An iron rheostat controls hematopoietic stem cell fate
Yun-Ruei Kao, Jiahao Chen, Rajni Kumari, Anita Ng, Aliona Zintiridou, Madhuri Tatiparthy, Yuhong Ma, Maria M. Aivalioti, Deeposree Moulik, Sriram Sundaravel, Daqian Sun, Julie A. Reisz, Juliane Grimm, Nuria Martínez-López, Stephanie Stransky, Simone Sidoli, Ulrich Steidl, Rajat Singh, Angelo D’Alessandro, Britta Will
Abstract
Mechanisms governing the maintenance of blood-producing hematopoietic stem and multipotent progenitor cells (HSPCs) are incompletely understood, particularly those regulating fate, ensuring long-term maintenance, and preventing aging-associated stem cell dysfunction. We uncovered a role for transitory free cytoplasmic iron as a rheostat for adult stem cell fate control. We found that HSPCs harbor comparatively small amounts of free iron and show the activation of a conserved molecular response to limited iron-particularly during mitosis. To study the functional and molecular consequences of iron restriction, we developed models allowing for transient iron bioavailability limitation and combined single-molecule RNA quantification, metabolomics, and single-cell transcriptomic analyses with functional studies. Our data reveal that the activation of the limited iron response triggers coordinated metabolic and epigenetic events, establishing stemness-conferring gene regulation. Notably, we find that aging-associated cytoplasmic iron loading reversibly attenuates iron-dependent cell fate control, explicating intervention strategies for dysfunctional aged stem cells.