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

Towards novel liver injury therapies based on design, synthesis and therapeutic efficacy of novel sulfone bis-compound on liver necrosis

Liver necrosis is the irreversible loss of hepatocytes through toxin-induced injury, ischemia, or infection to produce organ dysfunction. It is a significant pathological marker in many liver disorders, including cirrhosis, and hepatitis, and contributes to organ failure and general systemic effects. This research aims to evaluate the protective effects of a newly synthesized compound named 1-(5-((1-(1-(4-((4-(4-(1-((5-acetyl-3-phenyl-1,3,4-thiadiazol-2(3H)-ylidene)hydrazono)ethyl)-5-methyl-1H-1,2,3-triazol-1-yl)phenyl)sulfonyl)phenyl)-5-methyl-1H-1,2,3-triazol-4-yl)ethylidene)hydrazono)-4-phenyl-4,5-dihydro-1,3,4-thiadiazol-2-yl)ethan-1-one (TTTE) sulfone-bis chalcone derivative on liver necrosis caused by TAA therapy using murine model. The research investigates optimal cellular pathways which demonstrate the therapeutic properties of TTTE as a potential treatment for liver injuries. The newly prepared compound TTTE was successfully characterized by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance (1H-NMR) spectroscopy, carbon-13 nuclear magnetic resonance (13C-NMR), The safety of the as-prepared compound TTTE was determined based on weight changes and the behaviors in all the groups were monitored for 21 days. The effect of treatment of TTTE at different doses (300, 200, and 100 mg/kg B.W.) was studied. High-dose TTTE revealed a 62.5% survival rate compared to the untreated TAA group (40%). Molecular analysis exhibited that high-dose TTTE downregulated Cas-3, TIMP-1, and proinflammatory cytokines (TNF-α, NF-κB, and IL-6) compared to untreated TAA. Results of histopathological and IHC examinations exhibited high TTTE dose have no signs of liver injury with suppression in TGF-β expression as a result of anti-inflammatory response. Our study concluded that the synthesized compound, TTTE has a potential therapeutic strategy in mitigating liver necrosis.

Non-invasive liver fibrosis markers are increased in obese individuals with non-alcoholic fatty liver disease and the metabolic syndrome

The need for early non-invasive diagnostic tools for chronic liver fibrosis is growing, particularly in individuals with obesity, non-alcoholic fatty liver disease (NAFLD), and the metabolic syndrome (MetS) since prevalence of these conditions is increasing. This case-control study compared non-invasive liver fibrosis markers in obesity with NAFLD and MetS (NAFLD-MetS, n = 33), in obese (n = 28) and lean (n = 27) control groups. We used MRI (T1 relaxation times (T1) and liver stiffness), circulating biomarkers (CK18, PIIINP, and TIMP1), and algorithms (FIB-4 index, Forns score, FNI, and MACK3 score) to assess their potential in predicting liver fibrosis risk. We found that T1 (892 ± 81 ms vs. 818 ± 64 ms, p < 0.001), FNI (15 ± 12% vs. 9 ± 7%, p = 0.018), CK18 (166 ± 110 U/L vs. 113 ± 41 U/L, p = 0.019), and MACK3 (0.18 ± 0.15 vs. 0.05 ± 0.04, p < 0.001) were higher in the NAFLD-MetS group compared with the obese control group. Moreover, correlations were found between CK18 and FNI (r = 0.69, p < 0.001), CK18 and T1 (r = 0.41, p < 0.001), FNI and T1 (r = 0.33, p = 0.006), MACK3 and FNI (r = 0.79, p < 0.001), and MACK3 and T1 (r = 0.50, p < 0.001). We show that liver fibrosis markers are increased in obese individuals with NAFLD and MetS without clinical signs of liver fibrosis. More studies are needed to validate the use of these non-invasive biomarkers for early identification of liver fibrosis risk.

Glabridin ameliorates intracellular events caused by palmitic acid and alcohol in mouse hepatocytes and fast food diet and alcohol -induced steatohepatitis and fibrosis in C57BL/6J mice model

Steatohepatitis is a significant risk factor for end-stage liver disease. In this study, the therapeutic potential of Glabridin (GBD), an isoflavan derived from Glycyrrhiza glabra, is investigated in in-vitro and in-vivo models against palmitic acid (PA) or fast food (FF) diet + alcohol (EtOH). Mouse hepatocytes (AML-12 cells) were treated with PA; 250 μM + EtOH; 250 μM ± GBD (10 μM and 25 μM) for 24 h. C57BL/6J mice fed with standard chow (SC) diet, fast food (FF) diet + intermittent oral ingestion of EtOH (10-50%v/v) ± GBD (20 mg/kg and 40 mg/kg) for eight (8) weeks, were analyzed for histological features of steatohepatitis and fibrosis, biochemical indexes, and protein and gene expression studies related to oxidative stress, inflammation, lipogenesis, fibrosis, and apoptosis. GBD therapy considerably reduced intracellular events in AML-12 cells exposed to PA + EtOH. GBD treatments significantly improved body metrics, biochemical indexes, and histological features in C57BL/6J mice compared to FF + EtOH. Moreover, protein and gene expression investigations revealed a strong therapeutic effects on oxidative stress, inflammation, steatosis, fibrosis, and apoptosis -related molecular signaling cascades. In conclusion, these findings suggest that GBD has a strong therapeutic potential to be developed as anti-steatohepatitis/fibrosis medicine.

A small animal model of NASH with progressive steatohepatitis -induced by fast food diet and alcohol in C57BL/6J mouse with high human pathophysiological proximity

Non-alcoholic steatohepatitis (NASH) and alcoholic steatohepatitis (ASH) both can progress to end-stage liver disease (ESLD). No relevant animal models are available for studying the toxic consequences of concurrent fast food diet- and alcohol usage in fibrosing NASH. As a result, dependable and short-term In-vivo models capable of recapitulating human disease pathophysiology are required for deciphering mechanistic insights and preclinical drug discovery programs. The current study aims to develop a mouse model for progressive steatohepatitis employing a fast food (FF) diet with intermittent oral alcohol (EtOH) administration. For eight (8) weeks, C57BL/6 J mice were fed standard chow (SC) diet ± EtOH or FF ± EtOH. EtOH uses enhanced the histological characteristics of FF-induced steatohepatitis and fibrosis. A dysregulated molecular signaling cascade related to oxidative stress, steatosis, fibrosis, DNA damage, and apoptosis was evident at protein and gene expression levels in the FF + EtOH. The results from the in-vivo model were replicated in mouse hepatocyte cultures (AML-12) subjected to palmitic acid (PA) ± EtOH exposures. The results of the present study indicate that the clinical hallmarks of human progressive steatohepatitis and fibrosis were achieved in our mice model, showing its suitability for preclinical research.

Resolution of hepatic fibrosis after ZFN-mediated gene editing in the PiZ mouse model of human α1-antitrypsin deficiency

BACKGROUND

α1-antitrypsin deficiency is most commonly caused by a mutation in exon-7 of SERPINA1 (SA1-ATZ), resulting in hepatocellular accumulation of a misfolded variant (ATZ). Human SA1-ATZ-transgenic (PiZ) mice exhibit hepatocellular ATZ accumulation and liver fibrosis. We hypothesized that disrupting the SA1-ATZ transgene in PiZ mice by in vivo genome editing would confer a proliferative advantage to the genome-edited hepatocytes, enabling them to repopulate the liver.

METHODS

To create a targeted DNA break in exon-7 of the SA1-ATZ transgene, we generated 2 recombinant adeno-associated viruses (rAAV) expressing a zinc-finger nuclease pair (rAAV-ZFN), and another rAAV for gene correction by targeted insertion (rAAV-TI). PiZ mice were injected i.v. with rAAV-TI alone or the rAAV-ZFNs at a low (7.5×1010vg/mouse, LD) or a high dose (1.5×1011vg/mouse, HD), with or without rAAV-TI. Two weeks and 6 months after treatment, livers were harvested for molecular, histological, and biochemical analyses.

