Serum tissue inhibitor of metalloproteinases in patients with chronic liver disease and with hepatocellular carcinoma

AdhMMP8 Vector Administration in Muscle: An Alternate Strategy to Regress Hepatic Fibrosis

The development of several vaccines against the SARS-CoV2 virus and their application in millions of people have shown efficacy and safety in the transfer of genes to muscle turning this tissue into a protein-producing factory. Established advanced liver fibrosis, is characterized by replacement of hepatic parenchyma by tissue scar, mostly collagen type I, with increased profibrogenic and proinflammatory molecules gene expression. Matrix metalloproteinase 8 (MMP-8) is an interstitial collagen-degrading proenzyme acting preferentially on collagen type I when activated. This study was carried out to elucidate the effect of an intramuscularly delivered adenoviral vector containing proMMP-8 gene cDNA (AdhMMP8) in male Wistar rats with experimental advanced liver fibrosis induced by thioacetamide. Therapeutic effects were monitored after 1, 2, or 3 weeks of a single dose (3 × 1011 vp/kg) of AdhMMP8. Circulating and liver concentration of MMP-8 protein remained constant; hepatic fibrosis decreased up to 48%; proinflammatory and profibrogenic genes expression diminished: TNF-α 2.28-fold, IL-1 1.95-fold, Col 1A1 4-fold, TGF-β1 3-fold and CTGF 2-fold; and antifibrogenic genes expression raised, MMP-9 2.8-fold and MMP-1 10-fold. Our data proposes that the administration of AdhMMP8 in muscle is safe and effective in achieving liver fibrosis regression at a comparable extent as when the adenoviral vector is delivered systemically to reach the liver, using a minimally invasive procedure.

Mitochondria-targeted antioxidant mitoquinone attenuates liver inflammation and fibrosis in cirrhotic rats

In liver cirrhosis, oxidative stress plays a major role in promoting liver inflammation and fibrosis. Mitochondria dysregulation is responsible for excessive reactive oxygen species production. Therefore, in an experimental model of cirrhosis, we investigated the effect of mitochondria-targeted antioxidant mitoquinone. Liver cirrhosis was induced in Spraque-Dawley rats by common bile duct ligation (CBDL). Mitoquinone (10 mg·kg^-1·day^-1, oral gavage) or vehicle was administered from 3rd to 28th day after CBDL, when animals were euthanized; liver oxidative stress, inflammation, fibrosis, mitophagy were evaluated; and in vivo and ex vivo hemodynamic studies were performed. In cirrhotic rats, mitoquinone prevented liver inflammation, hepatocyte necrosis, and fibrosis at histological examination; decreased circulating TNF-α, gene expression of transforming growth factor-β1, collagen type 1a1, TNF-α, IL-6, IL-1β, tissue inhibitor of metalloproteinase-1, matrix metalloproteinase (MMP)-2, and MMP-13; and reduced hepatic oxidative stress, as shown by reduced oxidative carbonylation of the proteins, by modulating antioxidants catalase, Mn superoxide dismutase, and Cu/Zn superoxide dismutase. Furthermore, mitoquinone attenuated apoptosis by reducing hepatic protein expression of cleaved caspase-3. A selective removal of dysfunctional mitochondria was improved by mitoquinone, as shown by the increase in Parkin translocation to mitochondria. Treatment with mitoquinone normalized the weight of the spleen; however, it increased portal blood flow and reduced splenic artery intrahepatic resistance, suggesting an effect on resistance index. Mitochondria-targeted antioxidant mitoquinone improves liver inflammation and fibrosis in cirrhotic rats by reducing hepatic oxidative stress, preventing apoptosis, and promoting removal of dysfunctional mitochondria. Therefore, it may represent a promising strategy for the prevention and treatment of liver cirrhosis.

SOX9 regulated matrix proteins are increased in patients serum and correlate with severity of liver fibrosis

Extracellular matrix (ECM) deposition and resultant scar play a major role in the pathogenesis and progression of liver fibrosis. Identifying core regulators of ECM deposition may lead to urgently needed diagnostic and therapetic strategies for the disease. The transcription factor Sex determining region Y box 9 (SOX9) is actively involved in scar formation and its prevalence in patients with liver fibrosis predicts progression. In this study, transcriptomic approaches of Sox9-abrogated myofibroblasts identified >30% of genes regulated by SOX9 relate to the ECM. Further scrutiny of these data identified a panel of highly expressed ECM proteins, including Osteopontin (OPN), Osteoactivin (GPNMB), Fibronectin (FN1), Osteonectin (SPARC) and Vimentin (VIM) as SOX9 targets amenable to assay in patient serum. In vivo all SOX-regulated targets were increased in human disease and mouse models of fibrosis and decreased following Sox9-loss in mice with parenchymal and biliary fibrosis. In patient serum samples, SOX9-regulated ECM proteins were altered in response to fibrosis severity, whereas comparison with established clinical biomarkers demonstrated superiority for OPN and VIM at detecting early stages of fibrosis. These data support SOX9 in the mechanisms underlying fibrosis and highlight SOX9 and its downstream targets as new measures to stratify patients with liver fibrosis.

TIMP-1 is upregulated, but not essential in hepatic fibrogenesis and carcinogenesis in mice

Tissue inhibitor of metalloproteinases-1 (TIMP-1) is upregulated during hepatic fibrogenesis and considered to promote fibrosis in the injured liver by inhibition of matrix metalloproteases (MMP) and degradation of extracellular matrix. Moreover, TIMP-1 displays anti-apoptotic properties, in patients with hepatocellular carcinoma (HCC) TIMP-1 serum levels are elevated and high TIMP-1 expression levels in HCC are associated with a poor prognosis. Therefore, TIMP-1 could functionally link fibrogenesis and carcinogenesis in the liver. The aim of our study was to characterize the role of TIMP-1 in hepatic fibrogenesis and carcinogenesis. Experimental hepatic fibrogenesis as well as diethylnitrosamine (DEN) -induced hepatocarcinogenesis were studied in TIMP-1-deficient mice and wild type littermates. Hepatic TIMP-1 expression was upregulated following induction of liver fibrosis by bile duct ligation (BDL) or by carbon tetrachloride (CCl₄). Unexpectedly, in comparison to wild type littermates, TIMP-1-deficient mice were not protected from liver fibrosis induced by BDL or CCl₄. TIMP-1 expression was significantly higher in HCC nodules than in surrounding liver tissue. However, experimental hepatic carcinogenesis was similar in TIMP-1-deficient mice and wild type littermates following DEN-treatment or combined treatment with DEN and CCl₄. Therefore we concluded that TIMP-1 is not essential for hepatic fibrogenesis and carcinogenesis in mice.

