PDF(Pubmed)
Abstract：
Neurogenesis is stimulated in the subventricular zone (SVZ) of mice with cortical brain injuries. In most of these injuries, newly generated neuroblasts attempt to migrate toward the injury, accumulating within the corpus callosum not reaching the perilesional area.
We use a murine model of mechanical cortical brain injury, in which we perform unilateral cortical injuries in the primary motor cortex of adult male mice. We study neurogenesis in the SVZ and perilesional area at 7 and 14 dpi as well as the expression and concentration of the signaling molecule transforming growth factor alpha (TGF-α) and its receptor the epidermal growth factor (EGFR). We use the EGFR inhibitor Afatinib to promote neurogenesis in brain injuries.
We show that microglial cells that emerge within the injured area and the SVZ in response to the injury express high levels of TGF-α leading to elevated concentrations of TGF-α in the cerebrospinal fluid. Thus, the number of neuroblasts in the SVZ increases in response to the injury, a large number of these neuroblasts remain immature and proliferate expressing the epidermal growth factor receptor (EGFR) and the proliferation marker Ki67. Restraining TGF-α release with a classical protein kinase C inhibitor reduces the number of these proliferative EGFR+ immature neuroblasts in the SVZ. In accordance, the inhibition of the TGF-α receptor, EGFR promotes migration of neuroblasts toward the injury leading to an elevated number of neuroblasts within the perilesional area.
Our results indicate that in response to an injury, microglial cells activated within the injury and the SVZ release TGF-α, activating the EGFR present in the neuroblasts membrane inducing their proliferation, delaying maturation and negatively regulating migration. The inactivation of this signaling pathway stimulates neuroblast migration toward the injury and enhances the quantity of neuroblasts within the injured area. These results suggest that these proteins may be used as target molecules to regenerate brain injuries.
We use a murine model of mechanical cortical brain injury, in which we perform unilateral cortical injuries in the primary motor cortex of adult male mice. We study neurogenesis in the SVZ and perilesional area at 7 and 14 dpi as well as the expression and concentration of the signaling molecule transforming growth factor alpha (TGF-α) and its receptor the epidermal growth factor (EGFR). We use the EGFR inhibitor Afatinib to promote neurogenesis in brain injuries.
We show that microglial cells that emerge within the injured area and the SVZ in response to the injury express high levels of TGF-α leading to elevated concentrations of TGF-α in the cerebrospinal fluid. Thus, the number of neuroblasts in the SVZ increases in response to the injury, a large number of these neuroblasts remain immature and proliferate expressing the epidermal growth factor receptor (EGFR) and the proliferation marker Ki67. Restraining TGF-α release with a classical protein kinase C inhibitor reduces the number of these proliferative EGFR+ immature neuroblasts in the SVZ. In accordance, the inhibition of the TGF-α receptor, EGFR promotes migration of neuroblasts toward the injury leading to an elevated number of neuroblasts within the perilesional area.
Our results indicate that in response to an injury, microglial cells activated within the injury and the SVZ release TGF-α, activating the EGFR present in the neuroblasts membrane inducing their proliferation, delaying maturation and negatively regulating migration. The inactivation of this signaling pathway stimulates neuroblast migration toward the injury and enhances the quantity of neuroblasts within the injured area. These results suggest that these proteins may be used as target molecules to regenerate brain injuries.
摘要：
背景：在皮质脑损伤小鼠的脑室下区（SVZ）刺激神经发生。在大多数这些伤害中，新产生的成神经细胞试图向损伤迁移，在call体内积聚，未到达周围区域。
方法：我们使用机械性皮质脑损伤的小鼠模型，其中我们对成年雄性小鼠的初级运动皮质进行单侧皮质损伤。我们研究了7和14dpi时SVZ和病灶周围区域的神经发生，以及信号分子转化生长因子α（TGF-α）及其受体表皮生长因子（EGFR）的表达和浓度。我们使用EGFR抑制剂Afatinib促进脑损伤中的神经发生。
结果：我们表明，在损伤区域和SVZ内出现的小胶质细胞表达高水平的TGF-α，导致脑脊液中TGF-α浓度升高。因此，SVZ中成神经细胞的数量增加以响应损伤，大量这些成神经细胞仍未成熟并增殖表达表皮生长因子受体（EGFR）和增殖标志物Ki67。用经典的蛋白激酶C抑制剂抑制TGF-α的释放会减少SVZ中这些增生性EGFR未成熟神经母细胞的数量。InAccording,TGF-α受体的抑制，EGFR促进成神经细胞向损伤的迁移,导致在病灶周围区域内的成神经细胞数量增加。
结论：我们的结果表明，在对损伤的反应中，损伤内激活的小胶质细胞和SVZ释放TGF-α，激活存在于神经母细胞膜中的EGFR，诱导它们的增殖，延迟成熟和负调节迁移。该信号通路的失活刺激神经母细胞向损伤的迁移，并增加受伤区域内神经母细胞的数量。这些结果表明，这些蛋白质可以用作再生脑损伤的靶分子。
方法：我们使用机械性皮质脑损伤的小鼠模型，其中我们对成年雄性小鼠的初级运动皮质进行单侧皮质损伤。我们研究了7和14dpi时SVZ和病灶周围区域的神经发生，以及信号分子转化生长因子α（TGF-α）及其受体表皮生长因子（EGFR）的表达和浓度。我们使用EGFR抑制剂Afatinib促进脑损伤中的神经发生。
结果：我们表明，在损伤区域和SVZ内出现的小胶质细胞表达高水平的TGF-α，导致脑脊液中TGF-α浓度升高。因此，SVZ中成神经细胞的数量增加以响应损伤，大量这些成神经细胞仍未成熟并增殖表达表皮生长因子受体（EGFR）和增殖标志物Ki67。用经典的蛋白激酶C抑制剂抑制TGF-α的释放会减少SVZ中这些增生性EGFR未成熟神经母细胞的数量。InAccording,TGF-α受体的抑制，EGFR促进成神经细胞向损伤的迁移,导致在病灶周围区域内的成神经细胞数量增加。
结论：我们的结果表明，在对损伤的反应中，损伤内激活的小胶质细胞和SVZ释放TGF-α，激活存在于神经母细胞膜中的EGFR，诱导它们的增殖，延迟成熟和负调节迁移。该信号通路的失活刺激神经母细胞向损伤的迁移，并增加受伤区域内神经母细胞的数量。这些结果表明，这些蛋白质可以用作再生脑损伤的靶分子。
