Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019045 (hemoglobinopathies)
 2,704 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

An improved version of the method for electrofocusing of the globin chains extracted from the dried blood dots of newborn on the ultrathin polyacrylamide-ampholine gels at pH 5-8 is described. The method permits clinical diagnosing of hereditary hemoglobinopathies of the newborn.
Mol Gen Mikrobiol Virusol 1990 Jan
PMID:[Express diagnosis of hereditary hemoglobinopathies in newborn infants]. 233 78

Point mutations alpha 58 His----Tyr (Hb M Boston), beta 6 Glu--lys (Hb C) and beta 26 Glu----Lys (Hb E) have been identified in abnormal hemoglobins by means of tryptic hydrolysis of their alpha- and beta-chains followed by mass-spectrometry coupled with direct extraction of ions from solution. The abnormal hemoglobin Hb M Boston alpha 58 (E7) His----Tyr has been for the first time found in the blood of a patient from the USSR. This express-method is generally applicable for the identification of point mutation in proteins. The amount of protein necessary for the analysis is 100-1000 pmole. The stability, proteolytic degradation of the identified abnormal Hb's and Hb Bart's were investigated. The molecular pathogenesis of the hemoglobinopathies are discussed from the point of view of the observed properties.
Mol Biol (Mosk)
PMID:[Location of amino acid substitutions in human hemoglobin. Mass spectrometric rapid analysis of tryptic peptides]. 273 43

Hemoglobinopathies responsible for hemolytic anemias may be divided into two groups. The first one corresponds to thalassemias and the second to the presence of a structurally abnormal hemoglobin (Hb). In thalassemia, the primary biochemical abnormality is a quantitative defect in the biosynthesis of one type of Hb chain. This defect leads to an overall deficit of Hb accumulation in the erythrocyte (hypochromia) together with the presence of an excess of the normally synthesized chains. The unpaired subunits which are less soluble than HbA precipitate, bind to the membrane and ultimately lead to hemolysis. In the second group, the hemolytic anemia is a direct consequence of the physicochemical properties of the structurally abnormal Hb. This molecule may polymerize, precipitate or crystallize within the red blood cell (RBC) leading to membrane alterations and to the destruction of the cell. This chapter will emphasize several examples of structurally abnormal Hbs, such as sickle cell disease and congenital Heinz body hemolytic anemia (CHBHA).
Mol Aspects Med 1996 Apr
PMID:Hemolytic anemias due to hemoglobinopathies. 881 15

Short-chain fatty acids, such as butyrate and propionate, are under investigation as therapeutic stimulants of fetal hemoglobin production in the beta-hemoglobin disorders. Significant limitations to these fatty acids and derivatives as optimal therapeutics are their rapid metabolism in vivo and their induction of cell growth arrest in the G1 phase of the cell cycle. This antiproliferative activity is related to their inhibition of metabolic transport pumps which are essential for cell proliferation. Other small carbon compounds, the phenylalkyl acids, phenoxyacetic acids, and phenylacetic acids, which are structurally resistant to oxidative metabolism, are shown here to induce fetal globin production in human erythroid cultures at concentrations of 0.2 mM, lower than those required for most other fatty acids. Certain of these compounds were found not to inhibit cellular neutral amino acid transport function in erythroid cells, nor to inhibit erythroid colony (Bfu-e) growth. Certain of these compounds even stimulated human Bfu-e proliferation in vitro beyond that induced by optimal concentrations of hematopoietic growth factors. The combination of increased fetal globin chain production by these compounds and their stimulatory effects on erythropoiesis result in an increase in Hb F-expressing erythroid cells in culture several-fold greater than that achieved by the butyrates. These new compounds thus have the potential to provide superior therapy for the beta-hemoglobinopathies and other anemias.
Blood Cells Mol Dis 1996
PMID:Erythroid progenitor proliferation is stimulated by phenoxyacetic and phenylalkyl acids. 893 55

Short-chain fatty acids, such as butyrate and propionate, induce fetal globin gene expression and are under clinical investigation in the beta-hemoglobinopathies. Limitations of the short-chain fatty acids as therapeutics include their rapid metabolism and a tendency to induce cell growth arrest if administered for prolonged periods. In studies described here, the cellular effects of other inducers of fetal globin, phenoxyacetic acid and derivatives of short-chain fatty acids and cinnamic acids, were investigated in the human erythroid cell line K562, the IL-3 dependent multi-lineage cell line (32D), and in mice and primates. Several test compounds supported 32D cell proliferation despite a 50-fold depletion of IL-3, which resulted in growth arrest and apoptotic death in control cells. The degree of proliferation induced by certain test compounds was similar to the degree of proliferation induced by Erythropoietin and G-CSF in the cells. Eight of ten compounds induced gamma globin mRNA in K562 cells. A 2.5 to 6-fold increase in reticulocytosis was observed in vivo in mice treated with two prototype compounds. Pharmacokinetic studies of three prototype compounds demonstrated millimolar plasma concentrations after single oral doses for many hours in primates. These findings identify orally bioavailable compounds which induce gamma globin gene expression and hematopoietic cell proliferation through an activity which partially abrogates requirements for IL-3. Such compounds provide potential for oral therapeutics which stimulate proliferation of hematopoietic cells of multiple lineages, as well as inducing fetal globin.
Blood Cells Mol Dis 1997 Dec
PMID:Abrogation of IL-3 requirements and stimulation of hematopoietic cell proliferation in vitro and in vivo by carboxylic acids. 945 87

