Epigenetic and genetic changes during mouse hematopoietic stem cell aging [RNA-Seq]
To investigate the global transcriptome changes in mouse hematopoietic stem cell aging, we performed high-throughput sequencing of Poly A+ RNA (RNA-Seq) from purified 4 month, and 24 month-old HSCs (SP-KSL-CD150+). With biological duplicates, more than 200 million reads in total for each age of HSC were obtained.   Comparison of the young and old HSC transcriptomes revealed that 1,337 genes that were up-regulated, and 1,297 genes were down-regulated with HSC aging. The most highly represented upstream regulator was growth factor TGFB1, accounting for ~ 19% of differential gene expression in young versus old HSC (p-value = 1.96E-33). Gene ontology (GO) analyses indicated that up-regulated genes in 24mo HSCs are highly enriched in Regulation of Cell Adhesion, Regulation of Cell Proliferation and Ribosome, while down-regulated genes are enriched in DNA Base Excision Repair, DNA replication and Cell Cycle. RNA-seq also allowed us to examine alternative isoforms with aging including alternative splicing, promoter usage and pre-mRNA abundance. Overall design: Mouse hematopoietic stem cell mRNA profiles of 4 month and 24 month old WT mice were generated generated by deep sequencing, in duplicate, using Illumina Hiseq 2000