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

Detecting Coevolution of Functionally Related Proteins for Automated Protein Annotation

Sequence similarity based protein clustering methods organize proteins into families of similar sequences, a task that continues to be critical for automated protein characterization. However, many protein families cannot be automatically characterized further because little is known about the function of any protein in a family of similar sequences. We present a novel phylogenetic profile comparison (PPC) method called Automated Protein Annotation by Coordinate Evolution (APACE) that facilitates the automated characterization of proteins beyond their homology to other similar sequences. Our method implements a new approach for the normalization of similarity scores among multiple species and automates the characterization of proteins by their patterns of co-evolution with other proteins that do not necessarily share a similar sequence. We demonstrate that our method is able to recapitulate the topology of the latest, unresolved, composite deep eukaryotic phylogeny and is able to quantify the as yet unresolved branch lengths. We further demonstrate that our method is able to detect more functionally related proteins, given the same starting data, than existing methods. Finally, we demonstrate that our method can be successfully applied to much larger comparative genomic problem instances where existing methods often fail.

Role of host genetics in fibrosis

Fibrosis can occur in tissues in response to a variety of stimuli. Following tissue injury, cells undergo transformation or activation from a quiescent to an activated state resulting in tissue remodelling. The fibrogenic process creates a tissue environment that allows inflammatory and matrix-producing cells to invade and proliferate. While this process is important for normal wound healing, chronicity can lead to impaired tissue structure and function.

This review examines the major factors involved in transforming or activating tissues towards fibrosis. The role of genetic variation within individuals affected by fibrosis has not been well described and it is in this context that we have examined the mediators of remodelling, including transforming growth factor-beta, T helper 2 cytokines and matrix metalloproteinases.

Finally we examine the role of Toll-like receptors in fibrosis. The inflammatory phenotype that precedes fibrosis has been associated with Toll-like receptor activation. This is particularly important when considering gastrointestinal and hepatic disease, where inappropriate Toll-like receptor signalling, in response to the local microbe-rich environment, is thought to play an important role.

Hypoxia-inducible factor-1 alpha, in association with inflammation, angiogenesis and MYC, is a critical prognostic factor in patients with HCC after surgery

Background

Despite well-studied tumor hypoxia in laboratory, little is known about the association with other pathophysiological events in the clinical view. We investigated the prognostic value of hypoxia-inducible factor-1 alpha (HIF-1alpha) in hepatocellular carcinoma (HCC), and its correlations with inflammation, angiogenesis and MYC oncogene.

Methods

In a random series of 110 HCC patients, the mRNA of HIF-1alpha, inflammation related factors (COX-2, MMP7 and MMP9), angiogenesis related factors (VEGF and PDGFRA) and MYC in tumor tissue were detected by real-time RT-PCR and HIF-1alpha protein was assessed by immunohistochemistry. The correlations between HIF-1alpha mRNA and the factors mentioned previously, the relationship between HIF-1alpha and clinicopathologic features, and the prognostic value were analyzed.

Results

The expression of both HIF-1alpha mRNA and protein in HCC were independent prognostic factors for overall survival (OS) (P = 0.012 and P = 0.021, respectively) and disease-free survival (DFS) (P = 0.004 and P = 0.007, respectively) as well. Besides, the high expression of HIF-1alpha mRNA and protein proposed an advanced BCLC stage and more incidence of vascular invasion. The mRNA of HIF-1alpha had significantly positive correlations to that of COX-2, PDGFRA, MMP7, MMP9, MYC, except VEGF. In addition to HIF-1alpha, COX-2 and PDGFRA were also independent prognosticators for OS (P = 0.004 and P = 0.010, respectively) and DFS (P = 0.010 and P = 0.038, respectively).

Conclusion

HIF-1alpha in HCC plays an important role in predicting patient outcome. It may influence HCC biological behaviors and affect the tumor inflammation, angiogenesis and act in concert with the oncogene MYC. Attaching importance to HIF-1alpha in HCC may improve the prognostic and therapeutic technique.

