Liu Xian Shuang, Zhang Zheng Gang, Zhang Rui Lan, Gregg Sara R, Wang Lei, Yier Toh, Chopp Michael
Department of Neurology, Henry Ford Health Sciences Center, Detroit, Michigan, USA.
J Neurosci Res. 2007 Aug 1;85(10):2120-5. doi: 10.1002/jnr.21359.
Ischemic stroke stimulates neurogenesis in the adult rodent brain. The molecules that mediate stroke-induced neurogenesis have not been fully investigated. Using a microarray containing 113 known genes associated with angiogenesis, we analyzed transcriptional profiles in subventricular zone (SVZ) tissue and in cultured neural progenitor cells isolated from the SVZ of adult mice subjected to middle cerebral artery occlusion (MCAo). Among the genes most robustly up-regulated by MCAo were chemokine ligand 2 (CCL2) and chemokine ligand 10 (CXCL10). Consistent with the mRNA data, immunofluorescent staining revealed that MCAo substantially increased the number of CCL2-positive cells in the ipsilateral SVZ and that CCL2-positive cells were positive for both glial fibrillary acidic protein (GFAP) and nestin. In vitro studies showed that incubation of neural progenitor cells with recombinant human CCL2 substantially increased the number of Tuj1-positive cells dose dependently compared with the number in the control group, indicating that CCL2 promotes neuronal differentiation. Blockage of CCL2 with a neutralized antibody against CCL2 abolished the effects of CCL2 on neural progenitor cell migration and differentiation. Treatment of neural progenitor cells with CCL2 did not alter the number of BrdU cells and the number of apoptotic cells compared with those in the control group, suggesting that CCL2 does not affect neural progenitor cell proliferation and cell survival. These data demonstrate that in addition to its role in cell motility, CCL2 plays an important role in neuronal differentiation.
缺血性中风可刺激成年啮齿动物大脑中的神经发生。介导中风诱导神经发生的分子尚未得到充分研究。我们使用包含113个与血管生成相关的已知基因的微阵列，分析了成年小鼠大脑中动脉闭塞（MCAo）后室下区（SVZ）组织以及从SVZ分离的培养神经祖细胞中的转录谱。在MCAo最显著上调的基因中，有趋化因子配体2（CCL2）和趋化因子配体10（CXCL10）。与mRNA数据一致，免疫荧光染色显示MCAo显著增加了同侧SVZ中CCL2阳性细胞的数量，并且CCL2阳性细胞对胶质纤维酸性蛋白（GFAP）和巢蛋白均呈阳性。体外研究表明，与对照组相比，用重组人CCL2孵育神经祖细胞可剂量依赖性地显著增加Tuj1阳性细胞的数量，表明CCL2促进神经元分化。用针对CCL2的中和抗体阻断CCL2可消除CCL2对神经祖细胞迁移和分化的影响。与对照组相比，用CCL2处理神经祖细胞不会改变BrdU细胞数量和凋亡细胞数量，这表明CCL2不影响神经祖细胞增殖和细胞存活。这些数据表明，CCL2除了在细胞运动中发挥作用外，在神经元分化中也起着重要作用。
