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Query: UNIPROT:P06889 (Mol)
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Previous experiments showed that the presence of high levels of acute phase reactants (APR) enhance CCl4-induced liver fibrosis in the rat. A high correlation was found between the degree of fibrosis and alpha 2-macroglobulin of the rat (alpha 2-macrofetoprotein, alpha M-FP) used for monitoring the acute phase response. This acute phase reaction was provoked by epinephrine just before CCl4 treatment was started. In the present study we analyzed the effect of APR by repeating these experiments and estimating liver neutral collagenase with a synthetic substrate and endogenous collagen as a substrate, and liver prolyl-4-hydroxylase. A strong depression of liver collagenase activity was found in rats with a preceding acute phase reaction contrary to the rats that underwent CCl4 treatment only. A high level of alpha M-FP correlated negatively with collagenase activity. Also in vitro alpha M-FP proved to inhibit collagenase activity. Prolyl-4-hydroxylase was increased in the rats during acute phase reaction and correlated highly and positively with alpha M-FP, haptoglobin, and ceruloplasmin. Thus high levels of APR promote development of CCl4-induced fibrosis, partly by anticollagenase activity and partly because of enhancement of prolyl-4-hydroxylase activity. The latter phenomenon can also be explained by the presence of APR, but this has to be proved.
Exp Mol Pathol 1986 Oct
PMID:Mechanisms by which acute phase proteins enhance development of liver fibrosis: effects on collagenase and prolyl-4-hydroxylase activity in the rat liver. 242 60

Intratracheal application of Bleomycin (Bleo) in rats induces interstitial pneumonitis followed by progressive fibrosis. As the presence of high levels of acute-phase proteins (= reactants = APR), especially alpha 2-macroglobulin of the rat (alpha 2M), enhances liver fibrosis, we investigated whether this phenomenon also occurs in rats with Bleo-induced lung fibrosis. The experiments showed that this is the case; lung fibrosis assessed by measuring hydroxyproline, hexosamine, and prolyl-4-hydroxylase was enhanced when just before Bleo application an acute-phase reaction was induced. This effect can be explained by the inhibitory effect of alpha 2M on collagenase. The experiments showed a significant positive correlation between alpha 2M and parameters of fibrosis. This is especially the case in the third week after Bleo application. Bleo itself does not induce a strong acute-phase reaction, notwithstanding the pneumonitis during the first weeks. The increased fibrosis is accompanied by progressive ventilatory disturbances demonstrated by high arterial pCO2 and low pO2. In patients undergoing Bleo treatment, varying levels of APR can be expected, and this could explain the rapid development of fibrosis in individual cases.
Exp Mol Pathol 1988 Dec
PMID:Relation between acute-phase proteins and enhanced bleomycin-induced pulmonary fibrosis in the rat. 246 73

It has been reported that myofibroblasts contain actin and that Ito cells are positive for desmin. The distribution of desmin and actin detected by immunofluorescence, of vitamin A autofluorescence and of Sudan III staining of lipid droplets has been evaluated in sequential stages of experimental liver fibrosis induced in rats by intraperitoneal injections of swine serum. In the normal rat liver Ito cells were positive for desmin and weakly positive for actin. Prior to the development of hepatic fibrosis a clearcut increase in number and desmin staining of lobular Ito cells was observed in treated rats, but the overall actin pattern was unchanged. In the fibrotic rat livers, highly cellular septa contained large numbers of strongly desmin-positive, actin-weakly positive Ito cells and strongly desmin- and actin-positive myofibroblasts. These observations indicate that both Ito cells and myofibroblasts are positive for desmin, but only myofibroblasts contain large amounts of actin. Visualization of actin and desmin using relatively simple techniques, allows the monitoring of Ito cells proliferation, the accumulation of these cells in fibrous septa and their evolution into myofibroblasts as characterized by their increased desmin and actin content; it also allows an indirect evaluation of the process of fibrogenesis.
Virchows Arch B Cell Pathol Incl Mol Pathol 1988
PMID:Desmin and actin in the identification of Ito cells and in monitoring their evolution to myofibroblasts in experimental liver fibrosis. 290

