Search results for "Stellate cell"
showing 10 items of 106 documents
Neuroglobin and cytoglobin:two new entries in the hemoglobin superfamily.
2004
Abstract: Neuroglobin (Ngb) and cytoglobin (Cygb) are two newly discovered intracellular members of the vertebrate hemoglobin (Hb) family. Ngb, predominantly expressed in nerve cells, is of ancient evolutionary origin and is homologous to nerve-globins of invertebrates. Cygb, present in many different tissues, shares common ancestry with myoglobin (Mb) and can be traced to early vertebrate evolution. Ngb and Cygb display the classical three-on-three -helical globin fold and are endowed with a hexa-coordinate heme Fe atom, in both their ferrous and ferric forms, having the heme distal HisE7 residue as the endogenous sixth ligand. Reversible intramolecular hexa- to penta-coordination of the h…
Cytoglobin is a respiratory protein in connective tissue and neurons, which is up-regulated by hypoxia.
2004
Cytoglobin is a recently discovered vertebrate globin distantly related to myoglobin, and its function is unknown. Here we present the first detailed analysis of the distribution and expression of cytoglobin. Northern and Western blotting experiments show the presence of cytoglobin mRNA and protein in a broad range of tissues. Quantitative PCR demonstrates an up-regulation of cytoglobin mRNA levels in rat heart and liver under hypoxic conditions (22 and 44 h of 9% oxygen). Immunofluorescence studies with three antibodies directed against different epitopes of the protein consistently show cytoglobin in connective tissue fibroblasts as well as in hepatic stellate cells. Cytoglobin is also pr…
Coordinated induction of drug transporters and phase I and II metabolism in human liver slices
2008
Although regulation of phase I drug metabolism in human liver is relatively well studied, the regulation of phase II enzymes and of drug transporters is incompletely characterized. Therefore, we used human liver slices to investigate the PXR, CAR and AhR-mediated induction of drug transporters and phase I and II metabolic enzymes. Precision-cut human liver slices were incubated for 5 or 24 h with prototypical inducers: phenobarbital (PB) (50 mu M) for CAR, beta-naphthoflavone (BNF) (25 mu M) for AhR, and rifampicin (RIF) (10 mu M) for PXR, and gene expression of the phase I enzymes CYP1A1, 1A2, 3A4, 3A5, 2136, 2A6, the phase II enzymes UGT1A1 and 1A6, and the transporters MRP2, MDR1, BSEP, …
Synthesis, chemical characterization, computational studies and biological activity of new DNA methyltransferases (DNMTs) specific inhibitor. Epigene…
2015
This work deals with the synthesis, the chemical characterization of dibutyltin(IV) complex of caffeic acid (Bu2Sn(IV)HCAF, caf1) and its cytotoxic action on tumor cells. The coordination environment at the tin center was investigated by FTIR, (119)Sn{(1)H} cross polarization magic angle spinning, electrospray ionization mass spectroscopy in the solid state and UV-vis, fluorescence and (1)H, (13)C and (119)Sn NMR spectroscopy in solution phases. Density functional theory study confirmed the proposed structures in solution phase and indicated the most probably stable conformation. The effects on viability of breast cancer MDA-MB231, colorectal cancer HCT116, hepatocellular carcinoma HepG2 an…
Hypusinated eIF5A is required for the translation of collagen
2021
AbstractThe evolutionary conserved elongation factor eIF5A is required for the translation of mRNAs that encode protein sequences with consecutive prolines or combined with glycine and charged amino acids. Mammalian collagens are enriched in putative eIF5A-dependent Pro-Gly-containing tripeptides. Here, we show that eIF5A is needed for heterologous expression of collagen in yeast, and using a dual luciferase reporter system we confirmed that eIF5A depletion interrupts translation at Pro-Gly-collagenic motifs. Using mouse fibroblasts, we showed that depletion of active eIF5A reduced collagen 1α (Col1a1) content, which became concentrated around the nuclei, in contrast to a stronger and all o…
Expression of the gene of the alpha-smooth muscle-actin isoform in rat liver and in rat fat-storing (ITO) cells.
