Gene/Protein Disease Symptom Drug Enzyme Compound
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630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Since the genetic basis of sickle cell anemia was discovered over 50 years ago, many therapies have been developed for the treatment of this disorder. Hematopoietic cell transplantation offers curative potential, but it is associated with a 5-10% risk of dying. Patients who undergo allografting but develop stable donor-host hematopoietic chimerism appear to experience a significant clinical benefit. Our paper discusses the risks and benefits of hematopoietic cell transplantation in patients with sickle cell disease and summarizes the outcome of 147 patients who received allografts for sickle cell disease. We also review the development of new approaches to establish stable mixed chimerism after transplantation for sickle cell disease.
Pediatr Pathol Mol Med
PMID:Stem cell transplantation for sickle cell disease: can we reduce the toxicity? 1267 45

Microvascular complications in sickle cell disease occur as a result of obstruction of small vessels by deoxygenated sickle cells. Cerebrovascular complications are also common and result from obstruction of large blood vessels by thrombosis with changes in vessels that have some similarity to those found in arteriosclerotic vascular disease. Endothelial damage and activation from sickle cell-endothelial interactions may contribute to both. We find that endothelial cells have increased expression of VCAM-1, E-selectin, and ICAM-1 when exposed to sickle blood cells. The concentration-dependent, sickle-induced, adhesion molecule expression is significantly greater than that promoted by normal cells. The time course of Cell Adhesion Molecule (CAM) expression is similar to that induced by TNF-alpha and IL1. Studies after white cell enrichment and reduction suggest leukocytes are the primary mediators. CAM expression by endothelial cells appears stimulated by soluble factors. Antibody inhibition studies support TNF-alpha and IL-1, produced by sickle leukocytes, as the primary soluble factors responsible for the observed CAM expression. Both the induction of endothelial CAM expression and subsequent endothelial adherence of sickle erythrocytes may play significant roles in the pathophysiology of sickle-related complications, and reduction in CAM expression may provide a new approach to treatment.
Pediatr Pathol Mol Med
PMID:Activation of vascular endothelial cell adhesion molecule expression by sickle blood cells. 1267 44

We have applied a new method of genetic analysis, called 'minisequencing', to preimplantation genetic diagnosis (PGD) of monogenic disorders from single cells. This method involves computer-assisted mutation analysis, which allows exact base identity determination and computer-assisted visualization of the specific mutation(s), and thus facilitates data interpretation and management. Sequencing of the entire PCR product is unnecessary, yet the same qualitative characteristics of sequence analysis are maintained. The main benefit of the minisequencing strategy is the use of a mutation analysis protocol based on a common procedure, irrespective of the mutations involved. To evaluate the reliability of this method for subsequent application to PGD, we analysed PCR products from 887 blastomeres including 55 PGD cases of different genetic diseases, such as cystic fibrosis, beta-thalassaemia, sickle cell anaemia, haemophilia A, retinoblastoma, and spinal muscular atrophy. Minisequencing was found to be a useful technique in PGD analysis, due to its elevated sensitivity, automation, and easy data interpretation. The method was also efficient, providing interpretable results in 96.5% (856/887) of the blastomeres tested. Fifteen clinical pregnancies resulted from these PGD cases; conventional prenatal diagnosis confirmed all the PGD results, and 10 healthy babies have already been born. Its applicability to PGD could be helpful, particularly in cases in which the mutation(s) involved are difficult to assess by restriction analysis or other commonly used methods.
Mol Hum Reprod 2003 Jul
PMID:The minisequencing method: an alternative strategy for preimplantation genetic diagnosis of single gene disorders. 1280 47

Gilbert's syndrome is characterized by mild unconjugated hyperbilirubinemia. The molecular basis of this syndrome usually concerns an additional dinucleotide insertion (TA) in the A(TA)(n)TAA configuration residing in the promoter region of the UGT1 A1 gene. This configuration may vary in length; the "n" represents the different number of TA repeats. The homozygosity A(TA)(7)TAA/A(TA)(7)TAA is involved in Gilbert's syndrome. In many cases of patients with thalassemia intermedia and sickle cell disease considerable variation in bilirubin levels is observed. In this study we investigated the contribution of the A(TA)(7)TAA/A(TA)(7)TAA genotype in the variable unconjugated serum bilirubin levels in 31 Greek patients with thalassemia intermedia and 27 Greek compound heterozygotes for beta thalassemia and sickle cell anemia. Analysis of the A(TA)(n)TAA configuration in the promoter region of the latter patients showed that those who were carrying the homozygosity A(TA)(7)TAA/A(TA)(7)TAA had higher levels of unconjugated bilirubin. These findings suggest that the coexistence of Gilbert's syndrome in patients with thalassemia intermedia and sickle cell disease may be the cause of the elevated values of unconjugated bilirubin, reducing the possibility of excessive hemolysis in these patients.
Blood Cells Mol Dis
PMID:Analysis of the A(TA)(n)TAA configuration in the promoter region of the UGT1 A1 gene in Greek patients with thalassemia intermedia and sickle cell disease. 1285 Apr 81

