PKM2在新生鼠缺血缺氧性脑病中的表达变化*

目的：观察新生鼠缺血缺氧性损伤后，丙酮酸激酶M2(pyruvate kinase M2, PKM2)在大脑皮层中的表达变化。方法：选取9 d SD新生鼠40只，按随机数字表法分为假手术组(10只)和缺血缺氧性脑病(hypoxic-ischemic encephalopathy, HIE)模型组(30只)。采用2,3,5-氯化三苯基四氮唑(2,3,5-triphenyltetrazolium chloride, TTC)染色法检查两组的脑组织梗死面积；Western Blot法检测PKM2在大脑皮层的表达水平变化；组织免疫荧光染色检测PKM2在大脑皮层中的定位；将原代神经元经缺氧缺糖(oxygen glucose deprivation, OGD)处理后，通过细胞免疫荧光染色检测PKM2的入核情况。结果：TTC染色结果显示，HIE模型组新生鼠的大脑右侧半球发生梗死；PKM2在大脑皮层的神经元中表达；在OGD刺激之后PKM2的表达在神经元中出现入核现象。结论：新生鼠在缺血缺氧损伤后，PKM2可能通过O-乙酰氨基葡萄糖糖基化对大脑皮层神经元的应激性过程起到一定作用。

Changes of PKM2 expression in hypoxic-ischemic encephalopathy neonatal rats*

Objective: To observe the expression of pyruvate kinase M2(PKM2) in cerebral cortex after hypoxic-ischemic injury in neonatal rats. Methods: Forty newborn SD mice were randomly divided into sham operation group(n=10) and hypoxic-ischemic encephalopathy(HIE) model group(n=30). The infarct size of brain tissue in the two groups was examined by (2,3,5-triphenyltetrazolium chloride, TTC) staining. The expression of PKM2 in cerebral cortex after hypoxia-ischemia in neonatal rats was by analyzed by Western Blot. Fluorescence immunohistochemistry was used to detect the location of PKM2 in brain tissue. The primary neurons were treated with oxygen glucose deprivation(OGD) and the PKM2 nuclear import was detected by fluorescence. Result: In the HIE model group, brain TTC staining of neonatal rats showed that the right hemisphere was infarcted. PKM2 was expressed in neuronal cytoplasm of the cerebral cortex, and expression of PKM2 appears in the neuronal cytoplasm and nucleus after ischemia and hypoxia stimulation. Conclusion: PKM2 may play a role in the stress process of cerebral cortical neurons through O-GlcNAcylation glycosylation after hypoxic-ischemic injury in neonatal rats.