This current research was performed to investigate the role of typhae pollen polysaccharides (TPP) in hypoxia-treated PC12 cell which was an in vitro cell model of cerebral ischemia. Hypoxia-treated cells were treated with TPP for 12 h. Cell viability and apoptosis were detected by 3-(4,5-dimethylthiazol-2-yl)-2 5-diphenyl-2H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. Cell apoptotic proteins and PI3K/AKT and Ras/Raf/MEK/ERK signal pathway–associated proteins were also examined by western blot. Furthermore, abnormal expression of miR-34a and silent information regulator 1 (SIRT1) was achieved by transfection. Besides, the expression of miR-34a and SIRT1 was examined by quantitative real-time polymerase chain reaction (qRT-PCR). The expression of SIRT1 was detected by qRT-PCR and western blot. The relationship between miR-34a and SIRT1 was verified by luciferase assay. We found that TPP enhanced cell viability and inhibited apoptosis in hypoxia-treated PC12 cells. Moreover, TPP increased the accumulated levels of Bcl-2 while decreased expression of Bax, cleaved Caspase-3, and cleaved PARP. TPP downregulated miR-34a expression while induced by hypoxia. Further results showed that miR-34a overexpression reversed the results led by TPP in cell viability, apoptosis, and its related proteins. In addition, SIRT1 was upregulated by TPP and was verified to be a target of miR-34a. Silence of SIRT1 led to the opposite results led by TPP. In the end, TPP activated PI3K/AKT and Ras/Raf/MEK/ERK signal pathways. In conclusion, TPP plays important roles in regulating cell viability and apoptosis in hypoxia-treated PC12 cells via modulating miR-34a/SIRT1, as well as activating PI3K/AKT and Ras/Raf/MEK/ERK signal pathways.

本研究旨在研究香蒲花粉多糖 (TPP) 在缺氧处理的 PC12 细胞中的作用，PC12 细胞是脑缺血的体外细胞模型。缺氧处理的细胞用 TPP 处理 12 小时。分别通过 3-(4,5-二甲基噻唑-2-基)-2 5-二苯基-2H-溴化四唑 (MTT) 测定和流式细胞术检测细胞活力和细胞凋亡。还通过蛋白质印迹检查了细胞凋亡蛋白和 PI3K/AKT 和 Ras/Raf/MEK/ERK 信号通路相关蛋白。此外，通过转染实现了 miR-34a 和沉默信息调节因子 1（SIRT1）的异常表达。此外，通过定量实时聚合酶链反应（qRT-PCR）检测 miR-34a 和 SIRT1 的表达。通过qRT-PCR和蛋白质印迹检测SIRT1的表达。miR-34a 和 SIRT1 之间的关系通过荧光素酶测定验证。我们发现 TPP 增强了细胞活力并抑制了缺氧处理的 PC12 细胞的凋亡。此外，TPP 增加了 Bcl-2 的积累水平，同时降低了 Bax、裂解的 Caspase-3 和裂解的 PARP 的表达。TPP 在缺氧诱导下下调 miR-34a 的表达。进一步的结果表明，miR-34a 过表达逆转了 TPP 导致的细胞活力、细胞凋亡及其相关蛋白的结果。此外，SIRT1 被 TPP 上调并被证实是 miR-34a 的靶标。SIRT1 的沉默导致了 TPP 导致的相反结果。最后，TPP 激活了 PI3K/AKT 和 Ras/Raf/MEK/ERK 信号通路。综上所述，