Effect Of Cattle Encephalon Glycoside And Ignotion Injection On PSD-95 Palmitoylation And Protective Associated Proteins In The Brain Of APP/PS1 Mice

Background Alzheimer's Disease(AD)is the most usual degenerative disease in central nervous system.The complex pathogenesis of AD mainly includes ?-amyloid protein(A?)deposition,the over-phosphorylation of Tau,oxidative stress and so on.Recent studies have shown that synaptic loss is one of the earliest markers of AD and anomaly synaptic plasticity proteins and their palmitoylation modification are closely related to the progression of AD.Postsynaptic density protein 95(PSD-95),a marker of synaptic function,is a key target of palmitoylation signaling pathway in the nervous system and its palmitoylation determines the function of PSD-95 and the pathological synaptic stability of AD.Glial fibrillary acidic protein(GFAP)is a sign of astrocytes and has a protective effect on neurons.Our previous studies have confirmed that Cattle Encephalon Glycoside and Ignotion Injection(CEGI),which is widely used in the clinical treatment of nerve injury,has a multitarget neuroprotective effect on AD model mice.At present,CEGI has not been reported to improve cognitive function by affecting PSD-95 palmitoylation.Objectives Applicate APP/PS1 mice to investigate the effort of CEGI on AD by behavioral detection,co-immunoprecipitation and immunohistochemistry and provide theoretical basis and new ideas for exploring its effective role in the clinical prevention and treatment of AD.Methods 1.Animal grouping and drug administration: 48 five months APP/PS1 double transgenic model mice and 12 age-matched normal C57BL/6J mice were divided into 5 groups(each group contains 12),respectively named normal control group(nTg group),model group(Tg group),Cattle Encephalon Glycoside and Ignotion Injection group(Tg+CEGI group),N-(tert-Butyl)hydroxylamine group(Tg + NtBuHA group)and Donepezil group(Tg+Donepezil),mice were correspondingly given normal saline,CEGI,NtBuHA,Donepezil for six weeks.2.Behavioral test: Morris water maze test was conducted conducted after drug administration.3.Cortex and hippocampus morphological analysis: After anesthesia,mice were given heart perfusion and brain tissues were taken.The left half of brain was used for histological examination.The expression of PSD-95,NR2 B,SYT1 were detected by immunofluorescence assay(IF),and the expressions of A?,GFAP and NeuN were detected by immunohistochemistry assay(IHC).4.Biochemical and molecular biological assays: The right half of brain was respectively used to detect palmitoylation level of PSD-95 by acyl-bioton exchange assay(ABE),the expression of SOD and MDA by chemical colorimetry biochemical detection and the level of A? by enzyme-linked immunosorbent assay(ELISA).Results 1.The mice showed no abnormalities during the feeding period,suggesting that the drugs had no significant toxic effects on APP/PS1 mice.By comparing the A? level in the frontal cortex of AD mice between nTg group and Tg group,it was confirmed that these model mice were successful and could be used for the experimental study.2.Morris water maze experiment showed that CEGI can increase the the target quadrant time of AD mice.3.CEGI can significantly reduce the palmitoylation level of PSD-95 in the cortex of AD mice.4.CEGI can obviously reduce the level of A? in the cortex of AD mice.5.CEGI can alleviate the synaptic damage in the cortex of AD mice and significantly increase the expression of PSD-95,NR2 B and SYT1.6.CEGI can decrease the expression of GFAP in the hippocampus and increase the expression of NeuN and in the cortex.In terms of oxidative stress,CEGI can increase the activity of SOD and decrease MDA level in the cortex of AD mice.Conclusions Our study found that the ability for spatial learning and memory of AD model mice were meaningfully improved after 6 weeks of continuous administration,indicating that CEGI has a certain therapeutic effect on AD,which may be related to the following aspects:1.CEGI inhibits the deposition of A? in the cortex of AD mice,thereby reducing the neurotoxicity of A?.2.The protective effect of CEGI on synapses may be related to the reduction of PSD-95 palmitoylation level and the improvement of synaptic related protein expression.3.CEGI can reduce the expression of GFAP and increase the level of NeuN and inhibit oxidative stress damage.