Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We present a systematic comparison of three modules that enhance expression from retroviral gene transfer vectors at a posttranscriptional level: (i) splice signals (SS) that create an intron in the 5' untranslated region; (ii) constitutive RNA transport elements (CTE), originally discovered in D-type retroviruses; and (iii) the posttranscriptional regulatory element of woodchuck hepatitis virus (WPRE). Here we show that enhancement of expression depends not only on the specific element, but also on the gene of interest, implying context-dependent activity of the RNA elements. Interestingly, different results were obtained for genes that normally require or do not require such control elements. Expression of the HIV-1 gag-protease gene, which normally depends on the viral export factor Rev, was strongly enhanced by an oligomeric CTE, while WPRE had only a marginal effect. On the other hand, both CTE and WPRE compensated for the lack of an intron in the expression of human beta-globin. In this case, the strongest stimulation of RNA production was observed when functional SS were combined with the WPRE. Both CTE and, in particular, WPRE also enhanced expression of cDNAs that do not normally require any such element (green fluorescent protein, human multidrug resistance-1). In this study, functional SS and WPRE acted in an additive manner, resulting in a 10-fold higher level of expression. Our results indicate that the described modules act on different levels of RNA processing, transport, and translation and that the correct choice of a posttranscriptional enhancer configuration depends on the type of cDNA to be expressed.
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PMID:Context dependence of different modules for posttranscriptional enhancement of gene expression from retroviral vectors. 1108 17

A number of antibiotics have been reported to disturb the decoding process in prokaryotic translation and to inhibit the function of various natural ribozymes. We investigated the effect of several antibiotics on in vitro splicing of a eukaryotic nuclear pre-mRNA (beta-globin). Of the eight antibiotics studied, erythromycin, Cl-tetracycline and streptomycin were identified as splicing inhibitors in nuclear HeLa cell extract. The K(i) values were 160, 180 and 230 microm, respectively. Cl-tetracycline-mediated and streptomycin-mediated splicing inhibition were in the molar inhibition range for hammerhead and human hepatitis delta virus ribozyme self-cleavage (tetracycline), of group-I intron self-splicing (streptomycin) and inhibition of RNase P cleavage by some aminoglycosides. Cl-tetracycline and the aminocyclitol glycoside streptomycin were found to have an indirect effect on splicing by unspecific binding to the pre-mRNA, suggesting that the inhibition is the result of disturbance of the correct folding of the pre-mRNA into the splicing-compatible tertiary structure by the charged groups of these antibiotics. The macrolide, erythromycin, the strongest inhibitor, had only a slight effect on formation of the presplicing complexes A and B, but almost completely inhibited formation of the splicing-active C complex by binding to nuclear extract component(s). This results in direct inhibition of the second step of pre-mRNA splicing. To our knowledge, this is the first report on specific inhibition of nuclear splicing by an antibiotic. The functional groups involved in the interaction of erythromycin with snRNAs and/or splicing factors require further investigation.
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PMID:Inhibition of nuclear pre-mRNA splicing by antibiotics in vitro. 1178 11

Previous experiments have demonstrated the stable expression of factor IX (FIX) protein in mice and canine models of hemophilia B following portal vein gene transfer with a recombinant adeno-associated virus (rAAV) vector encoding FIX. Here, we present the results of studies that further optimized the rAAV vector transgene cassette used to express FIX and explored the use of the less-invasive intravenous (i.v.) route of vector administration for the treatment of hemophilia B. First, a liver-specific promoter was evaluated in conjunction with cis-acting regulatory elements in mice. Constructs that included both the beta-globin intron and the woodchuck hepatitis virus post-transcriptional regulatory element resulted in the highest level of FIX expression in vivo. Using this optimized vector, we demonstrate that i.v. injection was feasible for hepatic gene transfer in mice, achieving 70-80% of portal vein expression levels of FIX. In further studies using the Chapel Hill strain of hemophilia B dogs, we demonstrate for the first time FIX expression and partial correction of the bleeding disorder following i.v. administration of an AAV vector.
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PMID:Intravenous administration of an AAV-2 vector for the expression of factor IX in mice and a dog model of hemophilia B. 1471 5

Sickle cell disease (SCD) is an autosomal recessive abnormality of the beta-globin chain of hemoglobin (Hb), resulting in poorly deformable sickled cells that cause microvascular occlusion and hemolytic anemia. The spleen is almost always affected by SCD, with microinfarcts within the first 36 months of life resulting in splenic atrophy. Acute liver disorders causing right-sided abdominal pain include acute vaso-occlusive crisis, liver infarction, and acute hepatic crisis. Chronic liver disease might be due to hemosiderosis and hepatitis and possibly to SCD itself if small, clinically silent microvascular occlusions occur chronically. Black pigment gallstones caused by elevated bilirubin excretion are common. Their small size permits them to travel into the common bile duct but cause only low-grade obstruction, so hyperbilirubinemia rather than bile duct dilatation is typical. Whether cholecystectomy should be done in asymptomatic individuals is controversial. The most common laboratory abnormality is an elevation of unconjugated bilirubin level. Bilirubin and lactate dehydrogenase levels correlate with one another, suggesting that chronic hemolysis and ineffective erythropoiesis, rather than liver disease, are the sources of hyperbilirubinemia. Abdominal pain is very common in SCD and is usually due to sickling, which resolves with supportive care. Computed tomography scans might be ordered for severe or unremitting pain. The liver typically shows sickled erythrocytes and Kupffer cell enlargement acutely and hemosiderosis chronically. The safety of liver biopsies has been questioned, particularly during acute sickling crisis. Treatments include blood transfusions, exchange transfusions, iron-chelating agents, hydroxyurea, and allogeneic stem-cell transplantation.
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PMID:Gastrointestinal and hepatic complications of sickle cell disease. 2021 64