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Objective: To uncover the time-dependent expression pattern of ptk2b gene and ptk2b-encoded protein, protein tyrosine kinase 2 beta(PTK2B), in the brain tissues of transgenic animal models of Alzheimer's disease (AD) and its relationship with the levels of Aβ1-42, phosphorylation of Tau (p-Tau) and low density lipoprotein receptor-related protein-1(LRP-1) in blood and brain tissues. Methods: In this study, 5-, 10- and 15-month-old APPswe/PS1dE9 double-transgenic mice harboring the genotype of AD confirmed by the gene test were divided into the 5-, 10- and 15-month-old experiment groups, and simultaneously, age-matched C57BL/6J mice were placed into the corresponding control groups, with 8 mice in each group. All mice were subjected to the Morris Water Maze for test of cognitive and behavioral ability. Expression profiles of PTK2B, Aβ1-42, p-Tau/Tau and LRP-1 in the hippocampus or blood of mice were quantified by using the immunohistochemistry staining, Western blot or enzyme-linked immunosorbent assay (ELISA), while the mRNA expression of ptk2b in the hippocampus was quantified by using the real-time quantitative polymerase chain reaction (qRT-PCR). Results: Results of experiment groups demonstrated that as mice aged, the expression levels of PTK2B, ptk2b mRNA, Aβ1-42 and p-Tau/Tau in the hippocampus were increased, and the expression of LRP-1 was decreased gradually. While in the blood, the level of Aβ1-42 was decreased, and the cognitive and behavioral ability was decreased in an age-dependent manner (all P＜ 0.05). However, comparisons among the control groups, only the age-dependent downregulation of LRP-1 were observed in hippocampus(P＜0.05), but other indicators had no significant differences (P＞0.05). Conclusion: In the hippocampus of APP/PS1 double-transgenic mice, the expressions of PTK2B, Aβ1-42 and p-Tau/Tau are upregulated, LRP-1 is downregulated, while cognitive and behavioral ability is decreased, and such changes are presented in a time-dependent manner.
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Animals , Mice , Alzheimer Disease/metabolism , Amyloid beta-Peptides , Amyloid beta-Protein Precursor/genetics , Focal Adhesion Kinase 2/metabolism , Hippocampus/metabolism , Low Density Lipoprotein Receptor-Related Protein-1 , Maze Learning , Mice, Inbred C57BL , Mice, Transgenic , RNA, MessengerABSTRACT
Aim To investigate the effect of methyl salicylate lactoside (MSL) on the spatial memory and learning of Alzheimer' s disease mice. Methods APP/PS1 double transgenic mice were used as AD animal model to evaluate behavioral changes by Morris water test. At the end of the experiment the brain tissues were fixed for assessment of A(3 deposition by immunohistochemistry, neuronal function changes by Nissl staining, neuronal morphological changes by transmission electron microscopy. Results The results showed that MSL could improve the spatial learning and memory abilitiesof AD mice by shortening latency time, prolonging time spent in target quadrant and increasing number of crossings of APP/PS1 mice. MSL could reduce partial Aβ deposition, alleviate the damage of nerve cells and improve the ultrastructural lesions of neuropil projections. Conclusion MSL could reduce Aβ deposition and protect neurons through anti-inflammatory effects, thus improving the learning and memory abilities of Alzheimer' s APP/PS1 transgenic mice.
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Aim To explore mechanism of epigallocatechin-3-gallate (EGCG) on alleviation of hippocampal neuronal autophagy in APP/PSI transgenic mice. Methods 8-month old APP/PSI transgenic mice were randomly divided into three groups;model group (Tg), EGCG low dose group (Tg/EGCG-L), high dose group (Tg/EGCG-H). C57BL/6J mice were utilized as control. Learning and memory were detected by Morris water maze test. The hippocampal ULK1, P62, LC3 I I / LC3 I,mT0R and Aß M2 expressions were detected by Western blot, immunohistochemical staining and ELISA. Results Compared with NT mice, Tg mice showed a marked prolongation of the escape latency in MWM test (P <0. 05). Decreased ULK1 expression and increased P62, LC3 II/LC3 I and A ßM 2 were detected (P < 0. 05). EGCG-treated group showed marked improvement of all these abnormal changes (P < 0. 05). Conclusions EGCG treatment is able to improve cognitive function, which may be attributed to ameliorated autophagic networks dysfunction and reduced Aß plaques in the the hippocampi of APP/PS1 transgenic mice.
