Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:2.7.7.6 (RNA polymerase)
 34,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Deoxyribonucleases and DNA-dependent RNA polymerase activities in T and B lymphocytes isolated from patients with chronic renal failure and control subjects were studied. The data clearly shows that the nuclease activity in T and B cells isolated from uraemic patients is remarkably enhanced when compared to the control cells. Concomitant with the enhancement in enzyme activity, the reduction in RNA polymerase I activity and quantity was observed. It was found that the increase in nuclease activity and quantity was limited to the group of relatively small nucleases with molecular weights ranging from 14 kDa to 18 kDa. It has been reported previously that these nucleases are among the cleavage products of the largest subunit of DNA-dependent RNA polymerase I. Thus we suggest that the depressed metabolic activity is a characteristic feature of the uraemic lymphocyte cells and the observed increased in DNase activity in those cells is a result of polymerase I degradation.
Nephrol Dial Transplant 1993
PMID:Increase in deoxyribonuclease activity in uraemic lymphocytes is caused by the cleavage of the largest polymerase I subunit. 839 6

Hepatitis C virus (HCV) is an enveloped, single-stranded RNA virus that has been classified in the Flaviviridae family. The genome of 9400 nucleotides comprises two non-coding regions in 5' and 3' flanking a large reading frame which codes for a polyprotein of 3000 amino acids; this polyprotein is further cleaved into structural (C, E1, E2) and non-structural (NS1, NS2, NS3, NS4, NS5) proteins. The positive RNA acts as a cap-independent messenger; the transcription is mediated by the NS5 RNA polymerase. After the maturation step, the virion is liberated by budding through the cytoplasmic membrane. As for many other RNA viruses, the HCV genome exhibits a high degree of variability, especially in the E2/NS1, E1, NS3 and NS5b regions. Conversely the 5' non-coding region is highly conserved, at least in part, and can be used for diagnostic purposes by PCR technique. Six genotypes of HCV have already been reported, numbered from 1 to 6 in Simmonds' classification. The same genotype can be divided into subtypes (for instance, genotype 1 comprises three subtypes: 1a, 1b and 1c). Various minor variants of the same strain, called quasispecies, are commonly present in the blood of the same patient. Strains of genotype 1b--which is the most widespread worldwide--are correlated with more severe clinical manifestations, greater viral loads and lower response to interferon treatment. The high variability of the HCV genome contributes greatly to the difficulty of designing potent vaccines.
Nephrol Dial Transplant 1996
PMID:Structure, genomic organization, replication and variability of hepatitis C virus. 891 41

The present study investigated the role of heme oxygenase-1 (HO-1) in regulating the vascular tone of the peritoneum undergoing peritoneal dialysis. First, we used reverse-transcriptase polymerase chain reaction (RT-PCR) to measure changes in the expression of HO-1 mRNA in the peritoneum of dehydrated Wistar Kyoto (WKY) rats. Second, we used a charge-coupled-device (CCD) camera to measure changes in the diameter and blood flow in the small artery of the peritoneum after intravenous administration of saline, hemin (4-12 mumol/kg), and tin-protoporphyrin (4-12 mumol/kg) in dehydrated WKY rats. In non dehydrated rats (control), no expression of HO-1 mRNA in the peritoneum was seen. In dehydrated and 10% glucose-treated dehydrated rats, HO-1 expression was significantly enhanced as compared with the control rats. Intravenous administration of saline induced no significant changes in the diameter of the small artery in dehydrated WKY rats. Intravenous administration of hemin induced a significant increase in the diameter of the small artery in dehydrated WKY rats. Intravenous administration of tin-protoporphyrin induced a significant reduction in the diameter of the small artery in dehydrated WKY rats. Our results suggest that 10% glucose injection into the peritoneal cavity induces overexpression of HO-1 in the peritoneum of dehydrated rats. In addition, HO-1 regulates peritoneal function by the regulation of vascular tone in the peritoneum.
Adv Perit Dial 2001
PMID:Heme oxygenase-1 regulates vascular tone of the peritoneum undergoing peritoneal dialysis. 1151 Feb 65

