Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:3.1.27.4 (ribonuclease)
 6,621 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study is intended to establish biological correlation between the expression of lymphoid associated features in acute myeloid leukaemia (AML). In 62 AML patients, predominantly enrolled on Eastern Cooperative Oncology Group (ECOG) treatment protocols, in whom immunoglobulin (Ig) as well as T-cell receptor beta chain (TCR-beta) gene rearrangement analyses had been performed, morphology, cytochemistry, antigen profile and karyotype were reviewed retrospectively. Nuclear reactivity with anti-TdT antibody was demonstrated in 34 patients (55%) and confirmed by ribonuclease protection assay in all patients tested. Five TdT-protein negative patients were TdT-transcript positive. Lymphoid antigens (lyA) were detected in 24 of 51 cases tested (47%) with B-cell antigens (CD19, CD10) being restricted to TdT+ AML (P = 0.03). Only two patients had Ig heavy, none had Ig light chain or TCR-beta gene rearrangements. Although both patients with rearranged Ig loci were TdT+, either by protein or RNA analysis, the low incidence of such rearrangement within the TdT+ AML group (6%) argues against a significant association between the presence of TdT and crosslineage Ig gene rearrangements in AML. While FAB-diagnoses did not differ between TdT+ and TdT- or lyA+ and lyA- AML, particular immunophenotypic features correlated with TdT positively, e.g. the presence of early antigens, CD34 and HLA-DR, and the absence of the more mature myelo-monocytic antigens, CDw65 and CD14. Certain cytogenetic abnormalities were associated with TdT+ AML such as inv(16) (p13q22) or t(16;16) (p12;q22) (five patients; P = 0.03) and t(8;21) (q22;q22) (three patients). A greater number of TdT- than TdT+ AML patients had only normal karyotypes (P = 0.06). Neither immunophenotypic nor karyotypic correlations could be established for lyA+ AML.
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PMID:Lymphoid lineage-associated features in acute myeloid leukaemia: phenotypic and genotypic correlations. 141 14

In an attempt to analyze the cellular and molecular basis of the capacity of bone marrow stromal cells to support hematopoiesis in culture, we developed a series of murine stromal cell lines from a single long-term bone marrow culture (BMC). The cytokines produced by these cells were analyzed using immunohistochemical techniques, ribonuclease protection assays (RPA) and RT-PCR. We examined the capacity of these cloned cell lines to replace primary bone marrow-derived stromal cells in long-term bone marrow cultures (LT-BMC) and sought correlations between the capacity to support hematopoiesis in culture with the production of known cytokines. These immortalized lines replicate many of the functions of the hematopoietic microenvironment. They express cytokines known to play a role in hematopoiesis. All of the lines constitutively express mRNA for PBSF (SDF-1), macrophage colony-stimulating factor (M-CSF), stem cell factor (SCF), FLT-3, thrombopoietin (TPO), interleukin 7 (IL-7), leukemia inhibitory factor (LIF), tumor necrosis factor-beta (TNF-beta), and interferon-gamma (IFN-gamma). Most lines also express granulocyte-macrophage colony-stimulating factor (GM-CSF) and G-CSF. They vary in their expression of IL-6, tumor growth factor-beta1 (TGF-beta1), TGF-beta2, and TNF-alpha. Growing these lines in the presence of cytokines that influence hematopoiesis alters the levels of cytokine message. The most striking effects were produced by TNF-alpha. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as osteoblast-specific factor-2 (OSF-2) and bone morphogenetic protein-1 (BMP-1). They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). Several of the lines can maintain hematopoiesis in culture, as measured by the continuous production of myeloid colony-forming cells (CFU-c), for months. This capacity to support hematopoiesis does not correlate with any pattern of cytokine expression. Several of these lines also support the growth of human hematopoietic cells, and human CFU-c can be detected in the cultures in which CD34(+) bone marrow cells (BMC) are cultured on murine stromal cells. No correlation between the production of any of the known cytokines and the ability to support murine hematopoiesis was detected. In addition, there was no correlation between the capacity to support murine hematopoiesis and the capacity to maintain human HSC. Despite repeated cloning, the lines remain heterogeneous and are capable of producing cells with the properties of fibroblasts, osteoblasts, adipocytes, and myoblasts. In addition to the cytokine mRNAs, the cell lines express factors associated with bone formation such as OSF-2 and BMP-1. They also express the neural cell-adhesion molecule neuropilin and neurotrophic factors including NGF and BDNF.
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PMID:Immortalized multipotential mesenchymal cells and the hematopoietic microenvironment. 1127 66

