Transcriptome analysis of LT-HSC isolated from WT and CD169DTR/+ mice 5 days after a 2 Gy-Total Body Irradiation. Transcriptome analysis of LT-HSC isolated from WT and CD169DTR/+ mice 5 days after a 2 Gy-Total Body Irradiation

A 2 Gy-total body irradiation (TBI) of WT mice induces a second wave of ROS and a second wave of apoptosis in hematopoietic stem cells starting from 6 days after irradiation. In CD169DTR/+ mice, which are depleted in CD169+ resident macrophages after a diphtheria toxin injection, these two waves do not occur and a total recovery of the LT-HSC pool is observed, contrarily to the LT-HSC pool from WT mice, which is decreased. Our goal is to understand why these secondary waves of apoptosis and ROS occur in LT-HSC from irradiated WT mice and not in LT-HSC from irradiated mice depleted in resident macrophages, allowing a recovery of the LT-HSC pool. We used microarrays to compare the global gene expression in LT-HSC isolated from WT and CD169DTR/+ mice 5 days after irradiation, i.e. just before both secondary waves of ROS and apoptosis occurred in WT mice. Overall design: Two distinct experiments have been performed to obtain two replicates for each condition (i.e. for both mouse strains, irradiated or not).