Changes in TIMP-1 and -2 expression in the early stage of porcine serum-induced liver fibrosis in rats

It is widely recognized that tissue inhibitors of metalloproteinases (TIMPs), especially TIMP-1 and -2, play a key role in the progression of hepatic fibrosis. In the present study, we examined the changes in TIMP-1 and -2 expressions in the early stage of porcine serum (PS)-induced liver fibrosis in Brown Norway (BN) and Wistar rats. The rats were injected intraperitoneally with 0.5 ml/head of PS twice a week for up to 8 weeks and examined at 2, 4 and 8 weeks. Hepatic fibrosis and inflammatory cell infiltration developed at 4 and 8 weeks in BN and Wistar rats, respectively, and formation of pseudolobules was detected at 8 weeks in rats of both strains. The expression of liver TIMP-1 and -2 mRNAs significantly increased at 8 weeks in rats of both strains. At the same time, TIMP-1 and -2 activities were also detected in the liver of both strains. On the other hand, the expression of serum TIMP-1 and -2 proteins increased earlier (at 4 weeks for TIMP-1 and at 2 or 4 weeks for TIMP-2) than that of liver TIMP-1 and -2 mRNAs did. Although there are some reports suggestive of why the elevation of serum TIMP-1 and -2 proteins preceded that of liver TIMP-1 and -2 mRNAs, the exact reason is still obscure. In conclusion, the present study showed for the first time the mode of TIMP-1 and -2 expression and activity in the early stage of PS-induced rat liver fibrosis model.

Serum levels of hyaluronic acid and tissue metalloproteinase inhibitor-1 combined with age predict the presence of nonalcoholic steatohepatitis in a pilot cohort of subjects with nonalcoholic fatty liver disease

Hyaluronic acid (HA) and tissue inhibitor of metalloproteinase 1 (TIMP-1) are reliable markers of liver fibrosis and are closely linked to the proinflammatory status. In this pilot cohort study, we attempted to identify a clinical score that would predict the severity of nonalcoholic fatty liver disease (NAFLD) based on clinical variables and serum markers of fibrosis and inflammation. The cohort included 46 patients with histologically confirmed NAFLD (76.1% male; mean age, 43+/-13 years; mean body mass index [BMI], 27.8+/-3.5). Serum transforming growth factor beta (TGF-beta), HA, TIMP, and matrix metalloproteinase (MMP) levels were measured with commercial enzyme-linked immunoassay (ELISA) kits. Demographic features and clinical and laboratory findings were subjected to univariate and multivariate binary logistic regression analysis to construct the mathematical model. Receiver operating characteristic curve (ROC) analysis was used to identify a threshold value for diagnosis of NASH and to assess its sensitivity and specificity. Serum levels of HA and TIMP-1 were statistically different in patients with nonalcoholic steatohepatitis (NASH) (P<0.05). Logistic regression analysis of several clinical variables indicated patient age as the only independent predictor of NASH (odds ratio [OR], 1.129, 95% confidence interval [CI], 1.019-1.251, P=0.020). The mathematical model constructed on the basis of these results included age, TIMP-1, and HA levels. A value of 148.27 or more identified patients with NASH with 85.7% sensitivity, 87.1% specificity, and negative and positive predictive values of 96.4% and 60%, respectively. This model seems to represent a reliable noninvasive tool for excluding the presence of NASH. If validated in larger prospective cohort studies, it might be useful for determining when a liver biopsy is actually warranted in patients with NAFLD.

Matrix metalloproteinase gene delivery for liver fibrosis

The resolution of advanced liver fibrosis has been recently recognized to be possible, if the causative stimuli are successfully removed. However, whether complete resolution from cirrhosis, the end stage of liver fibrosis, can be achieved is still questionable. Delivery of interstitial collagenases, such as matrix metalloproteinase (MMP)-1, in the liver could be an attractive strategy to treat advanced hepatic fibrosis from the view point that the imbalance between too few interstitial collagenases and too many of their inhibitors is the main obstacle to the resolution from fibrosis. Remodeling of hepatic extracellular matrix by delivered interstitial collagenases also facilitates the disappearance of activated hepatic stellate cells, the main matrix-producing cells in the liver, and promotes the proliferation of hepatocytes. This review will focus on the impact of the gene delivery of MMPs for the treatment of advanced liver fibrosis while discussing other current therapeutic strategies for liver fibrosis, and on the need for the development of a safe and effective delivery system of MMPs.

Progression of fibrosis in hepatitis C with and without schistosomiasis: correlation with serum markers of fibrosis

Serial liver biopsies are the gold standard by which the progression of fibrosis is evaluated. This longitudinal cohort study assessed the different rates in the progression of fibrosis using serial liver biopsies and serum fibrosis markers YKL-40 and PIIINP and the cytokines, transforming growth factor beta (TGF-beta) and tumor necrosis factor alpha (TNuF-alpha). A 10-year cohort study was performed in patients with hepatitis C virus (HCV) alone or HCV and schistosomiasis. Patients were enrolled at the time of acute HCV infection and prospectively evaluated with two liver biopsies (at entry and end of follow-up), and true rates in the progression of fibrosis were calculated per year. Serum YKL-40, N-terminal propeptide of collagen III (PIIINP), TGF-beta, and TNF-alpha were measured, as well as the expression of TGF-beta, TNF-alpha, and YKL-40 mRNA in liver tissue. A significant increase in the progression rates of fibrosis occurred in the coinfected group (0.61 +/- 0.13) compared with the HCV monoinfection group (0.1 +/- 0.06; P < .001)). The progression of fibrosis rate/year had a direct linear correlation for YKL-40 (r = 0.892, P < .001) and for PIIINP (r = 0.577, P < .01). YKL-40 showed a linear correlation with TGF-beta (r = 0.897, P < .001). Hepatic mRNA levels of YKL-40 and TGF-beta correlated with the serum levels, confirming a hepatic source for the elevated serum levels. In conclusion, serial cytokine and fibrosis markers can accurately determine the rate at which fibrosis is progressing, identifying both those with rapid fibrosis and those with stable disease.

Review of Growth Inhibitory Peptide as a biotherapeutic agent for tumor growth, adhesion, and metastasis

This review surveys the biological activities of an alpha-fetoprotein (AFP) derived peptide termed the Growth Inhibitory Peptide (GIP), which is a synthetic 34 amino acid segment produced from the full length 590 amino acid AFP molecule. The GIP has been shown to be growth-suppressive in both fetal and tumor cells but not in adult terminally-differentiated cells. The mechanism of action of this peptide has not been fully elucidated; however, GIP is highly interactive at the plasma membrane surface in cellular events such as endocytosis, cell contact inhibition and cytoskeleton-induced cell shape changes. The GIP was shown to be growth-suppressive in nine human tumor types and to suppress the spread of tumor infiltrates and metastases in human and mouse mammary cancers. The AFP-derived peptide and its subfragments were also shown to inhibit tumor cell adhesion to extracellular matrix (ECM) proteins and to block platelet aggregation; thus it was expected that the GIP would inhibit cell spreading/migration and metastatic infiltration into host tissues such as lung and pancreas. It was further found that the cyclic versus linear configuration of GIP determined its biological and anti-cancer efficacy. Genbank amino acid sequence identities with a variety of integrin alpha/beta chain proteins supported the GIP's linkage to inhibition of tumor cell adhesion and platelet aggregation. The combined properties of tumor growth suppression, prevention of tumor cell-to-ECM adhesion, and inhibition of platelet aggregation indicate that tumor-to-platelet interactions present promising targets for GIP as an anti-metastatic agent. Finally, based on cholinergic studies, it was proposed that GIP could influence the enzymatic activity of membrane acetylcholinesterases during tumor growth and metastasis. It was concluded that the GIP derived from full-length AFP represents a growth inhibitory motif possessing instrinsic properties that allow it to interfere in cell surface events such as adhesion, migration, metastasis, and aggregation of tumor cells.