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OBJECTIVE To explore the potential effect and mechanisms of protopanaxadiol deriva-tive 1-(3,4-dimethoxyphenethyl)-3-(3-dehydroxyl-20(s)-protopa- naxadiol-3b-yl)-urea (DDPU) in the treatment of Alzheimer disease.METHODS ELISA assay was performed in both HEK293-APPswe and CHO-APP cells to demonstrate the efficacy of DDPU in reducing Ab level.SH-SY5Y,primary neurons and astrocyte cellswereused to study the regulation of DDPU against the signaling pathways involved in Aβ/ER-stress pathology. APP/PS1 transgenic mice wereusedto study the regulation of DDPU against ADL and cognitive deficits. APP/PS1 transgenic mice were randomly placed into three groups (n=10):The two 6-month transgenic groups were administrated with 30 mg·kg-1DDPU or vehicle and the 6-month non-transgenic group was administrated with vehicle for 100 days by intraperitonealinjec-tion.After 100-day administration,nest construction assay and Morris water maze(MWM)assay were applied to evaluate the daily living activities and cognitive abilities of the mice with continuous DDPU treatment. Upon completion of behavior assays, mice were euthanized, and the brains were removed and bisected in mid-sagittal plane.The right hemispheres were frozen and stored at-80°C,and the left hemispheres were fixed in 4% paraformaldehyde. RESULTS DDPU effectively improved learning and memory impairments in APP/PS1 transgenic mice, and the underlying mechanisms have been inten-sively investigated. DDPU reduced Ab production by inhibiting the PERK/eIF2a signaling-mediated BACE1 translation, while promoted Ab clearance as a PI3K inhibitor thus negatively regulating PI3K/AKT/mTOR signaling in promotion of autophagy.Moreover,DDPU also exhibited neuroprotective effect by attenuating ER stress. Therefore, all findings have clearly demonstrated the crosstalk between Ab and ER stress, and confirmed that targeting ER stress should be a potential target for innovative anti-AD drug development,while highlighted the potential of DDPU in the treatment of AD.
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Objective To investigate the effects of Abnormal Phlegmatic Munziq on ability of learning and memory, and protein expressions of brain tissue RAGE and LRP1 of APP/PS1 transgenetic mice model of AD;To discuss its mechanism of action. Methods Three-month-old APP/PS1 transgenic mice were randomly divided into 5 groups: model control group, positive control group, Abnormal Phlegmatic Munziq high-, medium-, and low-dose groups, 18 mice in each group. Another 18 three-month-old C57BL/6J mice were chosen as normal control group. All administration groups received relevant medicine for successive 6 months. Then the changes in ability of learning and memory of mice were detected by Step-down test; protein expressions of LRP1 and RAGE were detected by immunohistochemistry and Western blot. Results Compared with the normal control group, the reaction time of learning grades and the mistake times increased, incubation of memory grades decreased and the mistake times increased in the model control group (P<0.01);Compared with the model control group, the reaction time of learning grades and the mistake times decreased, incubation of memory grades increased and the mistake times decreased in all administration groups (P<0.05, P<0.01). Immunohistochemistry and Western blot results showed that compared with normal control group, the LRP1 expression decreased and RAGE increased in the model control group (P<0.05);Compared with the model control group, the LRP1 expression decreased and RAGE increased in Abnormal Phlegmatic Munziq high-, medium-, and low-dose groups (P<0.05,P<0.01). Conclusion Abnormal Phlegmatic Munziq can improve ability of spatial learning and memory in APP/PS1 mice and regulate the expressions of RAGE and LRP1.
