Further Proof for an Unpopular Concept: A Single Cell From Bone Marrow Can Serve as a Stem Cell for Both Hematopoiesis and Osteogenesis

Abstract

In science, unpopular concepts must be proven time and again. The article by Hofmann et al. in this issue of Molecular Therapy provides further proof for the unpopular idea that a single cell from bone marrow can serve as a stem cell for both hematopoiesis and osteogenesis.1 Moreover, Hofmann et al. establish that this single cell is actually an old friend: the long-term repopulating hematopoietic stem cell (LTR-HSC). These observations also suggest, but do not conclusively prove, the interesting idea that the same LTR-HSC can provide both the HSC and the microenvironmental niche required for the HSC to self-replicate and differentiate. Such a dual function can easily explain why an LTR-HSC is a long-term repopulating cell. The study provides new evidence for a refreshingly simple concept that probably should have occurred to us earlier.