Comparision Of Methimetical Model Of Alzheimer Disease's Risk Factors And Study On Lentivirus-mediated ABCA7 Improves Neurocognitive Function In The Mouse Model Of Alzheimer's Disease

Part I: Comparision of Methimetical Model of Alzheimer Disease's Risk FactorsObjective: To explore the prevalence of Alzheimer's disease(AD).Secondly,to analyze the risk factors associated with AD prevalence.Finally,the multi-logistics regression model and back propagation artificial neural networks(BP-ANN)explores the differences between the risk factors of AD and the prediction of AD performance.Methods: The survey was conducted by random sampling of multi-stage stratified clusters.The first stage of sampling: the province's cities according to GDP randomly divided into high,medium and low three levels in the extraction of three cities,ranked as Nanchang,Jiujiang City and Ji'an City.The second stage of sampling: the city's districts and rural counties(including county-level city)as the unit,according to the county GDP is divided into high,medium and low three levels,each level in the city randomly selected a district and one County,each city of the six districts and counties,three cities were 9 neighborhood offices and 9 townships.From the selected each street office / township,randomly selected two neighborhood / village committee,a total of 36 neighborhood committees / village committees were selected.The fifth stage of Sampling: 172 people aged 60 and over were surveyed by the cluster sampling method from each selected neighborhood / village committee.A total of 300 non-AD participants and 300 AD patients were randomly selected in multi-logistics regression model and BP-ANN model.Multi-logistics regression model and BP-ANN model were compared and analyzed to explore the risk factors of AD.Results: 1.A total of 6058 participants were conducted from the survey.2859 males(48.38%)and 3051 females(51.62%)which counted in 5910 valid questionnaires were collected and the response rate was 97.56%.300 patients with AD were found to have a total prevalence of 5.08%.2.One factor analysis showed that in demographic characteristics dimensions: "age","marital status","occupation","education"," income" have detected statistically difference(p<0.05)on variable "whether the risk of AD",The "sex" variable did not detect the difference(p=0.164)."Social support and daily life habits" dimension: "smoking","history of adverse events","physical exercise","reads newspaper" in the variable "whether to suffer from AD" detected statistically Differences(p<0.05)."Drinking","social activity",?live alone" did not detect the statistically difference(p>0.05).In the previous history of disease history: only the "family history of dementia" variable detected a statistical difference(p=0.025),the remaining variables were not statistically significant(p>0.05).Biological indicators dimension: control group measured value is lower than the AD7C-NTP AD group(0.57 ± 0.45 Vs.1.53 ± 0.87;p<0.001);A?42 measured value AD group than in the control group(25.40 ± 5.87 Vs.39.81 ± 6.80;p<0.001);the A?40 of the control group was significantly higher than that of the AD group(157.84 ± 18.23 Vs.154.13 ± 17.97;p= 0.012).3.The results of multi-logistics regression model showed that the higher incident risk of AD in the 60 to 69 year old age group rather than in the 80-year-old age group(OR=5.17,95%CI 1.89~14.13);Cadres and intellectuals have a lower risk of AD compare to farmers and worker(OR = 0.23,95%CI 0.06 ~0.84).The higher the AD7C-NTP content in the urine associate with the higher incident risk of AD(OR=2.71,95%CI 1.64~ 4.46);The higher the level of A?42 in plasma,the higher the risk of AD in the elderly population(OR = 0.78,95% CI 0.64 ~ 4.46).4.BP-ANN model results shows the most sensitive biological indicators,where the weight of plasma A?42 levels weights of 0.3206,right urine AD7C-NTP content weight of 0.3160,followed by plasma A?40 share weight is 0.0940.In addition,marital status is the highest importance factor score,has a weight of 0.0413,followed by family history of dementia,a weight of 0.0386.5.Under the ROC curve,The Logistics regression model area 0.955(95%CI 0.939-0.971);the area of BP-ANN model is 0.930,(95%CI 0.907-0.953).Both models in predicting prevalence of AD have good