Relationship between matrix metalloproteinase-2 activity and cystatin C levels in patients with hepatic disease

OBJECTIVES

A direct relationship between cystatin C levels and the severity of hepatic disease has been revealed in our previous study. This study was aimed to consider whether a correlation exists between matrix metalloproteinases (MMPs), which have been proven to be involved in liver cirrhosis, and cystatin C to reflect the severity of hepatic disease.

DESIGN AND METHODS

A total of 154 consecutive patients with various liver diseases were recruited to determine their serum levels of cystatin C, MMP-2 and-9, together with other hepatic parameters. These were compared with 40 normal controls.

RESULTS

Average levels of MMP-2 and cystatin C were significantly higher in patients while MMP-9 was significantly lower, as compared to controls. A linear regression analysis has revealed a direct relationship between cystatin C and MMP-2 (Y=83.39 + 270.56 X, R=0.38, P< 0.001), as well as between MMP-2 and the severity of liver diseases.

CONCLUSION

This is the first study to demonstrate a correlation between cystatin C and MMP-2, suggesting that there may be certain interactions between cystatin C and MMP-2 in patients with hepatic diseases.

Increased levels of tissue inhibitor of metalloproteinase-1 in human hepatocellular carcinoma

BACKGROUND

Invasion and metastasis of hepatocellular carcinoma (HCC) are regulated by matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs). However, the role of TIMPs in these processes is not clear.

AIM

To examine the potential involvement of TIMP-1 in HCC and the association between TIMP-1 and clinical outcome of patients with HCC.

METHODS

The study included 91 patients who underwent surgical removal of HCC. TIMP-1 concentrations in the supernatant of tissue homogenates of HCC and non-neoplastic liver were measured by enzyme immunoassay. The relationships between TIMP-1 concentration and various clinicopathological features and recurrence of HCC after surgical operation were examined.

RESULTS

The mean level of TIMP-1 in HCC (486 +/- 610 ng/mg protein, +/- SD) was significantly higher than in the non-neoplastic liver (75 +/- 69, P < 0.0001). The median level of TIMP-1 in poorly differentiated HCCs (701 ng/mg protein) was significantly higher than in well- (80) and moderately (172) differentiated HCCs (P = 0.0047 and P = 0.0082, respectively). TIMP-1 level in liver cirrhosis was higher than in chronic hepatitis (P = 0.0015). TIMP-1 levels in HCC did not influence the recurrence rate of HCC.

CONCLUSIONS

TIMP-1 concentration in HCC was higher than in non-neoplastic liver and correlated with the differentiation grade of HCCs. However, tissue TIMP-1 concentration does not seem to be an important determinant of HCC recurrence.

Increased cystatin C serum concentrations in patients with hepatic diseases of various severities

BACKGROUND

Indicators for long-term monitor of the progress of hepatic diseases are of great clinical importance. Since elevated cathepsin was observed in liver diseases, the aim of this study is to investigate the involvement of cystatin C, a very potent inhibitor of cathepsin and a recently introduced marker for renal function, and to see the applicability of serum cystatin C being a convenient marker for the progression of liver diseases.

METHODS

One hundred eighty consecutive patients with chronic liver disease of various severities and 45 healthy controls were recruited to determine their serum cystatin C concentrations by N Latex Cystatin C kit, as well as certain relevant clinical values, including alanine transaminase (ALT), aspartate transaminase (AST) and AFP.

RESULTS

Average serum cystatin C concentration of patients with hepatic diseases was significantly higher than that of control (0.0902+/-0.0025 mg/dl vs. 0.067+/-0.007 mg/dl; p<0.001), and a linear regression analysis has revealed a direct relation between cystatin C and the severity of liver diseases (Y=1.172+5.492X, R(2)=0.088, p<0.001).

CONCLUSION

This study suggested that cystatin C may be an applicable monitoring marker for monitoring liver functions and progression of liver fibrosis.

Hepatocytes express nerve growth factor during liver injury: evidence for paracrine regulation of hepatic stellate cell apoptosis

A key feature of recovery from liver fibrosis is hepatic stellate cell (HSC) apoptosis, which serves the dual function of removing the major source of neomatrix and tissue inhibitors of metalloproteinases thereby facilitating matrix degradation. The mechanisms regulating HSC apoptosis remain undefined but may include the interaction of nerve growth factor (NGF) with its receptor, p75, on HSC. In this study, by TaqMan polymerase chain reaction in situ hybridization and immunohistochemistry, we demonstrate that NGF is expressed by hepatocytes during fibrotic injury. Peak hepatocyte expression of NGF (48 hours after CCl(4) injection) coincides with maximal rate of apoptosis of HSC by terminal dUTP nick-end labeling staining. Addition of recombinant NGF to HSC in tissue culture causes a dose-dependent increase in apoptosis. NGF regulates nuclear factor (NF)-kappaB activity, reducing p50/p65 binding detected by electromobility shift assay and reduced NF-kappaB CAT reporter activities from both basal unstimulated levels and after NF-kappaB induction by tumor necrosis factor. In each case, a relative reduction in NF-kappaB binding was associated with a significant increase in caspase 3 activity. These data provide evidence that NGF is expressed during fibrotic liver injury and may regulate number of activated HSCs via induction of apoptosis.

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Tissue inhibitor of metalloproteinases-1 attenuates spontaneous liver fibrosis resolution in the transgenic mouse

It has been suggested that the tissue inhibitor of metalloproteinases-1 (TIMP-1) is involved in spontaneous resolution of liver fibrosis. The aim of this study was to investigate whether TIMP-1 altered spontaneous resolution of liver fibrosis in conjunction with matrix metalloproteinases (MMP) inhibition and hepatic stellate cell (HSC) activation. The livers of liver-targeted TIMP-1 transgenic (TIMP-Tg) and control hybrid (Cont) mice were harvested at 0, 3, 7, and 28 days following spontaneous recovery from CCl(4)-induced liver fibrosis. The extent of fibrosis resolution, MMP expression, alpha-smooth-muscle actin (alpha-SMA) positive cells, and procollagen-(I) messenger RNA (mRNA) in the liver were assessed at the respective periods in both groups. We also examined the effect of TIMP-1 on HSC apoptosis. The TIMP-Tg mice showed significantly attenuated resolution of spontaneous liver fibrosis compared with the Cont mice. The hydroxyproline content, number of alpha-SMA positive cells, and procollagen-(I) mRNA rapidly decreased with time in the Cont mice, whereas these markers were little changed in TIMP-Tg mice. The level of the active form of metalloproteinases-2 (MMP-2) in the TIMP-Tg mice was less than that in the Cont mice. TIMP-1 markedly decreased the nonparenchyma apoptotic cells in the liver fibrosis resolution model, and it also inhibited HSC apoptosis associated with suppression of caspase-3 activity in vitro. In conclusion, TIMP-1 significantly attenuated spontaneous resolution of liver fibrosis by the combination of a net reduction of the MMP activity and suppression of apoptosis in HSC.