Retrovirus vectors for A gamma-globin are being developed for the treatment of beta chain hemoglobinopathies. Toward the goal of achieving therapeutic expression levels, core elements of the beta-globin locus control region (LCR) hypersensitive sites (HS) were screened for enhancer activity in erythroid MEL and K562 cell lines using a drug-resistant colony assay. When used alone, core elements of HS1, HS3, and HS4 showed no activity and a fragment for HS2 showed only modest activity in the colony assay. However, a 1.1 kb combination of fragments for HS2, HS3, and HS4 (termed a nLCR) enhanced colony formation 17-fold in K562 cells and 94-fold in MEL cells. Addition of an HS1 fragment enhanced nLCR activity only modestly in MEL cells. When linked to a beta-globin gene, the 1.1 kb nLCR enhanced globin mRNA expression to 82% per copy of mouse alpha-globin in transfected MEL cells. Inclusion of a nLCR in retrovirus vectors containing a beta-globin promoter and various A gamma-globin gene expression cassettes resulted in extreme genetic instability and reduced titers. Specific deletions were abrogated by removing homologous sequences, but random recombinations were still observed at significant frequencies. In MEL cells containing intact provirus, A gamma-globin mRNA produced by an optimal vector containing the nLCR was only 2-fold higher (8.5% vs. 3.9% per copy of mouse alpha-globin) compared to the same vector without the nLCR. These data suggest that vector elements detract from the ability of the nLCR to enhance expression of the beta pr.A gamma cassettes.
Blood Cells Mol Dis 1998 Sep
PMID:Development of a condensed locus control region cassette and testing in retrovirus vectors for A gamma-globin. 1008 91

Allogeneic bone marrow transplantation is an effective curative therapy for both malignant and heritable diseases. The use of genetically altered autologous hematopoietic stem cells (HSC) is being increasingly investigated as a treatment for a variety of non-malignant but significantly morbid diseases, including hemoglobinopathies, immunodeficiencies and autoimmune diseases. Other hematopoietic cells capable of proliferation, such as antigen-specific T cells and dendritic cells, have also been used for adoptive immunotherapy. Genetic procedures to modify these various therapeutic cells so that they can be selectively amplified either in vitro or in vivo could enhance their efficacy. For example, HSC that contain a gene that confers a survival, selection or growth advantage may enhance their engraftment. Such enhancement could be expected to reduce graft failures and the intensity of the required conditioning regimen, thereby decreasing the toxicities of transplantation. In this review, the functions of cytokine receptor transgenes coding for erythropoietin receptors (EpoR) are analyzed. The characteristics of these transgenic cells and animals are discussed with regard to the possible therapeutic use of EpoR transgenes in the transplantation of hematopoietic cells.
Cytokines Cell Mol Ther 1999 Jun
PMID:The therapeutic potential of erythropoietin receptor transgenes. 1051 82