predictive value.6.The accuracy of the multi-logistics regression model was 89.29%,which was slightly higher than that of BP-ANN model(88.81%).The sensitivity of the logistics regression model(88.57%)was slightly higher than that BP-ANN(84.76%).In the test set,the accuracy of the Logistics regression model is 91.11% lower than the accuracy of the BP-ANN model,and the sensitivity of the two models is 91.11%,while the specificity of BP-ANN model was 95.56% which was higher than the logistics regression model with a specificity of 91.11%.7.The Youden Index of multi-logistics regression model counts 0.817 which was higher than BP-ANN model of Youden Index 0.803.The multi-logistics regression model has a maximum tangent point of 0.615 and a BP-ANN model of 0.488.The sensitivity of the multi-logistics regression model calculated from the predicted model is 88.33%,which is higher than that the sensitivity of BP-ANN model(86.67%),the specificity is 93.33%,which is slightly lower than that of the BP-ANN model(93.67%).Conclusion: 1.The risk of AD in elderly people over 60 years old in Jiangxi Province were related to age,education level,smoking history,a history of adverse events,family history of dementia,marital status,reads newspaper,income,physical exercise or physical activity.Among them,older age,low education level,smoking,a history of adverse events and family history of dementia is a risk factor for AD sick;while married and the spouse alive,reads newspaper,high-income,physical exercise or physical activity is protective factor of AD.2.One factor analysis of biological indicators that the higher the concentration of AD7C-NTP in urine and the lower the content of A?42 protein in plasma associate with the higher the prevalence of AD in the elderly.There is no sufficient evidence to show that plasma A?40 levels are associated with the prevalence of AD in the elderly and we call for much more research explored further.3.Multivariate logistics regression model and BP-ANN model are all good predictors and diagnostic of AD disease.In this paper,the result of multivariate logistics regression model is almost the same as that of BP-ANN model.However,considering the inclusion factor and the complexity of AD disease,BP-ANN model is recommended.4.According to the survey results in this article suggest that we should pay more attention to the physical and mental health of the elderly,to strengthen the elderly mental activity exercise,as soon as possible to prevent the elderly suffering from AD.When the elderly have been suffering from AD,the best way to patients is accompany by their children or take professional care.In addition,caregiver needs communicate with patients frequently,and increase in outdoor exercise.Part II: Study on Lentivirus-Mediated ABCA7 Improves Neurocognitive Function in the Mouse Model of Alzheimer's DiseaseBackground: ATP-binding cassette transporter A7(ABCA7)is expressed in the hippocampus and cortex of the brain and was confirmed to be involved in the development of Alzheimer's disease(AD).Previous studies have demonstrated that ABCA7 regulated A? production,lipid transport,leading to AD characteristic pathological changes.However,the role and mechanism of ABCA7 in the context of AD needs further research.Method: Three days before establishment of Alzheimer's disease model,the lentiviral vectors carrying the ABCA7 gene and the control were injected into the mice in a similar way.Establishing the mouse models of Alzheimer's disease test mice(males 8±1 weeks)were obtained from Animal Center of Nanchang University.Forty C57BL/6 mice were randomly divided into two groups: control group(10 mice)and AD model group(30mice).Mice in the AD model group were given injection of A?1-42(Sigma-Aldrich),and those in the control group were given saline of the same volume.After the modeling,the model mice were divided into the AD group,the AD + LVABCA7 group,and the AD + LV-NC group in random and injected with corresponding lentiviral vector.Seven days later we conducted the Morris Water Maze Test.The supernatant after centrifugation,was used to detect the content of non-soluble A?40 and A?42.The detecting processes were referred to the appropriate instruction manual of the ELISA.Besides,we studied the ER stress related proteins expression in hippocampal areas in each mice group including ERK,p-ERK,elf2?,p-elf2?.Later,we examined the ABCA7 effects on neurons in vitro experiments.We promoted primitive neurons in the hippocampus cells in mice,and transfection with Sh-ABCA7 and examined the expression of A? and ER stress related protein.In addition,we examined the protection effects of ABCA7 on neuronal in vitro experiment.We counted a cell injury of neurons model using A?1-42 processing in vitro and transfection ABCA7 in A?