Hematopoietic stem cells (HSCs) balance self-renewal and differentiation to maintain hematopoietic fitness throughout life. In steady-state conditions, HSC exhaustion is prevented by the maintenance of most HSCs in a quiescent state, with cells entering the cell cycle only occasionally. HSC quiescence is regulated by retinoid and fatty-acid ligands of transcriptional factors of the nuclear retinoid X receptor (RXR) family. Here, we show that dual deficiency for hematopoietic RXRa and RXRb induces HSC exhaustion, myeloid cell/megakaryocyte differentiation, and myeloproliferative-like disease. RXRa and RXRb maintain HSC quiescence, survival, and chromatin compaction; moreover, transcriptome changes in RXRa;RXRb-deficient HSCs include premature acquisition of an aging-like HSC signature, MYC pathway upregulation, and RNA intron retention. Fitness loss and associated RNA transcriptome and splicing alterations in RXRa;RXRb-deficient HSCs are prevented by Myc haploinsufficiency. Our study reveals the critical importance of RXRs for the maintenance of HSC fitness and their protection from premature aging.
Read the full article here: https://pubmed.ncbi.nlm.nih.gov/36347014/
Dr. Cancelas is a member of the Cincinnati Children’s Hospital Center of Excellence in Hematology U54 DK126108.