Liver fibrosis is an important feature of many liver diseases, and the assessment of fibrosis is essential for diagnosis and prognosis. Liver needle biopsy, however, tends to sample preferentially the soft parenchyma, which poorly reflects the true extent of fibrosis. Therefore, we have searched for capsule and parenchymal features that are correlated with the fibrosis. To test for these correlations, we used a morphometric analysis of a rat model of liver fibrosis. We demonstrated that, of the variables examined, capsule thickness was the best correlate of liver fibrosis. Our results also showed that there were parenchymal structures that underwent changes that were well-correlated with the development of fibrosis in the liver. These changes were identified as increases in hepatocyte nucleus, cytoplasm, and mitochondria. These facts suggest that, at least in a rat model of fibrosis, capsule thickness is a useful parameter by which to assess liver fibrosis and that specific and apparently adaptive parenchymal changes are well-correlated to fibrosis.
Exp Mol Pathol 1989 Feb
PMID:Hepatic structural correlates of liver fibrosis: a morphometric analysis. 292 Aug 17

The major cause of mortality in human schistosomiasis is the chronic granulomatous reaction of the liver tissue to Schistosoma mansoni eggs. Liver biopsy still provides the best evaluation of the degree of liver damage. However, liver biopsy does not provide an image of the dynamic process of fibrogenesis. Variations of concentrations of procollagen type III peptide in sera have been proposed to be significant markers of liver fibrosis. Thus, liver function tests in relation to histopathological diagnosis and procollagen type III peptide concentrations were studied in patients with schistosomiasis and revealed a high correlation between the serum procollagen type III peptide and the degree of fibrosis in liver tissue.
Exp Mol Pathol 1987 Jun
PMID:Serum concentration of N-terminal procollagen peptide of collagen type III in schistosomal liver fibrosis. 310 33

High levels of acute phase proteins (acute phase reactants, APR) suppress acute inflammatory reactions in the rat. As many APR have antiprotease properties, including an anticollagenase activity, the effect of APR on the development of CCl4-induced liver fibrosis was investigated in rats. APR were provoked by repeated injections of epinephrine, inducing a broad spectrum of APR. This reaction can be monitored measuring alpha 2-macroglobulin levels in the rat (alpha 2-macrofetoprotein, alpha M FP). This protein was found to inhibit both acute galactosamine hepatitis and acute CCl4-induced liver toxicity. The animals with high levels of APR at the start of CCl4 treatment developed a more severe degree of fibrosis and cirrhosis than the control group in which no acute phase reaction was induced. Epinephrine alone had no such effects. Additionally, the APR positive group showed an initially lower degree of hepatocellular damage when compared to control animals. This uncoupling of liver cell damage and subsequent fibrosis may demonstrate that higher levels of APR might be important as to the development of cirrhosis, possibly based on the anticollagenase activity of these proteins.
Exp Mol Pathol 1986 Apr
PMID:Acute phase reactants enhance CCl4 induced liver cirrhosis in the rat. 369 34

The extent of the covalent cross-linking of collagen molecules by pyridinoline was measured in skin lesions from patients with chromomycosis, a chronic fungal infection leading to an extensive and chronic dermal fibrosis. These data were compared to those collected from patients with a localized cutaneous leishmaniasis, an acute inflammatory process leading to an extensive and reversible remodelling of the extracellular matrix. The amount of the mature cross-linking amino acid pyridinoline increased in chromomycosis patients when compared to controls and was significantly higher than in leishmaniasis patients. These data confirm and extend our previous studies on liver fibrosis showing that a high level of pyridinoline is associated to irreversible fibrotic lesions. They also suggest that an increase in the mature collagen cross-linking by pyridinoline in the course of fibrosis is not restricted to liver, but might be a general feature of irreversible and chronic fibrosis.
Cell Mol Biol (Noisy-le-grand) 1993 Nov
PMID:Collagen cross-linking by pyridinoline occurs in non-reversible skin fibrosis. 826 58

