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Impact of osteoblast maturation on their paracrine growth enhancing activity on cord blood progenitors
Author(s) -
Alsheikh Manal,
AbuKhader Ahmad,
Michalicka Matthew,
Pasha Roya,
Pineault Nicolas
Publication year - 2017
Publication title -
european journal of haematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.904
H-Index - 84
eISSN - 1600-0609
pISSN - 0902-4441
DOI - 10.1111/ejh.12865
Subject(s) - progenitor cell , haematopoiesis , paracrine signalling , microbiology and biotechnology , osteoblast , cord blood , myelopoiesis , stem cell , myeloid , biology , immunology , chemistry , in vitro , biochemistry , receptor
Background Osteoblasts possess strong growth modulatory activity on haematopoietic stem cells and progenitors. We sought to characterise the growth and differentiation modulatory activities of human osteoblasts at distinct stages of maturation on cord blood ( CB ) progenitors in the context of osteoblast conditioned medium ( OCM ). Methods OCM was produced from MSC ‐derived osteoblasts (M‐ OST ) at distinct stages of maturation. The growth modulatory activities of the OCM were tested on CB CD 34 + cells using different functional assays. Results OCM s raised the growth of CB cells and expansion of CD 34 + cells independently of the maturation status of M‐ OST . However, productions of immature CB cells including committed and multipotent progenitors were superior with OCM produced with immature osteoblasts. Osteogenic differentiation was accompanied by the upregulation of IGFBP ‐2 , by several members of the Angpt‐L family of growth factor, and by the Notch ligands Dll‐1 and Dll‐4 . However, the growth activity of OCM and the in vivo engraftment properties of OCM ‐expanded CB cells were retained after IGFBP ‐2 neutralisation. Similarly, OCM ‐mediated expansion of CB myeloid progenitors was largely independent of Notch signalling. Conclusions These results demonstrate that immature osteoblasts possess greater regulatory activity over haematopoietic progenitors, and that this activity is not entirely dependent on Notch signalling.