This study aimed to clarify the role of laminin (a component of the extracellular matrix) in the mechanism of peritoneal fibrosis in continuous ambulatory peritoneal dialysis (CAPD) patients, and the effect of prednisolone on such fibrosis. We used semiquantitative reverse-transcriptase polymerase chain reaction (RT-PCR) and ELISA to study laminin mRNA expression and laminin protein production by human peritoneal mesothelial cells (HPMCs) cultured under various conditions. After 6 hours, medium 199 with a high glucose content (4.0%) increased laminin mRNA expression by 1.38-fold relative to control medium (0.1% glucose). Prednisolone (1 mumol/L) suppressed this increase by 92.9%. The laminin protein level in culture supernatant was increased 1.83-fold after incubation for 24 hours in high-glucose medium. Prednisolone (1 mumol/L) suppressed this increase by 58.3%. The effects of prednisolone were prevented by a glucocorticoid receptor antagonist (RU486) at 100 mumol/L. We conclude that culture of HPMCs in high-glucose medium increases laminin mRNA and protein expression, while prednisolone suppresses these changes via the glucocorticoid receptor, suggesting that prednisolone may prevent peritoneal fibrosis in CAPD patients.
Adv Perit Dial 2001
PMID:Effect of prednisolone on increased expression of laminin by human peritoneal mesothelial cells cultured with high glucose. 1151 Feb 74

Encapsulating peritoneal sclerosis (EPS) is an important complication of peritoneal dialysis in which all or part of the intestine is enveloped in a fibrous ball resulting in a cocoon. Previously, we reported that acid dialysis solution (DS) induces peritoneal fibrosis. In the present study, we examined the effect of treatment with glucocorticoid (GC) in a model of EPS in rats. We divided 20 male Wistar-Kyoto rats into four groups and dialyzed them with various solutions for 40 days as follows: (1) pH 3.5 DS, 10 mL (pH 3.5, containing 1.35% glucose, n = 5); (2) pH 3.5 DS, 10 mL + GC (0.1 mg dexamethasone daily, n = 5); (3) pH 7.0 DS, 10 mL (n = 5); and (4) pH 7.0 DS, 10 mL + GC (n = 5). At the end of 40 days, all rats were humanely killed by decapitation. Expression of mRNA of aquaporins (AQPs) and glucose transporters (GLUTs) were studied by reverse-transcriptase polymerase chain reaction. In rats treated with pH 3.5 DS, necropsy findings showed evidence of EPS. The typical appearance was multiple surfaces covered with granulation tissue or fibrotic tissue or both. Multiple adhesions were present. Microscopic findings revealed that low-pH DS induced peritoneal fibrosis and loss of mesothelium. In the dialyzed rats, mRNA of AQP-1, AQP-4, GLUT-1, GLUT-4, and GLUT-5 was expressed in peritoneum. In rats treated with pH 3.5 DS, expression of AQPs was significantly suppressed and expression of GLUTs was significantly enhanced. However, glucocorticoid treatment prevented the progression of peritoneal fibrosis and adhesion of peritoneum. In rats treated with pH 7.0 DS, no signs of EPS were seen. Our study suggests that low-pH DS induced the development of EPS. Glucocorticoid protects against the development of EPS on peritoneal dialysis.
Adv Perit Dial 2002
PMID:Glucocorticoid protects against the development of encapsulating peritoneal sclerosis on peritoneal dialysis. 1240 3

