Transcriptomes of Neural Stem and Progenitor Cells from the subgranular zone (SGZ) of Wild Type (NTG) and 3xTg-AD mice at juvenile age

The goals of this study are to compare transcriptome profiling (RNA-seq) in wild-type (NTG) and 3xTg-AD mice, to determine the transcriptomal changes of neural stem and progenitor cells (NSPC) from the SGZ at early stages of Alzheimer's Disease in a mouse model. Methods: A tamoxifen (TAM)-inducible Nestin-CreERT2;ROSA26-EYFP reporter mouse line was cross-bred with NTG or 3xTG-AD mice to label NSPC upon TAM administration. YFP-positive NSPCs were sorted through FACS (Fluorescence-Activated Cell Sorting) 10 days after TAM from NTG; Nestin-CreERT2;ROSA26-EYFP and 3xTg-AD;Nestin-CreERT2;ROSA26-EYFP mice. RNA was extracted with RNeasy Micro Kit and deep-sequenced on the NovaSeq SP flowcell SR200 platform. The sequence reads of Fastq files that passed quality filters were aligned to the mouse genome (build mm10) using hisat2. Samtools was used to index the BAM files. DESeq2 was used to establish differential gene expression between NTG and 3xTg-AD samples. Results: We mapped about 48 million sequence reads per sample to the mouse genome (build mm10) and identified 1391 genes that were differentially expressed in the 3xTg-AD, with 720 down- and 671 up-regulated. Genes were considered significantly different between two genotypes if they meet the following criteria: 1) adjusted p-value < 0.05, and 2) log2 fold change > 0.5 or < -0.5. Conclusions: Gene ontology analysis of differentially expressed genes uncovered several pathways that may contribute to early neural stem cell decline in the 3xTg mice. Our results revealed very early perturbations in the SGZ neurogenic niche in the 3xTg mouse model of AD, manifested by intrinsic molecular changes in neural stem and progenitor cells (NSPC) at juvenile age, resulting in dysregulated neural stem cell homeostasis. mRNA profiles of FACS-sorted neural stem and progenitor cells (NSPC) from wild type (NTG) and 3xTg-AD mice at 5 weeks of old