Asrij/OCIAD1 expression delineates functionally distinct hematopoietic stem cells in the bone marrow.

Abstract

Hematopoietic stem cells (HSCs) within the bone marrow (BM) display significant molecular and functional heterogeneity. Deciphering intrinsic factors that govern HSC diversity is key to enriching specific HSC subtypes for predictable and clinically relevant differentiation outcomes. Here, we show that the mitochondrial protein Asrij/OCIAD1, a conserved regulator of hematopoietic homeostasis, contributes to HSC heterogeneity. Asrij depletion is known to cause loss of quiescence, myeloid bias and aging-like changes in mouse BM HSCs. Interestingly, Asrij expression is inherently heterogeneous and enriched in only 47% of the HSC population. To investigate whether Asrij expression levels influence HSC fate, we generated a novel Asrij-mNeonGreen knock-in reporter mouse using CRISPR-Cas9 technology. We show that the Asrij reporter faithfully recapitulates its heterogeneous expression in the BM HSCs, allowing isolation of live cells based on Asrij expression levels. Ex-vivo culture of HSCs demonstrated that Asrij