We investigated the effect of transforming growthfactor beta (TGFbeta1) short hairpin RNA (shRNA) mediated by pcDU6 plasmid on TGFbeta1 expression in human peritoneal mesothelial cells (HPMCs) and compared that effect with the effect of antisense TGFbeta1 RNA. We designed two pairs of oligonucleotides for two selectedfragments of coding sequence containing a 21-nucleotide (nt) TGFbeta1 sequence starting with GGCC. After annealing, double-stranded DNA was formed and separately ligated to plasmid pcDU6 [pcDNA3.1(-) with U6 promoter). The inverted motif contained six spacers and four Ts, which made it possible to form shRNA (TGFbgeta1 shRNA1 and TGFbeta1 shRNA2). We generated recombinant human TGFbeta1 antisense mammalian expression vector, and we isolated HPMCs from human greater omentum by pancreatin disaggregation to establish a stable cell-culture model. We used Lipofectamine 2000 to transfect third-passage HPMCs with plasmid pcDU6 mediating the expression of TGFbeta1 and plasmid pcDNA3.1(-) mediating the expression of antisense TGFbeta1 messenger RNA (mRNA). The resulting transfected cells were then stimulated with 4.25% D-glucose and 10 microg/mL lipopolysaccharide (GS+LPS). We used semi-quantitative reverse-transcriptase polymerase chain reaction to detect the expression of TGFbeta1, fibronectin (FN), collagen 1, and plasminogen activator inhibitor type 1 (PAI-1) mRNA by the stimulated cells. The TGFbeta1, FN, and PAI-1 protein levels in the culture supernatant were measured with a sandwich enzyme-linked immunosorbent assay. Expression of TGFbeta1 was significantly upregulated in HPMCs stimulated with GS+LPS (p < 0.01). As compared with control HPMCs in serum-free F12 medium, HPMCs transfected with TGFbeta1 antisense RNA showed inhibited expression of FN, collagen 1, and PAI-1 mRNA (17%, 26%, and 9.6% respectively after 24 hours). Forty-eight hours after transfection, the FN and PAI-I proteins were inhibited by 54.55% and 61.13% respectively (p < 0.05). In the pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups, TGFbeta1 expression was obviously downregulated as compared with the GS+LPS group and the pcDU6 void vector group (p < 0.01). No significant difference was observed between the pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups (p > 0.05). No significant difference was observed between the pcDNA3.1(-) vector-mediated antisense RNA group and the pcDU6 void vector group (p > 0.05). The expression of TGFbeta1 in pcDU6 plasmid vector-mediated TGFbeta1 shRNA groups was obviously downregulated as compared with the pcDNA3.1(-) plasmid vector-mediated antisense RNA group (p < 0.01). In HPMCs stimulated with GS+LPS, pcDU6 plasmid vector-mediated shRNA can significantly inhibit the induced expression of TGFbeta1. These results suggest the possible application of pcDU6 plasmid vector-mediated shRNA in preventing peritoneal fibrosis in patients receiving peritoneal dialysis.
Adv Perit Dial 2005
PMID:Inhibition of transforming growth factor beta (TGFbeta1) expression and extracellular matrix secretion in human peritoneal mesothelial cells by pcDU6 vector-mediated TGFbeta1 shRNA and by pcDNA3.1(-)-mediated antisense TGFbeta1 RNA. 1668 83

Peritoneal dialysis requires large solution volumes that increase abdominal girth and stretch the mesothelial cells of the abdominal wall. To address the hypothesis that stretch stimulates those cells to increase synthesis and production of inflammatory cytokines, we grew MeT-5A human mesothelial cells to confluence and placed the cells in growth arrest on BioFlex Collagen membranes (Flexcell International Corporation, Hillsborough, NC, U.S.A.). After 48 hours, cells were either left stationary (STA) or cycled using a 3000T system (Flexcell International Corporation) with a sinusoidal stretch (STR) frequency of 10 cycles per minute and an amplitude of 30%. The supernatant and cells of individual wells were removed at 0, 4, 12, 24, 48, 72, and 96 hours. Supernatant was assayed by ELISA for transforming growth factor beta (TGF-beta), interleukin 6 (IL-6), and vascular endothelial growth factor (VEGF). After trypsinization, the total number of viable cells in each well was estimated from the lack of trypan blue staining. Total RNA from the cells was extracted, and real-time reverse-transcriptase polymerase chain reaction was used to determine messenger RNA (mRNA) for IL-6, TGF-beta, VEGF, TGF-beta receptors 2 and 3 (TGF-beta-R2, -R3), kinase insert domain receptor (KDR), and FMS-related tyrosine kinase 1 (Flt1). Because of decline of cell numbers and viability, results for STR were compared with those for STA at each time interval up to 72 hours. The mRNA for TGF-beta, VEGF, TGF-beta-R3, and KDR were significantly higher in the STR group throughout the 72 hours, and STR IL-6 mRNA declined nonsignificantly. Normalized to the number of viable cells, supernatant IL-6, TGF-beta, and VEGF were not significantly different between the groups. We conclude that mechanical stress from mesothelial stretch does not enhance mesothelial cell secretion oflL-6, TGF-f, or VEGF, but does increase expression ofTGF-P, VEGF, and their corresponding cell receptors TGF-f-R3 and KDR.
Adv Perit Dial 2012
PMID:Stretch of human mesothelial cells increases cytokine expression. 2331 Dec 5