Other non-invasive markers of liver fibrosis

An intensive research effort in the field of non-invasive evaluation of liver fibrosis has recently permitted the description and validation of several serum markers of fibrosis, mainly in chronic hepatitis C patients. In addition to the commonly used tests such as FibroTest or FibroMeters, other either indirect (aspartate aminotransferase, prothrombin time, platelets) or direct (PIIINP, hyaluronic acid, metalloproteinases) markers, usually used in combination, have been evaluated. Simple scores such as APRI or FIB-4 have also been widely studied and have revealed interesting, albeit non-comprehensive, data on liver fibrosis, especially in terms of significant, extensive fibrosis or cirrhosis. These simple scores may be proposed as a first-line investigation, bearing in mind their limitations and comparing them with more accurate methods for evaluating liver fibrosis if necessary. Other scores, including direct serum markers, which can be difficult to assess, have given disappointing results that, in general, were either similar to, or only slightly better than, the results of the simpler tests. Further studies are needed to identify new markers that are more accurate and, above all, able to predict the outcome of liver fibrosis.

A novel nonsynonymous variant of matrix metalloproteinase-7 confers risk of liver cirrhosis

Liver cirrhosis is characterized by progressive accumulation of extracellular matrix following chronic liver injuries. In the extracellular space, the constant turnover of liver matrix is regulated by the matrix metalloproteinase (MMP) class of enzyme. To assess whether genetic variations in MMP would result in diversity of liver cirrhosis, a case-control study of 320 patients with hepatocellular carcinoma, with or without cirrhosis, was conducted. Ten single-nucleotide polymorphism markers from four potential fibrosis-associated genes were selected for genotyping. Among these genes, a nonsynonymous single-nucleotide polymorphism which generates the variation of Gly-137 and Asp-137 in the MMP-7 gene was found to be strongly associated with the development of liver cirrhosis. In contrast to MMP-7(Gly-137) that predominantly secretes out into the cell culture medium, the cirrhosis-associated MMP-7(Asp-137) variant is preferentially localized on the extracellular membranes where it exerts its proteolytic activity on pericellular substrates. Functional analysis demonstrated an increased ability of the MMP-7(Asp-137) variant to associate with the cell surface CD151 molecule. In wound-healing and Boyden chamber assays, cell motility was specifically enhanced with the expression of MMP-7(Asp-137) as compared to the cells expressing MMP-7(Gly-137). These results demonstrate that the MMP-7(Asp-137) variant confers a gain-of-function phenotype for MMP-7.

CONCLUSION

We have identified a novel genetic association of MMP-7(Asp-137) variant with liver cirrhosis in patients with hepatocellular carcinoma. Whether the MMP-7 variant can be a new marker for liver cirrhosis will be further studied.

Effect of praziquantel treatment on the expression of matrix metalloproteinases in relation to tissue resorption during fibrosis in hamsters with acute and chronic Opisthorchis viverrini infection

