Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P04141 (granulocyte-macrophage colony-stimulating factor)
 6,790 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Poly(ethylene glycol) (PEG) is a water soluble polymer that when covalently linked to proteins, alters their properties in ways that extend their potential uses. PEG-modified conjugates are being exploited in many different fields. The improved pharmacological performance of PEG-proteins when compared with their unmodified counterparts prompted the development of this type of conjugate as a therapeutic agent. Enzyme deficiencies for which therapy with the native enzyme was inefficient (due to rapid clearance and/or immunological reactions) can now be treated with equivalent PEG-enzymes. PEG-adenosine deaminase has already obtained FDA approval. PEG-modified cytokines have been constructed and, interestingly, one of the conjugates, PEG-modified granulocyte-macrophage colony-stimulating factor, showed dissociation of two biological properties. This novel observation may open new horizons to the application of PEGylation technology. The biotechnology industry has also found PEG-proteins very useful because PEG-enzymes can act as catalysts in organic solvents, thereby opening the possibility of producing desired stereoisomers, as opposed to the racemic mixture usually obtained in classical organic synthesis. Covalent attachment of PEG to proteins requires activation of the hydroxyl terminal group of the polymer with a suitable leaving group that can be displaced by nucleophilic attack of the epsilon-amino terminal of lysine residues (other nucleophilic groups can also interact). Several chemical groups have been exploited to activate PEG, thereby giving rise to a variety of PEG-proteins. Some of these varieties retain part of the activating group as a coupling moiety between PEG and protein and others provide a direct linkage. For each particular application, different coupling methods provide distinct advantages.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:The uses and properties of PEG-linked proteins. 145 45

We have investigated the potential of PEGylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a molecule related to thrombopoietin (mpl ligand or TPO) in minimizing the thrombocytopenia associated with hematopoietic ablation and peripheral blood progenitor cell (PBPC) transplant. Irradiated mice that received PBPC mobilized by PEG-rHuMGDF or granulocyte colony-stimulating factor (G-CSF) had a reduced number of thrombocytopenic days with platelets below 100 x 10(6) per mL of blood. Recipients of unmobilized PBPC had a 9 day thrombocytopenic phase which was shortened to 7 days if they were given granulocyte-macrophage colony-stimulating factor (GM-CSF)-mobilized PBPC. This was further reduced to 2 or 3 days of thrombocytopenia in recipients of G-CSF- or PEG-MGDF-mobilized PBPC. Despite our observation that PEG-rHuMGDF is a relatively modest stimulator of the mobilization of myeloid progenitors to the blood, MGDF-mobilized PBPC do effect accelerated recovery of platelets after transplantation. However, the most effective use of PEG-rHuMGDF is when it is given during the recovery phase after PBPC transplantation to hematopoietically ablated mice. Posttransplant treatment with PEG-rHuMGDF reduces thrombocytopenia to a single day or less, in recipients of most types of PBPC. Mice that were treated during the first 2 weeks after PBPC transplant with PEG-rHuMGDF had 1 thrombocytopenic day compared to 9 days in carrier-treated recipients of unmobilized PBPC and 2 to 3 days in carrier-treated recipients of the optimally mobilized PBPC from G-CSF or G-CSF/PEG-rHuMGDF treated donors. In groups where PEG-rHuMGDF was included in the mobilization protocol and used to treat recipients as well thrombocytopenia was effectively eliminated. These data show that PEG-rHuMGDF is a highly effective agent in eliminating the thrombocytopenia associated with PBPC transplantation.
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PMID:Megakaryocyte growth and development factor accelerates platelet recovery in peripheral blood progenitor cell transplant recipients. 870 97

