Fibrogenesis In Patients Research Articles

Plasma transforming growth factor-beta 1 concentrations in patients with chronic viral hepatitis.

Transforming growth factor (TGF)-beta 1 is an important cytokine involved in the pathobiology of tissue fibrosis through its stimulation of the production of, and inhibition of the degradation of, extracellular matrix proteins. We examined the clinical usefulness of plasma TGF-beta 1 concentration as a marker of fibrogenesis in patients with chronic viral hepatitis. Thirty-five patients, 11 with minimal chronic hepatitis, 14 with mild chronic hepatitis and 10 with moderate chronic hepatitis and 20 healthy subjects were studied. Transforming growth factor-beta 1 concentrations in platelet-poor plasma were measured with a TGF-beta 1 enzyme-linked immunosorbent assay system kit after acid-ethanol extraction. Plasma TGF-beta 1 levels were significantly elevated in patients with mild and moderate chronic hepatitis, but not in those with minimal chronic hepatitis, compared with the levels in the controls. Plasma TGF-beta 1 levels were increased in parallel with the histological degree of necroinflammation and of liver fibrosis. Plasma TGF-beta 1 levels were positively correlated with blood levels of procollagen type III N-peptide, and 7S fragment and central triple-helix of type IV collagen. These results suggest that plasma TGF-beta 1 level is a useful marker in assessing the situation of liver active fibrogenesis in patients with chronic viral hepatitis.

Proliferation of hepatic stellate cells is inhibited by phosphorylation of CREB on serine 133.

Proliferating, activated, hepatic stellate cells have a high level of collagen type I expression. Therefore, stellate cell proliferation is a critical step in hepatic fibrosis. Here we show that proliferation of activated primary rat stellate cells was blocked by elevation of cAMP with 8 Br-cAMP or isomethylbutyl xanthine, a phosphodiesterase inhibitor, and by stimulation of Ca2+ fluxes with the Ca2+ ionophore A-23187. Because phosphorylation of CREB on Ser133 is an important mediator of cAMP-protein kinase (PKA) and Ca2+-calmodulin kinase II (CAMK-II) activation, we tested whether CREB-PSer133 was essential for stellate cell quiescence. Nuclear extracts from quiescent, but not from activated, stellate cells contained CREB-PSer133. Moreover, the phosphorylation of CREB on Ser133 was stimulated in activated cells by inducing the activity of PKA or CAMK-II. In addition, coexpression of CREB and either a constitutively active PKA or a constitutively active CAMK-II inhibited the proliferation of activated stellate cells. In contrast, expression of CREB alone, PKA or CAMK-II alone, CREB-Ala 133 (which lacks the Ser133 phosphoacceptor) with PKA or CAMK-II, or CREB with inactive PKA or CAMK-II mutants did not affect stellate cell proliferation, suggesting that CREB-PSer133 is necessary for blocking the stellate cell cycle. Conversely, expression of a trans-dominant negative CREB-Ala 133 mutant (which competes with CREB/CREB-PSer133 for cognate DNA binding sites and presumably for protein interactions) induced a greater than fivefold entry into S-phase of quiescent stellate cells, compared with control cells expressing either beta-galactosidase or wt CREB, indicating that CREB-PSer133 may be indispensable for the quiescent stellate cell phenotype. This study suggests that PKA and CAMK-II play an essential role on stellate cell activation through the induction of CREB phosphorylation on Ser133, and provides potential approaches for the treatment of hepatic fibrogenesis in patients with chronic liver diseases.

Serum hyaluronate reflects hepatic fibrogenesis in alcoholic liver disease and is useful as a marker of fibrosis.