Rational basis for oligodeoxynucleotides to inhibit collagen synthesis in lung fibroblasts and primary fibroblasts from liver granulomas of Schistosoma mansoni-infected mice

Hepatocellular carcinoma is associated with liver fibrosis. Murine schistosomiasis infection offers a model to study hepatic fibrogenesis. Single-stranded phosphorothiate oligodeoxynucleotides containing the TGF-beta regulatory element have been shown to regulate the transcription of this gene and effectively inhibit collagen synthesis in primary fibroblasts isolated from schistosomiasis-induced hepatic granulomas. While the single-stranded oligos did not decrease collagen and non-collagen protein synthesis below control levels, their double-stranded modified and unmodified counterparts did. Competitive cold oligodeoxynucleotide gel mobility shift analysis using control fibroblast nuclear extract demonstrated that the single-stranded oligos diminished binding of the TGF-beta activator protein to the TGF-beta regulatory element while the double-stranded oligos totally inhibited this binding. TGF-beta element containing single-stranded phosphorothioate oligodeoxynucleotides and their double-stranded counterparts may be successful therapeutic agents to inhibit hepatic fibrogenesis and associated hepatocellular carcinoma.

Effect of alcohol withdrawal on liver transaminase levels and markers of liver fibrosis

BACKGROUND AND AIM

Acute alcohol withdrawal causes changes in hepatic blood flow and metabolism that may result in liver damage. This study aims to assess liver function tests and markers of hepatic fibrogenesis following alcohol withdrawal in alcoholics with clinically compensated liver disease.

METHODS

Serial liver function tests and clinical assessments were performed on 22 male alcoholics during alcohol withdrawal. Plasma tissue inhibitor of metalloproteinase 1 (TIMP1), an inhibitor of collagen degradation, and plasma amino-terminal procollagen III peptide (PIIINP), a collagen precursor molecule, were measured in these alcoholics and in 11 control subjects.

RESULTS

Transaminase levels did not change significantly over 7 days when all subjects were analyzed together. However, 32% of subjects showed a marked transaminase rise. These subjects did not differ from the others in baseline characteristics or short-term outcome, but had a greater benzodiazepine requirement. Only one subject consumed paracetamol (acetaminophen; 1-2 g/day). He had the largest transaminase rise. By comparing PIIINP assays, intact PIIINP concentration appears to increase following alcohol withdrawal. The TIMP1 levels were elevated in alcoholic subjects, but did not change following withdrawal.

CONCLUSIONS

Increasing PIIINP suggests that hepatic fibrogenesis increases, or hepatic clearance falls, during acute alcohol withdrawal. The TIMP1 elevation in these alcoholics suggests that the inhibition of collagen degradation occurs while liver disease is still compensated. The period following alcohol withdrawal may be a time of marked increased susceptibility to paracetamol. The biochemical changes we observed were not associated with adverse short-term outcome, but the cumulative effect after repeated episodes of abrupt withdrawal may be of concern.

Elevation of serum cystatin C concentrations in patients with chronic liver disease

OBJECTIVE

We examined serum cystatin C concentrations in patients to explore the possible clinical application of cystatin C as a marker of disease severity in cases of chronic liver diseases.

METHODS

Serum cystatin C concentrations were determined by an enzyme-linked immunosorbent assay kit in 103 patients with various chronic liver diseases and compared with concentrations in healthy control volunteers.

RESULTS

The mean cystatin C concentration was 0.68 +/- 0.03 mg/l in chronic hepatitis patients, 1.13 +/- 0.09 mg/l in liver cirrhosis patients and 1.16 +/- 0.10 mg/l in hepatocellular carcinoma patients, all significantly higher than concentrations in the control volunteers (P < 0.0001). Significant correlations were observed between cystatin C concentrations and total bilirubin levels, albumin levels, platelet levels, type IV collagen levels and hyaluronic acid levels. Serum cystatin C concentrations correlated well with histological stages despite the lack of correlation with histological grades.

CONCLUSION

Our results show that serum cystatin C increases with the progression of chronic liver disease and that it is a potential marker for liver fibrosis.

Tissue inhibitor of metalloproteinases-1 promotes liver fibrosis development in a transgenic mouse model

Tissue inhibitor of metalloproteinases-1 (TIMP-1) has been shown to be increased in liver fibrosis development both in murine experimental models and human samples. However, the direct role of TIMP-1 during liver fibrosis development has not been defined. To address this issue, we developed transgenic mice overexpressing human TIMP-1 (hTIMP-1) in the liver under control of the albumin promoter/ enhancer. A model of CCl(4)-induced hepatic fibrosis was used to assess the extent of fibrosis development in TIMP-1 transgenic (TIMP-Tg) mice and control hybrid (Cont) mice. Without any treatment, overexpression of TIMP-1 itself did not induce liver fibrosis. There were no significant differences of pro-(alpha1)-collagen-I, (alpha2)-collagen-IV, and alpha-smooth muscle actin (alpha-SMA) mRNA expression in the liver between TIMP-Tg and Cont-mice, suggesting that overexpression of TIMP-1 itself did not cause hepatic stellate cell (HSC) activation. After 4-week treatment with CCl(4), however, densitometric analysis revealed that TIMP-Tg-mice had a seven-fold increase in liver fibrosis compared with the Cont-mice. The hepatic hydroxyproline content and serum hyaluronic acid were also significantly increased in TIMP-Tg-mice, whereas CCl(4)-induced liver dysfunction was not altered. An active form of matrix metalloproteinases-2 (MMP-2) level in the liver of TIMP-Tg-mice was decreased relative to that in Cont-mice because of the transgenic TIMP-1. Immunohistochemical analysis revealed that collagen-I and collagen-IV accumulation was markedly increased in the liver of CCl(4)-treated TIMP-Tg-mice with a pattern similar to that of alpha-SMA positive cells. These results suggest that TIMP-1 does not by itself result in liver fibrosis, but strongly promotes liver fibrosis development.

Serum matrix metalloproteinase-3 (stromelysin-1) concentration in patients with chronic liver disease

BACKGROUND/AIMS

Matrix metalloproteinase (MMP)-3 plays an important role in extracellular matrix degradation, because of its broad substrate specificity and its activation of other proMMPs. Our aims in the present study were to determine whether the measurement of serum MMP-3 is clinically useful for assessing ongoing liver fibrolysis in patients with chronic liver disease.

METHODS

We measured the serum MMP-3 concentrations with a sandwich enzyme immunoassay in 58 patients with chronic hepatitis, 22 patients with liver cirrhosis, 45 patients with hepatocellular carcinoma and 124 healthy individuals. The liver MMP-3 content was also measured in autopsied livers.

RESULTS

Among the healthy controls, the serum levels of MMP-3 were about 2-fold higher in the males than in the females. In this study, the serum MMP-3 results of mainly the male group were analyzed because of the large number of male subjects. Compared to the control level, the mean serum MMP-3 concentration was 55% lower in chronic hepatitis, 53% lower in liver cirrhosis and 46% lower in hepatocellular carcinoma. There was no significant difference in the serum MMP-3 levels among the chronic hepatitis, liver cirrhosis and hepatocellular carcinoma groups. The serum MMP-3 levels were not related to the histological degree of necroinflammation or of liver fibrosis in the patients with chronic hepatitis. No significant difference in serum MMP-3 levels was observed among three Child's subgroups in the group of cirrhotic patients. In the group of patients with hepatocellular carcinoma, the serum MMP-3 levels were not related to the severity of liver function, the HCC tumor size, or the histological differentiation. The serum MMP-3 level was not correlated with serum markers for connective tissue turnover, i.e. procollagen type III peptide, 7S fragment of type IV collagen, hyaluronan and tissue inhibitor of metalloproteinase-1 in the patients with chronic liver disease or hepatocellular carcinoma.

