| First Author | Zhou Q | Year | 2002 |
| Journal | Blood | Volume | 99 |
| Issue | 11 | Pages | 4030-8 |
| PubMed ID | 12010804 | Mgi Jnum | J:76790 |
| Mgi Id | MGI:2180278 | Doi | 10.1182/blood-2001-12-0271 |
| Citation | Zhou Q, et al. (2002) Normal hemostasis but defective hematopoietic response to growth factors in mice deficient in phospholipid scramblase 1. Blood 99(11):4030-8 |
| abstractText | Phospholipid scramblase 1 (PLSCR1) is an endofacial plasma membrane protein proposed to participate in transbilayer movement of phosphatidylserine and other phospholipids. In addition to its putative role in the reorganization of plasma membrane phospholipids, PLSCR1 is a substrate of intracellular kinases that imply its possible participation in diverse signaling pathways underlying proliferation, differentiation, or apoptosis. Because PLSCR1 is prominently expressed in a variety of blood cells, we evaluated PLSCR activity in platelets and erythrocytes, and cytokine-dependent growth of hematopoietic precursor cells, of PLSCR1 knock-out mice. Adult PLSCR1(-/-) mice showed no obvious hematologic or hemostatic abnormality, and blood cells from these animals normally mobilized phosphatidylserine to the cell surface upon stimulation. Whereas blood cell counts in adult PLSCR1(-/-) mice were normal, in both fetus and newborn animals neutrophil counts were significantly depressed relative to age-matched wild type (WT). Furthermore, when compared with WT, hematopoietic precursor cells from PLSCR1(-/-) mice showed defective colony formation and impaired differentiation to mature granulocytes as stimulated by stem cell factor and granulocyte colony-stimulating factor (G-CSF). By contrast, PLSCR1(-/-) cells showed normal colony formation stimulated by interleukin-3 or granulocyte-macrophage CSF, and expansion of megakaryocytic and erythroid progenitors by thrombopoietin or erythropoietin was unaffected. Stem cell factor and G-CSF were also found to induce marked increases in PLSCR1 levels in WT cells. Consistent with in vitro assays, PLSCR1(-/-) mice treated with G-CSF showed less than 50% of the granulocytosis observed in identically treated WT mice. These data provide direct evidence that PLSCR1 functionally contributes to cytokine-regulated cell proliferation and differentiation and suggest it is required for normal myelopoiesis. |