The high levels of hyaluronic acid (HA), a glycosaminoglycan of the liver extracellular matrix, which is synthesized and degraded in the liver sinusoidal cells, have been related with a decreased function of the endothelial sinusoidal cells. The relevance of HA in alcoholic liver disease has not been sufficiently evaluated, and therefore the current study was addressed to assess whether serum HA reflects the severity of liver fibrosis and fibrogenesis as well as the potential usefulness of hyaluronic acid as a marker of early fibrosis in alcoholics with liver damage. Serum HA and aminoterminal propeptide of collagen III (PIIIP) levels, a marker of liver fibrogenesis in alcoholics with liver disease, were assessed in 45 chronic alcoholic patients (31 men and 14 women, age: 44.1 +/- 1.5 years) (normal liver = 7; fatty changes = 8; fibrosis = 7; alcoholic hepatitis = 6; cirrhosis = 6; and cirrhosis plus alcoholic hepatitis = 11). The severity of liver inflammation and fibrosis were scored in liver specimens as: 0, no lesion; 1+ mild; 2+ moderate; and 3+ severe. Twenty-seven patients (60%) had HA above normal values (1 patient with fatty changes, 3 patients with fibrosis, and all patients with alcoholic hepatitis or cirrhosis). Hyaluronic acid and (PIIIP) levels increased in parallel with the severity of liver damage. Hyaluronic acid levels were higher in those patients with more liver inflammation (0, 128 +/- 38; 1+, 553 +/- 141; 2+, 668 +/- 259; 3+, and 1,073 +/- 419 microg/L; P = .004) and of fibrosis (0, 79 +/- 32; 1+, 156 +/- 70; 2+, 219 +/- 105; and 3+, 695 +/- 114 microg/L; P < .001). Procollagen III peptide levels were related with fibrosis (0, 17 +/- 1; 1+, 25 +/- 6; 2+, 47 +/- 13; 3+, and 55 +/- 9 ng/mL; P = .002) but not with inflammation (0, 29 +/- 7; 1+, 45 +/- 7; 2+, 54 +/- 9; 3+, and 66 +/- 30 ng/mL, P: not significant). Moreover, a direct linear correlation was observed between HA and PIIIP (r = .72, P < .001). A receiver operating characteristic (ROC) curve analysis revealed that HA was similar to PIIIP levels in discriminating between alcoholics without fibrosis and those with fibrosis (area under the ROC curves) .913 +/- .042 vs. .867 +/- .054; P: n.s). In conclusion, serum HA reflects the severity of liver inflammation, fibrosis, and fibrogenesis in patients with alcoholic liver disease and is useful as a marker of precirrhotic and cirrhotic stages.

Serum hyaluronate reflects hepatic fibrogenesis in alcoholic liver disease and is useful as a marker of fibrosis