CONCLUSIONS

The measurement of serum MMP-3 is of little use for assessing fibrolysis in chronically diseased livers.

Clinical usefulness of serum tissue inhibitor of metalloproteinases (TIMP)-2 assay in patients with chronic liver disease in comparison with serum TIMP-1

Tissue inhibitors of metalloproteinases (TIMPs) are involved in liver fibrosis through impaired matrix degradation. Previous studies showed that the serum level of TIMP-1 was increased in patients with chronic liver disease, reflecting the liver TIMP-1 level, and that it is useful for assessing liver fibrosis. An enzyme immunoassay for TIMP-2 is now available. In this study, we examined the clinical usefulness of this serum TIMP-2 test for liver fibrosis in patients with chronic liver disease, in comparison with the serum TIMP-1 test. The serum TIMP-2 concentration was 61 +/- 13 ng/ml in healthy controls (n = 32), and 18% higher in the group of chronic active hepatitis (CAH) patients (n = 34), 64% higher in the liver cirrhosis (LC) group (n = 33) and 44% higher in the hepatocellular carcinoma (HCC) group (n = 61), and similar to the control level in the chronic persistent hepatitis (CPH) group (n = 23). In contrast, the serum TIMP-1 concentration was 155 +/- 17 ng/ml in the healthy controls, 18% higher in CPH, 35% in CAH, 63% higher in LC and 92% higher in HCC. The serum TIMP-2 level was related to the histological degrees of both periportal necrosis and liver fibrosis, as well as to the serum TIMP-1 level. However, the relationships for TIMP-2 were weaker compared to those of serum TIMP-1. These results suggest that compared to the serum TIMP-1 level, changes in the serum TIMP-2 level in chronic liver disease are less liver-specific, and the serum TIMP-2 level is less useful in the assessment of liver fibrosis in chronic liver disease.

Serum matrix metalloproteinase-1 in patients with chronic viral hepatitis

BACKGROUND AND AIMS

Previously we found that serum matrix metalloproteinase (MMP)-1 activity decreased with progression of chronic liver disease. Our objectives in the present study were to observe the change in the serum MMP-1 protein concentration using recently developed specific enzyme immunoassays for MMP-1 and MMP-1 complexed with tissue inhibitor of metalloproteinases (TIMP)-1 and to elucidate the clinical usefulness of the serum MMP-1 test in chronic viral hepatitis. We measured the serum concentrations of MMP-1 and MMP-1/TIMP-1 complex using these immunoassays in 64 patients with histologically characterized chronic viral hepatitis.

RESULTS

Serum MMP-1 concentration was inversely related to the histological severity of chronic hepatitis (P< 0.0001). It was closely associated with the histological degree of periportal necrosis (P< 0.0001), intralobular necrosis (P< 0.005), portal inflammation (P<0.0001) and liver fibrosis (P< 0.05). The serum concentration of MMP-1/TIMP-1 complex was also related to the histological severity of chronic hepatitis (P< 0.0001). It was associated with the degree of portal inflammation (P< 0.05), but not with the degree of periportal necrosis, intralobular necrosis or liver fibrosis. As serum MMP-1 level was closely associated with the histological degree of necroinflammation, we examined the ability of the serum MMP-1 test to differentiate active and inactive forms of hepatitis with a receiver operating curve. The results were compared with those of serum procollagen type III N-peptide (PIIINP) test. We found that the serum MMP-1 test was superior to the serum PIIINP test in assessing liver necroinflammation.

CONCLUSIONS

In addition to the previously reported changes in enzyme activity, MMP-1 proteins in serum decreased during histological progression of chronic hepatitis. The serum MMP-1 test may be useful clinically to differentiate active and inactive types of hepatitis in patients with chronic viral hepatitis.

Altered balance between matrix metalloproteinases and their inhibitors in experimental biliary fibrosis

A rat model of common bile duct ligation (BDL)-induced hepatic fibrosis was used to assess the expression and activities of collagen-degrading proteinases and their inhibitors during the progression of fibrosis. Expression of four members of the matrix metalloproteinase (MMP) family (MMP-2/gelatinase A, MMP-3, MMP-9/gelatinase B, and MMP-13) and three tissue inhibitors of metalloproteinases-1, -2, and -3 (TIMP-1, TIMP-2, and TIMP-3) were evaluated by Northern blot analysis of RNA from liver tissue isolated at 0, 2, 5, 10, 20, and 30 days after either a BDL or sham operation. In addition, we analyzed free gelatinase and TIMP activities by zymography and reverse zymography, respectively. We found that the proteolytic activities of MMP-2 and MMP-9 increased by 2 days after ligation, reached maximal levels at day 10, and remained high through the study period, whereas the gelatinolytic activities in plasma were unchanged. The increase in gelatinase activities was accompanied by an increase in the TIMP mRNA transcripts. TIMP-1 transcripts appeared at day 2, increased until day 10, and remained elevated throughout the study period. TIMP-2 and TIMP-3 transcripts become detectable on day 10 and remained stable afterwards. No corresponding increase in TIMP protein activity was detected by reverse zymography. This appears to result from the formation of TIMP/MMP complexes. These findings indicate a likely surplus in the BDL model of fibrosis of free gelatinases as compared with the TIMPs. Thus, excessive TIMP production is not a sufficient explanation for the observed extracellular matrix accumulation, but complex changes in the local MMP/TIMP balance may underlie the pathomechanisms of fibrosis.

Effects of Fuzheng Huayu 319 recipe on liver fibrosis in chronic hepatitis B

AIM: To investigate clinic effects of Fuzheng Huayu 319 recipe (319 recipe) on liver fibrosis in chronic hepatitis B.

METHODS: Ninety-five patients with chronic hepatitis B were divide into the treated (63 cases) and control (32 cases) group, and orally administrated with 0.5g 319 capsule or 0.5g Dahuang Zhachong pill tid for 3 months, respectively. The liver functions and serological fibrotic markers were observed before and after treatment, 12 cases in the treated group were examined with liver biopsy.

RESULTS: Three hundreds nineteen recipe could remarkably decreased serum ALT level and total bilirubin and significantly improve serum albumin and A/G ratio. Its effects were better than Dahuang Zhachong pill. Before treatment, patients¡äserum monamine oxidase activities, tissue inhibitor of metalloproteinase (TIMP)-1, procollagen type III and laminin were all higher than those of health peoples. These levels decreased remarkably after treatment, and urine hydroxyproline level increased significantly (P<0.001-0.05). Compared with the control, the improvement in treated group was better than that in the control except TIMP-1. According to the scoring system for staging of chronic hepatitis, the fibrotic extents of 7 cases among 12 cases examined by liver biopsy decreased remarkably (1 case decreased by 3 scores, 5 by 2 scores, 1 by 1 score).

CONCLUSION: Fuzheng Huayu 319 recipe had good therapeutic effects on chronic hepatitis B, it could reverse the development of liver fibross to some extent. In general its effects were better than that of Dahuang Zhachong pill.