RESULTS

Two weeks after treatment, deep sequencing of the hepatic SA1-ATZ transgene pool showed 6%±3% or 15%±4% nonhomologous end joining in mice receiving LD or HD rAAV-ZFN, respectively, which increased to 36%±12% and 36%±12%, respectively, 6 months after treatment. Two weeks postinjection of rAAV-TI with LD or HD of rAAV-ZFN, repair by targeted insertion occurred in 0.10%±0.09% and 0.25%±0.14% of SA1-ATZ transgenes, respectively, which increased to 5.2%±5.0% and 33%±13%, respectively, 6 months after treatment. Six months after rAAV-ZFN administration, there was a marked clearance of ATZ globules from hepatocytes, and resolution of liver fibrosis, along with reduction of hepatic TAZ/WWTR1, hedgehog ligands, Gli2, a TIMP, and collagen content.

CONCLUSIONS

ZFN-mediated SA1-ATZ transgene disruption provides a proliferative advantage to ATZ-depleted hepatocytes, enabling them to repopulate the liver and reverse hepatic fibrosis.

The genetic background shapes the susceptibility to mitochondrial dysfunction and NASH progression

Non-alcoholic steatohepatitis (NASH) is a global health concern without treatment. The challenge in finding effective therapies is due to the lack of good mouse models and the complexity of the disease, characterized by gene-environment interactions. We tested the susceptibility of seven mouse strains to develop NASH. The severity of the clinical phenotypes observed varied widely across strains. PWK/PhJ mice were the most prone to develop hepatic inflammation and the only strain to progress to NASH with extensive fibrosis, while CAST/EiJ mice were completely resistant. Levels of mitochondrial transcripts and proteins as well as mitochondrial function were robustly reduced specifically in the liver of PWK/PhJ mice, suggesting a central role of mitochondrial dysfunction in NASH progression. Importantly, the NASH gene expression profile of PWK/PhJ mice had the highest overlap with the human NASH signature. Our study exposes the limitations of using a single mouse genetic background in metabolic studies and describes a novel NASH mouse model with features of the human NASH.

Cut loose TIMP-1: an emerging cytokine in inflammation

Appreciation of the entire biological impact of an individual protein can be hampered by its original naming based on one function only. Tissue inhibitor of metalloproteinases-1 (TIMP-1), mostly known for its eponymous function to inhibit metalloproteinases, exhibits only a fraction of its cellular effects via this feature. Recently, TIMP-1 emerged as a potent cytokine acting via various cell-surface receptors, explaining a so-far under-appreciated role of TIMP-1-mediated signaling on immune cells. This, at least partly, resolved why elevated blood levels of TIMP-1 correlate with progression of numerous inflammatory diseases. Here, we emphasize the necessity of unbiased name-independent recognition of structure-function relationships to properly appreciate the biological potential of TIMP-1 and other cytokines in complex physiological processes such as inflammation.

The antihypertensive agent hydralazine reduced extracellular matrix synthesis and liver fibrosis in nonalcoholic steatohepatitis exacerbated by hypertension

Hypertension is an important risk factor for nonalcoholic steatohepatitis. We have previously demonstrated that hypertensive rats fed a high fat and cholesterol (HFC) diet incurred a more severe hepatic inflammatory response and fibrosis. Here we investigated the role of hypertension in NASH by comparing HFC-induced hepatic fibrogenesis between spontaneously hypertensive rats (SHRs) and their normotensive Wistar Kyoto counterpart. Compared to the counterpart, the HFC diet led to stronger aggregation of CD68-positive macrophages in SHRs. HFC feeding also resulted in significantly higher upregulation of the fibrosis-related gene alpha-smooth muscle actin in SHR. The HFC diet induced higher overexpression of serum tissue inhibitor of metalloproteinase-1 (TIMP1) and greater suppression of matrix metalloproteinase-2 (MMP2):TIMP1, MMP8:TIMP1, and MMP9:TIMP1 ratios, as a proxy of the activities of these MMPs in SHR. Administration of the antihypertensive agent hydralazine to SHRs significantly ameliorated HFC-induced liver fibrosis; it suppressed the aggregation of CD68-positive macrophages and the upregulation of platelet-derived growth factor receptor beta, and collagen, type 1, alpha-1 chain. In conclusion, a hypertensive environment exacerbated the hepatic fibrogenetic effects of the HFC diet; while the effects were partially reversed by the antihypertensive agent hydralazine. Our data suggest that antihypertensive drugs hold promise for treating NASH exacerbated by hypertension.

Non-invasive assessment of liver fibrosis and prognosis: an update on serum and elastography markers

Non-invasive assessment of fibrosis is increasingly utilized in clinical practice to diagnose hepatic fibrosis. Non-invasive assessment of liver fibrosis relies on biologic and/or physical properties to assess tissue fibrosis. Serum markers estimate fibrosis by incorporating markers reflecting hepatic function (indirect markers) and/or markers measuring extracellular matrix degradation/fibrogenesis (direct markers). Radiology based techniques relay the mechanical properties and stiffness of a tissue, with increased stiffness associated with more advanced fibrosis. Areas covered: In this comprehensive review, the recent literature discussing serum markers and elastography-based techniques will be covered. These modalities are also explored in the setting of various liver diseases. Expert opinion: The etiology of liver disease and clinical context should be taken into consideration when non-invasive markers are incorporated in clinical practice. Non-invasive assessment of fibrosis has been most extensively utilized in hepatitis C, followed by hepatitis B and nonalcoholic fatty liver disease, but its role remains less developed in other etiologies of liver disease such as alcohol-associated liver disease and autoimmune liver disease. The role of non-invasive markers in predicting progression or regression of fibrosis, development of liver-related events and survival needs to be further explored.

Effect of siRNA-mediated down-regulation of receptor for advanced glycation end products on expression of matrix metalloproteinase-1 and tissue inhibitor of metalloproteinase-1 in rat hepatic stellate cells and hepatic fibrosis

AIM: To investigate the effect of small interfering RNA (siRNA)-mediated down-regulation of receptor for advanced glycation end products (RAGE) on the expression of matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in primary rat hepatic stellate cells (HSCs) and hepatic fibrosis (HF).

METHODS: In in vitro experiment, primary rat HSCs were cultured and isolated. The pAKD-GR126 vector carrying siRNA targeting RAGE was constructed and transfected to primary rat HSCs. Blank cells and cells transfected with unspecific siRNA vector pAKD-NC were used as controls. In in vivo experiment, liver fibrosis was induced in SD rats with CCl₄. pAKD-GR126 was transfected to liver fibrosis rats at different doses via the tail vein. A blank group, a liver fibrosis model group and an unspecific siRNA vector pAKD-NC-transfected group were used as controls. Real-time PCR and Western blot were used to detect the expression of RAGE, MMP-1 and TIMP-1. The histological changes of the liver were observed by HE and Masson staining methods.

RESULTS: The mRNA and protein expression of RAGE and TIMP-1 in pAKD-GR126-transfected primary HSCs was significantly lower than that in the blank group and unspecific siRNA vector pAKD-NC-transfected group (P < 0.05 for all). However, the level of MMP-1 in pAKD-GR126-transfected primary HSCs was significantly higher than that in the blank group and pAKD-NC-transfected group (P < 0.05 for all). In vivo, the mRNA and protein expression of RAGE and TIMP-1 was significantly lower and that of MMP-1 was significantly higher in the low-, medium-, and high-dose RAGE siRNA groups than in the liver fibrosis model group (P < 0.05 for all). Compared with the liver fibrosis model group, liver fibrosis was significantly milder in the low-, medium-, and high-dose RAGE siRNA groups, especially the high-dose group.

CONCLUSION: RAGE specific siRNA could decrease the expression of RAGE and TIMP-1, increase the expression of MMP-1 in primary rat HSCs and HF rats, and reduce the degree of rat hepatic fibrosis.

Is the neutrophil to lymphocyte ratio associated with liver fibrosis in patients with chronic hepatitis B?

AIM

To determine the association between the neutrophil to lymphocyte (N/L) ratio and the degree of liver fibrosis in patients with chronic hepatitis B (CHB) infection.

METHODS

Between December 2011 and February 2013, 129 consecutive CHB patients who were admitted to the study hospitals for histological evaluation of chronic hepatitis B-related liver fibrosis were included in this retrospective study. The patients were divided into two groups based on the fibrosis score: individuals with a fibrosis score of F0 or F1 were included in the "no/minimal liver fibrosis" group, whereas patients with a fibrosis score of F2, F3, or F4 were included in the "advanced liver fibrosis" group. The Statistical Package for Social Sciences 18.0 for Windows was used to analyze the data. A P value of < 0.05 was accepted as statistically significant.

