Department of Neurology, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453000, P.R. China.
Department of Neurosurgery, The First Affiliated Hospital of Xinxiang Medical University, Xinxiang, Henan 453000, P.R. China.
Mol Med Rep. 2018 Nov;18(5):4328-4334. doi: 10.3892/mmr.2018.9425. Epub 2018 Aug 24.
The aim of the present study was to investigate the effect and mechanism of protein phosphatase 2A (PP2A) on the migration of astrocytes. The primary astrocytes of neonatal mice were isolated and cultured in vitro, and treated with the PP2A activator D‑erythro‑sphingosine (DES) (activated group) or inhibitor okadaic acid (inhibitory group). The control group was treated with equal amounts of dimethyl sulfoxide. The activity of PP2A in the cells was detected using a commercial kit and the migration of cells was investigated using a Transwell migration assay. The protein expression of p38, phosphorylated (p)‑p38, matrix metalloproteinase (MMP)‑2 and MMP‑9 was detected by western blotting. Cell migration and the protein expression of p38, p‑p38, MMP‑2 and MMP‑9 was also determined following treatment of astrocytes with the p38 signaling pathway inhibitor SB202190 with or without the PP2A activator DES. The results demonstrated that the activity of PP2A in the PP2A inhibitory group was significantly decreased compared with the control group, while that of the PP2A‑activated cells was significantly increased compared with the control. The protein levels of MMP‑2 and MMP‑9 in the PP2A inhibitory group astrocytes were significantly decreased compared with the control group, while PP2A‑activated astrocytes exhibited significantly increased levels of these proteins. By contrast, the p‑p38 level in PP2A inhibitory group astrocytes was significantly increased compared with the control group, while astrocytes in the activated group exhibited significantly lower levels compared with the control group. Furthermore, the cell migration ability, and MMP‑2 and MMP‑9 protein levels, of astrocytes that received combined treatment with SB202190 and the PP2A activator DES were significantly increased compared with the levels in astrocytes treated with SB202190 alone. The results of the current study indicate that PP2A may negatively regulate the p38 signaling pathway to promote astrocyte migration.
本研究旨在探讨蛋白磷酸酶 2A（PP2A）对星形胶质细胞迁移的作用及其机制。分离培养新生小鼠原代星形胶质细胞，分别用 PP2A 激活剂 D-erythro-赤藓糖醇（DES）（激活组）和抑制剂冈田酸（抑制组）处理，对照组用等体积二甲基亚砜处理。采用试剂盒检测细胞内 PP2A 的活性，Transwell 迁移实验检测细胞迁移。Western blot 检测 p38、磷酸化 p38（p-p38）、基质金属蛋白酶（MMP）-2 和 MMP-9 蛋白表达。用 p38 信号通路抑制剂 SB202190 处理星形胶质细胞，或用 SB202190 与 PP2A 激活剂 DES 联合处理星形胶质细胞，检测细胞迁移和 p38、p-p38、MMP-2 和 MMP-9 蛋白表达。结果显示，与对照组相比，抑制组 PP2A 活性显著降低，激活组细胞中 PP2A 活性显著升高。与对照组相比，抑制组星形胶质细胞中 MMP-2 和 MMP-9 蛋白水平显著降低，而激活组星形胶质细胞中 MMP-2 和 MMP-9 蛋白水平显著升高。相反，与对照组相比，抑制组星形胶质细胞中 p-p38 水平显著升高，而激活组星形胶质细胞中 p-p38 水平显著降低。此外，与单独用 SB202190 处理的星形胶质细胞相比，同时用 SB202190 和 PP2A 激活剂 DES 处理的星形胶质细胞的迁移能力、MMP-2 和 MMP-9 蛋白水平显著升高。本研究结果表明，PP2A 可能通过负调控 p38 信号通路促进星形胶质细胞迁移。