The promoter region of adult beta globin genes in humans and other mammals contains conserved regions of pivotal importance for their regulated tissue specific expression. These include the CACCC and CAAT motifs. The CACCC motif is duplicated in humans and other mammals. The human delta-globin gene lacks these conserved regions and its expression in normal individuals is about 3% that of the beta globin gene. Previous studies have shown that the introduction of the beta-globin CACCC or CAAT can activate the delta-globin gene promoter, but the effect of the distal CACCC element has not yet been tested. In the present study, using site-specific mutagenesis, we have introduced the consensus sequence for the distal and proximal CACCC motif and the CAAT box alone or in combination in the wild-type delta-globin gene promoter. The resulting mutants, as well as the wild type (wt) delta- and beta-globin gene promoters, have been analyzed in a transient expression assay in Cos7, K562, and MEL cell lines. The results show that the CACCC boxes can increase the transcription efficiency of the delta-globin gene promoter in both erythroid and non-erythroid cell systems. The contribution of the two CACCC elements is almost equal in the non-erythroid (Cos7) and erythroid embryonic-fetal cell lines (K562), while the proximal CACCC element is more active in adult erythroid cells (MEL). Nonetheless, duplication of this element does not appear to affect the efficiency of the promoter synergistically. Furthermore, to assess the competitive ability of the delta globin promoter containing the proximal or distal CACCC consensus sequences over the wt beta globin gene promoter, we have carried out transient expression experiments using DNA constructs in which the delta and beta globin gene promoters are linked in cis and are sharing a single enhancer (competitive transient expression). The results show that both CACCC elements are able to activate the delta globin gene promoter in Cos7 and K562 cells, although to a different extent, whereas only the proximal CACCC element is effective in increasing the transcription efficiency in MEL cells. These findings are in agreement with the more severe clinical phenotype produced by the beta-thalassemia mutations affecting the proximal CACCC box as compared with those within the distal CACCC box. The Erythroid Kruppel Like Factor (EKLF) is a nuclear protein restricted to erythroid cells which specifically bind the CACCC box sequence and activate the beta-globin gene. In the present study we carried out transactivation experiments of the mutagenized delta-globin gene promoter by introducing an EKLF expressing construct in erythroid cells. Constructs containing the proximal but not those bearing the distal CACCC element are transactivated. Our results indicate that the proximal CACCC box and, to a lesser extent, also the distal box have a role in the regulated stage specific expression of a beta-like globin gene, and show that the insertion of a single CACCC motif in the delta-globin gene promoter is sufficient to increase its activity. Nevertheless only the delta globin gene promoter containing the proximal CACCC element is able to compete with the wt beta globin gene promoter in the adult erythroid environment. These findings have potential relevance for the future prospective treatment of inherited hemoglobinopathies based on the conversion of the low functioning delta-globin gene into a high functioning beta-like globin gene.
Blood Cells Mol Dis
PMID:Activation of the delta-globin gene by the beta-globin gene CACCC motif. 1057 45

Pharmacologic agents such as hydroxyurea (HU), N, 3-4 trihydroxybenzamide (didox), and isobutyramide (ISB) can elevate gamma-globin as a potential treatment for the beta-hemoglobinopathies. In these experiments, transgenic mice with 5'HS2 from the human beta-globin locus control region, the fetal (A gamma), and adult (beta s) globin genes were used. Mice were treated with HU, didox, or ISB individually, or with combinations of HU or didox with ISB. The aim was to determine whether these drugs have synergistic effects on the induction of fetal hemoglobin (HbF) and whether the combination regimens are more hematotoxic. In the combination regimens, injections of HU or didox for five weeks were concomitant with ISB treatment every other day for the final three weeks of treatment. The combination of HU + ISB was more hematotoxic than the individual drugs based on significantly increased percentages of reticulocytes and reduced hemoglobin, indicating that caution should be taken in treatments involving combinations of these types of drugs. The didox + ISB combination was not more hematotoxic than the individual drugs. HbF was not induced in the groups treated with the combinations of HU or didox with ISB compared to the individual agents. There was a negligible effect on the percentage of HbF and an unexpected negative effect on the percentage of F cells. The results also have implications for future testing of HbF-inducing drugs in mouse models. In control mice that were phlebotomized but not treated with any drugs, increased percentages of F cells were observed, indicating that blood sampling can cause this effect. In addition, increases in the percentage of F cells did not correlate with increases in the percentage of HbF, indicating that monitoring F cells alone is not a sufficient measure of HbF induction.
Blood Cells Mol Dis
PMID:A combination of hydroxyurea and isobutyramide to induce fetal hemoglobin in transgenic mice is more hematotoxic than the individual agents. 1057 51

One approach to gene therapy for the treatment of hemoglobinopathies has been focused on increasing normal globin gene expression. However, because of the high concentration of hemoglobin in the red blood cell (32-34 g/dl), merely introducing the normal globin gene may not be enough to counteract the effect of an abnormal globin. We propose that in addition to strategies to add normal beta- or gamma-globin production to sickle erythrocytes, a decrease in overall hemoglobin concentration would further decrease the polymerization potential and should be considered with other gene therapy approaches. Ribozymes offer the potential to target a selected gene product. A model system has been set up using the human alpha-globin gene for specific gene suppression by ribozymes by cleaving alpha-globin mRNA transcripts. Ribozymes, specifically targeted to five different sites in the 5' portion of human alpha-globin mRNA, have been designed and tested in vitro. Cleavage of 32P-labeled alpha-globin mRNA by these ribozymes has been observed in vitro and the highest level of activity has been found for a multi-ribozyme combining all five ribozymes. The multi-ribozyme gene along with promoters with varying activities in erythroid cells was transfected into human erythroleukemia K562 cells. The multi-ribozyme gene, under the control of human alpha-2-globin promoter alone and combined with the locus control region enhancer, caused a decrease in the level of alpha-globin mRNA of 50-75% compared to the control, determined by RNase protection and by real-time quantitative PCR. The decrease in alpha-globin transcripts has been found to be correlated with expression of the multi-ribozyme in a dose-dependent manner and does not appear to be mediated by an antisense effect. These results suggest that the multi-ribozyme may be useful in gene therapy as an effective suppressor of a specific globin gene.
Blood Cells Mol Dis
PMID:Multi-ribozyme targeting of human alpha-globin gene expression. 1066 Apr 85


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