+ ABCA7 group.We determined cell survival rate and the expression of endogenous A?40,A?42 by MTT method.Finally,we detected the apoptosis related proteins and the expression of ER stress related proteins.Results: 1.the learning and memory power of the mice was assayed by Morris water maze test.Escape latency of mice in each experimental group decreased with increasing training time.And,the escape latency of the AD group was higher than that of the normal mice,while that of the AD mice treated with AD + LV-ABCA7 was decreased compared with of the AD + LV-NC group.The distance traveled by the AD mice across the target platform was significantly lower than that by the normal mice.Compared with the AD + LV-NC group,the distance traveled by the AD + LV-ABCA7 mice across the target platform was significantly increased.2.The expressions of non-soluble A?42,A?40 and soluble A?42,A?40 in the hippocampus of AD mice were significantly higher than those of normal mice,while AD mice with over expressed ABCA7 could obviously reduce the expression of non-soluble A?42,A?40 and soluble A?42,A?40 compared with the AD + LV-NC group.The expression of ABCA7 was significantly increased in the hippocampus of AD+ AD + LV-ABCA7 mice and indicated that lentiviral vector of ABCA7 could be expressed effectively.In AD mice,the expression of caspase-3 was increased,and the Bcl-2/Bax ratio was significantly lower than that in normal mice.However,the expression of caspase-3 decreased and the Bcl-2/Bax ratio was significantly increased with ABCA7 over expression in AD mice.3.Results of western blot showed that the expressions of p-ERK1/2 and p-elf2? were significantly increased in AD mice.Over expression of ABCA7 in AD mice,the expressions of p-ERK1/2 and p-elf2? were significantly decreased.The amount of target protein was calculated by gray scanning,and we observed the ratio of p-ERK1/2/ERK1/2 and p-elf2?/ elf2?.Obviously,ABCA7 over expression decreased the high p-ERK1/2/ERK1/2 and p-elf2?/elf2? ratio in AD mice.4.Inhibition of ABCA7 expression significantly increased the content of A?40,A?42 in the cell culture medium.Knockdown of ABCA7 promoted the expression of CTF-?,CTF-?,p-ERK1/2,and p-elf2? in hippocampus neuron cells.Further analysis showed that the expressions of p-ERK1/2,p-elf2?,and CTF-?/? were significantly increased with the decrease of ABCA7.5.Hippocampus neuron cells were treated by 5 ?M A?1-42 and transfected with or without over expression vector of ABCA7.The results of MTT assay showed that A?1-42 could significantly reduce the cell viability,while ABCA7 over expression eliminated the inhibitory effect of A?1-42 on cell viability.Similarly,ABCA7 over expression also reduced the high expression of endogenous A?42 and A?40 induced by A?1-42.A?1-42 promoted the expression of cleaved-caspase-3,Bax,p-ERK1/2,p-elf2?,and CTF-?/? and reduced Bcl-2 in the cells.ABCA7 over expression obviously decreased the expression of cleaved-caspase-3,Bax,p-ERK1/2,p-elf2?,and CTF-?/? and increased Bcl-2 compared with A?1-42 treatment alone.The results of gray scanning further confirmed that the expression of cleaved-caspase-3,p-ERK1/2,p-elf2?,and CTF-?/? was increased and Bcl-2/Bax ratio was notably decreased with the A?1-42 treatment,and ABCA7 over expression obviously reversed the effect of A?1-42 on hippocampus neuron cells.Conclusion: This study found that ABCA7 over expression could effectively improve the cognitive function of mice and reduce the deposition of A?.At the same time,ABCA7's over expression significantly alleviated neurotoxicity,promoted cell vitality and impeded ER stress.Our findings showed that ABCA7 had obvious anti-A? effect and appeared to improve the cognitive function of AD mice.The study provides a new thought and basic scientific data for the clinical treatment of AD.