尼氟灭酸对氯化钴诱导海马神经元凋亡的抑制作用

目的:探讨尼氟灭酸(NFA)对氯化钴(CoCl₂)诱导的海马神经元凋亡的抑制作用,阐明其可能的机制。方法:原代培养乳鼠海马细胞,并在倒置显微镜下观察海马细胞的形态变化。将海马神经元随机分为对照组(含1%血清培养液)、CoCl₂损伤组(含200 μmol·L^-1NFA等体积培养液)和不同浓度NFA组(在CoCl₂损伤组基础上加入20、40、80 μmol·L^-1 NFA)。MTT法检测各组海马神经元的存活率,流式细胞术分析海马神经元调亡率, ELISA法检测神经元培养液上清中相关凋亡蛋白Bcl-2、Bax、caspase-3和缺氧相关蛋白低氧诱导因子(HIF-1α)的表达水平。结果:海马神经元在培养7 d后形态规则,突触相互交织形成网络。MTT检测,与对照组比较,CoCl₂损伤组神经元存活率明显降低(P<0.01);与CoCl₂损伤组比较,20、40和80 μmol·L^-1NFA组神经元存活率升高(P<0.05或P<0.01)。流式细胞术检测,与对照组比较,CoCl₂损伤组神经元早期凋亡率、晚期凋亡率和总凋亡率升高(P<0.05或P<0.01);与CoCl₂损伤组比较,20、40和80 μmol·L^-1NFA组神经元早期凋亡率、晚期凋亡率及总凋亡率下降 (P<0.05或P<0.01)。ELISA法检测,与对照组比较,CoCl₂损伤组神经元培养液上清中HIF-1α、caspase-3 和Bax表达水平升高(P<0.01);与CoCl₂损伤组比较,20和40 μmol·L^-1 NFA组神经元培养上清中HIF-1α、caspace-3 和Bax表达水平下降,Bcl-2表达水平升高(P<0.05或P<0.01)。结论:NFA可以降低CoCl₂对海马神经元的缺氧损伤作用,其机制与抑制HIF-1α的表达、下调Bax/Bcl-2及抑制神经元凋亡有关联。

Inhibitory effects of niflumic acid on apoptosis induced by cobalt chloride in hippocampus neurons

Objective To explore the inhibitory effects of niflumic acid (NFA) on the apoptosis of hippocampal neurons induced by cobalt chloride (CoCl₂),and to elucidate the possible mechanisms. Methods The hippocampal neurons of rats were isolated and cultured,and inverted phase contrast microscope was used to observe the morphological changes of neurons.The hippocampal neurons were cultured and randomly divided into control group (1% serum medium),CoCl₂ injury group (200 μmol·L^-1 CoCl₂) and different concentrations(20,40,80 μmol·L^-1)of NFA groups.The survival rates of hippocampal neurons in various groups were measured by MTT assay.The apoptotic rates of hippocampal neurons were analyzed by flow cytometry.ELISA method was performed to observe the expression levels of apoptosis associated proteins Bax,Bcl-2,caspase-3 and hypoxia-inducible factor 1α (HIF-1α) in the supernatant of neurons. Results The hippocampal neurons showed regular shapes and the synapses reticulated after cultured for 7 d. Compared with control group,the survival rate of neurons in CoCl₂ injury group was decreased (P<0.01).Compared with CoCl₂ injury group,the survival rates of neurons in 20,40,and 80 μmol·L^-1 NFA groups were increased significantly (P<0.05 or P<0.01).The results of flow cytometry showed that compared with control group,the apoptotic rate in CoCl₂ injury group was increased (P<0.05);compared with CoCl₂ injury group,the apoptotic rates of neurons in 20,40,and 80 μmol·L^-1 NFA groups were decreased (P<0.05 or P<0.01).The ELISA results showed that the expression levels of HIF-1α,caspase-3,and Bax in the supernatant of neurons in CoCl₂ injury group were increased compared with control group(P<0.01);compared with CoCl₂ injury group,the expression levels of HIF-1α,caspase-3,and Bax in the supernatant of neurons in 20 and 40 μmol·L^-1 NFA groups were decreased,while the expression level of Bcl-2 was increased (P<0.05 or P<0.01). Conclusion NFA can protect the hippocampal neurons from hypoxia injury induced by CoCl₂,which may be related to suppressing the expression of HIF-1α,reducing the ratio of Bax/Bcl2 and suppressing the apoptosis of neurons.