Establishment A APP695^{V652I/K596N/M597L} Transgenic Mouse Model And The Analysis Of Pathological Phonotype

Alzheimer's disease(AD) is a common neurodegenerative disease, which is characterized clinically by a progressive loss of memory and cognitive impairment.Its main neuropathological features include accumulation of extracellular amyloid or senile plaques,diffuse loss of neurons in the hippocampus and neocortex,decrease of synapse density neurofibrillary tangles,excess phosphorylation of tau protein.For penetrating investigating the pathogenesis of AD,researchers have constructed a serial of animal models as research tool.The amyloid precursor protein takes a central position in AD pathogenesis:APP processing generates theβ-amyloid(Aβ) peptides,which are deposited as the amyloid plaques in brains of AD individuals;Point mutations and duplications of APP are causal for a subset of early onset of familial Alzheimer's disease.At present,There are a certain number of mutation APP mice models,such as PDAPP transgenic mice model,APP 23 transgenic mice model et al.However,most of these models have appeared the pathology and ethology changes after six months.We have constructed and established the APP695^{V652I/K596N/M597L} transgenic mice model of Alzheimer's disease.This kind of model can show up disorders earlier,elevate the utilization efficiency of model.The main works were included below.1.The construction of the London/Swedish hAPP mutation gene transgenic vector and the establishment of transgenic mice:The London/Swedish hAPP mutation transgenic vector was constructed by inserting the APP^{695V652I/K596N/M597L} gene into the downstream of PDGF promoter.The transgenic mice were generated for the APP^{695V6521/K596N/M597L} gene using microinjection method.2.Genotyping and pathological analysis:PCR was used to genotype the potential transgenic mice and 4 APP695^{V652I/K596N/M597L} founders were identified.The expression levels of the mutated gene were determined with the RT-PCR and Western blotting and 2 lines of APP695^{V652I/K596N/M597L} transgenic mice with high expression of the target gene were screened.The transgenic hAPP protein was localized in brain tissue immunohistochemistry.Compared with wild type mice and the APP695^V652I transgenic mice,more positive cells in the hippocampus was observed in the APP695^{V652I/K596N/M597L} brain.3.Behavioral test:The behavioral tests were examined by the water maze trials.We found that APP695^{V652I/K596N/M597L} transgenic mouse showed the longest average latency to find the hidden platform in the water maze than the APP695^V652I transgenic mouse and wild type mouse. APP695^{V652I/K596N/M597L} transgenic mouse have the less annulus crossing index than the other group in the probing test. Therefore,The APP695^{V652I/K596N/M597L} transgenic mouse showed the earlier pathological changes and spatial memory deficits compared with that of the APP695^V652I transgenic mouse and wild type mouse.It suggested that we have established an AD animal model successfully,and The APP695^{V652I/K596N/M597L} transgenic mouse is a useful AD animal model.