神经干细胞外泌体对低氧所致神经元凋亡的抑制作用

Neural stem cell-derived exosomes inhibit apoptosis of neurons induced by hypoxia neural cells

目的:初步探讨神经干细胞分泌的外泌体是否能抑制氯化钴(cobalt chloride,CoCl_2)诱导的缺氧模型中神经元的凋亡,并促进神经元的存活。方法:超速离心法分离大鼠神经干细胞分泌的外泌体;Western blot检测外泌体表面标志物ALG-2相互作用蛋白X(ALG-2-interacting protein X,Alix)和肿瘤易感基因101(tumor susceptibility gene 101,TSG101)的表达水平;用透射电子显微镜观察外泌体的形态;q Nano纳米生物颗粒分析仪检测外泌体的粒径分布。采用不同剂量的Co Cl_2处理神经元,建立CoCl_2诱导神经元凋亡的模型;将神经干细胞分泌的外泌体加入凋亡组神经元,CCK-8法检测细胞活力,TUNEL法检测细胞凋亡。结果:神经干细胞分泌的外泌体可表达Alix和TSG101;外泌体在透射电镜下的形态呈"杯口"状,大小约为100 nm;q Nano纳米生物颗粒分析仪检测外泌体的粒径为(95.0±23.5)nm(n=370);CCK-8实验结果显示不同浓度(200、400和600μmol/L)CoCl_2作用24 h,神经元活力呈剂量依赖性下降(P<0.05);将神经干细胞分泌的外泌体加入凋亡组(CoCl_2浓度为400μmol/L)神经元后,神经元活力升高(P<0.05),凋亡率下降(P<0.05)。结论:神经干细胞分泌的外泌体能抑制低氧状态下神经元的凋亡并促进存活。

AIM:To investigate whether neural stem cell-derived exosomes promote the viability and inhibit the apoptosis of neurons under cobalt chloride(CoCl 2)-induced hypoxia in vitro.METHODS:The exosomes were isolated based on ultracentrifugation.The exosomal markers,ALG-2-interacting protein X(Alix)and tumor susceptibility gene 101(TSG101)were identified by Western blot.The shape of exosomes was observed under transmission electron microscope(TEM).The size distributions of exosomes were analyzed by nanoparticle analysis(qNano).The neurons were exposed in CoCl 2 at different doses(200~600μmol/L)for 24 h.The exosomes were co-cultured with the neurons pre-treated with CoCl 2.The viability and apoptosis of the neurons were measured by CCK-8 assay and TUNEL method.RESULTS:The exosomes released from the neural stem cells expressed exosomal markers Alix and TSG101.They also displayed a cup-shaped appearance observed under TEM and their sizes were(95.0±23.5)nm(n=370).The neuronal viability was significantly inhibited by CoCl 2 in a dose-dependent manner(P<0.05).After treatment with exosomes,the viability of the neuron pre-treated with CoCl 2 was increased and the apoptotic rate was decreased(P<0.05).CONCLUSION:Neural stem cell-derived exosomes promote the viability and inhibit the apoptosis of rat neurons uneder hypoxia.