The Study On Nano Neodymium Oxide Effect On Nerve System In Mouse And Apoptosis In PC12 Cells

Objective The ICR mice and rat adrenal chromaffin cells PC12 were chosen as the research objects to study the effect of nano neodymium oxide on apoptosis in rat chromaffin cells PC12 and nerve system in mouse in this experiment,and the biological effects and toxic effects of nano neodymium oxide on organisms were investigated on the cellular level and in vitro.Method?1?A total of 48 healthy famale ICR rats[about 20 g]were randomly divided into control group,low dose?1?g/m L?nano-particles?<100 nm?group and high dose?40?g/m L?nano-particles?<100 nm?group and low dose?1?g/m L?micro-particles?1?5?m?group.Normal saline,low dose nano-particles,high dose nano-particles and low dose micro-particles were driped respectively in the mice nasal cavity,a total of ten days,once every other day.After the second nasal instillation,water maze experiment navigation experiment were conducted for seven days,a unit one day.The space exploration experiments were done in the seventh day.?2?The PC12 cells were respectively treated with the nano neodymium oxide with final mass concentrations in 3.125,6.25,12.5,25,50,75?g/m L for 24 hours,control group was serum-free DMEM medium.CCK-8 method was used to detect the cell viability.The release of lactate dehydrogenase?LDH?in the culture supernatant,the content of malondialdehyde?MDA?,the levels of glutathione?GSH?and superoxide dismutase?SOD?in the cells were measured by enzyme-linked immunosorbent assay.the apoptosis rate of PC12 cells and the reactive oxygen species?ROS?content of PC12 cells were detected by flow cytometry.The expression of Bcl-2,Bax and Caspase-3 protein was detected by Western blot and the transcriptional level of Bcl-2,Bax and Casepase-3 m RNA in PC12 cells was detected by real-time fluorescence quantitative PCR and.Results?1?In mice intranasal behavioral experiments,different concentrations of nano-neodymium nanoparticles nasal instillation of mice,mice in each group from the first day to the seventh day escape latency showed a downward trend.On the second day of training,compared with the control group,mice in the high dose nano neodymium oxide had a shorter escape latency and had statistically significant?P<0.05?.Compared with the low dose nano neodymium oxide group,the target quadrant runs accounted for a higher percentage of total run?P<0.05?.?2?With the increase of Nano Nd₂O₃exposure dose,PC12 cell survival rate,GSH level and Bcl-2/Bax m RNA and protein ratios were decreased,MDA content and LDH release increased,all showed dose effect relationship?P<0.05?.Compared with the control group,the ROS content of PC12 cells in the Nano Nd₂O₃group was increased at12.5 and 25?g/m L,with significant differences?P<0.05?.The SOD activity of PC12 cells in group 12.5,25,50 and 75?g/m L Nano Nd₂O₃was lower than that of the control group?P<0.05?.Compared with the control group,the apoptosis rate of Nano Nd₂O₃group with different concentrations was significantly increased,and the difference was statistically significant?P<0.05?.Each dose group PC12 beta cell Caspase-3/?-actin ratio was higher than that of control group?P<0.05?.At 0?25?g/m L Nano Nd₂O₃dose range,with the increasing of Nano Nd₂O₃dose,Caspase-3/?-actin ratio of PC12 cells decreased in a dose effect relationship?P<0.05?.The Caspase-3 m RNA level ratio of PC12 cells in each dose group was higher than that of the control group?P<0.05?.With the increase of Nano Nd₂O₃exposure dose,the Caspase-3 m RNA level of PC12 cells fluctuated upward and downward without obvious dose-response relationship,while the Bcl-2 m RNA level of PC12 cells gradually increased,and Bax m RNA level gradually increased,showing a dose-response relationship.Conclusions?1?Nano neodymium drip on the nervous system in mice have a certain impact,high-dose nano neodymium oxide on mice had a slight stimulation to learning and memory in mice,but the dose effect and size effect were not obvious.?2?Nano Nd₂O₃can inhibit the proliferation of PC12 cells,resulting in the increase of ROS content,the decrease of SOD activity and GSH level,the increase of MDA content and LDH release in PC12 cells,Nano Nd₂O₃caused oxidative damage of PC12 cells.?3?Nano Nd₂O₃induced apoptosis of PC12 cells,which may be mediated by inhibiting the Bcl-2 transcription and translation level,promoting the transcription and the translation level of Bax,decreasing the ratio of Bcl-2/Bax m RNA and protein,activating the expression of Caspase-3 protein in PC12 cells,Initiating apoptosis in PC12cells.