苦瓜多糖通过 SIRT1/Β-连环蛋白轴调节脑缺血/再灌注后神经干细胞的分化。
Momordica charantia polysaccharides modulate the differentiation of neural stem cells via SIRT1/Β-catenin axis in cerebral ischemia/reperfusion.
机构信息
Research Center for Biochemistry and Molecular Biology and Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China.
School of Medical Technology, Xuzhou Medical University, Xuzhou, China.
出版信息
Stem Cell Res Ther. 2020 Nov 16;11(1):485. doi: 10.1186/s13287-020-02000-2.
BACKGROUND
Stroke is the leading cause of long-term motor disability and cognitive impairment. Recently, neurogenesis has become an attractive strategy for the chronic recovery of stroke. It is important to understand the molecular mechanism that promotes neural stem cell (NSC) neurogenesis for future NSC-based therapies. Our previous study showed that Momordica charantia polysaccharides (MCPs) exerted neuroprotective effects on stroke via their anti-oxidant and anti-inflammation activities. However, it remains unknown whether MCPs promote NSC neurogenesis after cerebral ischemic/reperfusion injury (IRI).
METHODS
We investigated MCPs' function in differentiation of neural stem cells (NSCs) in vivo and in vitro experiments. Based on a middle cerebral artery occlusion (MCAO) rat model, the effect of MCPs on neuronal differentiation after MCAO was analyzed. Primary NSCs and neural stem cell line C17.2 were cultured and subjected to glutamate stimulation to establish the cell model of IRI. We evaluated the effect of MCPs on NSC differentiation in IRI cell model by Western blot and immunofluorescence staining. The SIRT1 activity of NSCs post glutamate stimulation was also evaluated by CELL SIRT1 COLORIMETRY ASSAY KIT. In addition, molecular mechanism was clarified by employing the activator and inhibitor of SIRT1.
RESULTS
MCPs had no effects on the differentiation of neural stem cells under physiological conditions while shifted NSC differentiation potential from the gliogenic to neurogenic lineage under pathological conditions. Activation of SIRT1 with MCPs was responsible for the neuronal differentiation of C17.2-NSCs. The neuronal differentiation effect of MCPs was attributed to upregulation SIRT1-mediated deacetylation of β-catenin. MCP-induced deacetylation via SIRT1 promoted nuclear accumulation of β-catenin in NSCs.
CONCLUSION
Our findings indicate that the deacetylation of β-catenin by SIRT1 represents a critical mechanism of action of MCPs in promoting NSC neuronal differentiation. It provides an improved understanding of molecular mechanism underlying neuroprotective effects of MCPs in IRI, indicating its potential role on treating ischemic stroke especially chronic recovery.
背景
中风是长期运动障碍和认知障碍的主要原因。最近，神经发生已成为中风慢性恢复的一种有吸引力的策略。了解促进神经干细胞（NSC）神经发生的分子机制对于未来基于 NSC 的治疗方法很重要。我们之前的研究表明，苦瓜多糖（MCPs）通过其抗氧化和抗炎作用对中风发挥神经保护作用。然而，目前尚不清楚 MCPs 是否会在脑缺血/再灌注损伤（IRI）后促进 NSC 神经发生。
方法
我们在体内和体外实验中研究了 MCPs 对神经干细胞（NSCs）分化的功能。基于大脑中动脉闭塞（MCAO）大鼠模型，分析了 MCPs 对 MCAO 后神经元分化的影响。培养原代 NSCs 和神经干细胞系 C17.2，并进行谷氨酸刺激以建立 IRI 细胞模型。我们通过 Western blot 和免疫荧光染色评估 MCPs 在 IRI 细胞模型中对 NSC 分化的影响。还通过 CELL SIRT1 COLORIMETRY ASSAY KIT 评估谷氨酸刺激后 NSCs 中 SIRT1 的活性。此外，通过 SIRT1 的激活剂和抑制剂阐明了分子机制。
结果
MCPs 在生理条件下对神经干细胞的分化没有影响，而在病理条件下将 NSC 分化潜能从神经胶质向神经发生转变。用 MCPs 激活 SIRT1 负责 C17.2-NSCs 的神经元分化。MCPs 的神经元分化作用归因于 SIRT1 介导的β-连环蛋白去乙酰化的上调。MCP 通过 SIRT1 诱导的去乙酰化促进 NSCs 中β-连环蛋白的核积累。
结论
我们的研究结果表明，SIRT1 介导的β-连环蛋白去乙酰化是 MCPs 促进 NSC 神经元分化的关键作用机制。它提供了对 MCPs 在 IRI 中神经保护作用的分子机制的深入了解，表明其在治疗缺血性中风，特别是慢性恢复期的潜在作用。
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