apoptosis rate of model group was significantly increased (P <0.05), the expression of Bcl-2 and Bax was up-regulated, the ratio of Bcl-2 / Bax was significantly decreased Compared with model group, the apoptosis rate of brain tissue in ulinastatin group was significantly decreased (P <0.05), the expression of Bax was significantly decreased (P <0.05), and the expression of Bcl-2 / Bax (P <0.05), the expression of HSP70 was up-regulated (P <0.05), the expression of JNK was not significantly changed, but p-JNK was significantly decreased (P <0.05). The protective effect of ulinastatin disappeared after HSP70 was silenced, and had no significant effect on the above protein expression. Conclusion: Ulinastatin may protect the brain against ischemia-reperfusion injury by up-regulating the expression of HSP70 and then inhibiting the JNK signal transduction pathway.