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AIM To explore the effects of Kaixin Powder (Polygalae Radix,Ginseng Radix et Rhizoma,Poria and Acori tatarinowii Rhizoma) on hippocampal long-term potentiation (LTP) in vivo in APP/PS1 transgenic mice and expression of PSD-95 in hippocampus CA1 area and cerebral cortex.METHODS Thirty-two 3-monthold male APP/PS1 mice were randomly divided into model group,Donepezil [0.75 mg/(kg · d)] group,Kaixin Powder [1.5,3 g/(kg · d)] groups.C57/BL6 mice were used as the control group.Kaixin Powder and Donepezil were administered to the APP/PS1 mice for three months,respectively.Afterwards,the LTP in vivo was recorded in a perforant pathway-dentate gyrus in the hippocampus.Immunohistochemical method was used for measuring the expression of PSD-95 in hippocampus CA1 area and cerebral cortex.RESULTS The fEPSPs slopes were significantly decreased in the model group as compared with the control group.Kaixin Powder or Donepezil treatment significantly enhanced the fEPSPs slopes in the model group.The average optical density of PSD-95 positive cells in hippocampus CA1 area and cerebral cortex was obviously decreased in the model group.Donepezil increased the average optical density of PSD-95 positive cells in hippocampus CA1 area.Kaixin Powder [1.5 g/(kg · d)] increased the average optical density of PSD-95 positive cells in hippocampus CA1 area and cerebral cortex.Kaixin Powder [3 g/(kg · d)] increased the average optical density of PSD-95 positive cells in cerebral cortex.CONCLUSION Kaixin Powder can promote the LTP formation in APP/PS1 transgenic mice and enhance synaptic plasticity,which may be related to the regulation of protein expression of PSD-95.
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Objective:The non targeted high-throughput urine metabolomics technology was used to study the pathogenesis of APP/PS 1 double transgenic mice and the mechanism of action of Gouteng san.Methods:5-month-old APP/PS 1 double transgenic mice were test with Morris water maze for spatial learning ability.Then we employed the non targeted high-throughput urine metabolomics technology to study the pathogenesis of APP/PS1 double transgenic mice based on the metabolic network.The focus investigation of the key pathways and the observation of the treatment by Morris water maze and metabolic level have been used after spatial learning ability damaged confirmed.Results:The comparison between APP/PS1 double transgenic mice and normal mice suggested that a significant longer was existed in former,which was call-back by Gouteng san.With the non targeted high-throughput urine metabolomics analysis and pathway focused analysis,we found certain signals from metabolic profiling,which was identified to be 6 biomarkers associated with learning and memory function by mass spectrometry analysis or authoritative database.Respectively,they were taurine,pteroylglutamic acid,neopterin,glutaurine,2-oxoglutarate and dihydroneopterin.They were mainly related to taurine metabolism and folate metabolism and represented an effective callback.Conclusion:Gouteng san possess a favorable effect on learning and memory ability of APP/PS1 double transgenic mice,6 biomarkers may be a potential target for the pathogenesis of APP/PSI double transgenic mice and provide experimental basis for the study of Gouteng san.
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Objective To study the effect of electroacupuncture on the behavior of APP/PS1 transgenic mice of different age, and to explore the optimal intervention time of electroacupuncture in treating Alzheimer's disease (AD). Method APP/PS1 double-transgenic mice of 4 months, 6 months and 9 months old, 20 in each age group, were randomized into a model group and an electroacupuncture group, and ten C57BL/6 wild-type mice were taken as a control group; after 6-week electroacupuncture treatment, the Morris water maze was adopted for spatial memory and behavioral test, and the changes of behavior in each group were observed.Result Of the 5-month-old mice, there were no significant between-group differences (P>0.05), while the time factor (day) produced a statistical significance (P<0.01); of the 7-month-old mice, there were significant differences considering the different groups, time factor and interaction (P<0.01); of the 10-month-old mice, there were significant differences considering the different groups, time factor and interaction (P<0.05). The spatial probe test showed that there were significant between-group differences in comparing the platform crossings and swimming distance in platform quadrant in each age group (P<0.05).Conclusion Electroacupuncture can improve the learning and memory of APP/PS1 double-transgenic mice, the age of 6-7 months old is possibly the optimal intervention time of electroacupuncture for AD, but there still requires further mechanism studies.
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Objective To investigate the distribution pattern of genome?wide CpG methylation in the animal model of APP/PS1 transgenic mice with Alzheimer′s disease(AD). Methods This study investigated the genome?wide DNA methylation profiles in the cortex tissues using methylat?ed DNA immunoprecipitation(MeDIP)combined with high?throughput sequencing. Results The analysis revealed 2 346 CpG sites existed only in AD mice,representing 485 unique genes as potentially associated with AD and these methylated DNA fragments distributed in different chromo?somes. Some hyper?methylated genes displayed familial aggregation. Conclusion There is significant difference in DNA methylation sites between APP/PS1 transgenic AD mice and corresponding wild mice,suggesting that DNA methylation may be involved in onset and development of AD.
