Abstract
Osteoblasts are a key component in the regulation of the hematopoietic stem cell (HSC) niche. Manipulating osteoblast numbers results in a parallel change in HSC numbers. We tested the activity of strontium (Sr), a bone anabolic agent that enhances osteoblast function and inhibits osteoclast activity, on hematopoiesis. In vitro treatment of primary murine osteoblasts with Sr increased their ability to form bone nodules, and in vivo it increased osteoblast number, bone volume, and trabecular thickness and decreased trabecular pattern factor. However, the administration of Sr had no influence on primitive HSCs, although the number of hematopoietic progenitors was higher than in control cells. When Sr-treated mice were used as donors for HSC transplantation, no difference in the engraftment ability was observed, whereas hematopoietic recovery was delayed when they were used as recipients. Despite the changes in osteoblast numbers, no increment in the number of N-cadherin(+) osteoblasts and N-cadherin transcripts could be detected in Sr-treated mice. Therefore, increasing the overall number and function of osteoblasts without increasing N-cadherin(+) cells is not sufficient to enhance HSC quantity and function. Our study further supports the notion that N-cadherin(+) osteoblasts are fundamental in the hematopoietic niche.
Original language | English |
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Pages (from-to) | 1173-1181 |
Number of pages | 9 |
Journal | Blood |
Volume | 111 |
Issue number | 3 |
Early online date | 25 Jan 2008 |
DOIs | |
Publication status | Published - 1 Feb 2008 |
Keywords
- Animals
- Bone Marrow/drug effects
- Cell Differentiation/drug effects
- Cell Shape/drug effects
- Cells, Cultured
- Hematopoietic Stem Cell Transplantation
- Hematopoietic Stem Cells/cytology
- Mice
- Mice, Inbred BALB C
- Osteoblasts/cytology
- Osteogenesis/drug effects
- Parathyroid Hormone/pharmacology
- Strontium/pharmacology