Praziquantel has been used for the treatment of diseases caused by infection with various parasites. Praziquantel treatment in Opisthorchis viverrini-infected patients reduces the hepatobiliary fibrosis due to tissue resorption, however, some fibroses are irreversible. To clarify the effect of praziquantel treatment on hepatobiliary fibrosis, we examined the expression of matrix metalloproteinases (MMPs) in relation to fibrolysis on praziquantel-treated hamsters after O. viverrini acute infection (AI) for 21 days and chronic infection (CI) for 4 months. The reduction rate of hydroxyproline content in the livers of the AI group with 6-month praziquantel treatment (71%) was higher than that of corresponding praziquantel-treated CI group (13%), similar to the decrease in the thickness of peribiliary fibrosis. Hepatic mRNA levels of collagen I significantly decreased compared with untreated control after praziquantel treatment both in AI and CI groups. Expression of collagen III significantly decreased in the AI group but unchanged in the CI group. MMP-9 and MMP-13 (except 3 months in CI group) levels significantly decreased in both groups. Notably, expression of MMP-7 level increased at 1 and 6 months in both AI and CI groups, respectively. MMP-2 level did not change in both groups. Gelatinase activity of MMPs-2 and -9 was associated with their transcriptional levels. Tissue inhibitors of MMP (TIMP)-1 and TIMP-2 significantly decreased in the AI group, whereas TIMP-1 levels did not change and TIMP-2 level was significantly increased in CI group. Praziquantel treatment increased the expression of TNF-alpha in both groups, suggesting an association with MMP-7 expression. TGF-beta expression was significantly increased only in the CI group indicating its may involve in TIMPs expression. These results suggest that in animals with chronic O. viverrini infection, praziquantel treatment induces the expression of TGF-beta, and TIMPs and resultant inhibition of MMP activity, leading to slow resorption of hepatic fibrosis.

Effect of tissue inhibitors of metalloproteinases and matrix metalloproteinases on capsular formation around smooth and textured silicone gel implants

BACKGROUND

Capsular contracture is one of the most distressing complications after cosmetic breast augmentation. Evidence suggests that matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) may play a key role in the onset or progression of several fibrotic disorders. In this study we used quantitative reverse-transcription PCR methodology to profile the expression of TIMP-1, TIMP-2, MMP-2, and MMP-9 in the tissue of patients with capsular contracture after breast augmentation with smooth and textured silicone breast implants.

METHODS

The study included 20 female patients (average age = 37 +/- 15 years) with capsular contracture after bilateral subglandular cosmetic breast augmentation with smooth silicone implants. Ten patients developed grade II capsule contracture, 8 grade III contracture, and 1 grade IV contracture. Twenty other female patients (average age = 41 +/- 9 years) with capsular contracture after breast augmentation with textured silicone implants were also included (Baker grade II = 10 patients, grade III = 8, grade IV = 2). Expression of mRNA in capsular tissue was calculated using a relative quantification method (Pfaffl). Statistical analysis was performed using the Mann-Whitney test. The level of significance was considered to be p < 0.05.

RESULTS

The expression of MMP-2 was significantly increased in tissue of patients with textured implants and capsular contracture grades II and III/IV in comparison to grade I (p < 0.05). In comparison to grade I, the capsular tissue from patients with Baker II and III/IV fibrosis showed a significant increase for TIMP-1 and TIMP-2 (p < 0.05) in both smooth and textured silicone implants. The expression was significantly higher in tissue from patients with severe contracture (Baker III/IV) and smooth silicone implants compared with that in tissue from patients with textured implants (p < 0.05).

CONCLUSION

The decrease in MMP-to-TIMP expression can cause increased synthesis and deposition of collagen surrounding alloplastic breast implants, leading to a profibrotic state. The higher expression of TIMPs in capsular tissue of patients with smooth silicone gel implants might be a reason for the observed higher rates of capsular contracture. In the future, a nonoperative treatment that decreases TIMPs but increases the activity of MMPs may be an appropriate therapy for patients with capsular contracture.

Immunological investigation of the hepatic tissue from infants with biliary atresia

PURPOSE

Matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors [tissue inhibitors of metalloproteinases (TIMPs)] have been implicated in tissue injury and remodeling in many organs. The objective of this study was to evaluate the expression of MMP-3 and -9, and TIMP-1, -2, and -3 and their relationship to liver fibrosis in infants with biliary atresia.

METHODS

The expression of MMP-3 and-9 and TIMP-1, -2 and -3 was investigated in liver tissue samples of nine patients with biliary atresia. In addition, the expression of CCR-4 and CCR-5 was analyzed to investigate the activation of Th1 and Th2 cells. The mRNA levels were measured by semiquantitative reverse transcriptase polymerase chain reaction.

