黃芪多糖對C17.2神經干細胞定向分化的調控作用

葉妮 馬金昀 程曉東

摘要 目的：觀察黃芪多糖（APS）對C17.2神經干細胞體外定向分化的調控作用。方法：建立C17.2神經干細胞的體外培養體系及分化模型，設置APS干預組及PBS對照組。誘導分化4 d后，通過細胞免疫熒光染色的方法檢測2組細胞中神經干細胞的標志性蛋白巢蛋白（Nestin）、星形膠質細胞的標志性蛋白膠質纖維酸性蛋白（GFAP）、少突膠質細胞的標志性蛋白髓鞘堿性蛋白（MBP）及神經元的標志性蛋白神經元特異性核心抗原（NeuN）的表達水平。結果：與PBS對照組比較，APS干預組細胞的Nestin及GFAP蛋白表達水平明顯下調，MBP及NeuN蛋白表達水平明顯上調，差異有統計學意義（P<0.05）。APS下調了分化模型中的細胞Nestin蛋白的表達水平;APS下調了GFAP蛋白的表達水平，上調了MBP及NeuN蛋白的表達水平。結論：APS可抑制C17.2神經干細胞向星形膠質細胞的定向分化，促進向少突膠質細胞及神經元的定向分化，APS可抑制C17.2神經干細胞的干性維持，促進其進入分化狀態，有可能成為治療神經退行性疾病的潛在藥物。

關鍵詞 神經干細胞;定向分化;黃芪多糖;少突膠質細胞;神經元;星形膠質細胞;神經退行性疾病;體外研究

Abstract Objective：To observe regulatory effects of Astragalus Polysaccharide（APS）on directional differentiation of C17.2 neural stem cells in vitro.Methods：Cultivation system and differentiation model of C17.2 neural stem cells were established in vitro.APS intervention group and PBS control group were set up.Immunofluorescence staining was used to detect expression levels of Nestin，GFAP，MBP and NeuN，the simbolic marker proteins of neural stem cells，astrocytes，oligodendrocytes and neurons，so as to explore the regulatory effects of APS on directional differentiation of C17.2 neural stem cells.Results：Compared with the PBS control group，the expression levels of Nestin and GFAP proteins in the APS intervention group were down-regulated while the expression levels of MBP and NeuN proteins were up-regulated.The differences were statistically significant（P<0.05）.APS down-regulated the expression level of Nestin protein in the differentiation model，which meant it could inhibit the stemness maintenance of C17.2 neural stem cells and lead them to enter the differentiation state.APS down-regulated the expression level of GFAP protein，and up-regulated the expression levels of MBP and NeuN proteins，which meant it could promote C17.2 neural stem cells to differentiate into oligodendrocytes and neurons directionally，and inhibit them to differentiate into astrocytes.Conclusion：APS can effectively regulate the directional differentiation of C17.2 neural stem cells in vitro，which suggests that it might be a potential drug for the treatment of neurodegenerative diseases.

Key Words Neural stem cells; Directional differentiation; Astragalus polysaccharides; Oligodendrocytes; Neurons; Astrocytes; Neurodegenerative diseases; Study in vitro

中圖分類號：R284 文獻標識碼：A doi：10.3969/j.issn.1673-7202.2019.10.012

神經干細胞（Neural Stem Cell，NSC）是指一類可以自我更新，主要分化為星形膠質細胞、少突膠質細胞及神經元細胞，廣泛存在于胚胎及成年哺乳動物的中樞神經系統中[1]。由于具有多向分化的潛能，神經干細胞自1992年發現以來便備受關注，有望成為治療神經退行性疾病（Neurodegenerative Diseases，ND）的種子細胞[2]。隨后的研究發現，在體外自然分化狀態下，神經干細胞絕大多數分化為星形膠質細胞，分化為神經元的比例次之，最小一部分分化為少突膠質細胞[3]。在ND的動物模型體內移植研究中也發現，移植的神經干細胞往往不能有效分化為目標細胞群[4]。因此，適當調控神經干細胞的定向分化，促進目標細胞的再生，或可成為治療ND的有效手段。……