Mutant Human Apoe Transfer Genetic Mouse Models Of Disease And Gene Expression Of The Preliminary Study Of The Characteristics

Apolipoprotein E (apoE for the gene, APOE for the protein) is a 34-kDa glycoprotein associated with plasma lipoproteins, its role in peripheral lipid metabolism is well known. In humans, three allele of APOE, i.e. ε2, ε3 and ε4, exist at a single genetic locus. In contrast to other apolipoproteins, APOE is expressed ubiquitously in all tissues and appears to have a wide variety of functions in addition to lipid transport. Recently studies showed that apoE is a multifunctional molecule, with potential roles in cell growth, intracellular signaling, glucose metabolism, immune modulation, neuronal growth and repair, and other biological processes. Moreover, apoE4 has been identified as a major risk factor for Alzheimer's disease (AD). The inheritance of each dose of apoE4 increases the risk of AD and decreases the age of onset. The genetic association between the apoE4 isoform and the risk for AD has prompted interest in the study of apoE neurobiology and the relationship between lipoprotein metabolism in the brain and neurodegenerative disease.To establish an animal model of human disease and investigate the role of APOE in lipoprotein metabolism and Alzheimer's disease, the human apoE transgenic mice were generated via microinjection. This mouse models can be used to examine the efficacy and safety of novel treatment strategies to prevent or reduce CNS impairments as well.In first of all, we established inbreed transgenic stains of human mutant apoE and related disease models. Southern blot hybridization was used to identify the integration of the transgene. Two apoE4 founders and one apoE7 founder were detected from the newborn mice; the copy numbers were 1, 2, and 1 respectively. The founders of TgN(apoE4)2QiL and TgN(apoE7)3QiL were used to found the transgenic strains. We found the normal biological characteristics, such as the body weight etc., have no differences compared to the normal mice. The exogenous gene can be inherited stably in the transgenic mice and the inheritance pattern of the transgene was compatible with a single autosomal integration site.The result of the Northern blot hybridization showed that human apoE mRNA can be detected in the brain, kidney, heart and liver, but not in the spleen of F1 heterozygotes. Compared with the controls, serum cholesterol and triglyceride was also elevated (P<0.05). Behavior task test showed that the expressing of human apoE variants result in impairment in learning and memory abilities in transgenic mice, especially in apoE4 transgenic mice. The results demonstrated that the relativity between the plasma lipid levels and the impairment in learning and memory abilities is not obviously in human apoE inbred transgenic mice.Then we bred apoE4 hemizygous (+/-) transgenic mice to mice homozygous (+/+) for double mutants amyloid precursor protein (APPV717F) transgene that develop the bigenic mice with age-dependent AD neuropathology. We tested the serum lipids and the spontaneous alternation...