Alveolar type II cells increase lipogenesis and convert glycogen into the phospholipids of surfactant in the late term fetal lung. Recent studies suggest that CCAAT/enhancing-binding protein (C/EBP) isoforms and sterol regulatory element binding protein (SREBP)-1c regulate fatty acid synthesis in adult type II cells in vitro. To define the temporal relationships and enzymes involved in lipogenesis in fetal rat lung, the mRNA levels of selected transcription factors and enzymes were determined. There was an increase in the mRNA levels of C/EBPalpha, C/EBPbeta, C/EBPdelta, peroxisomal proliferator-activated receptor gamma (PPARgamma), and SREBP-1c, but not SREBP-1a or SREBP-2 from fetal Days 19-21. There was also an increase in the mRNA levels of fatty acid synthase, stearoyl-CoA desaturase 1 (SCD-1), fatty acid translocase, glycerol-3-P acyl transferase, and phosphatidate cytidylyltransferase. By in situ hybridization, there was detectible expression of fatty acid synthase, SCD-1, and C/EBPalpha along the alveolar septae with the same distribution pattern as surfactant protein-C, whereas PPARgamma expression appeared to be restricted to macrophages. Regulation of lipogenesis at the mRNA level is predominately on enzymes of fatty acid synthesis and appears to be regulated by C/EBPalpha and SREBP-1c. SCD-1 and phosphatidate cytidylyltransferase are important components of the lipogenic response in the fetal lung that have not been recognized previously.
Am J Respir Cell Mol Biol 2004 Feb
PMID:Lipogenesis in fetal rat lung: importance of C/EBPalpha, SREBP-1c, and stearoyl-CoA desaturase. 1289 75

As a result of an in vitro screening effort the antiviral agent acyclovir was found to inhibit aggregation of hemoglobin S and the sickling of erythrocytes from individuals with sickle cell disease. Sickling of the erythrocytes was significantly inhibited at 200 microg/ml under essentially anaerobic conditions, considerably more hypoxic than the conditions in which sickling occurs in sickle cell patients. The structurally related guanine-based antiviral agents ganciclovir, valacyclovir, and penciclovir were also tested. Valacyclovir and ganciclovir showed comparable anti-sickling activity at concentrations similar to that of acyclovir. An examination of the shared structural characteristics of the four guanine derivatives linked anti-sickling activity to the presence of an oxygen atom alpha to the N9 of the guanine moiety. These findings suggest a new approach in the search for new agents for the treatment of patients with sickle cell disease.
Blood Cells Mol Dis
PMID:Inhibition of sickling in vitro by three purine-based antiviral agents: an approach to the treatment of sickle cell disease. 1297 37

Vaso-occlusive events are the major source of morbidity and mortality in sickle cell disease (SCD); however, the pathogenic mechanisms driving these events remain unclear. Using hypoxia to induce pulmonary injury, we investigated mechanisms by which sickle hemoglobin increases susceptibility to lung injury in a murine model of SCD, where mice either exclusively express the human alpha/sickle beta-globin (halphabetaS) transgene (SCD mice) or are heterozygous for the normal murine beta-globin gene and express the halphabetaS transgene (mbeta+/-, halphabetaS+/-; heterozygote SCD mice). Under normoxia, lungs from the SCD mice contained higher levels of xanthine oxidase (XO), nitrotyrosine, and cGMP than controls (C57BL/6 mice). Hypoxia increased XO and nitrotyrosine and decreased cGMP content in the lungs of all mice. After hypoxia, vascular congestion was increased in lungs with a greater content of XO and nitrotyrosine. Under normoxia, the association of heat shock protein 90 (HSP90) with endothelial nitric oxide synthase (eNOS) in lungs of SCD and heterozygote SCD mice was decreased compared with the levels of association in lungs of controls. Hypoxia further decreased association of HSP90 with eNOS in lungs of SCD and heterozygote SCD mice, but not in the control lungs. Pretreatment of rat pulmonary microvascular endothelial cells in vitro with xanthine/XO decreased A-23187-stimulated nitrite + nitrate production and HSP90 interactions with eNOS. These data support the hypotheses that hypoxia increases XO release from ischemic tissues and that the local increase in XO-induced oxidative stress can then inhibit HSP90 interactions with eNOS, decreasing *NO generation and predisposing the lung to vaso-occlusion.
Am J Physiol Lung Cell Mol Physiol 2004 Apr
PMID:Hypoxia-induced acute lung injury in murine models of sickle cell disease. 1500 34

