Dynamin-1和磷酸化dynamin-1在内侧颞叶癫癎患儿及大鼠海马组织中的表达

Expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with mesial temporal lobe epilepsy

摘要:

目的：观察内侧颞叶癫癎（mesial temporal lobe epilepsy, MTLE）患儿及MTLE大鼠海马组织中dynamin-1和磷酸化dynamin-1蛋白的表达变化，探讨其在MTLE发生发展中的作用。方法：25日龄Sprague-Dawley雄性大鼠随机分为急性期对照组、急性期模型组、潜伏期对照组、潜伏期模型组、慢性期对照组、慢性期模型组，应用氯化锂-匹罗卡品诱导建立MTLE动物模型。同时收集接受神经外科手术、并经病理结果确认存在海马硬化的5例患儿的海马组织，及病理科尸检4例对照组海马组织。提取海马组织蛋白，采用Western blot方法和免疫组织化学技术检测总dynamin-1蛋白及磷酸化dynamin-1蛋白在MTLE患儿及不同时间点MTLE大鼠海马组织中的表达变化。结果：Western blot显示磷酸化dynamin-1蛋白在MTLE大鼠急性期及慢性期表达较同时期对照组显著降低（P<0.05）；同时，磷酸化dynamin-1蛋白在MTLE患儿海马组织表达较对照组显著下降（P<0.05）。而dynamin-1总蛋白在MTLE大鼠各期、MTLE患儿及对照组海马之间表达无明显差异 （P>0.05）。免疫组化结果显示磷酸化dynamin-1在对照组大鼠急性期、慢性期、对照组患儿海马神经元胞浆中高表达，而在同时期MTLE大鼠和MTLE患儿海马神经元胞浆中表达下降（P<0.05）。结论：磷酸化dynamin-1而不是dynamin-1总蛋白在MTLE患儿及MTLE大鼠出现癎性发作期间表达下调，其表达变化提示dynamin-1可能通过磷酸化/去磷酸化方式参与MTLE的发生发展。

Abstract:

OBJECTIVE: To observe the expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with mesial temporal lobe epilepsy (MTLE) and to investigate the roles of dynamin-1 and phosphor-dynamin-1 in the development of MTLE. METHODS: Male Sprague-Dawley rats (aged 25 days) were randomly divided into acute control (AC), acute seizure (AS), latent control (LC), latent seizure (LS), chronic control (CC) and chronic spontaneous seizure (CS) groups. Lithium chloride-pilocarpine was used to induce a rat model of MTLE. The hippocampus samples of 5 children with a pathologically confirmed hippocampal sclerosis who received surgical operation were collected as a human model (HM) group, and the hippocampus samples of 4 dead children (without organic lesion of the hippocampus) were collected by autopsy as a human control (HC) group. The expression of dynamin-1 and phosphor-dynamin-1 in the hippocampus of children and rats with MTLE was measured by Western blot and immunohistochemistry. RESULTS: The Western blot showed that the expression of phosphor-dynamin-1 was significantly lower in the AS and CS groups than in the corresponding control groups (AC and CC groups) (P<0.05). The expression of phosphor-dynamin-1 was significantly lower in the HM group than in the HC group (P<0.05). There were no significant differences in the expression of dynamin-1 among the AS, LS and CS groups and between the HM and HC groups (P>0.05). The immunohistochemical results showed that phosphor-dynamin-1 was highly expressed in the cytoplasm of hippocampal neurons of AC, CC and HC groups, but its expression was significantly reduced in the AS, CS and HM groups (P<0.05). CONCLUSIONS: The expression of phosphor-dynamin-1, not dynamin-1, is downregulated in the hippocampus of children and rats with MTLE during seizures, which suggests that the phosphorylation/dephosphorylation of dynamin-1 may be involved in the development of MTLE.