局灶性脑缺血再灌注损伤对小鼠脑组织SUV39H1、H3K9及GFAP表达的影响

Effects of focal cerebral ischemia reperfusion injury on SUV39H1,H3K9 and GFAP expression in mouse brain tissue

目的探讨局灶性脑缺血再灌注损伤中病变区域组蛋白3赖氨酸9(H3K9)及其甲基化转移酶(SUV39H1)与星形胶质细胞活化标志物胶质纤维酸性蛋白(GFAP)的变化特点。方法选用C57BL/6小鼠作为实验对象,运用Koizumi法建立左侧大脑中动脉局灶性缺血再灌注小鼠模型(MCAO model),采用行为学、切片染色、qRT-PCR、相关分析、Western blot等方法,对比观察空白对照组、假手术组、脑缺血2 h再灌注24 h(实验组)小鼠大脑组织SUV39H1、H3K9及GFAP的表达情况。结果氯化三苯四氮唑(TTC)染色结果显示,与假手术组和空白对照组相比,实验组小鼠脑梗死面积明显增加、脑水肿明显。qRT-PCR及Western blot结果显示,与假手术组和空白对照组相比,实验组小鼠脑组织SUV39H1、H3K9及GFAP的表达明显增加(P<0.05)。结论局灶性脑缺血再灌注损伤的小鼠脑组织SUV39H1和H3K9的表达增加,同时GFAP的表达也显著增加,提示星形胶质细胞活化对局灶性缺血再灌注损伤的小鼠脑组织中SUV39H1和H3K9表达增加可能具有重要作用。

Objective To investigate the changes of histone 3 lysine 9(H3K9),methylated transferase(SUV39H1)and glial fibrin acidic protein(GFAP),an active marker of astrocytes,in focal cerebral ischemia reperfusion injury.Methods The left middle cerebral artery occlusion model(MCAO model)was established by Koizumi method in the C57BL/6 mouse model.The expressions of SUV39H1,H3K9 and GFAP in the cerebral ischemia reperfusion mice cerebral ischemia 2 h reperfusion 24 h group(the experimental group),the sham operation group and the blank control group were observed by behavioral analysis,slice staining,qRT-PCR,correlation analysis and Western blot.Results 2,3,5-triphenyltetrazolium chloride(TTC)staining showed that the cerebral infarct size of the experimental group was significantly higher than those of the sham operation group and the blank control group.The experimental group had obvious cerebral edema.qRT-PCR and Western blot showed that the expressions of SUV39H1,H3K9 and GFAP in focal cerebral ischemia-reperfusion group were significantly higher than those in the sham operation group and blank control group(P<0.05).Conclusion Focal cerebral ischemia reperfusion injury can stimulate the expression of SUV39H1 and H3K9.Meanwhile,the expression of GFAP also increases significantly.These results suggest that astrocyte activation may play an important role in increasing SUV39H1 and H3K9 expression in brain tissue of mice with focal ischemia reperfusion injury.