The FDA approved drug granulocyte-colony stimulating factor (G-CSF) displays anti-apoptotic and immunomodulatory properties with neurogenesis and angiogenic functions. It is known to demonstrate neuroprotective mechanisms against ischemic global stroke. Autophagy is a method for the degradation of intracellular components and in particular, unrestrained autophagy may lead to uncontrolled digestion of affected neurons as well as neuronal death in cerebral ischemia. Mitochondrial dynamics is vital for the regulation of cell survival and death after cerebral ischemia and an early upstream event in neuronal death is mitochondrial fission. We examined the pro-survival mechanisms of G-CSF against apoptosis resulting from autophagy, mitochondrial stress and endoplasmic reticulum (ER) stress. Male Swiss Webster mice (20 weeks of age) were subjected to bilateral common carotid artery occlusion (BCAO) for 30 min. After occlusion, mice were injected with G-CSF (50 μg/kg) subcutaneously for 4 days. Behavioral analysis was carried out using the corner test and locomotor activity test before animals were sacrificed on day 4 or day 7. Key proteins in ER stress, autophagy and mitochondrial stress induced apoptosis were analyzed by immunoblotting. G-CSF improved neurological deficits and improved behavioral performance on corner and locomotor test. G-CSF binds to G-CSF receptors and its activation leads to upregulation of Akt phosphorylation (P-Akt) which in turn decreases levels of the ER stress sensor, GRP 78 and expression of proteins involved in ER stress apoptosis pathway; ATF6, ATF4, eIF2α, XBP1, Caspase 12 and CHOP. G-CSF treatment significantly decreased Beclin-1, an autophagy marker, and decreased mitochondrial stress biomarkers DRP1 and P53. G-CSF also up-regulated the mitochondrial fusion protein, OPA1 and anti-apoptotic protein Bcl-2 while down-regulating the pro-apoptotic proteins Bax, Bak and PUMA. G-CSF is an endogenous ligand in the CNS that has a dual activity that is beneficial both in reducing acute neuronal degeneration and adding to long-term plasticity after cerebral ischemia. G-CSF treatment exerts neuroprotective effects on damaged neurons through the suppression of the ER stress and mitochondrial stress and maintains cellular homeostasis by decreasing pro-apoptotic proteins and increasing of anti-apoptotic proteins.

中文翻译：

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粒细胞集落刺激因子（G-CSF）作为小鼠模型中风新疗法的作用模式

FDA 批准的药物粒细胞集落刺激因子 (G-CSF) 显示出抗细胞凋亡和免疫调节特性以及神经发生和血管生成功能。众所周知，它具有针对缺血性中风的神经保护机制。自噬是一种降解细胞内成分的方法，特别是，不受限制的自噬可能导致受影响神经元的不受控制的消化以及脑缺血时神经元的死亡。线粒体动力学对于脑缺血后细胞生存和死亡的调节至关重要，神经元死亡的早期上游事件是线粒体裂变。我们研究了 G-CSF 对抗自噬、线粒体应激和内质网 (ER) 应激引起的细胞凋亡的促生存机制。雄性瑞士韦氏小鼠（20 周龄）接受双侧颈总动脉闭塞 (BCAO) 30 分钟。封堵后，给小鼠皮下注射G-CSF (50 μg/kg)，持续4天。在第4天或第7天处死动物之前，使用角测试和运动活动测试进行行为分析。通过免疫印迹分析内质网应激、自噬和线粒体应激诱导的细胞凋亡中的关键蛋白。G-CSF 改善了神经缺陷并改善了角和运动测试中的行为表现。G-CSF 与 G-CSF 受体结合，其激活导致 Akt 磷酸化 (P-Akt) 上调，进而降低 ER 应激传感器 GRP 78 的水平以及参与 ER 应激凋亡途径的蛋白质表达；ATF6、ATF4、eIF2α、XBP1、Caspase 12 和 CHOP。G-CSF 治疗显着降低了自噬标记物 Beclin-1，并降低了线粒体应激生物标记物 DRP1 和 P53。G-CSF 还上调线粒体融合蛋白 OPA1 和抗凋亡蛋白 Bcl-2，同时下调促凋亡蛋白 Bax、Bak 和 PUMA。G-CSF 是 CNS 中的内源性配体，具有双重活性，既有利于减少急性神经元变性，又有利于增加脑缺血后的长期可塑性。G-CSF治疗通过抑制内质网应激和线粒体应激对受损神经元发挥神经保护作用，并通过减少促凋亡蛋白和增加抗凋亡蛋白来维持细胞稳态。