RESULTS

Three experienced and blinded pathologists evaluated the fibrotic status and inflammatory activity of 129 liver biopsy samples from the CHB patients. Following histopathological examination, the "no/minimal fibrosis" group included 79 individuals, while the "advanced fibrosis" group included 50 individuals. Mean (N/L) ratio levels were notably lower in patients with advanced fibrosis when compared with patients with no/minimal fibrosis. The mean value of the aspartate aminotransferase-platelet ratio index was markedly higher in cases with advanced fibrosis compared to those with no/minimal fibrosis.

CONCLUSION

Reduced levels of the peripheral blood N/L ratio were found to give high sensitivity, specificity and predictive values in CHB patients with significant fibrosis. The prominent finding of our research suggests that the N/L ratio can be used as a novel noninvasive marker of fibrosis in patients with CHB.

Activity of MMP1 and MMP13 and amino acid metabolism in patients with alcoholic liver cirrhosis

Background

Alcoholic liver disease remains one of the most common causes of chronic liver disease worldwide.

The aim of this study was to assess the usefulness of metalloproteinases (MMP1 and MMP13) as diagnostic markers of alcoholic liver disease and to determine the changes in free amino acid profile in the patients with alcoholic liver cirrhosis.

Material/Methods

Sixty patients with alcoholic liver cirrhosis treated in various hospitals of the Lublin region were randomly enrolled. The control group consisted of 10 healthy individuals without liver disease, who did not drink alcohol. Additionally, a group of alcoholics (22 persons) without liver cirrhosis was included in the study. The activity of MMP-1 and MMP-13 in blood plasma of patients and controls was measured using the sandwich enzyme immunoassay technique with commercially available quantitative ELISA test kits. Amino acids were determined by automated ion-exchange chromatography.

Results

No significant differences were observed in the activity of MMP-1 in alcoholics with or without liver cirrhosis or in controls. Increased serum MMP-13 was found in patients with liver cirrhosis (stage A, B, C) compared to the control group. Patients with alcoholic liver cirrhosis (stage A, B, C) demonstrated reduced concentrations of glutamic acid and glutamine compared to the control group. Plasma levels of valine, isoleucine, leucine, and tryptophan were significantly lower in patients with alcoholic liver cirrhosis (stage C) than in controls.

Conclusions

MMP-13 can be useful to confirm the diagnosis of alcoholic liver cirrhosis, but levels of MMP-1 are not significantly increased in patients with liver cirrhosis compared to controls. The serum branched-chain amino acid (BCAA) is markedly reduced in patients with stage C alcoholic liver cirrhosis.

Adiponectin reduces hepatic stellate cell migration by promoting tissue inhibitor of metalloproteinase-1 (TIMP-1) secretion

Hepatic stellate cells (HSC) are central players in liver fibrosis that when activated, proliferate, migrate to sites of liver injury, and secrete extracellular matrix. Obesity, a known risk factor for liver fibrosis is associated with reduced levels of adiponectin, a protein that inhibits liver fibrosis in vivo and limits HSC proliferation and migration in vitro. Adiponectin-mediated activation of adenosine monophosphate-activated kinase (AMPK) inhibits HSC proliferation, but the mechanism by which it limits HSC migration to sites of injury is unknown. Here we sought to elucidate how adiponectin regulates HSC motility. Primary rat HSCs were isolated and treated with adiponectin in migration assays. The in vivo actions of adiponectin were examined by treating mice with carbon tetrachloride for 12 weeks and then injecting them with adiponectin. Cell and tissue samples were collected and analyzed for gene expression, signaling, and histology. Serum from patients with liver fibrosis was examined for adiponectin and tissue inhibitor of metalloproteinase-1 (TIMP-1) protein. Adiponectin administration into mice increased TIMP-1 gene and protein expression. In cultured HSCs, adiponectin promoted TIMP-1 expression and through binding of TIMP-1 to the CD63/β1-integrin complex reduced phosphorylation of focal adhesion kinase to limit HSC migration. In mice with liver fibrosis, adiponectin had similar effects and limited focal adhesion kinase phosphorylation. Finally, in patients with advanced fibrosis, there was a positive correlation between serum adiponectin and TIMP-1 levels. In sum, these data show that adiponectin stimulates TIMP-1 secretion by HSCs to retard their migration and contributes to the anti-fibrotic effects of adiponectin.

Association of TIMP-1 and TIMP-2 gene polymorphisms with progression of liver fibrosis in patients with type C chronic liver disease

We examined the association of TIMP-1 and TIMP-2 gene polymorphisms with the progression of chronic liver disease related to the hepatitis C virus (HCV). We used PCR to analyze 188 patients with HCV-related liver disease (95 with chronic hepatitis and 93 with cirrhosis) for TIMP-1 372 T/C and TIMP-2 -418 G/C polymorphisms. Comparing chronic hepatitis and cirrhosis, there were no significant differences in TIMP-1 and TIMP-2 gene polymorphisms. Among chronic hepatitis patients, TIMP-2 -418 G homozygotes showed significantly faster fibrosis progression than C carriers. Among cirrhotic patients, males with the TIMP-1 372 T allele developed cirrhosis at a younger age, and patients who were homozygous for the higher-transcription TIMP-2 -418 G allele had significantly lower serum albumin concentrations. These results suggest that faster progression of liver fibrosis could be associated with TIMP-2 -418 G homozygotes.

Serum levels of tissue inhibitor of metalloproteinase-1 are correlated with liver fibrosis in patients with chronic hepatitis B

OBJECTIVE

To investigate the relationship between tissue inhibitor of metalloproteinase-1 (TIMP-1) expression and the severity of liver fibrosis in chronic hepatitis B (CHB) patients, and to explore the diagnostic value of serum TIMP-1.

METHODS

A total of 159 CHB patients underwent liver biopsy for the analysis of liver fibrosis stages and inflammation. Serum TIMP-1 was determined by ELISA. Hyaluronic acid (HA), procollagen type III (PCIII), collagen type IV (CIV), laminin (LN), and FIB-4 index were determined and calculated, and diagnostic accuracy was analyzed using receiver operating characteristic (ROC) curve.

RESULTS

Serum levels of TIMP-1 were associated with the grade of liver inflammation in CHB patients (r = 0.695, P < 0.01), especially in those without fibrosis or with stage 1 fibrosis, and were also positively correlated with liver fibrosis in CHB patients (r = 0.854, P < 0.01), particularly in those with inflammation at grade 1, 2 and 3. The area under the ROC curve (AUROC) of serum TIMP-1 was 0.918 for significant liver fibrosis (≥stage 2), and a sensitivity of 89.4% and specificity of 83.6% were obtained with a cut-off value of ≥174.5 ng/mL of serum TIMP-1, which were higher than that of HA, CIV and FIB-4 index.

CONCLUSION

TIMP-1 is a valuable single biomarker for the evaluation of significant fibrosis in CHB patients.

Integrated transcriptional and proteomic analysis with in vitro biochemical assay reveal the important role of CYP3A46 in T-2 toxin hydroxylation in porcine primary hepatocytes

Both T-2 toxin and its metabolites are highly potent mycotoxins that can cause severe human and animal diseases upon exposure. Understanding the toxic mechanism and biotransformation process of T-2 toxin at a cellular level is essential for the development of counter-measures. We investigated the effect of T-2 toxin in porcine primary hepatocytes using porcine genome array and two-dimensional difference gel electrophoresis with matrix-assisted laser desorption/ionization tandem time of flight mass spectrometry. Integrated transcriptional and proteomic analysis demonstrated that T-2 toxin adversely affected porcine hepatocytes by initiating lipid metabolism disorder, oxidative stress response, and apoptosis. In addition, xenobiotic metabolism genes, including cytochrome P450 3As (CYP3A46 and CYP3A39), carboxylesterase 1Cs (CES1C4 and CES1C5), and epoxide hydrolase (EPHX1), increased in T-2 toxin treatment cells. Using HepG2 cells to over-express the recombinant xenobiotic metabolism genes above and rapid resolution liquid chromatography/tandem mass spectrometry to detect metabolites of T-2 toxin, we determined that porcine CYP3A46 mainly catalyzed T-2 to form 3'-hydroxy-T-2, which was further confirmed by purified CYP3A46 protein. However, recombinant porcine CES1C5 and EPHX1 did not enhance hydrolysis and de-epoxidation of T-2 implying that other esterases and epoxide hydrolases may play dominant roles in those reactions.

