海马神经元损伤及保护的纳米级三维构像变化研究

Three-dimensional nano-level morphological changes of hippocampal neurons either being damaged or protected

目的 观察海马神经元细胞表面形态的三维构像变化 ,探讨抑制p38MAPK信号通路对减轻红藻氨酸 (KA)毒性作用引起大鼠海马神经元所造成损伤的作用和机制。 方法 原代培养海马神经元给予SB2 0 35 80 (0 .2 μmol/L)预处理 ,30min后再予不同浓度 (0 ,2 5和2 5 0 μmol/L)红藻氨酸分别作用 10min和 10 0min ,利用原子力显微镜 (AFM)对胞膜表面结构进行纳米级水平扫描和观测。 结果 正常海马神经元表面光滑 ,起伏均匀、规律 ;红藻氨酸作用后神经元呈损伤性改变 ,表现为胞体肿胀 ,胞膜表面粗糙 ,出现“孔洞”样结构 ,并且其变化程度分别与作用时间和红藻氨酸浓度呈量 -效关系 ;预先给予SB2 0 35 80处理 ,以上变化有所减轻。 结论 抑制p38MAPK信号通路 ,对红藻氨酸诱导海马神经元胞膜的损伤起一定保护作用。

Objective To investigate the effect and mechanism of p38 MAPK inhibition in reducing the damage to rat's hippocampal neurons caused by kainic acid (KA) and observe the three-dimensional morphological changes on the cell surface. Methods The rat's hippocampal neurons cultured primarily for 10 days were pretreated with SB203580 (0.2 μmol/L, a p38 MAPK inhibitor). Thirty minutes later, the hippocampal neurons were administered with KA at concentrations of 0, 25 and 250 μmol/L for action for 10 and 100 minutes respectively. The cellular membrane structure was scanned and examined at nano-level by using atomic force microscope. Results Normal neurons displayed smooth membrane surface with homogeneous and regular undulation. In contrast, the neurons treated with KA showed coarse membrane surface with holes. Furthermore, the degree changes increased with the action time and the KA concentrations in a dose-effect dependent fashion. The above-mentioned changes were obviously mitigated by means of pretreatment with SB203580 (200 nmol/L). Conclusions Inhibition of p38 MAPK may, in certain degrees, protect the neurons against the impairments on cytomembrane resulted from the toxic effect of KA.