Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.24.3 (collagenase)
 18,340 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

It is proposed that interferon may be an active agent in the treatment of patients with idiopathic myelofibrosis. In this disorder the megakaryocyte cell lineage plays a major role in the deposition of bone marrow collagen by the release of growth promoting factors, including platelet-derived growth factor, which are mitogenic for fibroblast proliferation. Interferon reduces collagen deposition in the bone marrow by suppressing the activity of the proto-oncogene, which is involved in the production of growth factors from abnormal megakaryocytes and platelets. A direct myeloid cytoreductive effect of interferon upon the megakaryocyte proliferation contributes to reducing growth factor activity in the bone marrow. Finally, interferon induces monocytoid differentiation, thereby increasing bone marrow collagenase-activity. Thus, interferon has several actions, which in concert might reduce bone marrow collagen in myelofibrosis.
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PMID:Hypothesis: a possible role for interferon in the treatment of idiopathic myelofibrosis. 322 65

Quantitative and qualitative changes in granulocyte-macrophage (CFU-GM) and fibroblast colony-forming cells (CFU-F) were studied in 7 patients with primary myelofibrosis (MF). Marrow cells were collected from bone biopsy specimens after treatment with collagenase. The number of CFU-GM correlated with the amount of haemopoietic tissue noted in the bone marrow histology and ranged between 0-400/mg of bone. CFU-F were increased in 2 patients with moderate fibrosis. Circulating CFU-GM were increased in all patients studied (169-3749/ml of blood). There was no significant correlation between the number of CFU-GM in the bone marrow and that in the blood. Cytochemical studies showed a high incidence in eosinophil progenitors in the bone marrow and especially in the blood of patients with MF. These data suggest a functional abnormality of myeloid progenitors in this disease.
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PMID:Granulocytic and stromal progenitors in the bone marrow of patients with primary myelofibrosis. 399 91

The pathological and ultrastructural features of the bone marrow and the kinetics of megakaryopoiesis in patients with primary myelofibrosis indicate that a vast number of developing megakaryocytes die within the bone marrow (ineffective megakaryopoiesis). This leads to an excessive concentration of megakaryocyte intracytoplasmic components in the marrow intercellular space. Current concepts of marrow collagen regulation and megakaryocyte composition lend support to the hypothesis advocating that the development of marrow fibrosis involves two megakaryocyte components: growth factor and factor 4. The growth factor stimulates fibroblast proliferation and collagen secretion while factor 4 inhibits the activity of the enzyme collagenase. The imbalance between increased collagen production and decreased collagen degradation results in an excessive deposition of collagens in bone marrow matrix.
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PMID:Pathogenesis of myelofibrosis: role of ineffective megakaryopoiesis and megakaryocyte components. 608 32

In this article current concepts on the regulation of bone marrow collagen are reviewed and a hypothesis regarding the mechanisms leading to marrow fibrosis associated with Primary Myelofibrosis (PMF) is presented. Type I and type III collagen, products of marrow fibroblasts, are the main constituents of myelofibrotic tissue and megakaryocytes are the predominant cells proliferating in PMF. There is evidence for the clonal nature of the hematopoietic cell proliferation and the secondary origin of myelofibrosis. Also, evidence exists indicating that defective megakaryocyte maturation, i.e. ineffective megakaryocytopoiesis occurs in patients with PMF. It is postulated that ineffective megakaryocytopoiesis leads to an excessive concentration of megakaryocyte components in the marrow intercellular space and that the development of marrow fibrosis involves mainly 2 megakaryocytic products: growth factor and factor 4. The growth factor stimulates fibroblast proliferation and collagen secretion. Factor 4 inhibits the activity of the enzyme collagenase. Thus, the imbalance between increased collagen production and decreased collagen degradation leads to an excessive deposition of collagens in bone marrow matrix.
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PMID:Pathophysiological mechanisms operating in the development of myelofibrosis: role of megakaryocytes. 629 27

Agnogenic myeloid metaplasia (AMM) is characterized by bone marrow fibrosis with abnormal accumulation of extracellular matrix components (ECM), which is dependent on the balance between matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). Twenty-five patients with AMM, 30 with essential thrombocythemia (ET), 12 with polycythemia vera (PV) and 20 normal control subjects were studied. AMM patients had decreased plasma levels of MMP-3 and marked elevated levels of TIMP-1, but MMP-1, MMP-2 and MMP-9 levels were not significantly different from control subjects. Elevated levels of plasma TIMP-1, but not MMPs, were found in ET and PV. Reduced MMP activity together with increased TIMP-1 activity may be essential in fibrosis formation.
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PMID:Plasma matrix metalloproteinase and tissue inhibitor of metalloproteinase in patients with agnogenic myeloid metaplasia or idiopathic primary myelofibrosis. 1243 48

Bone marrow fibrosis in chronic idiopathic myelofibrosis (cIMF) most likely represents an imbalance between synthesis and turnover of collagen fibers. Because the JAK-STAT signaling pathway is involved in the regulation of genes encoding matrix metalloproteinases (MMPs), we examined the expression of MMPs, their tissue inhibitors (TIMPs), and collagen types in relation to the JAK2 status (V617F mutation versus wild-type) in cIMF (n = 64). Whereas no correlation was found between the JAK2 status and MMP gene products, there was an evident association with the stage of disease. Membrane type 1-MMP (MMP-14) was overexpressed by up to 80-fold in advanced stages that progressed to fibrosis (P < 0.001), and megakaryocytes and endothelial cells were unmasked as the major cellular source. By contrast, a significantly higher expression of neutrophil collagenase (MMP-8) was encountered in the prefibrotic stages of cIMF (P < 0.001). Altogether, the stepwise progress of myelofibrosis in cIMF was associated with expression of a defined subset of target genes as shown in sequential trephine biopsies of cIMF patients. We conclude that the expression of matrix-modeling genes in cIMF is not influenced by the JAK2 mutation status but is predominantly related to the stage of disease.
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PMID:Aberrant collagenase expression in chronic idiopathic myelofibrosis is related to the stage of disease but not to the JAK2 mutation status. 1687 49