[Effects of Chinese herbal medicine Yiguanjian Decoction on collagen metabolism of hepatic tissues in rats with CCl4-induced liver fibrosis]

OBJECTIVE

To investigate the effects of Yiguanjian Decoction, a compound traditional Chinese herbal medicine, on collagen metabolism of hepatic tissues in rats with carbon tetrachloride (CCl(4))-induced liver fibrosis.

METHODS

Liver fibrosis was induced in rats by intraperitoneal injection of 50% CCl(4)-olive oil solution at a dose of 1 mL/kg body weight, twice per week for 9 consecutive weeks. Six rats were sacrificed for dynamic observation at the end of the 3rd and 6th week respectively, and the other rats were divided into 9-week untreated group and Yiguanjian Decoction group which was given Yiguanjian Decoction intragastrically in the subsequent 3-week modeling period. Another 6 rats were used as normal group. Rats in the normal group and 9-week untreated group were treated with distilled water. At the end of the 9th week, all rats were sacrificed, and their blood serum and liver tissue were collected for measuring hepatic histology and expressions of α-smooth muscle actin (α-SMA), tissue inhibitor of metalloproteinase (TIMP)-1, TIMP-2, matrix metalloproteinase (MMP)-13, MMP-14, collagen type I (Col I), and activities of MMP-2 and -9.

RESULTS

Compared with the normal group, collagen fiber deposition, expressions of α-SMA, Col I, TIMP-1, TIMP-2, MMP-13 and MMP-14 and activities of MMP-2 and -9 in the liver tissues gradually increased in the untreated group (P<0.05, P<0.01). These changes were significantly suppressed by Yiguanjian Decoction.

CONCLUSION

Yiguanjian Decoction exerts inhibition on formation of CCl(4)-induced cirrhosis in rats. The therapeutic mechanism may be related to inhibiting hepatic stellate cell activation, collagen secretion, and promoting collagen fiber degradation.

Soy isoflavone delays the progression of thioacetamide-induced liver fibrosis in rats

OBJECTIVE

Our aim was to investigate the effect of soy isoflavone (SI) on liver fibrosis in a thioacetamide (TAA)-induced rat model.

MATERIALS AND METHODS

Twenty-eight rats were assigned to four groups: sham group, fibrosis group, low-dose treatment group (LDg) and high-dose treatment group (HDg). SI (90 or 270 mg/kg) was administered daily during the model development by TAA. Standard liver tests, platelet derived growth factor-BB (PDGF-BB) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. The expression of collagen, α-smooth muscle actin (α-SMA) and transforming growth factor-β1 (TGF-β1) in liver tissue was determined. Electron microscopy was used to perform ultrastructural analysis of the livers.

RESULTS

Hepatic fibrosis was induced by 8 weeks of TAA administration. However, following the administration of SI, collagen staining significantly declined as compared with the fibrosis group (p < 0.01). Less collagen fibers around the hepatic stellate cells (HSCs) were observed in HDg as compared to the fibrosis group and LDg. There was no significant difference in standard liver tests between the fibrosis group and the two treatment groups. The levels of PDGF-BB and TIMP-1 in the two SI-treated groups were significantly lower than in the fibrosis group (p < 0.01). The expression of α-SMA and TGF-β1 in HDg was less than that in the fibrosis group and LDg (p < 0.01).

CONCLUSION

Administration of a high dose of SI resulted in an obvious inhibitory effect on liver fibrosis induced by TAA in rats. One hypothesis is that the effect may be related to the inhibition of HSC activation and proliferation.

Significance of serum matrix metalloproteinase-9 and tissue inhibitor of metalloproteinase-1 in chronic hepatitis C patients

Liver fibrosis (LF), where the chronic HCV infection is a major cause, is a characteristic of chronic liver diseases. LF results from chronic damage to the liver in conjunction with the accumulation of ECM proteins. Matrix metalloproteinases (MMPs) and their specific inhibitors (TIMPs) are thought to play an essential role in the hepatic lesions. The available data concerning the circulating levels of matrix metalloproteinase-9 (MMP-9) and tissue inhibitor of metalloproteinase-1 (TIMP-1) in chronic hepatitis C are not conclusive. Therefore, the present study was designed to seek the relationship between serum MMP-9, and TIMP-1 to liver status in chronic liver disease in fifty patients divided into three groups (chronic hepatitis, liver cirrhosis and hepatocellular carcinoma). MMP-9 and TIMP-1 were analyzed by the enzyme linked immunosorbent assay (ELISA). The results showed that the lowest serum level of MMP-9 was found in chronic hepatitis patients compared to the control ( P < 0.05). Serum MMP-9 is decreasing during progression of chronic hepatitis to cirrhosis showing the least level in the cirrhotic group. Serum TIMP-1 was significantly higher in the cirrhotic group compared to chronic hepatitis ( P < 0.05) and controls ( P < 0.001). MMP-9 was negatively correlated to both TIMP-1 and the histological severity in chronic hepatitis. There was a positive correlation between TIMP-1 and the degree of fibrosis (r = 0.73, P < 0.001). Lastly, there was a statistically significant increase of MMP-9 ( P < 0.001) and TIMP-1 ( P < 0.05) in HCC patients compared with the other groups. In conclusion, these findings raise the possibility of using serum TIMP-1 as a non-invasive assay in liver fibrosis. Further, the altered balance between circulating MMP-9 and TIMP-1 during HCV infection may play an important role in aggravating liver injury progression in chronic liver diseases.

Metabolism of collagen is altered in hypertensives with increased intima media thickness

BACKGROUND

Increased intima media thickness (IMT) of common carotid arteries (CCAs) and left ventricular mass index (LVMI) are independent risk factors for vascular events and may be related to accumulation of extracellular proteins due to altered metabolism of collagen.

METHODS

IMT and LVMI were measured ultrasonographically in 50 males with newly diagnosed, untreated, essential hypertension (HTN, 37.7 +/- 13.1 years), and 14 controls (C, 32.6 +/- 9.7 years). Serum levels of procollagen type I carboxy-terminal propeptide (PICP), procollagen type III amino-terminal propeptide (PIIINP), carboxy-terminal telopeptide (ICTP), matrix metalloproteinase (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were determined using immunoassays.

RESULTS

IMT was significantly higher in HTN than in C (0.6 +/- 0.1 vs 0.4 +/- 0.1 mm, p < 0.001) as well as LVMI (119.5 +/- 39.9 vs 106.8+/-18.7 g/m2, p = 0.04) and serum TIMP-1 (in HNT 691.7 +/- 124.6 ng/ml; in C 577.5+/-70.8 ng/ml, p < 0.001). Other parameters did not differ between these groups. The sum of PICP and ICTP was higher in HTN (165.0 +/- 46.9 microg/l), than in C (147.1 +/- 26.0 microg/l, p = 0.03). TIMP-1 correlated with IMT (r = 0.33, p = 0.02) in hypertensives.

CONCLUSIONS

We suggest that the collagenase-anticollagenase system is abnormal in essential hypertension and contributes to cardiovascular remodeling. Increased IMT may be related to the accumulation of extracellular proteins due to altered metabolism of collagen.

Inhibition of hepatic stellate cell activation following Yinchenhao decoction administration to dimethylnitrosamine-treated rats

AIM

In an effort to investigate the mechanism by which Yinchenhao decoction (YCHD) acts on liver injury, we investigated the potential antifibrogenic effects of YCHD in an experimental liver fibrosis rat model, with special focus on the mechanisms inhibiting the activation and promoting apoptosis of hepatic stellate cells (HSC).

