Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.1.26.9 (ribonuclease)
 6,589 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To provide a basis for studies of the expression of genes encoding the diverse kinds of intermediate-filament (IF) proteins during embryogenesis of Xenopus laevis we have isolated and characterized IF protein cDNA clones. Here we report the identification of two types of Xenopus vimentin, Vim1 and Vim4, with their complete amino acid sequences as deduced from the cloned cDNAs, both of which are expressed during early embryogenesis. In addition, we have obtained two further vimentin cDNAs (Vim2 and 3) which are sequence variants of closely related Vim1. The high evolutionary conservation of the amino acid sequences (Vim1: 458 residues; Mr approximately 52,800; Vim4: 463 residues; Mr approximately 53,500) to avian and mammalian vimentin and, to a lesser degree, to desmin from the same and higher vertebrate species, is emphasized, including conserved oligopeptide motifs in their head domains. Using these cDNAs in RNA blot and ribonuclease protection assays of various embryonic stages, we observed a dramatic increase of vimentin RNA at stage 14, in agreement with immunocytochemical results obtained with antibody VIM-3B4. The significance of very weak mRNA signals detected in earlier stages is discussed in relation to negative immunocytochemical results obtained in these stages. The first appearance of vimentin has been localized to a distinct mesenchymal cell layer underlying the neural plate or tube, respectively. The results are discussed in relation to programs of de novo synthesis of other cytoskeletal proteins in amphibian and mammalian development.
 ...
PMID:Expression of intermediate filament proteins during development of Xenopus laevis. I. cDNA clones encoding different forms of vimentin. 280 27

Connective tissue growth factor (CTGF) is a downstream mediator of transforming growth factor-beta1 (TGF-beta1) and thus a potential target for antifibrotic treatment strategies. CTGF is up-regulated in disorders such as atherosclerosis, scleroderma, and fibrosis of kidneys and lungs. We investigated the temporospatial expression patterns of CTGF and TGF-beta1 mRNA in rat livers with acute fibrogenesis (after a single dose of CCl(4)) and with advanced fibrosis (6 weeks after complete bile duct occlusion). Multiprobe ribonuclease protection assay revealed increasing TGF-beta1 and CTGF mRNA levels 6 hours after injection of CCl(4), with peak levels after 72 hours. In biliary fibrosis TGF-beta1 and CTGF mRNA levels increased fourfold and sevenfold, respectively (P: < 0.001). In situ hybridization combined with cell-specific markers revealed CTGF transcripts in desmin-positive cells after a single dose of carbon tetrachloride, whereas no transcripts were found in normal livers. In biliary fibrosis, however, proliferating bile duct epithelial cells were the predominant source of CTGF mRNA. We conclude that in rat liver fibrogenesis CTGF is up-regulated in close association with TGF-beta1 and that, contrary to a previous report, not solely hepatic stellate cells but activated bile duct epithelial cells are the main source of this profibrogenic factor.
 ...
PMID:Proliferating bile duct epithelial cells are a major source of connective tissue growth factor in rat biliary fibrosis. 1129 May 41

Podocytes in the renal glomerulus express unusual intermediate filament (IF) proteins for epithelial cells. To gain insight into the role of IF proteins in podocytes, we investigated the expression of nestin, vimentin, and desmin in puromycin aminonucleoside (PAN) nephrosis. A Western blot analysis for nestin, vimentin, and desmin demonstrated their exclusive expression in glomeruli and showed their increase in expression in nephrotic glomeruli. Immunolocalization studies showed nestin and vimentin to be located predominantly in the podocytes in both normal and nephrotic glomeruli and that enhancement of desmin staining only occurred in podocytes. A ribonuclease protection assay showed high levels of vimentin and nestin expression in normal glomeruli and an upregulation of all three IF transcripts in nephrotic glomeruli. One day after the PAN injection, however, the vimentin transcripts were found to already have significantly increased, whereas those of nestin or desmin showed no such increase. These findings indicate that podocytes express three IF proteins, namely, vimentin, desmin, and nestin, which are differentially regulated in response to injury. An upregulation of IF proteins may increase the mechanical stability of cells, thus enabling podocytes to undergo morphological changes on the tensile glomerular capillary wall.
 ...
PMID:Upregulation of nestin, vimentin, and desmin in rat podocytes in response to injury. 1641 42