The transcription factors GATA-1 and GATA-2 have been implicated in promoting differentiation of eosinophilic leukocytes. In this study, we examined the roles of GATA-1 and GATA-2 in activating transcription of the secretory ribonuclease, the eosinophil-derived neurotoxin (EDN/RNase 2). Augmented expression of both GATA-1 and GATA-2 was detected in eosinophil promyelocyte HL-60 clone 15 cells in response to biochemical differentiation with butyric acid. Deletion or mutation of one or both of the two consensus GATA-binding sites in the extended 1000-bp 5' promoter of the EDN gene resulted in profound reduction in reporter gene activity. Antibody-augmented electrophoretic mobility shift and chromatin immunoprecipitation analyses indicate that GATA-1 and GATA-2 proteins bind to both functional GATA consensus sequences in the EDN promoter. Interestingly, RNA silencing of GATA-1 alone had no impact on EDN expression; silencing of GATA-2 resulted in diminished expression of EDN, and also diminished expression of GATA-1 in both butyric acid-induced HL-60 clone 15 cells and in differentiating human eosinophils derived from CD34(+) hematopoietic progenitors. Likewise, overexpression of GATA-2 in uninduced HL-60 clone 15 cells resulted in augmented transcription of both EDN and GATA-1. Taken together, our data suggest that GATA-2 functions directly via interactions with the EDN promoter and also indirectly, via its ability to regulate the expression of GATA-1 in differentiating eosinophils and eosinophil cell lines.
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PMID:GATA transcription factors regulate the expression of the human eosinophil-derived neurotoxin (RNase 2) gene. 1927 13

Homologous tissues, such as adipose tissue, may be an interesting source of acellular scaffolds, maintaining a complex physiological three-dimensional (3D) structure, to be recellularized with autologous cells. The aim of the present work is to evaluate the possibility of obtaining homologous acellular scaffolds from decellularization of the omentum, which is known to have a complex vascular network. Adult rat and human omenta were treated with an adapted decellularization protocol involving mechanical rupture (freeze-thaw cycles), enzymatic digestion (trypsin, lipase, deoxyribonuclease, ribonuclease) and lipid extraction (2-propanol). Histological staining confirmed the effectiveness of decellularization, resulting in cell-free scaffolds with no residual cells in the matrix. The complex 3D networks of collagen (azan-Mallory), elastic fibers (Van Gieson), reticular fibers and glycosaminoglycans (PAS) were maintained, whereas Oil Red and Sudan stains showed the loss of lipids in the decellularized tissue. The vascular structures in the tissue were still visible, with preservation of collagen and elastic wall components and loss of endothelial (anti-CD31 and -CD34 immunohistochemistry) and smooth muscle (anti-alpha smooth muscle actin) cells. Fat-rich and well vascularized omental tissue may be decellularized to obtain complex 3D scaffolds preserving tissue architecture potentially suitable for recellularization. Further analyses are necessary to verify the possibility of recolonization of the scaffold by adipose-derived stem cells in vitro and then in vivo after re-implantation, as already known for homologus implants in regenerative processes.
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PMID:Decellularized omentum as novel biologic scaffold for reconstructive surgery and regenerative medicine. 2354 63