Pinin (Pnn), a multifunctional protein, participates in embryonic development as well as in cellular apoptosis, proliferation, and migration through regulating mRNA alternative splicing and gene transcription. Previous studies have shown that Pnn plays important roles in neural system development and the expression level of Pnn in astrocytes is altered by ischemic stress and associated with cellular apoptosis. In the present study, we further utilized primary cultured rat neurons and astrocytes with oxygen-glucose deprivation (OGD) and a mouse model with middle cerebral artery occlusion (MCAO)-induced ischemic stroke to examine the effect of ischemic stress on Pnn expression and distribution in different types of neural cells. Under normoxia, Pnn is mainly localized in the nuclear speckle of primary cultured neurons. The expression level of Pnn was increased after the OGD treatment and then decreased in the reoxygenation period. Moreover, the cytoplasmic expression of Pnn was observed in neurons with OGD and reoxygenation (OGD/R). Unlike that in neurons, the Pnn expression in astrocytes was decreased after OGD treatment and then gradually increased during the reoxygenation period. Of interest, the nuclear–cytoplasmic translocation of Pnn was not observed in astrocytes with OGD/R. In the MCAO mouse model, the neuronal expression of Pnn in the peri-ischemic region was reduced by three days post induction of ischemic stroke. However, the Pnn expression in astrocytes was not altered. Moreover, the nuclear speckle distribution of Pnn in neurons was also diminished following ischemic stroke. In conclusion, the Pnn expression and distribution after OGD and during reoxygenation showed distinct manners in neurons and astrocytes, implying that Pnn may play different roles in different types of neural cells in the stress response to ischemic injury.

中文翻译：

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缺氧-葡萄糖剥夺后缺血性大脑皮层和神经细胞中Pnn的表达和分布模式

Pinin（Pnn）是一种多功能蛋白，通过调节mRNA的可变剪接和基因转录，参与胚胎发育以及细胞凋亡，增殖和迁移。先前的研究表明，Pnn在神经系统发育中起着重要作用，并且缺血应激会改变星形胶质细胞中Pnn的表达水平，并与细胞凋亡相关。在本研究中，我们进一步利用具有氧葡萄糖剥夺（OGD）的原代培养大鼠神经元和星形胶质细胞以及具有大脑中动脉闭塞（MCAO）诱导的缺血性中风的小鼠模型来研究缺血应激对Pnn表达和分布的影响在不同类型的神经细胞中。在常氧下，Pnn主要位于原代培养神经元的核斑中。在OGD处理后，Pnn的表达水平升高，然后在复氧期间降低。此外，在具有OGD和复氧（OGD / R）的神经元中观察到Pnn的胞质表达。与神经元中的神经元不同，在OGD处理后，星形胶质细胞中Pnn的表达降低，然后在复氧期间逐渐增加。有趣的是，在具有OGD / R的星形胶质细胞中未观察到Pnn的核质转移。在MCAO小鼠模型中，缺血性脑卒中诱发后三天，周围缺血区域Pnn的神经元表达减少。但是，星形胶质细胞中的Pnn表达没有改变。此外，缺血性中风后神经元中Pnn的核斑点分布也减少。结论，