Mechanisms of spontaneous resolution of rat liver fibrosis. Hepatic stellate cell apoptosis and reduced hepatic expression of metalloproteinase inhibitors

Liver fibrosis results from the excessive secretion of matrix proteins by hepatic stellate cells (HSC), which proliferate during fibrotic liver injury. We have studied a model of spontaneous recovery from liver fibrosis to determine the biological mechanisms mediating resolution. Livers were harvested from rats at 0, 3, 7, and 28 d of spontaneous recovery from liver fibrosis induced by 4 wk of twice weekly intraperitoneal injections with CCl4. Hydroxyproline analysis and histology of liver sections indicated that the advanced septal fibrosis observed at time 0 (peak fibrosis) was remodeled over 28 d of recovery to levels close to control (untreated liver). alpha-Smooth muscle actin staining of liver sections demonstrated a 12-fold reduction in the number of activated HSC over the same time period with evidence of HSC apoptosis. Ribonuclease protection analysis of liver RNA extracted at each recovery time point demonstrated a rapid decrease in expression of the collagenase inhibitors TIMP-1 and TIMP-2, whereas collagenase mRNA expression remained at levels comparable to peak fibrosis. Collagenase activity in liver homogenates increased through recovery. We suggest that apoptosis of activated HSC may vitally contribute to resolution of fibrosis by acting as a mechanism for removing the cell population responsible for both producing fibrotic neomatrix and protecting this matrix from degradation via their production of TIMPs.

Activation of tissue inhibitor of metalloproteinases-3 (TIMP-3) mRNA expression in scleroderma skin fibroblasts

Excessive accumulation of fibrillar collagens is a hallmark of the cutaneous fibrosis in both systemic and localized scleroderma. Turnover of the collagenous extracellular matrix is dependent on the balance between collagenolytic matrix metalloproteinases and their specific inhibitors. We have examined the expression of the novel, matrix associated tissue inhibitor of metalloproteinases-3 (TIMP-3) in normal and scleroderma skin fibroblasts in culture and in vivo. The levels of TIMP-3 mRNA were elevated up to 2.5-fold in five of seven systemic sclerosis fibroblast strains, whereas TIMP-1 mRNA expression was elevated up to 1.8-fold in two and TIMP-2 mRNA expression up to 1.8-fold in two systemic sclerosis strains. Using in situ hybridization, TIMP-3 mRNA was detected in seven of 12 localized scleroderma skin samples, specifically in fibroblasts within fibrotic collagen fibers or in the vicinity of inflammatory cells. TIMP-1 mRNA was detected in three of eight scleroderma skin samples in fibroblasts adjacent to inflammatory cells. The expression of TIMP-3 mRNA by systemic sclerosis and normal skin fibroblasts was enhanced to a similar extent (by 8.6- and 8.1-fold, respectively) by transforming growth factor-beta, and suppressed down to 34 and 54%, respectively, by tumor necrosis factor-alpha. Specific activation of TIMP-3 gene expression in scleroderma skin fibroblasts in culture and in vivo suggests a role for TIMP-3 in the pathogenesis of dermal fibrosis via inhibition of turnover of fibrotic dermal extracellular matrix, possibly due to upregulation of TIMP-3 expression by transforming growth factor-beta.

Serum levels of tissue inhibitor of metalloproteinases-2 and of precursor form of matrix metalloproteinase-2 in patients with liver disease

Serum levels of tissue inhibitor of metalloproteinases-2 (TIMP2) and of precursor form of matrix metalloproteinase-2 (proMMP2) were determined in patients with chronic hepatitis and hepatocellular carcinoma by a one-step sandwich enzyme immunoassay. Serum levels of TIMP2 and proMMP2 were significantly higher in patients with chronic liver disease, than in normal controls. Serum levels of TIMP2 showed a weak negative correlation with the serum albumin level and prothrombin time (PT). Serum levels of proMMP2 in patients with chronic hepatitis were strongly correlated with those of type IV collagen and were negatively correlated with PT and serum albumin levels. Serum proMMP2 levels were also significantly correlated with histological stages. These data indicate that serum levels of proMMP2 might be useful in the follow-up of patients with chronic hepatitis.

TIMP expression in toxic and cholestatic liver injury in rat

BACKGROUND/AIMS

Hepatic fibrosis is a dynamic pathological process with a net accumulation of extracellular matrix proteins. Recent evidence suggests that besides their increased synthesis, inhibition of matrix degradation plays a significant role. ECM degradation occurs via metalloproteinases which are inhibited in situ by specific tissue inhibitors of metalloproteinases (TIMPs). The aim of our studies was to determine the expression of TIMPs during toxic liver injury and cholestatic liver injury leading to fibrosis.

METHODS

We examined the expression of TIMP-1, -2 and -3 in two different rat models for liver injury (intraperitoneal CCl4 injection and bile duct ligation) by Northern blot analysis and in situ hybridization. For comparison, the mRNA expression of the acute phase protein haptoglobin was measured.

RESULTS

TIMP-1 was increased during the early phase of toxic liver injury and in cholestasis. Its expression occurred predominantly in areas of inflammation, in hepatocytes, and in mesenchymal and endothelial cells. There was a slight upregulation of TIMP-2 expression during cholestasis. TIMP-3 was not detected at all.

CONCLUSIONS

Our results emphasize an involvement of TIMP-1 in matrix homeostasis, indicating its possible participation in liver fibrosis.

Tissue inhibitor of metalloproteinase-1 in the liver of patients with chronic liver disease

BACKGROUND/AIMS

Tissue inhibitor of metalloproteinase (TIMP)-1 is an important regulator of matrix metalloproteinase activity. To clarify the changes in TIMP-1 in diseased livers, we measured TIMP-1 concentrations in liver tissue samples from patients with chronic liver disease. The relationship between serum and liver levels of TIMP-1 was also examined in some patients.

METHODS

The subjects were 68 patients who underwent liver biopsy. The liver TIMP-1 concentration was measured using an enzyme immunoassay after the extraction of TIMP-1 with 2 M guanidine.

RESULTS

As compared with the controls (n=10), the liver TIMP-1 level was increased 2.2-fold in the 24 chronic active hepatitis 2A patients, 2.9-fold in the 10 chronic active hepatitis 2B patients and 4.1-fold in the six liver cirrhosis patients, but no significant increase was observed among the 18 chronic persistent hepatitis patients. The liver TIMP-1 levels were closely correlated with the histological degrees of periportal necrosis, portal inflammation, and liver fibrosis. When the localization of TIMP-1 was examined immunohistochemically, TIMP-1 was stained mainly in hepatocytes, and the intensity was stronger in the livers of chronic active hepatitis and liver cirrhosis patients than in those of the chronic persistent hepatitis patients. The serum TIMP-1 and liver TIMP-1 levels were significantly correlated, indicating that serum TIMP-1 could reflect the change of liver TIMP-1 in patients with chronic liver disease.

CONCLUSION

Liver TIMP-1 concentration increases with progression of the liver disease, when the degradation of extracellular matrix proteins is decreased, resulting in the development of liver fibrosis.

Evidence that "myofibroblast-like" cells are the cellular source of capsular collagen in hepatocellular carcinoma

BACKGROUND/AIMS

The prognosis for patients with hepatocellular carcinoma is poor although tumour encapsulation has been associated with improved survival and disease-free rates. While the source of the tumour capsule is unclear, the major role that activated hepatic stellate cells play in the deposition of liver matrix in normal and diseased states suggests the possible involvement of these cells in tumour encapsulation.

