中性内肽酶高表达对β-淀粉样肽诱导的PC12细胞凋亡的保护作用

目的 确定中性内肽酶（NEP）高表达对β-淀粉样肽（AB）诱导的PC12细胞凋亡保护作用的分子机制。方法 利用脂质体转染法建立可稳定表达NEP和失活NEP的PC12细胞系。逆转录-聚合酶链反应（RT-PCR）法和免疫印迹法（Western blot法）检测基因在细胞中的表达。利用AB25-35诱导PC12细胞，CellTiter96AQueous单溶液检测系统（MTS）检测细胞存活率；分光光度法检测乳酸脱氢酶（LDH）含量、活性氧（ROS）生成量水平变化；化学发光法检测细胞三磷酸腺苷（ATP）生成量和Caspase-3表达量的变化。结果 在AB25-35诱导PC12细胞凋亡中，NEP高表达可明显提高细胞存活率，降低培养基中LDH含量和ROS生成量；提高细胞ATP释放量；抑制Caspase-3在细胞凋亡中的激活，与正常PC12细胞相比，差异均有统计学意义（P〈0．05）。稳定表达失活NEP的PC12细胞则对细胞凋亡没有影响。结论 NEP通过降低氧化应激反应对细胞线粒体的损伤，抑制凋亡关键蛋白Caspase-3的激活，从而提高AB25-35诱导的神经细胞的存活率。

Protective effect of NEP on Aβ-induced apoptosis in PC12 cells

OBJECTIVE: To identify the effect of NEP on Abeta -induced apoptosis in PC12 cells. METHODS: PC12 cells that stably express NEP is generated and the effect of NEP on the process of apoptosis induced by Abeta is analyzed, including the viability of the cells, the production of LDH, ROS and ATP, the activity of Caspase-3. RESULTS: NEP could improve the viability of cells and the production of ATP, inhibit the release of LDH and ROS. In the same time, the activity of caspase-3 descended (P < 0.05). But iNEP hadn't significant effect on cells apoptosis (P > 0.05). CONCLUSION: NEP has the protective effect on Abeta-induced apoptosis in PC12 cells.