METHODS

The rats were initially randomized into two groups: the control (n = 10) and dimethylnitrosamine-treated (DMN; n = 30) groups. DMN (10 mg/kg body weight) was administered intraperitoneally to the DMN-treated rats for three consecutive days each week. At the end of the second week, three rats from the control and six rats from the DMN-treated groups were killed for the fibrosis development assessment. The remaining DMN rats were further randomized into two groups: the DMN-water group (n = 12) and the DMN-YCHD group (n = 12). Both groups continued to receive weekly DMN treatment for another 2 weeks in addition to daily administration of either water or YCHD, which were given intragastrically at a dose of 0.418 g/100 g body weight.

RESULTS

Hepatic hydroxyproline content decreased and had improved histopathology in the DMN-YCHD rats. Compared to the DMN group, alpha-smooth muscle actin (SMA) and CD68 expression in the DMN-YCHD group was reduced significantly; however, alpha-SMA-positive HSC apoptosis was not observed by confocal microscopy; Fibrogenic proteins (tissue inhibitor matrix proteinases-1 and 2 and matrix metalloproteinase [MMP]-2/14) and cytokines (tumor necrosis factor-alpha and transforming growth factor-beta(1)) were decreased; MMP-9 was significantly upregulated.

CONCLUSION

Yinchenhao administration attenuates liver fibrosis at least in part by inhibiting HSC activation directly, rather than promoting cell apoptosis of activated HSC, and the suppressive activation of Kupffer cells.

Noninvasive diagnosis of hepatic fibrosis in HIV/HCV-coinfected patients

BACKGROUND

Several serum markers reflecting extracellular matrix status have been correlated with liver fibrosis in non-HIV-infected patients with chronic hepatitis C infection. These indexes have been less examined in HIV/HCV-coinfected individuals.

OBJECTIVE

We aimed to evaluate the predictive value of serum markers for liver fibrosis in HIV-infected patients with chronic hepatitis C virus (HVC).

METHODS

Serum levels of metalloproteinases 1 and 2 (MMP-1 and -2), tissue inhibitors of matrix metalloproteinases (TIMP-1), procollagen type III N-terminal peptide (PIIINP), and hyaluronic acid (HA) were measured in HIV-infected patients with chronic hepatitis C at the time of obtaining a liver biopsy and before the consideration of anti-hepatitis C therapy.

RESULTS

One hundred and nineteen consecutive HIV-HVC coinfected patients were included. TIMP-1 (r = 0.6; P < 0.001), TIMP-1/MMP-1 ratio (r = 0.5; P < 0.001), TIMP-1/MMP-2 ratio (r = 0.3; P < 0.001), MMP-2 (r = 0.2; P = 0.044), PIIINP (r = 0.4; P < 0.001), and HA (r = 0.5; P < 0.001) were positively and significantly correlated with the fibrosis stage. In the multivariate analysis, TIMP-1 (odds ratio [OR] = 1.004, 95% confidence interval [CI]: 1.002 to 1.006, P = 0.001) and HA >95 microg/dL (OR = 6.041, 95% CI: 1.184 to 30.816, P = 0.031) were independently associated with liver fibrosis. The area under the curve of score to discriminate mild (F0-F1) from significant (F2-F4) fibrosis in the received-operating analysis using the variables TIMP-1 and HA was 0.84, with a sensitivity of 72.9% and a specificity of 83.1%.

CONCLUSION

TIMP-1 and HA were quite sensitive and specific for predicting the degree of liver fibrosis in HIV-infected patients with chronic hepatitis C. These parameters may become a noninvasive alternative to liver biopsy when the degree of liver fibrosis needs to be estimated.

Prominent contribution of portal mesenchymal cells to liver fibrosis in ischemic and obstructive cholestatic injuries

Liver fibrosis is produced by myofibroblasts of different origins. In culture models, rat myofibroblasts derived from hepatic stellate cells (HSCs) and from periductal portal mesenchymal cells, show distinct proliferative and immunophenotypic evolutive profiles, in particular regarding desmin microfilament (overexpressed vs shut-down, respectively). Here, we examined the contributions of both cell types, in two rat models of cholestatic injury, arterial liver ischemia and bile duct ligation (BDL). Serum and (immuno)histochemical hepatic analyses were performed at different time points (2 days, 1, 2 and 6 weeks) after injury induction. Cholestatic liver injury, as attested by serum biochemical tests, was moderate/resolutive in ischemia vs severe and sustained in BDL. Spatio-temporal and morphometric analyses of cytokeratin-19 and Sirius red stainings showed that in both models, fibrosis accumulated around reactive bile ductules, with a significant correlation between the progression rates of fibrosis and of the ductular reaction (both higher in BDL). After 6 weeks, fibrosis was stabilized and did not exceed F2 (METAVIR) in arterial ischemia, whereas micronodular cirrhosis (F4) was established in BDL. Immuno-analyses of alpha-smooth muscle actin and desmin expression profiles showed that intralobular HSCs underwent early phenotypic changes marked by desmin overexpression in both models and that the accumulation of fibrosis coincided with that of alpha-SMA-labeled myofibroblasts around portal/septal ductular structures. With the exception of desmin-positive myofibroblasts located at the portal/septal-lobular interface at early stages, and of myofibroblastic HSCs detected together with fine lobular septa in BDL cirrhotic liver, the vast majority of myofibroblasts were desmin-negative. These findings suggest that both in resolutive and sustained cholestatic injury, fibrosis is produced by myofibroblasts that derive predominantly from portal/periportal mesenchymal cells. While HSCs massively undergo phenotypic changes marked by desmin overexpression, a minority fully converts into matrix-producing myofibroblasts, at sites, which however may be important in the healing process that circumscribes wounded hepatocytes.

Effect of Chinese traditional compound, Gan-fu-kang, on CCl(4)-induced liver fibrosis in rats and its probable molecular mechanisms

AIM

To explore the antifibrotic effect of traditional Chinese medicine compound Gan-fu-kang (GFK) on CCl(4)-induced liver fibrosis in rats and its probable mechanisms.

METHODS

The effects of GFK on CCl(4)-induced liver fibrosis were tested in rats. The liver histopathology was examined by light microscope, polaring microscope and electron microscope. The activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were assayed and the content of albumin (ALB) and hydroxyproline in the liver was measured. The expression of transforming growth factor-beta(1) (TGF-beta(1)) and laminin (LN) was determined by immunohistochemistry. Semi-quantitive computation of collagen types I and III and laminin was done. The expression of MMP-2 and TIMP-1 was assayed by reverse transcription polymerase chain reaction (RT-PCR).

RESULTS

Upon pathological examination, GFK treatment had significantly reversed liver fibrosis. Hepatic extracellular matrix (ECM) deposition was significantly reduced, as evidenced by the reduction of the content of hydroxyproline, collagen types I and III, and laminin. Hepatic function was improved by GFK treatment, as evidenced by the increase of plasma ALB and A/G, and by the decrease of serum ALT and AST. TGF-beta(1) in liver was significantly reduced. A significant expression of MMP-2 and TIMP-1 mRNA in liver were downregulated after GFK treatment.

CONCLUSION

The traditional Chinese medicine compound recipe GFK has an antifibrotic effect on CCl(4)-induced liver fibrosis in rats, which improves hepatic function and lessens the deposition of collagen in the liver. The probable antifibrotic mechanisms were: inhibiting the expression of TGF-beta(1) and decreasing expressions of MMP-2 and TIMP-1.

Correlation between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models

AIM

To evaluate serum TIMP-1 level and the correlation between TIMP-1 expression and liver fibrosis in immune-induced and CCL4-induced liver fibrosis models in rats.

METHODS

Immune-induced and CCL4-induced liver fibrosis models were established by dexamethasone (0.01 mg) and CCL4 respectively. Serum TIMP-1 level was detected with ELISA, while histopathological grade of liver biopsy was evaluated. Spearman rank-correlation test was used to analyse the difference of the correlation between the TIMP-1 expression and hepatic fibrosis in the two fibrosis models. Furthermore, in situ hybridization was used to determine the expression difference of TIMP-1 mRNA in the two models.

RESULTS

Positive correlation existed between serum TIMP-1 level of immune induced group and the histopathological stages of fibrosis liver of corresponding rats (Spearman rank-correlation test, r(s) = 0.812, P < 0.05), and the positive in situ hybridization signal of TIMP-1 mRNA was strong. In CCL4-induced liver fibrosis model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant(Spearman rank-correlation test, r(s) = 0.229, P > 0.05). And compared with immune-induced model, the positive in situ hybridization signal of TIMP-1 mRNA was weaker, while the expression variation was higher in hepatic fibrosis of the same severity.

