Division of Translational Brain Sciences, Department of Neurology, Duke University Medical Center, Durham, NC, USA.
Center for Genomic and Computational Biology, Duke University Medical Center, Durham, NC, USA.
J Alzheimers Dis. 2023;94(4):1563-1576. doi: 10.3233/JAD-230451.
The human chromosome 19q13.32 is a gene rich region and has been associated with multiple phenotypes, including late onset Alzheimer's disease (LOAD) and other age-related conditions.
Here we developed the first humanized mouse model that contains the entire TOMM40 and APOE genes with all intronic and intergenic sequences including the upstream and downstream regions. Thus, the mouse model carries the human TOMM40 and APOE genes and their intact regulatory sequences.
We generated the APOE-TOMM40 humanized mouse model in which the entire mouse region was replaced with the human (h)APOE-TOMM40 loci including their upstream and downstream flanking regulatory sequences using recombineering technologies. We then measured the expression of the human TOMM40 and APOE genes in the mice brain, liver, and spleen tissues using TaqMan based mRNA expression assays.
We investigated the effects of the '523' polyT genotype (S/S or VL/VL), sex, and age on the human TOMM40- and APOE-mRNAs expression levels using our new humanized mouse model. The analysis revealed tissue specific and shared effects of the '523' polyT genotype, sex, and age on the regulation of the human TOMM40 and APOE genes. Noteworthy, the regulatory effect of the '523' polyT genotype was observed for all studied organs.
The model offers new opportunities for basic science, translational, and preclinical drug discovery studies focused on the APOE genomic region in relation to LOAD and other conditions in adulthood.
人类染色体 19q13.32 是一个基因丰富的区域，与多种表型相关，包括晚发性阿尔茨海默病（LOAD）和其他与年龄相关的疾病。
本研究开发了第一个包含完整 TOMM40 和 APOE 基因及其所有内含子和基因间序列的人源化小鼠模型，包括上下游区域。因此，该小鼠模型携带人类 TOMM40 和 APOE 基因及其完整的调节序列。
我们使用重组技术将整个小鼠区域替换为包含其上下游侧翼调节序列的人类（h）APOE-TOMM40 基因座，从而生成 APOE-TOMM40 人源化小鼠模型。然后，我们使用 TaqMan 基于 mRNA 表达测定法测量了小鼠大脑、肝脏和脾脏组织中人类 TOMM40 和 APOE 基因的表达。
我们使用新的人源化小鼠模型研究了'523'多态性（S/S 或 VL/VL）、性别和年龄对人类 TOMM40 和 APOE-mRNAs 表达水平的影响。分析揭示了'523'多态性、性别和年龄对人类 TOMM40 和 APOE 基因调节的组织特异性和共同影响。值得注意的是，研究观察到'523'多态性对所有研究器官的调节作用。
该模型为基础科学、转化和临床前药物发现研究提供了新的机会，这些研究集中在 APOE 基因组区域与 LOAD 和成年期的其他疾病有关。
