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Absence of Bone Sialoprotein (BSP) Alters Profoundly Hematopoiesis and Upregulates Osteopontin
Author(s) -
Granito Renata neves,
Bouleftour Wafa,
Sabido Odile,
Lescale Chloé,
Thomas Mireille,
Aubin Jane E.,
Goodhardt Michèle,
Vico Laurence,
Malaval Luc
Publication year - 2015
Publication title -
journal of cellular physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.529
H-Index - 174
eISSN - 1097-4652
pISSN - 0021-9541
DOI - 10.1002/jcp.24877
Subject(s) - bone sialoprotein , osteopontin , haematopoiesis , bone marrow , microbiology and biotechnology , progenitor cell , chemistry , extracellular matrix , hematopoietic stem cell , biology , stem cell , immunology , biochemistry , osteocalcin , alkaline phosphatase , enzyme
Matrix proteins of the SIBLING family interact with bone cells, extracellular matrix and mineral and are thus in a key position to regulate the microenvironment of the bone tissue, including its hematopoietic component. In this respect, osteopontin (OPN) has been implicated in the hematopoietic stem cell (HSC) niche as negative regulator of the HSC function. We investigated the impact on hematopoietic regulation of the absence of the cognate bone sialoprotein (BSP). BSP knockout (−/−) mice display increased bone marrow cellularity, and an altered commitment of hematopoietic precursors to myeloid lineages, leading in particular to an increased frequency of monocyte/macrophage cells. The B cell pool is increased in −/− bone marrow, and its composition is shifted toward more mature lymphocyte stages. BSP‐null mice display a decreased HSC fraction among LSK cells and a higher percentage of more committed progenitors as compared to +/+. The fraction of proliferating LSK progenitors is higher in −/− mice, and after PTH treatment the mutant HSC pool is lower than in +/+. Strikingly, circulating levels of OPN as well as its expression in the bone tissue are much higher in the −/−. Thus, a BSP‐null bone microenvironment affects the hematopoietic system both quantitatively and qualitatively, in a manner in part opposite to the OPN knockout, suggesting that the effects might in part reflect the higher OPN expression in the absence of BSP. J. Cell. Physiol. 230: 1342–1351, 2015. © 2014 Wiley Periodicals, Inc., A Wiley Company