The high levels of hyaluronic acid (HA), a glycosaminoglycan of the liver extracellular matrix, which is synthesized and degraded in the liver sinusoidal cells, have been related with a decreased function of the endothelial sinusoidal cells. The relevance of HA in alcoholic liver disease has not been sufficiently evaluated, and therefore the current study was addressed to assess whether serum HA reflects the severity of liver fibrosis and fibrogenesis as well as the potential usefulness of hyaluronic acid as a marker of early fibrosis in alcoholics with liver damage. Serum HA and aminoterminal propeptide of collagen III (PIIIP) levels, a marker of liver fibrogenesis in alcoholics with liver disease, were assessed in 45 chronic alcoholic patients (31 men and 14 women, age: 44.1 +/- 1.5 years) (normal liver = 7; fatty changes = 8; fibrosis = 7; alcoholic hepatitis = 6; cirrhosis = 6; and cirrhosis plus alcoholic hepatitis = 11). The severity of liver inflammation and fibrosis were scored in liver specimens as: 0, no lesion; 1+ mild; 2+ moderate; and 3+ severe. Twenty-seven patients (60%) had HA above normal values (1 patient with fatty changes, 3 patients with fibrosis, and all patients with alcoholic hepatitis or cirrhosis). Hyaluronic acid and (PIIIP) levels increased in parallel with the severity of liver damage. Hyaluronic acid levels were higher in those patients with more liver inflammation (0, 128 +/- 38; 1+, 553 +/- 141; 2+, 668 +/- 259; 3+, and 1,073 +/- 419 microg/L; P = .004) and of fibrosis (0, 79 +/- 32; 1+, 156 +/- 70; 2+, 219 +/- 105; and 3+, 695 +/- 114 microg/L; P < .001). Procollagen III peptide levels were related with fibrosis (0, 17 +/- 1; 1+, 25 +/- 6; 2+, 47 +/- 13; 3+, and 55 +/- 9 ng/mL; P = .002) but not with inflammation (0, 29 +/- 7; 1+, 45 +/- 7; 2+, 54 +/- 9; 3+, and 66 +/- 30 ng/mL, P: not significant). Moreover, a direct linear correlation was observed between HA and PIIIP (r = .72, P < .001). A receiver operating characteristic (ROC) curve analysis revealed that HA was similar to PIIIP levels in discriminating between alcoholics without fibrosis and those with fibrosis (area under the ROC curves) .913 +/- .042 vs. .867 +/- .054; P: n.s). In conclusion, serum HA reflects the severity of liver inflammation, fibrosis, and fibrogenesis in patients with alcoholic liver disease and is useful as a marker of precirrhotic and cirrhotic stages. (Hepatology 1996 Dec;24(6):1399-403)

Elevated serum aminoterminal procollagen type-III-peptide parallels collagen accumulation in rats with secondary biliary fibrosis

Background/Aims: The aminoterminal procollagen type-III-peptide, which can be released during collagen type III deposition, has been suggested as a serum marker of fibrogenesis in patients with chronic liver disease. However, longitudinal studies correlating procollagen type-III-peptide concentrations in serum with the evolution of liver fibrosis are still needed. The purpose of the present study was to prove the significance of procollagen type-III-peptide concentrations in serum as a non-invasive marker of liver fibrogenesis in an animal model that best resembles progressive human liver fibrosis. Methods: In 88 female Wistar rats the biliary system was occluded by double ligation of the choledochal duct followed by retrograde injection of a mixture of prolamine/ethanole (Ethibloc®). Sixteen rats served as controls. Groups of 8–10 rats were sacrificed at days 2, 7, 14, 21, 30, 32, 35, 60 and 90 after bile duct occlusion. In the groups histological staging (fibrosis score), determination of total liver hydroxyproline, measurement of serum procollagen type-III-peptide and routine liver function tests were performed. Results: First histological signs of liver fibrosis were seen as early as 7 days after bile duct occlusion. Progressive fibrosis was paralleled by an increase of serum procollagen type-III-peptide. There was a significant correlation between serum procollagen type-III-peptide and histological stages of fibrosis ( r=0.80; p<0.0001) as well as between serum procollagen type-III-peptide and hydroxyproline in total liver tissue ( r=0.85; p<0.0001) Conclusions: These results indicate that: (1) complete bile duct occlusion in rats produces progressive hepatic fibrosis resembling human secondary biliary fibrosis, and (2) procollagen type-III-peptide concentrations in serum reflect ongoing collagen formation in the liver unrelated to serum markers of cholestasis and inflammation.

Kupffer cell iron overload induces intercellular adhesion molecule-1 expression on hepatocytes in genetic hemochromatosis

