| 摘要: |
| 目的观察大鼠惊厥持续状态后海马中 Toll 样受体 4（TLR4）、NF-κB 和半胱氨酸蛋白酶 -3（caspase-3）的动态表 达及神经细胞凋亡的变化，探讨吡咯烷二硫代氨基甲酸盐（PDTC）对惊厥后脑损伤的可能保护机制。 方法 将 106 只 SD 大鼠随机 分为 0.9%氯化钠组（A 组）、SC 组（B 组）和 PDTC 组（C 组），B 组根据大鼠惊厥后处死时间（4、24、48 和 72h），分为 B1~B4 组，B 组和 C 组大鼠惊厥持续状态模型的制作采用氯化锂 - 匹罗卡品法，C 组在大鼠制模成功后，每天腹腔注射 PDTC（100mg/kg）1 次，连用 3d，于惊厥后 72h 处死。电镜观察海马超微结构改变；免疫组化法测定大鼠海马 NF-κB/p65 的表达；RT-PCR 法检测海马 TLR4、 caspase-3 mRNA 表达的动态变化；TUNEL 法检测神经细胞凋亡数的变化。 结果 B 组大鼠海马神经元超微结构损伤存在动态变 化，72h 内病变进行性加重；C 组大鼠病理改变较 B4 组减轻。B1~B4 组海马神经元胞核内有不同程度 NF-кB/p65 的表达，且较 A 组 明显升高（P＜0.05 或 0.01）。C 组较 B4 组 NF-κB/p65 表达明显下降（P＜0.01）。B1~B4 组 TLR4、caspase-3 mRNA 的表达量均高 于 A 组 （P＜0.05 或 0.01），且随时间延长逐渐升高，72h 达到高峰；C 组 TLR4、caspase-3 mRNA 的表达较 B4 组明显降低 （P＜ 0.05）。B 组在惊厥 24h 后海马 CA1 区 TUNEL 阳性细胞数已明显高于 A 组（P＜0.01），72h 达高峰，而 C 组 TUNEL 阳性细胞数较 B4 组明显下降（P＜0.01）。 结论 惊厥持续状态后大鼠海马 TLR4、NF-κB/p65 和 caspase-3 的表达增强。NF-κB 抑制剂 PDTC 可 以下调 TLR4 和 caspase-3 的表达，并使神经细胞凋亡减轻；提示 TLR4/NF-κB 信号通路在惊厥后海马细胞凋亡的发生、发展过程 中起促进作用。 |
| 关键词: 惊厥 凋亡 Toll 样受体 4 NF-κB 半胱氨酸蛋白酶 -3 吡咯烷二硫代氨基甲酸盐 |
| DOI： |
| 分类号: |
| 基金项目:浙江省中医药科学研究基金计划 |
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| Effects of PDTC on expression of Toll-like receptor 4, caspase-3 and neuron apoptosis in hippocampus of status convulsion rats |
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ZHOU Qin,ZHANG Qin,LI Guangqian,ZHOU Suya
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Zhejiang Provincial People’s Hospital
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| Abstract: |
| Objective To investigate the effects of pirrolidine dithiocarbamate (PDTC) on expression of TLR4, NF-кB, caspase-3 and the change of neuron apoptosis in hippocampus of status convulsion rats. Methods One hundred and six male Sprague-Dawley（SD）rats were randomly divided into control group (A), convulsion group (B) and PDTC group (C). then group B were randomly divided into four subset groups (B1-B4), which would be executed at 4h, 24h, 48h, 72h after convulsion discontinued. Continuous epilepticus was induced by injecting lithium chloride and pilocarpine, and rats in group C were daily injected with 100mg/kg PDTC 30 min after convulsion discontinued for 3 days. The histopathological changes in hippocampus were observed with electron microscope, NF-κB/p65 protein was detected by immunohistochemistry (IHC), the expression of TLR4 and caspase-3 mRNA was detected by RT-PCR. The neuron apoptosis was examined by TUNEL. Results Neuronal injury was observed in group B with electron microscope, and the change was increased gradually after seizure induced; neuronal injury in group C was milder than that in group B at 72h. IHC staining showed that more positive expression of NF-кB/p65 was observed in nuclei of hippocampal neurons in group B, compared with group A (P ＜0.05), and the protein expression of NF-кB/p65 in group C was much lower than that in group B4 (P＜0.01). The mRNA expression of TLR4 and caspase-3 in rat hippocampus of group B was significantly elevated than that in group A (P＜0.05); and the tendency was increased gradually reaching the peak at 72 h after seizure, and that in group C was much lower than that in B4 group (P＜0.01). The TUNEL positive cells in hippocampus CAl of groupB were more than those of group A at 24h after seizure (P＜0.01) reaching the peak at 72h; and the TUNEL positive cells in group C were lower than those in B4 group (P＜0.01). Conclusion The expression of TLR4, NF-кB and caspase-3 increased after SC in rats. PDTC can down-regulate the expression of TLR4 and caspase-3 and inhibit neuronal apoptosis in hippocampus of rats with pilocarpine-induced seizures．These results suggest that TLR4/NF-κB may have protec- tive effect on the development of the hippocampus apoptosis caused by status convulsion． |
| Key words: Convulsion Apoptosis Toll like receptor4 NF-κB Caspase-3 PDTC |