METHODS

Twenty-four liver tumours (seven encapsulated HCC, seven non-encapsulated HCC, 10 colorectal metastases) were studied. Activated hepatic stellate cells were identified by immunohistochemistry for alpha-smooth muscle actin (alpha-SMA) and in situ hybridization for pro-collagen alpha1 (I) mRNA. Collagen deposition was localized using Masson's trichrome stain.

RESULTS

Pro-collagen alpha1 (I) mRNA co-localized to alpha-SMA positive hepatic stellate cells within the region of increased collagen deposition in (i) the tumour capsule of encapsulated HCC, and (ii) the tumour junction of non-encapsulated HCC and colorectal metastasis. In addition, there was marked peritumour expression of alpha-SMA and procollagen alpha1 (I) mRNA, which diminished with distance away from the tumour in all tumour groups. The degree of expression was greatest with encapsulated HCC, less with non-encapsulated HCC and least with colorectal metastasis. This contrasted with the absence of alpha-SMA expression in normal liver from the same patients. Within the tumours, colorectal metastases differed from HCC by demonstrating marked alpha-SMA expression and collagen deposition in the septa.

CONCLUSIONS

Our findings demonstrate that activated hepatic stellate cells (i) are responsible for increased peritumour collagen production in non-encapsulated HCC and colorectal metastasis, and (ii) may be implicated in tumour capsule formation in HCC and metastasis stroma development. Thus, stellate cells may influence the local hepatic invasion by these tumours.

Tissue inhibitors of metalloproteinases in liver fibrosis

Liver fibrosis and its end stage sequelae cirrhosis represent a major worldwide health problem. By definition progressive fibrosis occurs when the rate of matrix synthesis exceeds matrix degradation. Considerable evidence suggests that the hepatic stellate cell is central to the fibrotic process. During liver injury these cells transform from a quiescent retinoid filled phenotype to a proliferative myofibroblast like cell. In this 'activated' phenotype the HSC is the major source of the interstitial collagens, which characterize fibrosis. Recent work suggests that the HSCs are also a source of matrix degrading metalloproteinase (MMPs), indicating that, together with other cells, hepatic stellate cells (HSC) could participate in matrix remodelling. However, HSC activation in tissue culture models and in vivo is also associated with expression of the powerful MMP inhibitors: tissue inhibitors of metalloproteinases 1 and 2 (TIMP-1 and TIMP-2). TIMP expression has also been demonstrated in fibrotic human liver disease and animal models of liver fibrosis. TIMPs 1 and 2 may therefore promote progression of hepatic fibrosis through inhibition of matrix degradation.

Oncostatin M differentially regulates tissue inhibitors of metalloproteinases TIMP-1 and TIMP-3 gene expression in human synovial lining cells

Tissue inhibitor of metalloproteinases (TIMP) 1, 2 and 3 are related proteins that can form complexes with all known matrix metalloproteinases (MMPs). They inhibit the action of MMPs on extracellular matrix components. The balance of MMPs and TIMPs is important for tissue remodeling and its disturbance is believed to play a crucial role in pathophysiological processes such as tumor metastasis, destruction of cartilage and fibrosis. Cytokines and growth factors were found to regulate TIMPs and MMPs in a complex manner. In order to better understand the role of TIMPs in inflammatory joint diseases we have studied in vitro the regulation of TIMP-1 and TIMP-3 by inflammatory cytokines in cultured human synovial lining cells. We found that transforming growth factor beta 1 as well as interleukin-1 beta induce gene expression of both TIMP-1 and TIMP-3. In contrast, oncostatin M, an interleukin-6-type cytokine produced by activated T-lymphocytes and monocytes, had a differential effect on TIMP mRNA levels. After oncostatin M treatment, TIMP-1 expression was up-regulated but basal, as well as interleukin-1 beta-induced, TIMP-3 expression was inhibited. Interleukin-6 itself had no effect on synovial lining cells but a complex of interleukin-6 and the soluble interleukin-6 receptor induced activation of signal transducer and activator of transcription (STAT) factors in these cells and regulated TIMP-1 and TIMP-3 expression in a similar fashion as oncostatin M. Since TIMP-3 is matrix-associated whereas TIMP-1 is found in many body fluids, the role of oncostatin M during inflammatory processes might be to promote ECM degradation in the local environment but to prevent it systemically.

Serum markers for fibrosis and plasma transforming growth factor-beta 1 in patients with hepatocellular carcinoma in comparison with patients with liver cirrhosis

In order to elucidate collagen metabolism in hepatocellular carcinoma (HCC) tissue, we compared levels of different potential markers of collagen metabolism and plasma transforming growth factor-beta 1 in patients with HCC and in patients with liver cirrhosis. Serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1 in patients with HCC were significantly higher than those in patients with liver cirrhosis and increased with the size of the HCC tumour, whereas the serum levels of procollagen type III propeptide and type IV collagen 7S domain were similar in the two groups. In HCC, the increased plasma transforming growth factor-beta 1 levels were closely correlated with serum levels of prolyl hydroxylase and the tissue inhibitor of metalloproteinase-1. These findings suggest that, in HCC tissue, the intracellular biosynthesis of collagen is enhanced, whereas the secretion of procollagen is disturbed and the degradation of collagen is suppressed by the excess production of the tissue inhibitor of metalloproteinase-1. The results also suggest that plasma transforming growth factor-beta 1 plays an important role in the altered metabolism of collagen in HCC.

Significance of serum tissue inhibitor of metalloproteinases-1 in various liver diseases

BACKGROUND/AIMS

This study was performed to assess the significance of elevated serum tissue inhibitor of metalloproteinases-1 concentration in various liver diseases.

METHODS

Tissue inhibitor of metalloproteinases-1 levels were measured in patients with various liver diseases, and were compared with serum type III procollagen-N-peptide (P III P), type IV collagen and laminin P1 levels, as well as with the histology of liver biopsy specimens.

RESULTS

Mean tissue inhibitor of metalloproteinases-1 levels were significantly higher in subjects with acute viral hepatitis, cirrhosis, alcoholic hepatitis, and alcoholic cirrhosis than in the control group (p < 0.05). Serum tissue inhibitor of metalloproteinases-1 levels in the various liver diseases showed positive correlation with serum type IV collagen, P III P, and laminin P1 levels. Regarding the relationship between tissue inhibitor of metalloproteinases-1 and liver histology, serum tissue inhibitor of metalloproteinases-1 levels correlated with the degree of hepatic fibrosis and inflammation, such as focal necrosis and cell infiltration. Furthermore, elevated serum tissue inhibitor of metalloproteinases-1 levels were especially related to the cell infiltration, focal necrosis, portal fibrosis, and serum type IV collagen level.

CONCLUSIONS

These findings suggest that the measurement of the serum tissue inhibitor of metalloproteinases-1 level in various liver diseases may be useful to estimate the active hepatic fibrogenesis associated with the active inflammatory stage of the liver injury.

Expression of a biologically active murine tissue inhibitor of metalloproteinases-1 (TIMP-1) in baculovirus-infected insect cells. Purification and tissue distribution in the rat

Murine tissue inhibitor of metalloproteinases-1 (mTIMP-1) was expressed in baculovirus-infected insect cells (Sf9). The protein secreted into the culture medium was purified to homogeneity by means of heparin-Sepharose CL-6B and FPLC. The purified protein showed metalloproteinase-inhibitory activity in two independent assays: reverse zymography and inhibition of collagenase activity. Digestion of the recombinant TIMP-1 with peptide-N-glycanaseF revealed that both N-glycosylation sites are used. 125I-mTIMP-1 intraveneously injected into a male Sprague Dawley rat disappeared within 2 min from the circulation. 5 min after injection more than 50% of the 125I-mTIMP-1 were found in the liver and 20% in the kidneys. At later times, trichloroacetic-acid-soluble material accumulated in the intestinal tract.