We have prepared a new formulation for mucosal delivery of GM-CSF or PEGylated GM-CSF based on a chitosan carrier plus added glycerol to control the rate of release of the protein. Thin dry films comprised of various weight ratios of chitosan to glycerol and containing either granulocyte-macrophage colony-stimulating factor (GM-CSF) or PEGylated GM-CSF, PEG-(GM-CSF), were prepared. The amount of GM-CSF or PEG-(GM-CSF) released from the chitosan/glycerol films was determined using size exclusion high performance liquid chromatography (HPLC-SEC). The amount of PEG-(GM-CSF) released from the films decreased with an increase in the amount of glycerol present in the film. In parallel with this, films with higher glycerol content exhibited a lower degree of equilibrium swelling when immersed in release media. pH measurements of the release media and analysis of the dried films by Fourier-transform infrared spectroscopy (FTIR) suggested that the amount of residual acetic acid in the dry films decreased as the glycerol content increased. This indicates that glycerol may act by displacing and releasing bound acetic acid from the chitosan molecules, resulting in chitosan--glycerol hydrogen bond formation as the film dries. Further, it was found that the release rate and the amount of PEG-(GM-CSF) released decreased with increasing molecular weight of the conjugated PEG. This effect was not observed with films containing physical mixtures of PEG and GM-CSF. The decrease in the fraction of PEG-(GM-CSF) released with increasing PEG molecular weight is believed to be due to the increased steric hindrance of the PEGylated protein molecule during its diffusion out of the swollen chitosan/glycerol film.
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PMID:Release of PEGylated granulocyte-macrophage colony-stimulating factor from chitosan/glycerol films. 1138 83

Colony-stimulating factor-1 (CSF-1) regulates the survival, proliferation and differentiation of macrophages. CSF-1-deficient mice are osteopetrotic due to a lack of osteoclasts, while their tissue macrophage deficiencies and an absence of CSF-1 regulation of CSF-1 receptor-expressing cells in the female reproductive tract contribute to their pleiotropic phenotype. To further understand CSF-1 regulation of macrophages in vivo, we developed a neutralizing anti-mouse CSF-1 antibody which was expressed as a recombinant Fab' fragment and coupled to 40 kDa polyethylene glycol. As developmental regulation by CSF-1 is highest during the early post-natal period, the ability of this anti-CSF-1 reagent to inhibit development was tested by regular subcutaneous injection of mice from post-natal days 0.5-57.5. Antibody treatment decreased growth rate, decreased osteoclast number, induced osteopetrosis, decreased macrophage density in bone marrow, liver, dermis, synovium and kidney and decreased adipocyte size in adipose tissue, thereby inducing phenotypes shared by CSF-1- and CSF-1 receptor-deficient mice. While the antibody blocked macrophage development in some tissues, macrophage densities in other tissues were initially high and were reduced by treatment, proving that the antibody also blocked macrophage maintenance. Since cell surface CSF-1 is sufficient for the maintenance of normal synovial macrophage densities, these studies suggest that anti-CSF-1 Fab'-PEG efficiently neutralizes all three CSF-1 isoforms in vivo, namely the secreted proteoglycan, secreted glycoprotein and cell surface glycoprotein. Since CSF-1 has been shown to enhance chronic disease development in a number of mouse model systems, these studies demonstrate the feasibility of neutralizing CSF-1 effects in these models with an anti-CSF-1 antibody.
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PMID:Modulation of CSF-1-regulated post-natal development with anti-CSF-1 antibody. 1616 17

Granulocyte-macrophage colony-stimulating factor (GM-CSF) regulates proliferation, differentiation, and function of hematopoietic progenitor cells. Aside from expansion of hematopoietic cells, GM-CSF has shown efficacy in other diseases, including Crohn's disease. While GM-CSF being clinically used in humans, the ability to perform mechanistic studies in murine models is difficult due to the limited availability and rapid clearance of murine GM-CSF in the peripheral blood. To address these issues, we efficiently expressed murine GM-CSF under the control of the AOX1 gene promoter in Pichia pastoris using the Mut(S) strain KM71H. We describe the unique conditions that are required for efficient production by high-density fermentation and purification of mGM-CSF protein. Recombinant mGM-CSF protein was purified by tangential flow ultrafiltration and preparative reverse phase chromatography. To address limited half life or rapid clearance in mice, recombinant murine GM-CSF was modified by lysine-directed polyethylene glycol conjugation (PEGylation). PEG-modified and unmodified proteins were characterized by amino terminus sequence analysis and matrix assisted laser desorption ionization time-of-flight mass spectrometry. Under the mild reaction conditions, the recombinant protein is efficiently modified by PEGylation on an average of 2-3 sites per molecule. In vivo treatment of mice with PEGylated mGM-CSF, but not the unmodified recombinant mGM-CSF, reproduces the potent colony stimulating effects of human GM-CSF in patients on myeloid progenitor populations, as assessed by FACs analysis. This simplified approach for the expression, purification, and modification of a biologically potent form of murine GM-CSF should facilitate the study of central mechanisms of action in murine disease models.
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PMID:PEGylated murine Granulocyte-macrophage colony-stimulating factor: production, purification, and characterization. 1621 50