CONCLUSION

The correlations between TIMP-1 expression and liver fibrosis in two rat liver fibrosis models are different. In immune-induced model, serum TIMP-1 level could reflect the severity of liver fibrosis, while in CCL4-induced model, the correlation between the serum TIMP-1 level and the severity of hepatic fibrosis was not statistically significant.

Antisense oligonucleotides-based inhibition of gene and protein expression of tissue inhibitor of metalloproteinase-2 on experimental liver fibrosis in rats

AIM: To investigate the inhibitory effect of tissue inhibitor of metalloproteinase-2 (TIMP-2) targeted antisense oligonucleotide (asON) on the progress of experimental liver fibrosis in rats.

METHODS: Twenty-two rats were divided into asON treatment (n = 6), model (n = 6), and normal control group (n = 10). The liver fibrosis model was induced by human serum albumin (HSA). During modeling, the rats were treated with antisense oligonucleotides via tail vein. The level of TIMP-2 expression was detected by reverse transcription polymerase chain reaction (RT-PCR), in situ hybridization, immunohistochemical staining and enzyme linked immunosorbent assay (ELISA). The effect of asON on liver fibrosis was analyzed by histopathological exami-nation, immunohistochemical staining of collagenⅠand Ⅳ, and special staining of collagen fiber as well as electron microscopy.

RESULTS: The pathological grading was notably im-proved in asON group than that in model group (u = 2.071, P <0.05). The serum and tissue expression of TIMP-2 were lower in asON group than those in model group (T = 55, P <0.05; t = 3.332, P <0.05), but higher than those in the control (T = 55, P <0.05; t = 5.550, P <0.05). Image quantitative analysis for immunohistochemical staining of collagen Ⅳ showed that the value was significant decreased in asON group as compared with that in model group (t = 2.310, P <0.05), but still higher than that in the control (t = 3.623, P <0.05); The value for collagenⅠwas also decreased in asON group as compared with that in model group (t = 2.845, P <0.05). Less collagen deposition was found in the hepatic sinusoid of asON group, which was not significantly different from that of model group.

CONCLUSION: TIMP-2 targeted asON can inhibit the progress of experimental liver fibrosis in rats.

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.

Induction of cell death in activated hepatic stellate cells by targeted gene expression of the thymidine kinase/ganciclovir system

Liver fibrosis is the result from a relative imbalance between synthesis and degradation of matrix proteins. Following liver injury of any etiology, hepatic stellate cells undergo a response known as activation, which is the transition of quiescent cells into proliferative, fibrogenic, and contractile myofibroblasts. Upon this cellular transdifferentiation the effector cell becomes the major source of fibrillar and non-fibrillar matrix proteins resulting in excessive scar formation and cirrhosis, the end stage of fibrosis. Concomitant with progressive liver fibrosis, the tissue inhibitor of metalloproteinases-1 (TIMP-1) is strongly activated in hepatic stellate cells. We have developed a recombinant replication-defective adenovirus in which the TIMP-1 promoter is coupled to the herpes simplex virus thymidine kinase gene rendering activated hepatic stellate cells susceptible to ganciclovir. This novel targeted suicide gene approach was validated in a culture model considered to reflect an accelerated time course of the cellular and molecular events that occur during liver fibrosis. We demonstrate that transfer of the suicide gene to culture-activated hepatic stellate cells results in a strong expression of the respective transgene as assessed by Northern blot and Western blot analyses. The enzyme catalyzed the proper conversion of its prodrug subsequently initiating programmed cell death as estimated by caspase-3 assay and Annexin V-Fluos staining. Altogether, these results indicate that induction of programmed cell death is a promising approach to eliminate fibrogenic HSC.

Elevated levels of matrix metalloproteinase 9 and tissue inhibitor of metalloproteinase 1 during the acute phase of Kawasaki disease

Kawasaki disease (KD) is an acute, self-limiting, multisystem vasculitis of unknown etiology affecting infants and young children. Unless treated promptly with high-dose intravenous gamma globulin and aspirin, patients frequently develop coronary aneurysms. Previously, matrix metalloproteinase 9 (MMP-9), which is secreted complexed to tissue inhibitor of metalloproteinase 1 (TIMP-1), has been implicated in abdominal aortic aneurysm formation. Since the clinical and pathological features of KD include inflammation and weakening of blood vessels, we analyzed acute- and convalescent-phase paired plasma or serum samples from 31 KD patients, 7 patients who did not completely meet the criteria for KD, and 26 non-KD controls (9 febrile and 17 afebrile patients) for pro-MMP-9 (92 kDa) enzyme activity by gelatin zymography and for active MMP-9 (83 kDa), pro-MMP-9, and TIMP-1 protein levels by enzyme-linked immunosorbent assay. Statistical analysis was performed by using Student t tests, linear regression, and the Wilcoxon rank-sum test. Markedly elevated pro-MMP-9 enzymatic activity, pro-MMP-9 protein levels, and TIMP-1 protein levels were found during the acute phase of illness in patients with clinically established KD and in patients who were suspected of having KD but did not meet all of the criteria. There was no significant difference in active MMP-9 levels. Furthermore, pro-MMP-9 and TIMP-1 protein levels were significantly elevated among KD patients, compared to those of febrile and afebrile non-KD controls. The significantly elevated pro-MMP-9 enzyme and protein levels during the acute phase of KD may reflect vascular remodeling or an inflammatory response to a microbial agent, suggesting a pathophysiological role for MMP-9 in coronary aneurysm formation.

Expression of exogenous rat collagenase in vitro and in a rat model of liver fibrosis

AIM: The present study was conducted to test the hypothesis that the introduction of the collagenase gene into tissue culture cells and into a rat model of liver fibrosis would result in the expression of enzymatically active product.

METHODS: FLAG-tagged full-length rat collagenase cDNA was PCR amplified and cloned into a mammalian expression vector. NIH3T3 cells were then transiently transfected with this construct. Expression of exogenous collagenase mRNA was assessed by RT-PCR, and the exogenous collagenase detected by Western blotting using anti-FLAG monoclonal antibody. Enzymatic activity was detected by gelatin zymography. To determine the effects of exogenous collagenase production in vivo, the construct was bound to glycosyl-poly-L-lysine and then transduced into rats that had developed liver fibrosis as a result of CCl₄ plus ethanol treatment. The hepatic expression of the construct and its effect on the formation of liver fibrosis were demonstrated using RT-PCR and immunohistochemistry.

RESULTS: It was found that exogenously expressed rat collagenase mRNA could be detected in NIH3T3 cells following transfection. Enzymatically active collagenase could also be detected in the culture medium. The recombinant plasmid was also expressed in rat liver after in vivo gene transfer. Expression of exogenous rat collagenase correlated with decreased deposition of collagen types I and III in the livers of rats with experimentally induced liver fibrosis.

CONCLUSION: The expression of active exogenous rat collagenase could be achieved in vitro and in vivo. It was suggested that in vivo expression of active exogenous collagenase may have therapeutic effects on the formation of liver fibrosis.

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.

Halofuginone, a collagen type I inhibitor improves liver regeneration in cirrhotic rats

BACKGROUND/AIMS

Hepatic fibrosis involves excess deposition of extracellular connective tissue of which collagen type I fibers form the predominant component. Left untreated it develops into cirrhosis, often linked with hepatocellular carcinoma. Owing to the fact that cirrhotic liver regeneration is impaired, resection of hepatocellular carcinoma associated with cirrhosis is questionable. The aim of the present study was to determine the potential of halofuginone, a collagen type I inhibitor, in improving liver regeneration in cirrhotic rats.

METHODS

Partial hepatectomy (70%) was performed in thioacetamide-induced cirrhotic rats fed a halofuginone-containing diet. Liver regeneration was monitored by mass and proliferating cell nuclear antigen. The Ishak staging system and hydroxyproline content were used to evaluate the level of fibrosis.

RESULTS

Halofuginone administered prior to and following partial hepatectomy did not inhibit normal liver regeneration despite the reduced levels of collagen type I mRNA. When given to rats with established fibrosis, it caused a significant reduction in alpha smooth muscle actin, TIMP-2, collagen type I gene expression and collagen deposition. Such animals demonstrated improved capacity for regeneration.

