高迁移率族蛋白B1通过调节Bcl-2和Bax蛋白表达促进氧糖剥夺/复氧星形胶质细胞的凋亡

目的：研究高迁移率族蛋白B1（high mobility group box 1，HMGB1）在氧糖剥夺/复氧后对星形胶质细胞凋亡的影响，同时通过检测凋亡相关蛋白Bcl 2和Bax表达变化探讨其可能的作用机制。方法：将体外培养新生大鼠大脑皮质星形胶质细胞分为正常组、模型组、干扰组、对照组，用携带大鼠HMGB1的短发夹RNA（short hairpin RNA，shRNA）慢病毒载体干扰星形胶质细胞抑制HMGB1表达后进行氧糖剥夺/复氧处理，氧糖剥夺6 h、复氧24 h后检测。通过Western blotting法检测RNA干扰效果，通过MTT细胞存活实验检测细胞损伤，通过TUNEL法检测细胞凋亡，最后通过Western blotting法检测凋亡相关蛋白Bcl-2和Bax表达。结果：与正常组比较，模型组经过氧糖剥夺/复氧处理后星形胶质细胞内HMGB1表达明显升高（P<0.001）， MTT实验检测细胞存活率下降（P<0.001），TUNEL法检测凋亡细胞数增多（P<0.001）， 凋亡相关蛋白Bcl 2/Bax蛋白比值下降（P<0.001）；与模型组比较，RNA干扰有效抑制HMGB1蛋白表达（P<0.001）， MTT实验检测细胞存活率升高（P<0.001），TUNEL法标记凋亡细胞数减少（P<0.001）， 凋亡相关蛋白Bcl-2/Bax蛋白比值升高（P<0.001）。结论：氧糖剥夺/复氧后HMGB1的释放可以导致星形胶质细胞损伤及细胞凋亡，其作用机制可能与调控凋亡相关蛋白Bcl-2及Bax表达有关。

High mobility group box 1 promotes apoptosis of astrocytes after oxygen glucose deprivation/reoxygenation by regulating the expression of Bcl-2 and Bax

Objective： To investigate the effect of high mobility group protein box 1 (HMGB1) on apoptosis of astrocytes after oxygen glucose deprivation/reoxygenation (OGD/R), and to investigate the possible mechanism by evaluating the expression of apoptosis related protein Bcl-2 and Bax. Methods: The cerebral cortex astrocytes of neonatal rats were divided into normal group, model group, interference group and control group. Lentivirus vector of rat HMGB1 short hairpin RNA (shRNA) was used to suppress the HMGB1 protein expression in the astrocytes. Then the detection was made after astrocytes were deprived of oxygen and glucose 6 h, reoxygenation for 24 h. The effect of RNA interference was evaluated by Western blotting. The cell survival rate was measured by MTT assay. The apoptosis of astrocytes was determined by TUNEL assay. The expressions of Bcl-2 and Bax were detected by Western blotting. Results: Compared with the normal group, the protein expression of HMGB1 was significantly increased in model group after OGD/R (P<0.001), the astrocytes survival rate was decreased (P<0.001), the number of apoptotic cells labeled with TUNEL was increased (P<0.001), and the ratio of Bcl-2/Bax was decreased (P<0.001). Compared with the model group, RNA interference effectively inhibited the expression of HMGB1 in interference group (P<0.001), the astrocytes survival rate was increased (P<0.001), the number of apoptotic cells labeled with TUNEL was reduced (P<0.01), and the ratio of Bcl-2/Bax was increased (P<0.001). Conclusion: The apoptosis of astrocytes can be induced by HMGB1 after OGD/R, and the mechanism may be related to regulating the expression of apoptosis related proteins Bcl-2 and Bax.