Abstract
Self-renewal and differentiation of hematopoietic stem and progenitor cells (HSPCs) are carefully controlled by extrinsic and intrinsic factors, to ensure the lifelong process of hematopoiesis. Apurinic/apyrimidinic endonuclease 1 (APEX1) is a multifunctional protein implicated in DNA repair and transcriptional regulation. Although previous studies have emphasized the necessity of studying APEX1 in a lineage-specific context and its role in progenitor differentiation, no studies have assessed the role of APEX1, nor its two enzymatic domains, in supporting adult HSPC function. In this study, we demonstrated that complete loss of APEX1 from murine bone marrow HSPCs (induced by CRISPR/Cas9) caused severe hematopoietic failure following transplantation, as well as a HSPC expansion defect in culture conditions maintaining in vivo HSC functionality. Using specific inhibitors against either the nuclease or redox domains of APEX1 in combination with single cell transcriptomics (CITE-seq), we found that both APEX1 nuclease and redox domains are regulating mouse HSPCs, but through distinct underlying transcriptional changes. Inhibition of the APEX1 nuclease function resulted in loss of HSPCs accompanied by early activation of differentiation programs and enhanced lineage commitment. By contrast, inhibition of the APEX1 redox function significantly downregulated interferon-stimulated genes and regulons in expanding HSPCs and their progeny, resulting in dysfunctional megakaryocyte-biased HSPCs, as well as loss of monocytes and lymphoid progenitor cells. In conclusion, we demonstrate that APEX1 is a key regulator for adult regenerative hematopoiesis, and that the APEX1 nuclease and redox domains differently impact proliferating HSPCs. Graphical Abstract: [Figure not available: see fulltext.]
| Original language | English |
|---|---|
| Pages (from-to) | 2052-2072 |
| Number of pages | 21 |
| Journal | Stem Cell Reviews and Reports |
| Volume | 19 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - Aug 2023 |
Bibliographical note
Funding Information:This research was funded by the Research Foundation Flanders (FWO), Belgium (grants no. 11C3821N to S.Z, 1S33916N to J.D.S and G0E0117N to C.V.) and by EMBO (EMBO Short-Term Fellowship 7975 to S.Z. for collaborative research stay at Erasmus MC University in Rotterdam). J.A.M. obtained a grant from the Dutch Organization for Scientific Research (NWO-ALW) VICI (VI.C.182.025). J.H.G.L. and C.L. were fundedby the Gravitation program CancerGenomiCs.nl (NWO) and the Dutch Cancer Society.
Funding Information:
The authors thank the KU Leuven FACS Core, as well as the Bioimaging Core Leuven, VIB Flow Core Leuven, VIB Single Cell Core and VIB Nucleomics Core for support and access to the instruments. The authors also acknowledge Rob Van Rossom for his help with FACS sorts, Aidana Sheryazdanova and Anna Sablina for help with the nanocapillary immunoassay (WES), Anaïs Mestdagh and Olga Gielen for their support with transplantation experiments, Francheska Cadacio for her help with the sgRNA selection against Apex1 and Fatemeharefeh Nami for her help with the OFT amplicons. All the illustration including the visual abstract were created with BioRender.com.
Publisher Copyright:
© 2023, The Author(s).
