| First Author | Ludin A | Year | 2012 |
| Journal | Nat Immunol | Volume | 13 |
| Issue | 11 | Pages | 1072-82 |
| PubMed ID | 22983360 | Mgi Jnum | J:188567 |
| Mgi Id | MGI:5441118 | Doi | 10.1038/ni.2408 |
| Citation | Ludin A, et al. (2012) Monocytes-macrophages that express alpha-smooth muscle actin preserve primitive hematopoietic cells in the bone marrow. Nat Immunol 13(11):1072-82 |
| abstractText | Hematopoietic stem and progenitor cells (HSPCs) are regulated by various bone marrow stromal cell types. Here we identified rare activated bone marrow monocytes and macrophages with high expression of alpha-smooth muscle actin (alpha-SMA) and the cyclooxygenase COX-2 that were adjacent to primitive HSPCs. These myeloid cells resisted radiation-induced cell death and further upregulated COX-2 expression under stress conditions. COX-2-derived prostaglandin E(2) (PGE(2)) prevented HSPC exhaustion by limiting the production of reactive oxygen species (ROS) via inhibition of the kinase Akt and higher stromal-cell expression of the chemokine CXCL12, which is essential for stem-cell quiescence. Our study identifies a previously unknown subset of alpha-SMA(+) activated monocytes and macrophages that maintain HSPCs and protect them from exhaustion during alarm situations. |
