中文摘要：

目的：探讨红景天苷诱导小鼠骨髓间充质干细胞marrow mesenchymal stem cells（MSCs）向神经元细胞定向分化的相关分子机制。方法：以MSCs（D1细胞）为对象,红景天苷作为诱导剂,运用流式细胞术、荧光免疫化学染色和Western blot方法分别检测红景天苷对细胞周期及Cyclin D1和p21蛋白表达的影响。结果：红景天苷诱导细胞24,48 h后,G0/G1期细胞比例升高,S期细胞比例下降,说明红景天苷能显著促进细胞发生G0/G1期阻滞;荧光免疫化学染色表明,对照组和诱导12-24 h后Cyclin D1为阳性表达,阳性细胞数为71%,71%和44%,而48-72 h组表达呈阴性;诱导12-72 h后p21呈阳性表达,阳性细胞数为85%,90%,65%和73%,与对照组相比差异显著（P〈0.01）;Western blot检测表明Cyclin D1表达量随诱导时间的延长下调,p21蛋白表达水平上调。结论：红景天苷通过影响细胞周期相关蛋白Cyclin D1和p21抑制细胞增殖,使MSCs阻滞于G0/G1期,进而促进MSCs定向分化。本试验为阐明红景天苷诱导MSCs定向分化的分子机制奠定了坚实的理论基础。

英文摘要：

Through studying the effects of salidrosides on cell cycle changes in MSCs to futher invesgate themolecular mechanism of cell directional differentiation. METHODS We chose Mouse Bone Marrow Mesenchymal Stem Cell line （D1 cell） asmeterial stimulated by salidrosides. The cell cycle （analysis） and related proteins such as Cyclin D1 and p21 were detected by flow cytometry, western blot and immunofluorescence （methods）. RESULTS After salidrosides stimulation for 24 and 48 hours, the number of cells in C-0/G1 phase was increased, but which in S phase was decreased. These results indicated that salidrosides could promote cell cycle arrest in G0/G1 phase. Immunofluorescence analysis suggested that the Cyclin D1 in control and 12 - 24 h after stimulation were expressed positively, the ratio of positive cells were 71 %,71 % and 44%, but 48- 72 h after stimulation were expressed negatively;The p21 was positively expressed after 12- 72 h stimulation, the ratio of ceils were 85 %, 90 %, 65 % and 73 % which were obviously diffierent from control （P〈0.01） ;Western blot results confirmed the expression of Cyclin D1 was down-regulated and the p21 expression was up-regulated along with the time prolonged. CONCLUSION Salidrosides could induce MSCs cell cycle arrest in G0/G1 phase through regulating the expression of Cyclin D1 and p21. The suppression effect on proliferation may lead to directional differentiation in MSCs.