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Objective To explore the relationship between the gait behavior changes and cognitive function in APP/PS1 transgenic mice .Methods 16 APP/PS1 transgenic mice were divided into model group and Huperzine A group, C57/BL6J mice with the same age were chosed as control group .After a 150 days consecutive treatment , Morris water maze(MWM) was used to detect the learning and memory ability and Gait analysis system (GAS-2) was used to detect the gait behavior after the treatment when the mice were 8-month-old.Results The escape latency of the model group was significantly higher than that of the control group ( P <0.05 ) , the time spended in the target quadrant , swimming distance in the target quadrant significantly lower than that of the control group ( P <0.05 ) , the first time passing through the platform prolonged significantly than the control group (P <0.05), and the number of passing though the platform reduced significantly than the control group (P <0.05).In the gait behavior experiments , compared with the control group, the average walking speed of the model group reduced significantly (P <0.05), the average walking cycle, the absolute average body angle and lateral movement increased significantly (P <0.05);The percentage of support time in a walking cycle of the left and right foot increased significantly (P <0.05).Accordingly, the percentage of swing time in a walking cycle of the left and right foot reduced significantly (P <0.05).The propulsion index of the left hand , right hand, right foot increased significantly ( P <0.05), and then the braking index of the above three feet decreased significantly ( P <0.05) .Huperzine A can improve the cognitive function , rectify the changes in the gait behavior .The two behavioral relevance shows that cognitive function and the front two feet braking , propulsion index have a high correlation index (correlation coefficients were -0.433, -0.379, P values were 0.039,0.079), the others were not. Conclusion APP/PS1 transgenic mice of 8-months-old have a remarkable impairment of learning and memory ability and disorder of gait behavior , and these two behaviors have a correlation in some extent .
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Aim To investigate whether EGCG treat-ment ameliorates cognitive deficits in APP/PS1 trans-genic mice and, whether it has the ameliorating effect of p75 NTR signaling to neuronal apoptosis in the hippo-campus of APP/PS1 mice. Methods Morris water maze test and locomotivity test were used to predict be-havioral changes; further TUNEL staining and Fluoro-Jade B staining were applied to confirm the neuronal apoptosis and neuronal degeneration;Western blot was employed to detect protein expression levels of p75 NTR signaling in the hippocampus of APP/PS1 mice. Re-sults EGCG treatment dramatically ameliorated the cognitive impairments, and inhibited the neuronal ap-optosis in the APP/PS1 mice. Moreover, EGCG treat-ment dramatically inhibited the p75 NTR signaling by de-creasing the p75ICD expression, JNK2 phosphorylation, and cleaved-caspase 3 expression. Conclusion EGCG treatment dramatically ameliorates the cognitive impairments, and inhibits the neuronal apoptosis by in-hibiting the p75NTR signaling.
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Objective To investigate the effects of partial hepatectomy on spatial learning and memory abilities and the expression of spinophilin,which was used as a marker to quantify changes in dendritic spine density in the hippocampus of APP/PS1 transgenic mice.Methods 3-month-old and 6-month-old male APP/PSI transgenic mice and 3-month-old wild-type male littermates were divided into five groups based on their genetic background:3-month-old control (group A,n =8),anesthesia (group B,n =32),surgery (group C,n =32),littermates control(group D,n =8),6-month-old control (group E,n =8).According to the different time points at day 1,3,7,14 after anesthesia or surgery,group B and C were divided randomly into 4 subgroups:B1,B3,B7,B14 and C1,C3,C7,C14.The spatial learning and memory abilities were detected by Morris water maze test in each group at the corresponding time points.Meanwhile,spinophilin expression was detected by Western blot and Immunocytochemistry in the hippocampus.Results Compared with the same time point subgroup B,the latency to find a hidden platform was longer and the frequency of passing through the platform was decreased in Group C at day 3,7,14(P ＜ 0.05).No significant differences were found among group A,group D,and group B (P ＞ 0.05).The grey value and Western blot relative integrated optical density of spinophilin in group A(1 609 453 ±92 801/0.471±0.015),approached the Group D(1 329 398.4±77 783/0.434±0.008)(P＞0.05),were significantly increased compared with that(801 678 ± 10 505/0.053 ± 0.003) in group E (P ＜ 0.01).Compared with the Group A,the same time point subgroup B and subgroup C14,the grey value and Western blot relative integrated optical density of spinophilin were decreased in Group C at day 1,3,7 (P ＜ 0.05).Conclusion Partial hepatectomy can impair spatial learning and memory abilities of the APP/PS1 transgenic mice,which is closely related to the decrease expression of spinophilin in hippocampus.