1990
Fat storing cells (FSCs) in the liver represent the main site of vitamin A deposition in the body. These cells are considered to play an important role during scar formation and fibrogenesis in the liver. The putative descent of FSCs from the fibroblastic or from the myofibroblastic system have not been determined yet by morphological or immunohistochemical studies. To further define the origin of these liver cells, we analysed the pattern of expression of three structural proteins: vimentin, desmin and the α-smooth muscle (SM)-actin isoform in FSCs of the rat liver, in smooth muscle cells (SMCs) from the aorta and in rat skin fibroblasts. FSCs were studied by immunohistochemical methods im…
Evaluation of the cytotoxic effects of MEIC chemicals 31-50 on primary culture of rat hepatocytes and hepatic and non-hepatic cell lines
1997
The cytotoxicities of 20 chemicals (numbers 31–50) from the Multicenter Evaluation of In Vitro Cytotoxicity (MEIC) programme were assessed with a primary culture of rat hepatocytes and with two hepatic cell lines (Hep G2 and FaO) and one non-hepatic cell line (3T3). The cytotoxicities of the chemicals were evaluated by using the MTT test after the cells had been exposed to the chemicals for 24 hours. For a better evaluation of results, dose–response curves were mathematically linearised and cytotoxicity was expressed as IC50 values and IC10 values (the concentration causing 50% and 10% loss of cell viability, respectively). We found that all the compounds showed similar acute basal cytotox…
TGF-beta1 in liver fibrosis: an inducible transgenic mouse model to study liver fibrogenesis.
1999
Transforming growth factor-beta1 (TGF-beta1) is a powerful stimulus for collagen formation in vitro. To determine the in vivo effects of TGF-beta1 on liver fibrogenesis, we generated transgenic mice overexpressing a fusion gene [C-reactive protein (CRP)/TGF-beta1] consisting of the cDNA coding for an activated form of TGF-beta1 under the control of the regulatory elements of the inducible human CRP gene promoter. Two transgenic lines were generated with liver-specific overexpression of mature TGF-beta1. After induction of the acute phase response (15 h) with lipopolysaccharide (100 microgram ip), plasma TGF-beta1 levels reached600 ng/ml in transgenic animals, which is100 times above normal …
Spontaneous hepatic fibrosis in transgenic mice overexpressing PDGF-A.
2008
Platelet derived growth factor (PDGF) plays a central role in repair mechanisms after acute and chronic tissue damage. To further evaluate the role of PDGF-A in liver fibrogenesis in vivo, we generated transgenic mice with hepatocyte-specific overexpression of PDGF-A using the CRP-gene promoter. Transgenic but not wildtype mice showed expression of PDGF-A mRNA in the liver. Hepatic PDGF-A overexpression was accompanied by a significant increase in hepatic procollagen III mRNA expression as well as TGF-beta1 expression. Liver histology showed increased deposition of extracellular matrix in transgenic but not in wildtype mice. PDGF-A-transgenic mice showed positive sinusoidal staining for alp…
Inhibitory effect of resveratrol on the proliferation of human and rat hepatic derived cell lines.
2000
Resveratrol is a polyphenolic compound especially produced by grapevine and consequently found in wine. Based on epidemiological studies resveratrol may act as a cancer chemopreventive compound. The ability of resveratrol to inhibit cell proliferation was studied in rat hepatoma Fao cell line and human hepatoblastoma HepG2 cell line. The results show that resveratrol strongly inhibits cell proliferation at the micromolar range in a time- and dose-dependent manner. Concentrations higher than 50 microM become toxic. Fao cells are more sensitive than HepG2 cells. Interestingly, the presence of ethanol lowers the threshold of resveratrol effect. Resveratrol appears to prevent or to delay the en…