CONCLUSIONS

Halofuginone may prove useful in improving survival of patients with hepatocellular carcinoma and cirrhosis undergoing surgical resection.

Methodologic research on TIMP-1, TIMP-2 detection as a new diagnostic index for hepatic fibrosis and its significance

AIM

To set up a new method to detect tissue inhibitors of metalloproteinase-1 and -2(TIMP-1 and TIMP-2) in sera of patients with hepatic cirrhosis, and to investigate the expression and location of TIMP-1 and TIMP-2 in liver tissue of patients with hepatic cirrhosis, and the correlation between TIMPs in liver and those in sera so as to discuss whether TIMPs can be used as a diagnosis index of hepatic fibrosis.

METHODS

The monoclonal antibodies (McAbs) of TIMP-1 and TIMP-2 were used to sensitize erythrocytes, and solid-phase absorption to sensitized erythrocytes (SPASE) was used to detect TIMP-1 and TIMP-2 in the sera of patients with hepatic cirrhosis. Meanwhile, with the method of in situ hybridization and immunohistochemistry, we studied the mRNA expression and antigen location of TIMP-1 and TIMP-2 in the livers of 40 hepatic cirrhosis patients with pathologic diagnosis.

RESULTS

With SPASE, they were 16.4% higher in the acute hepatitis group, 33.3% higher in the chronic hepatitis group, and the positive rates were 73.6% and 61.2% respectively in sera of hepatic cirrhosis patients, which were remarkably higher than those in chronic hepatitis and acute hepatitis group (P<0.001). In 40 samples of hepatic cirrhosis tissues, all of them showed positive expression of TIMP-1 and TIMP-2 mRNA detected with immunohistochemistry or in situ hybridization (positive rate was 100%). Expression of TIMPs in different degrees could be found in liver tissue with cirrhosis. TIMPs were located in cytoplasm of liver cells of patients with hepatic cirrhosis. There was a significant correlation between serum TIMPs level and liver TIMPs level.

CONCLUSION

SPASE is a useful method to detect the TIMP-1 and TIMP-2 in sera of patients with hepatic cirrhosis, and TIMP-1 and TIMP-2 can be considered as a useful diagnostic index of hepatic fibrosis, especially TIMP-1.

Diagnostic potential of circulating TIMP-1 and MMP-2 as markers of liver fibrosis in patients with chronic hepatitis C

BACKGROUND

Circulating levels of tissue inhibitor of metalloproteinase (TIMP)-1 and matrix metalloproteinase (MMP)-2 are investigated as parameters for the diagnosis of fibrosis in chronic liver disease. We evaluated their diagnostic potential in comparison to hepatic histology, serum hyaluronate and standard liver function tests.

METHODS

Commercially available ELISA assays were used to study circulating values of TIMP-1 and MMP-2 (Bindazyme, Biotrak, Quantikine) in patients with chronic hepatitis C (CAH; n=59), hepatitis C virus-induced cirrhosis (n=19) and 30 healthy controls. Hepatic histology was evaluated using the Hepatitis-Activity-Index according to Ishak et al. [J. Hepatol., 22 (1995) 696-699], quantifying separately inflammatory activity and fibrosis.

RESULTS

Normal ranges for TIMP-1 and MMP-2 values differed for the different assays. Nevertheless, the various assays showed similar diagnostic ability and linear correlation. MMP-2 values were similar in controls and in CAH patients with and without fibrosis, but increased significantly in cirrhosis. TIMP-1 values showed a steady increase from normal to CAH without fibrosis, hepatitis with fibrosis, and cirrhosis. The diagnostic potential of serum MMP-2 to detect fibrosis was low with a sensitivity of 7% in the two assays used and an overall diagnostic efficiency of 56% and 58%. The potential of circulating MMP-2 to detect cirrhosis was higher with sensitivities of 74% and 83% and specificities of 96% and 100%, resulting in a diagnostic efficiency of 92% in the different assays. Plasma TIMP-1 values detect fibrosis with a sensitivity of 52% and 67% and a specificity of 68% and 88% resulting in overall efficiency rates of 68% and 71%, respectively. TIMP-1 values detect cirrhosis with 100% sensitivity but only 56% and 75% specificity. The diagnostic potential of circulating TIMP-1 was similar to that of hyaluronate and better than that of enzymes or albumin values.

CONCLUSION

Plasma values of TIMP-1 and MMP-2 are able to detect cirrhosis with high sensitivity. TIMP-1 values also detect fibrosis with comparable efficiency. Regular determinations of both TIMP-1 and MMP-2 in CAH patients may be used as indicators of increasing fibrosis and the development of cirrhosis.

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.

Inhibiting effect of antisense oligonucleotides phosphorthioate on gene expression of TIMP-1 in rat liver fibrosis

AIM

To observe the inhibition of antisense oligonucleotides (asON) phosphorthioate to the tissue inhibitors metalloproteinase-1 (TIMP-1) gene and protein expression in the liver tissue of immunologically induced hepatic fibrosis rats. The possibility of reversing hepatic fibrosis through gene therapy was observed.

METHODS

Human serum albumin (HSA) was used to attack rats, as hepatic fibrosis model, in which asONs were used to block the gene and protein expressing TIMP-1. According to the analysis of modulator, structure protein, coding series of TIMP-1 genome, we designed four different asONs. These asONs were injected into the hepatic fibrosis models through coccygeal vein. The results was observed by RT-PCR for measuring TIMP-1 mRNA expression, immunohistochemistry and in situ hybridization for collagen I, II, special staining of collagen fiber, and electron microscopic examination.

RESULTS

Hepatic fibrosis could last within 363 days in our modified model. The expressing level of TIMP-1 was high during hepatic fibrosis process. It has been proved by the immunohistochemical and the electron microscopic examination that the asON phosphorthioate of TIMP-1 could exactly express in vivo. The effect of colchicine was demonstrated to inhibit the expressing level of mRNA and the content of collagen I, III in the liver of experimental hepatic fibrosis rats. However, the electron microscopy research and the pathologic grading of hepatic fibrosis showed that there was no significant difference between the treatment group and the model group (P> 0.05).

CONCLUSION

The experimental rat model of hepatic fibrosis is one of the preferable models to estimate the curative effect of anti-hepatic fibrosis drugs. The asON phosphorthioate of TIMP-1 could block the gene and protein expression of TIMP-1 in the liver of experimental hepatic fibrosis rats at the mRNA level. It is possible to reverse hepatic fibrosis, and it is expected to study a new drug of antihepatic fibrosis on the genetic level. Colchicine has very limited therapeutic effect on hepatic fibrosis, furthermore, its toxicity and side effects are obvious.

Characterization of serum activin-A and follistatin and their relation to virological and histological determinants in chronic viral hepatitis

BACKGROUND/METHODS

Hepatocyte proliferation in viral hepatitis is regulated by a number of growth factors. Activin-A inhibits hepatocyte DNA synthesis while follistatin, a potent activin-A antagonist, promotes liver regeneration. We report the first study of activin-A and follistatin in human viral hepatitis. Sera from 15 normal subjects, 22 hepatitis B and 47 hepatitis C patients were analysed for activin-A and follistatin and correlated with serological and histological markers of liver injury and with specific immunohistochemistry.

RESULTS

All groups showed immunoreactivity for activin with hepatocyte localisation. Serum activin-A was significantly increased in viral hepatitis patients compared to controls, was greater in hepatitis B compared to hepatitis C, and correlated with serum aminotransferase and hepatitis B viral replication. A concurrent rise in serum follistatin was not observed in either group, but serum follistatin correlated inversely with hepatitis B DNA levels. Although hepatocyte apoptosis in hepatitis C and proliferation in both groups was significantly elevated compared to controls, there was no correlation with serum activin-A or follistatin.

CONCLUSIONS

Activin-A and follistatin are constitutively expressed in human liver and serum concentrations are increased in viral hepatitis. Dysregulation of the activin/follistatin axis may be linked to hepatitis B replication but does not correlate with hepatocyte apoptosis.