The mechanisms underlying iron-induced liver fibrogenesis in patients with genetic hemochromatosis are poorly understood. We studied signs of Kupffer cell activation and inflammatory responses in liver biopsy specimens obtained from 15 patients with untreated and six patients with treated hemochromatosis. Immunohistochemistry was performed on 11 of the untreated and all treated patients. Three of the untreated patients (20%) had cirrhosis and eight (53%) had fibrosis. None had chronic active hepatitis (CAH). Immunohistochemistry indicated that 55% of the untreated patients had sparse intercellular adhesion molecule-1 (ICAM-1) expression by hepatocytes, and all of these had Kupffer cell iron overload. No ICAM-1 expression was seen by hepatocytes in treated patients or healthy controls. ICAM-1 was strongly expressed by hepatocytes from control patients with inflammatory liver disease. HLA-DR reactivity was seen on sinusoidal cells in all groups, but not on hepatocytes except for two of the control patients with CAH. Twenty-seven percent of the untreated hemochromatosis patients displayed moderate infiltration by CD3-positive lymphocytes. Electron microscopy of samples from untreated hemochromatosis patients showed hypertrophic Kupffer cells containing iron-rich remnants of phagocytosed hepatocytes. Fat-storing cells close to iron-laden hepatocytes contained multiple lipid droplets and adjacent collagen fibril bundles. Thus, in patients with untreated genetic hemochromatosis and Kupffer cell iron overload, hepatocytes occasionally express ICAM-1. In regions with heavy iron overload, Kupffer cell hypertrophy and transition of fat-storing cells are seen. Our findings indicate that release of factors from iron-loaded, activated Kupffer cells is of importance for the transformation of fat-storing cells and increased collagen deposition seen in genetic hemochromatosis.

Kupffer cell iron overload induces intercellular adhesion molecule-1 expression on hepatocytes in genetic hemochromatosis

The mechanisms underlying iron-induced liver fibrogenesis in patients with genetic hemochromatosis are poorly understood. We studied signs of Kupffer cell activation and inflammatory responses in liver biopsy specimens obtained from 15 patients with untreated and six patients with treated hemochromatosis. Immunohistochemistry was performed on 11 of the untreated and all treated patients. Three of the untreated patients (20%) had cirrhosis and eight (53%) had fibrosis. None had chronic active hepatitis (CAH). Immunohistochemistry indicated that 55% of the untreated patients had sparse intercellular adhesion molecule-1 (ICAM-1) expression by hepatocytes, and all of these had Kupffer cell iron overload. No ICAM-1 expression was seen by hepatocytes in treated patients or healthy controls. ICAM-1 was strongly expressed by hepatocytes from control patients with inflammatory liver disease. HLA-DR reactivity was seen on sinusoidal cells in all groups, but not on hepatocytes except for two of the control patients with CAH. Twenty-seven percent of the untreated hemochromatosis patients displayed moderate infiltration by CD3-positive lymphocytes. Electron microscopy of samples from untreated hemochromatosis patients showed hypertrophic Kupffer cells containing iron-rich remnants of phagocytosed hepatocytes. Fat-storing cells close to iron-laden hepatocytes contained multiple lipid droplets and adjacent collagen fibril bundles. Thus, in patients with untreated genetic hemochromatosis and Kupffer cell iron overload, hepatocytes occasionally express ICAM-1. In regions with heavy iron overload, Kupffer cell hypertrophy and transition of fat-storing cells are seen. Our findings indicate that release of factors from iron-loaded, activated Kupffer cells is of importance for the transformation of fat-storing cells and increased collagen deposition seen in genetic hemochromatosis.

Serum lysyl oxidase activity in patients with various liver diseases.

Serum lysyl oxidase activity was examined in patients with various liver diseases. The activity of the enzyme was detected mainly in the serum fraction of the supernatant 80% saturated with (NH4)2SO4, and its molecular weight was estimated to be about 30,000 by Sephadex G-150 column filtration. Mean serum lysyl oxidase activity in 18 healthy controls was 129 +/- 50 (+/- SEM) cpm/ml and was significantly increased in patients with acute hepatitis, chronic active hepatitis, alcoholic liver disease and primary biliary cirrhosis, but not in those with chronic inactive hepatitis or liver cirrhosis. Serum lysyl oxidase activity was not correlated with the histological grade of hepatic fibrosis, but appeared to reflect active hepatic fibrogenesis in patients with liver diseases.