The hemoglobin disorders of beta-thalassemia and sickle cell disease together constitute the most prevalent of human monogenic diseases. Although palliative therapies and curative allogeneic stem cell transplantation therapy have been developed for these disorders, many patients still suffer significant morbidity and early mortality. Therefore, development of alternative treatment based on a gene therapy approach continues to be a worthwhile endeavor. Several laboratories have recently achieved major progress towards this goal. Using lentiviral vectors to obtain high-level expression of relatively complex globin gene cassettes, therapeutic correction of several murine models of both beta-thalassemia and sickle cell disease has been achieved. These breakthroughs, coupled with recent significant developments in the ability to select and expand genetically modified stem cells in vivo, have greatly advanced the possibility of gene therapy for the hemoglobin disorders in the near future. These advances, together with recent information regarding safety issues of retroviral gene transfer, are reviewed here.
Curr Opin Mol Ther 2003 Oct
PMID:Update on gene therapy for hemoglobin disorders. 1460 20

The S+S-Antilles transgenic mouse used in this study has renal defects similar to those seen in sickle cell anemia patients: congested glomeruli, medullary fibrosis, renal enlargement, vasoocclusion, and a urine concentrating defect. We used gene expression microarrays to identify genes highly up-regulated in the kidneys of these mice and validated their expression by real-time PCR. Kidney hypoxia, as demonstrated by the presence of deoxyhemoglobin, was detected by blood oxygen dependent magnetic resonance imaging (BOLD-MRI). Some of the up-regulated genes included cytochrome P450 4a14, glutathione-S-transferase alpha-1, mitochondrial hydroxymethylglutaryl CoA synthase, cytokine inducible SH-2 containing protein, retinol dehydrogenase type III, arginase II, glycolate oxidase, Na/K ATPase, renin-1, and alkaline phosphatase 2. An increase in enzyme activity was also demonstrated for one of the up-regulated genes (arginase II). These genes can be integrated into several different pathophysiological processes: a hypoxia cascade, a replacement cascade, or an ameliorating cascade, one or all of which may explain the phenotype of this disease. We conclude that microarray technology is a powerful tool to identify genes involved in renal disease in sickle cell anemia and that the identification of various metabolic pathways may open new avenues for therapeutic interventions.
Blood Cells Mol Dis
PMID:Differential gene expression in the kidney of sickle cell transgenic mice: upregulated genes. 1463 54

Reactivation of fetal hemoglobin (HbF) expression using pharmacological agents represents a potential strategy for the therapy of beta-thalassemia, sickle cell disease, HbE and other beta-hemoglobinopathies. However, the drugs currently available have low efficacy and specificity and are associated with high toxicity. We describe the development of stable cellular genomic reporter assays (GRAs) based on the green fluorescence protein (EGFP) gene under the Ggamma-globin promoter in the intact human beta-globin locus. We show that human erythroleukemic cell lines stably transfected with a Ggamma-EGFP beta-globin locus construct can maintain a uniform basal level of EGFP expression over long periods of continuous culture and that induction of EGFP expression parallels the induction of the endogenous globin genes. We compared the EGFP-induction potency of a number of chemotherapeutic agents, including histone deacetylase inhibitors and DNA-binding agents. We show that hydroxyurea and butyrate result in moderate levels of induction (70-80%) but with an additive inductive effect. Among the DNA-binding agents tested, cisplatin was the most potent inducer of HbF expression, (442+/-32%), a level which is comparable to hemin (764+/-145%). These results indicate that cellular GRAs containing Ggamma-EGFP-modified beta-globin locus constructs can be used to develop novel inducers of HbF synthesis for the therapy of beta-hemoglobinopathies.
Hum Mol Genet 2004 Jan 15
PMID:Cellular genomic reporter assays for screening and evaluation of inducers of fetal hemoglobin. 1464 8


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