Matrix metalloproteinase (MMP)-2, MMP-7, and tissue inhibitor of metalloproteinase-1 are closely related to the fibroproliferative process in the liver during chronic hepatitis C

BACKGROUND/AIMS

To study whether expression of matrix metalloproteinases and their inhibitors correlate with ongoing fibrogenesis, we measured hepatic mRNA levels of matrix metalloproteinase (MMP) -2, MMP-7, and MMP-9 as well as tissue inhibitor of metalloproteinase (TIMP) -1, TIMP-2, and TIMP-3 and compared it to histology, procollagen IV alpha-1 chain mRNA levels, and biochemical parameters in patients with chronic active hepatitis C (CAH).

METHODS

Quantitative reverse transcription-polymerase chain reaction/enzyme-linked immunossorbent assay using in vitro transcribed competitor and standard RNA were performed from ten normal livers (N), 29 CAH liver biopsies and seven samples with hepatitis C virus (HCV)-induced end-stage cirrhosis (Ci).

RESULTS

From N to Ci both TIMP and MMP RNA expression increased. However, none of the RNA levels differed significantly between CAH patients with and without fibrosis. Non-parametric correlation analysis and receiver operating characteristics curves show that MMP-2, MMP-7, and TIMP-1 provide the best discrimination between cirrhosis and pre-cirrhotic stages. They also correlate with histologic and biochemical inflammatory activity and with procollagen IV mRNA.

CONCLUSION

Hepatic fibroproliferation is associated with alterations of hepatic TIMP and MMP expression. The relation of hepatic TIMP and MMP mRNA levels to disease stage and inflammatory activity underlines their potential as diagnostic markers in chronic liver disease.

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.

Changes in serum tissue inhibitor of matrix metalloproteinase-1 after interferon alpha treatment in chronic hepatitis C

BACKGROUND/AIMS

The aim of this study was to evaluate the effect of interferon alpha on the metabolism of hepatic fibrosis in chronic hepatitis C, monitoring serum tissue inhibitor of matrix metalloproteinase-1(TIMP-1) and N-terminal propeptide of type III procollagen (PIIINP) reflecting fibrolysis and fibrogenesis, respectively.

METHODS

Serum levels of TIMP-1 and PIIINP were serially measured in 112 treated and 31 untreated patients with chronic hepatitis C during and after interferon alpha treatment. Furthermore, the relationships between these serum markers and the grades of hepatic fibrosis after interferon therapy were also investigated.

RESULTS

Serum pretreatment levels of TIMP-1 and PIIINP in non-responders were significantly higher than those in sustained and transient responders, but these levels were not different in the latter two groups. Serum TIMP-1 levels decreased significantly during and after treatment in sustained responders, and decreased temporarily at the end of treatment in transient responders, although these levels were unchanged during and after treatment in non-responders and untreated patients. In contrast, serum PIIINP levels decreased significantly during and after treatment in all treated groups, but were unchanged in untreated patients. Histological examination 12 months after interferon was completed demonstrated that hepatic fibrosis improved in sustained responders and was unchanged in transient and non-responders, but progressed in untreated patients.

CONCLUSION

These results suggest that interferon alpha treatment of chronic hepatitis C may improve hepatic fibrosis in sustained responders by the acceleration of fibrolysis as well as the inhibition of fibrogenesis, and that it may suppress the progression of hepatic fibrosis in non-sustained responders by the inhibition of fibrogenesis.

Expression of Matrix Metalloproteinase-2 and -9 and Their Inhibitors in Peripheral Blood Cells of Patients with Chronic Hepatitis C

Background: To clarify whether circulating matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) can be used as serum markers of fibroproliferation in chronic liver diseases, we studied the expression of MMP-2 and MMP-9 in relation to TIMP-1 and TIMP-2 in peripheral blood mononuclear leukocytes (MNLs) and polymorphonuclear leukocytes (PMLs), and compared this expression to circulating concentrations and hepatic histology in patients with chronic active hepatitis C (CAH).

Methods: Quantitative reverse transcription-PCR/ELISA assays were performed for MMP and TIMP RNA, and corresponding circulating protein concentrations were studied by ELISA in 20 healthy controls, 40 patients with CAH, and 20 patients with hepatitis C-induced cirrhosis (Ci).

Results: MMP-2 mRNA was found almost exclusively in the liver, MMP-9 mRNA in leukocytes. TIMP RNA-equivalents were decreased in MNLs of CAH patients, but neither MMP-9 nor TIMP RNA expression showed any correlation to the extent of inflammation and fibrosis. MMP-2 and TIMP-1 protein concentrations were increased in Ci patients and showed a wide overlap in CAH patients and healthy controls. MMP-9 values were lower in CAH and Ci patients than in healthy controls. TIMP-2 values showed a wide overlap in all three groups. The MMP-2/TIMP-1 and MMP-9/TIMP-1 ratios were lower in Ci patients than in healthy controls; the MMP-2/TIMP-2 and MMP-9/TIMP-2 ratios were not different. Circulating TIMP-1 and the MMP-2/TIMP-1 ratio correlated to the inflammatory activity in liver biopsies, but only the circulating MMP-2/TIMP-1 ratio also correlated with the degree of fibrosis.

Conclusions: Peripheral blood cell expression of MMP-2, MMP-9, and TIMP revealed no correlation with the circulating concentrations of these proteins. Only the circulating MMP-2/TIMP-1 ratio correlated to the histological degree of fibrosis in hepatitis C and should be further evaluated as a progression marker in patients with chronic liver disease.

Differential regulation of extracellular matrix synthesis during liver regeneration after partial hepatectomy in rats

Little is known about the modulation of the extracellular matrix (ECM) during liver regeneration. We studied the temporospatial expression of procollagens and of matrix metalloproteinases (MMPs) and their physiological antagonists, the tissue inhibitors of metalloproteinases (TIMPs) after two-thirds partial hepatectomy (PH) by Northern blot analysis and in situ hybridization. The entry of hepatocytes into the S-phase at 24 hours after PH was accompanied by a peak (sixfold induction) of hepatic TIMP-1 RNA levels that steadily declined thereafter to reach normal levels 144 hours after PH. Moderate MMP-2 and TIMP-2 RNA levels remained constant up to 144 hours after PH, and MMP-1 and -13 RNA were always undetectable. In situ hybridization showed a dramatic upregulation of TIMP-1 RNA transcripts in mesenchymal cells of portal, perisinusoidal and, to a lesser extent, pericentral areas. In contrast, scattered hepatocytes represented only a minor fraction (below 10%) of TIMP-1 RNA positive cells. When hepatocytes stopped DNA synthesis at 72 hours after PH, an upregulation of procollagen alpha1(I) and alpha2(III) transcripts was observed paralleled by threefold increased PIIINP levels in the sera. Our data reveal a tightly regulated program of de novo matrix synthesis after PH. Whereas interstitial procollagens appear to participate in the induction and maintenance of the quiescent hepatocyte phenotype, the early and localized expression of TIMP-1 indicates a role unrelated to its function as a general MMP-antagonist, e.g., as a growth promoting agent for hepatocytes.

Induction of TIMP-1 expression in rat hepatic stellate cells and hepatocytes: a new role for homocysteine in liver fibrosis

Elevated plasma levels of homocysteine have been shown to interfere with normal cell function in a variety of tissues and organs, such as the vascular wall and the liver. However, the molecular mechanisms behind homocysteine effects are not completely understood. In order to better characterize the cellular effects of homocysteine, we have searched for changes in gene expression induced by this amino acid. Our results show that homocysteine is able to induce the expression and synthesis of the tissue inhibitor of metalloproteinases-1 (TIMP-1) in a variety of cell types ranging from vascular smooth muscle cells to hepatocytes, HepG2 cells and hepatic stellate cells. In this latter cell type, homocysteine also stimulated alpha 1(I) procollagen mRNA expression. TIMP-1 induction by homocysteine appears to be mediated by its thiol group. Additionally, we demonstrate that homocysteine is able to promote activating protein-1 (AP-1) binding activity, which has been shown to be critical for TIMP-1 induction. Our findings suggest that homocysteine may alter extracellular matrix homeostasis on diverse tissular backgrounds besides the vascular wall. The liver could be considered as another target for such action of homocysteine. Consequently, the elevated plasma levels of this amino acid found in different pathological or nutritional circumstances may cooperate with other agents, such as ethanol, in the onset of liver fibrosis.