Serum tissue inhibitor of metalloproteinases in patients with systemic sclerosis

BACKGROUND

One of the suggested contributory factors to the development of dermal fibrosis is a decrease in collagenase activity, which may be related to levels of serum tissue inhibitors of metalloproteinase-1 (TIMP-1).

OBJECTIVE

The aim of this study was to determine the clinical significance of serum TIMP-1 levels in systemic sclerosis (SSc).

METHODS

We measured serum TIMP-1 concentration in 62 patients with SSc, 11 patients with systemic lupus erythematosus, 14 patients with rheumatoid arthritis, and 22 members of a normal control group. The clinical features of the patients with SSc and elevated TIMP levels were examined.

RESULTS

The mean TIMP-1 level in the patients with SSc was significantly higher than that in the members of the control group or the patients with systemic lupus erythematosus or rheumatoid arthritis. In 44% of the patients with SSc the serum TIMP-1 level was elevated. The mean serum TIMP-1 level in patients with diffuse cutaneous SSc (dSSc) was significantly higher than that in those with limited cutaneous SSc. The patients with dSSc and elevated serum TIMP-1 levels showed a significantly greater incidence of lung fibrosis and anti-topoisomerase I antibody than those with normal serum TIMP-1 levels. The TIMP-1 level and diffusing capacity for carbon monoxide in the patients with SSc were negatively correlated. Increased mitogenic activity on dermal fibroblasts caused by serum from patients with dSSc was partially blocked by anti-TIMP-1 IgG.

CONCLUSIONS

These findings suggest that serum TIMP-1 level is a useful indicator of disease activity in patients with SSc and that TIMP is involved in the pathogenesis of SSc.

Role of Ito cells in the degradation of matrix in liver

Liver fibrosis is a dynamic process caused by changes in not only the synthesis of matrix proteins but also their degradation. Current evidence indicates that Ito cells, when activated to a myofibroblastic phenotype, play a very active role in regulating matrix degradation in liver. This is mediated via their ability to synthesize and release several members of the matrix metalloproteinase family, a class of enzymes which are responsible for degradation of matrix proteins in the extracellular space. Activated Ito cells have been demonstrated to release prostromelysin, progelatinase A and the pro-enzyme form of interstitial collagenase. In addition, these cells can express appropriate systems for cleaving pro-metalloproteinases to active forms (e.g. the plasminogen activator system, urokinase) as well as specific tissue inhibitors of the activated metalloproteinases (TIMP). In the early phases of liver injury, enzymes with the ability to degrade components of normal liver matrix are expressed (stromelysin and gelatinase A). In contrast, in the fibrotic phase of liver injury, during which fibrillar collagens accumulate, there is little (if any) expression of interstitial collagenase but marked expression of TIMP. These findings suggest that metalloproteinase and their inhibitors play a significant role in liver injury and fibrosis.

Serum markers for connective tissue turnover in patients with chronic hepatitis B and chronic hepatitis C: a comparative analysis

BACKGROUND/AIMS

Clinical and pathological differences between chronic hepatitis B and chronic hepatitis C have now been established.

METHODS

To compare hepatic connective tissue metabolism in chronic hepatitis B and C, we determined serum levels of prolyl 4-hydroxylase beta-subunit, procollagen III aminoterminal peptide, type IV collagen 7S domain, the central helix region of type IV collagen, tissue inhibitor of metalloproteinase, and hyaluronan in 55 patients with chronic hepatitis B and 83 patients with chronic hepatitis C.

RESULTS

There were no significant differences in the above markers for connective tissue turnover between the chronic hepatitis B group and the chronic hepatitis C group.

CONCLUSIONS

These results suggest that the accelerated connective tissue metabolism observed in chronic viral hepatitis is independent of the causative virus.

Tissue inhibitor of metalloproteinases-2 (TIMP-2) in rat liver cells is increased by lipopolysaccharide and prostaglandin E2

To explore the functional role of TIMP-2 in liver, we determined TIMP-2 mRNA levels in primary rat hepatocytes and in total rat liver. Rat hepatocytes constitutively express TIMP-2 mRNA at a low level. Incubation with dexamethasone, prostaglandin E2 and a combination of inflammatory cytokines leads to an up-regulation of TIMP-2 mRNA. In rats in vivo we found a dramatic increase of TIMP-2 expression after intraperitoneal injection of lipopolysaccharide. Compared to our previous findings on TIMP-1 we conclude that TIMP-2 mRNA expression is regulated in a distinct and partially opposite manner. Over-production of TIMP-2 could inhibit the activity of metalloproteinases and thus lead to matrix accumulation. Dysregulation of TIMP-2 synthesis might be involved in the development of liver fibrosis.

Serum type III procollagen peptide, type IV collagen 7S domain, central triple-helix of type IV collagen and tissue inhibitor of metalloproteinases in patients with chronic viral liver disease: relationship to liver histology

To assess the clinical value of serum biochemical markers, the aminoterminal peptide of type III procollagen, type IV collagen 7S domain, the central triple-helix of type IV collagen and tissue inhibitor of metalloproteinases, as a marker of hepatic fibrosis, we measured these four serum markers in 132 patients with chronic viral liver disease and compared these serum markers with liver histological findings. Serum levels of these markers increased closely with the progress of liver disease, and the abnormal percentages of type III procollagen peptide, type IV collagen 7S domain, central triple-helix of type IV collagen and tissue inhibitor of metalloproteinases in patients with cirrhosis were 97%, 95%, 83% and 48%, respectively. These four serum markers strongly correlated with the histological degree of periportal with or without bridging hepatocellular necrosis and of liver fibrosis and correlated weakly with the degree of intralobular degeneration and focal necrosis and the degree of portal inflammation. The correlation coefficients of serum type IV collagen 7S domain with periportal with or without bridging hepatocellular necrosis and with liver fibrosis were the highest among these four serum markers, suggesting that serum type IV collagen 7S domain is the most valuable diagnostic marker to assess the degree of liver fibrosis in chronic viral liver disease. When we assessed the ability of each serum marker to detect cirrhosis with a receiver operating curve, the best test was type IV collagen 7S domain, and the second best was type III procollagen peptide.(ABSTRACT TRUNCATED AT 250 WORDS)

TIMP-1 protein expression is stimulated by IL-1 beta and IL-6 in primary rat hepatocytes

Degradation of extracellular matrix proteins is performed by metalloproteinases which are inhibited by tissue inhibitors of metalloproteinases (TIMP). We expressed the murine TIMP-1 protein in E. coli and prepared a polyclonal antiserum against the recombinant protein. Using this antiserum we studied the biosynthesis and glycosylation of murine TIMP-1 protein in COS-7 cells transfected with a TIMP-1 expression plasmid by metabolic labeling and indirect immunofluorescence studies. In primary rat hepatocytes we show for the first time that TIMP-1 protein expression is up-regulated upon stimulation with IL-1 beta and IL-6. Since TIMP-1 is induced during the acute phase reaction it could possibly be involved in the pathogenesis of liver fibrosis.