RESULTS

The expression of MMP-3 was higher than that of MMP-9 in all samples (P < 0.01). The expression of TIMP-1 was higher than that of TIMP-2 and -3 in all samples (P < 0.01). The expression of CCR-5 was higher than that of CCR-4 (P < 0.05), which implied higher activation of Th1 cells relative to Th2 cells.

CONCLUSION

Our findings suggest that MMP-3, possibly induced by Th1 cytokines, and its balance with TIMP-1, may be one of the factors involved in the pathogenesis of biliary atresia.

Time profiles of the expression of metalloproteinases, tissue inhibitors of metalloproteases, cytokines and collagens in hamsters infected with Opisthorchis viverrini with special reference to peribiliary fibrosis and liver injury

The liver fluke Opisthorchis viverrini is endemic in southeastern Asia, and causes cholangiocarcinoma and liver fibrosis. We investigated the time profile of the expression of matrix metalloproteinases (MMPs) and tissue inhibitors of MMPs (TIMPs) in relation to peribiliary fibrosis in O. viverrini-infected hamsters. Hepatic mRNA expression of MMPs, TIMPs, cytokines and collagens I and III was assessed by quantitative reverse transcription-PCR. Zymography and immunohistochemistry were also used to examine MMPs-2 and -9 expression. After infection, an increase of peribiliary fibrosis was time-dependent. Opisthorhis viverrini-induced gene expression in hamster liver, with increased mRNA expression levels of IL-1beta, TNF-alpha, TGF-beta, and collagens I and III, was observed at 21 days p.i. Expression of MMPs-2, -13 and -14 and TIMPs-1 and -3 genes, was significantly higher at 1 month, and maximal levels of most MMPs (MMPs-2, -9, -13 and -14) were observed at 2 months p.i. The cytoplasmic levels of MMP-2 and MMP-9 were similar to mRNA expression. Immunohistochemistry revealed that MMP-9 was expressed mainly in the cytoplasm of inflammatory cells at the invasive front of the fibrous area. In contrast, the highest levels of mRNA expression of TIMPs-2 and -3, and TGF-beta were observed 10 months p.i. Concentration of TIMP-2 protein in the plasma correlated with its transcriptional level (r=0.320, P=0.040). Peribiliary fibrosis correlated positively with liver hydroxyproline content (r=0.846, P<0.001), plasma hydroxyproline concentration (r=0.770, P<0.001), plasma TIMP-2 level (r=0.335, P=0.046), and mRNA expression levels of MMP-7 (r=0.511, P=0.006), TIMP-1 (r=0.320, P=0.040), TIMP-2 (r=0.428, P=0.026), and TIMP-3 (r=0.553, P=0.003). This study suggests that expression of MMPs is associated with an inflammatory reaction in the early phase and TIMPs expression at the late phase may contribute to both fibrosis and liver injury. MMPs and TIMPs may serve as diagnostic markers for the severity of O. viverrini-induced liver injury.

Hepatic expression of A disintegrin and metalloproteinase (ADAM) and ADAMs with thrombospondin motives (ADAM-TS) enzymes in patients with chronic liver diseases

BACKGROUND/AIMS

ADAMs (A Disintegrin And Metalloprotease) are multifunctional, membrane-bound and soluble cell surface glycoproteins with numerous functions in cell physiology. We assessed the expression of ADAMs in fibrotic liver disease of different aetiologies and clarified whether the expression of ADAMs is related to histological staging of fibrosis. In addition, the expression of ADAMs was determined in different cell types of liver.

METHODS

Seventy-one biopsy samples from patients with chronic liver diseases were analyzed for mRNA expression of ADAM-8, -9, -12, -28, -TS1, -TS2, matrix metalloprotease (MMP)-2, -9 and tissue inhibitor of metalloproteinases-1 and -2 by quantitative real-time RT-PCR.

