局灶脑缺血再灌注成年模型大鼠大脑髓鞘相关蛋白的基因表达

Gene expression of myelin associated protein in adult rats after focal cerebral ischemia and reperfusion

背景:髓鞘蛋白是少突胶质细胞的主要成分,研究脑缺血再灌注后大脑髓鞘相关蛋白基因表达的变化有助于探讨少突胶质前体细胞在缺血性脑损伤和修复中的作用。目的:观察脑缺血再灌注后成年模型大鼠大脑髓鞘蛋白相关基因,在脑缺血后不同时间及部位表达变化和差异。方法:以线栓法制作成年SD大鼠局灶性脑缺血再灌注模型,采用5′末端标记地高辛的寡核苷酸探针荧光原位核酸分子杂交检测模型大鼠再灌注后早期大脑梗死中心区、梗死周边区和梗死对侧区皮质髓鞘蛋白脂质蛋白mRNA、髓鞘碱性蛋白mRNA和髓鞘转录因子1mRNA表达变化。结果与结论:在梗死中心区,脑缺血再灌注后早期3种髓鞘相关蛋白基因表达均明显减少;在梗死周边区,再灌注后1d时3种髓鞘相关蛋白基因表达与对照组比较无明显变化,之后逐渐增加,至14d时均高于对照组(P<0.05,0.01),以髓鞘转录因子1mRNA阳性细胞数升高最早(7d)最为显著(P<0.01)。因此,成年SD大鼠脑缺血再灌注后急性期梗死周边区皮质髓鞘相关蛋白的基因表达增加,提示少突胶质前体细胞对脑缺血性损伤敏感,其可能参与了脑缺血后损伤的修复过程。

BACKGROUND： Myelin proteins are the main components in oligodendroglia cells. Research on gene expression changes of myelin related proteins after focal cerebral ischemia and reperfusion will help to understand the role of oligodendroglia cells in focal cerebral ischemia and reperfusion. OBJECTIVE： To explore the gene expression change of myelin related proteins in different cerebral regions and at different time points after focal cerebral ischemia and reperfusion in adult model rats. METHODS： Focal cerebral ischemia and reperfusion model in adult SD rats was constructed using suture method. The early phase mRNA expression changes of myelin proteolipid protein, myelin basic protein and myelin transcription factor 1 in the cerebral cortex regions of infraction center, infarction borders and contralateral area of infarction were detected by fluorescent in situ hybridization with the dig-labeled oligonucleotides. RESULTS AND CONCLUSION： The gene expression of the three myelin related proteins in infraction center decreased significantly in the early phase of focal cerebral ischemia and reperfusion. In infarction borders, there was no significant change in the gene expression of the three myelin related proteins between experiment group and control group on the 1~t day after focal cerebral ischemia and reperfusion. Then the gene expression of experiment group increased, and exceeded that of the control group on the 14th day after focal cerebral ischemia and reperfusion （P 〈 0.05, 0.01）; the content of myelin transcription factor 1 positive cells raised the earliest （P 〈 0.01）. The gene expression of cerebral cortex myelin related proteins in infarction borders increased after focal cerebral ischemia and reperfusion in adult SD rats. It indicates that oligodendrocyte precursors are sensitive to cerebral ischemic injury and may involve in the repairing process of cerebral post-ischemic injury.