17β雌二醇减轻凝血酶诱导的原代皮质神经元损伤及可能机制

The protectvie effects of 17 β-estradiol against thrombin -induced injury in primary cortical neuron cultures

目的：探讨17β雌二醇（ E 2）对凝血酶诱导的原代皮层神经元损伤的神经保护作用及可能机制。方法体外培养胎鼠大脑皮层神经元8天，将其分为对照组、凝血酶组、溶剂对照组〔凝血酶＋二甲基亚砜（ DMSO）〕、E 2预处理组（凝血酶＋E2）。用10 nmol／L E2或DMSO孵育原代皮层神经元24 h后，予1＆#215;10^5 U／L凝血酶处理24 h。监测各组乳酸脱氢酶（ LDH）释放量，并用流式细胞技术评估各组神经元损伤。采用Western blot法检测各组磷酸化jun氨基末端激酶（p－JNK）的激活和半胱氨酸天冬氨酸蛋白酶3（caspase－3）的表达。结果与对照组比较，凝血酶组的LDH释放增加，神经元凋亡增加，p－JNK的激活和caspase－3的表达增加，差异有统计学意义（P＜0．01）。与凝血酶组比较，E 2预处理组的LDH释放减少，神经元凋亡减少，p－JNK的激活和caspase－3的表达减少，差异有统计学意义（P ＜0．01）。结论 E2减轻凝血酶诱导的神经元损伤，其神经保护机制可能与其抑制p－JNK的激活和caspase－3的表达有关。

Objective To investigate the protective effects of 17β-estradiol on primary cortical neurons cultures a -gainst thrombin-induced injury and related mechanism. Methods Fetal rat cortical neurons were cultivated in vitro for eight days and then divided into a control group, a thrombin group, a solvent control group （ using thrombin and DMSO） and an E2 pre-treatment group （ using thrombin and E2 ） .Primary cortical neuron cultures were treated with 10 nmol/L E2 or DMSO for 24 h followed by exposure to 1 ＆#215;10^5 U/L thrombin for 24 h.The release of lactate dehydrogenase （ LDH） was measured, while neuronal apoptosis was examined by flow cytometry.The phosphorylation of c-Jun-N-terminal kinase （ p-JNK） and the expression of caspase-3 were determined by Western blotting.Results Compared with the control group, the thrombin group presented increases in the release of LDH and the amounts of p -JNK and caspase-3, as well as enhanced neuronal apoptosis （P〈0.01）. Compared with the thrombin group, E2 pre-treatment resulted in decreases in the release of LDH and the amounts of p-JNK and caspase-3, as well as weakened neuronal apoptosis （P〈0.01）.Conclusion E2 can relieve thrombin-induced neuronal injury, which may be associated with its abilities to block the activation of p-JNK and the expression of caspase-3.