Apolipoprotein A-I, a protein produced mainly by hepatocytes, is of major importance in prevention of atherosclerosis. Its serum level varies according to the degree of liver fibrosis and the mechanism of this regulation is unknown. The aim of this study was to investigate the role of extracellular matrix in the regulation of apolipoprotein A-I by the liver. Primary mouse hepatocytes were cultured on different extracellular matrix components. The apolipoprotein A-I mRNA level was quantified in these different culture conditions by a sensitive quantitative RT-PCR procedure and compared according to the extracellular matrix component used as substrate. A significant decrease in the apolipoprotein A-I mRNA level was observed when cells were plated on fibronectin by comparison with cells cultured on all other components. Potential binding of apolipoprotein A-I to the different matrix components was also studied in vitro. We demonstrated that apolipoprotein A-I significantly bound to fibronectin in a concentration-dependent, saturable and specific manner. Thus, fibronectin, a major liver extracellular matrix component, can interact with apolipoprotein A-I both by downregulating its mRNA level in liver cells and by binding this molecule after its secretion in the extracellular space. Since fibronectin is the first matrix component to be produced in excess and deposited in liver fibrosis, it could be involved in the decrease in serum apolipoprotein A-I in alcoholic patients with liver fibrosis and cirrhosis.
Cell Mol Biol (Noisy-le-grand) 1996 Jun
PMID:Role of liver extracellular matrix in transcriptional and post-transcriptional regulation of apolipoprotein A-I by hepatocytes. 882 8

Erythrocyte membrane Na+,K+: Ca2+ ATP ase activities, cholesterol (CH) phospholipid (PL) composition and erythrocyte glutathione (GSH) contents were determined in controls, in patients with chronic active hepatitis and liver cirrhosis. NA+,K+ ATP ase activities were significantly (P < 0.0001) less in patients with chronic active hepatitis and liver cirrhosis (n = 8, 0.102 +/- 0.02 mumol P/mg protein/hour; n = 8, 0.081 +/- 0.02 mumol P/mg protein/hour) than in controls (n = 10, 0.219 +/- 0.05). Histopathological analysis of liver sections obtained from patients with chronic active hepatitis (n = 3) and liver cirrhosis (n = 2) correlated well with erythrocyte biochemical findings. There was a significant negative correlation between Na+,K+ ATP ase activity and portal fibrosis (P < 0.05, r = -8680). However, further experiments performed on larger study populations are needed to better elucidate this correlation. Therefore, NA+K+ ATP ase activity measurement can be reliable assessment of liver fibrosis.
Biochem Mol Biol Int 1996 Nov
PMID:Erythrocyte membrane Na+,K+ ATP ase activity can be a marker of liver histopathology. 895 35

Lobular hepatic fibrosis and the presence of myofibroblasts were studied in heroin abusers, by quantitative automatic image analysis. Nineteen addicts (DA) and thirteen patients having stopped consumption (exDA) were compared to a non-addict group (CONTROL). Addicts, all anti-HIV and HBsAg negative, showed increased transaminase levels. Hepatitis C markers were ot available, at the time of biopsy. The surface of the centrolobular fibrosis, measured on picrosirius stained slides, was respectively 1.9 and 3.5 times larger in DA and exDA than in CONTROL (p < 0.0001). Immunolabelling with an alpha-smooth muscle actin antibody (alpha-SMA) revealed stellate cells in a perisinusoidal location, mainly in areas of matrix thickening in the space of Disse. Morphometric analysis of alpha-SMA expression showed significant differences between the three groups of patients, p < 0.0001 (CONTROL: 198.06 +/- 5.59 microns2; DA: 2227.91 +/- 88.02 microns2; exDA: 3469.10 +/- 154.98 microns2). The surface density of collagen and of alpha-SMA reactivity was also significantly different between these groups (p < 0.0001). These data strongly suggest that heroin is responsible for an early and progressive centrolobular liver fibrosis, occurring simultaneously with a myofibroblastic response. It might represent a reparative phenomenon arising from a direct vascular injury, leading to an impairment of blood-hepatocyte exchange.
Cell Mol Biol (Noisy-le-grand) 1997 Jun
PMID:Quantitative studies on liver fibrosis and alpha-smooth muscle actin expression in heroin abusers. 922 Jan 52


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