RESULTS

The ADAM expression in liver injury is independent of aetiology. A strong correlation between ADAM -9, -28, -TS1 versus MMP-2 and SMA was identified. Activated hepatic stellate cells (HSC) showed increased mRNA expression of ADAM-8, -9, -12, -28, -TS2 compared to quiescent HSC. Significant differences between histological stages of fibrosis were found for ADAM-28, MMP-2 and MMP-9.

CONCLUSIONS

The results suggest that ADAMs are differentially expressed in the liver. We assume that ADAM-9, -TS1 and -TS2 play a crucial role in extracellular matrix remodeling during fibrotic processes in the liver.

A study of the effect of splenectomy on hepatic functional reserve and structural damage in patients with chronic hepatitis C virus infection by non-invasive serum markers. A prospective study

Several beneficial effects of splenectomy on the liver integrity have been recently reported by both experimental and clinical studies. However, the effects of splenectomy on hepatic functional reserve and structural damage in patients with chronic hepatitis C (CHC) were not studied by objective evidence. The aim of this study was to assess the effect of splenectomy on hepatic functional reserve and structural damage in patients with CHC by non-invasive serum markers. The study involved 22 patients with histopathological diagnosis of CHC undergoing splenectomy for treatment of associated hypersplenism. The hepatic functional reserve and structural damage markers were assessed before and after splenectomy surgery on the 2nd and 60th postoperative days by aspartate aminotransferase to alanine aminotransferase (AST/ALT ratio), AST to platelet ratio index (APRI) and serum levels of gamma-glutamyl transferase (GGT), hyaluronic acid (HA), type IV collagen (CIV) and tissue inhibitor of metalloproteinase-1 (TIMP-1). After splenectomy, the levels of serum HA showed a significant decrease in relation to the preoperative values both in PO-1 (mean pre-splenectomy: 272+/-88.6 versus 185+/-77.4 ng/ml; P=0.01) and PO-2 (169+/-58.1 ng/ml; 0.017). The levels of type IV collagen showed a significant decrease in relation to the preoperative values both in PO-1 (mean pre-splenectomy: 208+/-134 versus 125+/-100 ng/ml; P=0.01) and PO-2 (121+/-74.7 ng/ml; P=0.02). Serum levels of TIMP-1 also showed a significant decrease in relation to the preoperative values both in PO-1 (mean pre-splenectomy: 764+/-571 versus 261+/-195 ng/ml; P=0.006) and PO-2 (149+/-110.1 ng/ml; P=0.004). There was no significant difference between PO-1 and PO-2 mean values for each of those serum markers. This study found that splenectomy induced a reduction of biochemical markers of liver functional reserve and fibrosis in patients with chronic hepatitis C which reflect a change in the processes involved in of liver fibrosis. However, it cannot be concluded whether this reflects a change in the rate of its progression or a prevention of further fibrosis.

Inflammation and repair in viral hepatitis C

Hepatitis C viral infection (HCV) results in liver damage leading to inflammation and fibrosis of the liver and increasing rates of hepatic decompensation and hepatocellular carcinoma (HCC). However, the host's immune response and viral determinants of liver disease progression are poorly understood. This review will address the determinants of liver injury in chronic HCV infection and the risk factors leading to rapid disease progression. We aim to better understand the factors that distinguish a relatively benign course of HCV from one with progression to cirrhosis. We will accomplish this task by discussion of three topics: (1) the role of cytokines in the adaptive immune response against the HCV infection; (2) the progression of fibrosis; and (3) the risk factors of co-morbidity with alcohol and human immunodeficiency virus (HIV) in HCV-infected individuals. Despite recent improvements in treating HCV infection using pegylated interferon alpha (PEGIFN-alpha) and ribavirin, about half of individuals infected with some genotypes, for example genotypes 1 and 4, will not respond to treatment or cannot be treated because of contraindications. This review will also aim to describe the importance of IFN-alpha-based therapies in HCV infection, ways of monitoring them, and associated complications.

