title: Stromal-derived factor 1-induced megakaryocyte migration and platelet production is dependent on matrix metalloproteinases.
abstract: Despite the discovery of thrombopoietin (TPO) and its contribution to megakaryocytopoiesis, the exact mechanisms and sites of platelet production are unknown. It has been shown that mature megakaryocytes (MKs) functionally express the stromal-derived factor 1 (SDF-1) receptor, CXCR4. SDF-1-induced migration of mature MKs through endothelial cell layers results in increased platelet production. Because the migration of polyploid MKs from the bone marrow microenvironment requires remodeling of the perivascular extracellular matrix, it was hypothesized that mature polyploid MKs may express matrix metalloproteinases (MMPs), facilitating their exit into the bone marrow extravascular space. In this report, it is demonstrated that SDF-1 induces the expression and release of gelatinase B (MMP-9) by purified mature polyploid human MKs and an adeno-CXCR4-infected megakaryocytic cell line. Neutralizing antibody to MMP-9, but not MMP-2, blocked SDF-1-induced migration of MKs through reconstituted basement membrane, suggesting that expression of MMP-9 is critical for MK migration. Incubation of mature MKs with a synthetic MMP inhibitor, 5-phenyl-1,10-phenanthrolene, resulted in the inhibition of platelet formation, suggesting that the expression of MMPs is not only critical for megakaryocyte migration but also for subsequent platelet release. Confirming these results, adeno-SDF-1 injection into normal mice resulted in increased platelet counts, a process that could be blocked by a synthetic MMP inhibitor. These results suggest mobilization of MKs involves sequential expression and activation of chemokine receptors such as CXCR4, MMP-9, followed by transendothelial migration. MMP inhibitors may have potential use in the treatment of thrombotic and myeloproliferative disorders. (Blood. 2000;96:4152-4159)
authors: Division of Hematology-Oncology, Weill Medical College of Cornell University, Ithaca, NY 10021, USA.
authors: W J
authors: WJ
authors: Lane
authors: S
authors: S
authors: Dias
authors: K
authors: K
authors: Hattori
authors: B
authors: B
authors: Heissig
authors: M
authors: M
authors: Choy
authors: S Y
authors: SY
authors: Rabbany
authors: J
authors: J
authors: Wood
authors: M A
authors: MA
authors: Moore
authors: S
authors: S
authors: Rafii
mesh_terms: D000328:Adult; D000818:Animals; D001792:Blood Platelets / Q000166:cytology*; D002478:Cells, Cultured / Q000187:drug effects; D054377:Chemokine CXCL12; D019743:Chemokines, CXC / Q000235:genetics / Q000502:physiology*; D002630:Chemotactic Factors / Q000494:pharmacology*; D002633:Chemotaxis / Q000187:drug effects*; D016895:Culture Media, Serum-Free; D004790:Enzyme Induction / Q000187:drug effects; D016326:Extracellular Matrix Proteins / Q000502:physiology*; D006801:Humans; D006877:Hydroxamic Acids; D007947:Leukemia, Megakaryoblastic, Acute / Q000473:pathology; D020780:Matrix Metalloproteinase 9 / Q000096:biosynthesis / Q000378:metabolism; D061965:Matrix Metalloproteinase Inhibitors; D008533:Megakaryocytes / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D008666:Metalloendopeptidases / Q000037:antagonists & inhibitors / Q000502:physiology*; D051379:Mice; D008807:Mice, Inbred BALB C; D011480:Protease Inhibitors / Q000494:pharmacology; D011719:Pyrazines; D019718:Receptors, CXCR4 / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology; D011993:Recombinant Fusion Proteins / Q000502:physiology; D013449:Sulfonamides; D013917:Thrombin / Q000494:pharmacology; D013926:Thrombopoietin / Q000494:pharmacology; D019715:Tissue Inhibitor of Metalloproteinase-1 / Q000096:biosynthesis / Q000235:genetics; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: C097658:CGS 27023A; C515255:CXCL12 protein, human; D054377:Chemokine CXCL12; D019743:Chemokines, CXC; D002630:Chemotactic Factors; D016895:Culture Media, Serum-Free; C515256:Cxcl12 protein, mouse; D016326:Extracellular Matrix Proteins; D006877:Hydroxamic Acids; D061965:Matrix Metalloproteinase Inhibitors; D011480:Protease Inhibitors; D011719:Pyrazines; D019718:Receptors, CXCR4; D011993:Recombinant Fusion Proteins; D013449:Sulfonamides; D019715:Tissue Inhibitor of Metalloproteinase-1; D013926:Thrombopoietin; D013917:Thrombin; D008666:Metalloendopeptidases; D020780:Matrix Metalloproteinase 9