Alcam-a and Pdgfr-α are essential for the development of sclerotome-derived stromal cells that support hematopoiesis

Emi Murayama (1, 2) , Catherine Vivier (1) , Anne Schmidt (3, 4) , Philippe Herbomel (1)

1 CNRS UMR3738 - Biologie du Développement et Cellules souches (Département)
2 INSERM - Institut National de la Santé et de la Recherche Médicale
3 Cellules Souches et Développement / Stem Cells and Development
4 Macrophages et Développement de l’Immunité

Abstract Mesenchymal stromal cells are essential components of hematopoietic stem and progenitor cell (HSPC) niches, regulating HSPC proliferation and fates. Their developmental origins are largely unknown. In zebrafish, we previously found that the stromal cells of the caudal hematopoietic tissue (CHT), a niche functionally homologous to the mammalian fetal liver, arise from the ventral part of caudal somites. We have now found that this ventral domain is the sclerotome, and that two markers of mammalian mesenchymal stem/stromal cells, Alcam and Pdgfr-α, are distinctively expressed there and instrumental for the emergence and migration of stromal cell progenitors, which in turn conditions the proper assembly of the vascular component of the CHT niche. Furthermore, we find that trunk somites are similarly dependent on Alcam and Pdgfr-α to produce mesenchymal cells that foster HSPC emergence from the aorta. Thus the sclerotome contributes essential stromal cells for each of the key steps of developmental hematopoiesis.

Domaines: Biologie du développement

Emi Murayama, Catherine Vivier, Anne Schmidt, Philippe Herbomel. Alcam-a and Pdgfr-α are essential for the development of sclerotome-derived stromal cells that support hematopoiesis. Nature Communications, 2023, 14 (1), pp.1171. ⟨10.1038/s41467-023-36612-y⟩. ⟨hal-04233146v2⟩