title: Pharmacologic modulation of the calcium-sensing receptor enhances hematopoietic stem cell lodgment in the adult bone marrow.
abstract: The ability of hematopoietic stem cells (HSCs) to undergo self-renewal is partly regulated by external signals originating from the stem cell niche. Our previous studies with HSCs obtained from fetal liver of mice deficient for the calcium-sensing receptor (CaR) have shown the crucial role of this receptor in HSC lodgment and engraftment in the bone marrow (BM) endosteal niche. Using a CaR agonist, Cinacalcet, we assessed the effects of stimulating the CaR on the function of murine HSCs. Our results show that CaR stimulation increases primitive hematopoietic cell activity in vitro, including growth in stromal cell cocultures, adhesion to extracellular matrix molecules such as collagen I and fibronectin, and migration toward the chemotactic stimulus, stromal cell-derived factor 1α. Receptor stimulation also led to augmented in vivo homing, CXCR4-mediated lodgment at the endosteal niche, and engraftment capabilities. These mechanisms by which stimulating the CaR dictates preferential localization of HSCs in the BM endosteal niche provide additional insights into the fundamental interrelationship between the stem cell and its niche. These studies also have implications in the area of clinical stem cell transplantation, where ex vivo modulation of the CaR may be envisioned as a strategy to enhance HSC engraftment in the BM.
authors.affiliation: Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Keck School of Medicine, University of Southern California, Los Angeles, CA.
authors.forename: Ben S
authors.initials: BS
authors.lastname: Lam
authors.forename: Cynthia
authors.initials: C
authors.lastname: Cunningham
authors.forename: Gregor B
authors.initials: GB
authors.lastname: Adams
mesh_terms: D000367:Age Factors; D000818:Animals; D001853:Bone Marrow / Q000187:drug effects* / Q000378:metabolism; D002454:Cell Differentiation / Q000187:drug effects / Q000276:immunology; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D002478:Cells, Cultured; D000069449:Cinacalcet; D018380:Hematopoietic Stem Cell Transplantation / Q000379:methods; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D009281:Naphthalenes / Q000494:pharmacology*; D044169:Receptors, Calcium-Sensing / Q000819:agonists* / Q000378:metabolism; D055153:Stem Cell Niche / Q000166:cytology / Q000187:drug effects*; D019172:Transplantation Conditioning / Q000379:methods
chemical_list: D009281:Naphthalenes; D044169:Receptors, Calcium-Sensing; D000069449:Cinacalcet