Chow A, Lucas D, Hidalgo A, Méndez-Ferrer S, Hashimoto D, Scheiermann C, Battista M, Leboeuf M, Prophete C, van Rooijen N, Tanaka M, Merad M, Frenette PS. Bone marrow CD169+ macrophages promote the retention of hematopoietic stem and progenitor cells in the mesenchymal stem cell niche. J Exp Med. 2011 Feb 14;208(2):261–71.
[toggle_content title=”Abstract”]Hematopoietic stem cells (HSCs) reside in specialized bone marrow (BM) niches regulated by the sympathetic nervous system (SNS). Here, we have examined whether mononuclear phagocytes modulate the HSC niche. We defined three populations of BM mononuclear phagocytes that include Gr-1hi monocytes (MOs), Gr-1lo MOs, and macrophages (MΦ) based on differential expression of Gr-1, CD115, F4/80, and CD169. Using MO and MΦ conditional depletion models, we found that reductions in BM mononuclear phagocytes led to reduced BM CXCL12 levels, the selective down-regulation of HSC retention genes in Nestin+ niche cells, and egress of HSCs/progenitors to the bloodstream. Furthermore, specific depletion of CD169+ MΦ, which spares BM MOs, was sufficient to induce HSC/progenitor egress. MΦ depletion also enhanced mobilization induced by a CXCR4 antagonist or granulocyte colony-stimulating factor. These results highlight two antagonistic, tightly balanced pathways that regulate maintenance of HSCs/progenitors in the niche during homeostasis, in which MΦ cross talk with the Nestin+ niche cell promotes retention, and in contrast, SNS signals enhance egress. Thus, strategies that target BM MΦ hold the potential to augment stem cell yields in patients that mobilize HSCs/progenitors poorly.[/toggle_content]
[toggle_content title=”Clodronate Liposome Parameters”]
Total Lipid Concentration
Lipid Mole %
[toggle_content title=”Animals and Dosing”]
Liposome prep method cited — van Rooijen N, Sanders A. Liposome mediated depletion of macrophages: mechanism of action, preparation of liposomes and applications. Journal of Immunological Methods. 1994 Sep 14;174(1–2):83–93.
Animals were dosed with clodronate (or control) liposomes at 1 d (14 h), 7 d, 10 d, 16 d, or 28 d before harvest.
Encapsula NanoSciences LLC
5409 Maryland Way
Brentwood, TN 37027
email: [email protected]
Clodrosome®, Encapsome®, and Fluoroliposome®
are trademarks of Encapsula NanoSciences.
The content of the website can only be used
by researchers, educators and students for educational
purposes. Any commercial use of the content of the website
is legally prohibited by the laws of the United States of
All the products sold on the website are for research purposes only. Any use of these products in humans or animals/ pets for treatment purposes is legally prohibited by U S Food and Drug Administration.