Impact of chewing betel-nut (Areca catechu) on liver cirrhosis and hepatocellular carcinoma: a population-based study from an area with a high prevalence of hepatitis B and C infections

BACKGROUND

Chewing betel-nuts (Areca catechu) is carcinogenic but the risk for hepatocellular carcinoma (HCC) and liver cirrhosis (LC) is little considered. Worldwide 600 million people chew betel, including emigrants from palm-growing countries.

OBJECTIVE

We aimed to assess the relationships and dose-response effects of betel chewing on LC and HCC risks, since habit cessation could reduce the increased risks of HCC and LC found in such communities.

SUBJECTS

Screening 60 326 subjects aged 30-79 years in a population-based study in Taiwan identified LC in 588 and HCC in 131 subjects. Demographic features, hepatitis B/C infections, other risk factors and betel chewing were noted. Multiple Cox regression models were used to assess independent relationships, interactions and synergisms between age, betel chewing and hepatitis B/C.

RESULTS

Betel chewing increased LC and HCC risk 4.25-fold (95 % CI 2.9, 6.2) in current chewers and 1.89-fold (95 % CI 1.13, 3.16) in ex-chewers v. never-chewers, with dose effects for quantity, duration and cumulative exposure in chewers. Subjects without hepatitis B/C infections had 5.0-fold (95 % CI 2.87, 9.03) increased risk of LC/HCC v. never-chewers, and betel chewing had an additive synergistic effect on hepatitis B/C-related risks. Risk reduction with betel habit cessation could exceed that expected from immunization programmes for hepatitis B and C.

CONCLUSION

Increased risks of cirrhosis and hepatocellular cancer were found in betel chewers free of hepatitis B/C infection, and these risks were synergistically additive to those of hepatitis B/C infections. Estimated risk reduction from effective anti-betel chewing programmes would be sizeable.

Moderately high folic acid supplementation exacerbates experimentally induced liver fibrosis in rats

Under certain clinical circumstances, folic acid can have undesirable effects. We investigated the following: (i) the effects of moderately high folic acid supplementation on the course of liver impairment in CCl(4)-treated rats and (ii) the influence of folic acid supplements on the hepatic recovery following the interruption of the CCl(4)-induced toxic injury. Four experimental groups of rats were used: CCl(4)-treated rats (0.5 ml of CCl(4) twice a week i.p.) fed standard chow for up to 12 weeks (Group A); treated rats fed chow supplemented with 25 mg/kg folic acid from weeks 6 to 12 (Group B); treated rats fed a standard diet but with CCl(4) discontinued after 6 weeks to allow for tissue recovery over 4 weeks (Group C); rats as Group C but fed a diet supplemented with 25 mg/kg folic acid from weeks 6 to 10 (Group D). Liver and blood samples were obtained for biochemical, histological, and gene expression analyses. Animals that received the supplement had a higher content of collagen, activated stellate cells, and apoptotic parenchymal cells in biopsy tissue at weeks 8 and 10 of treatment and more extensive alterations in serum albumin and bilirubin concentrations (Group B vs. Group A). In some of the time periods analyzed, alterations were observed in the expression of genes related to apoptosis (B-cell leukemia/lymphoma 2, inhibitor of apoptosis 2) and to fibrosis (procollagen I, matrix metalloproteinase 7). In the recovery period (Groups C and D), folic acid administration was associated with increased hepatic inflammation and apoptosis and with a decrease in the tissue inhibitor of metalloproteinase-3 expression following 1 week of recovery. We conclude that folic acid administration aggravates the development of fibrosis in CCl(4)-treated rats. Follow-up studies are needed to determine whether folic acid treatment would be contraindicated in patients with chronic liver diseases.

Effect of angiotensin-converting enzyme inhibition on experimental hepatic fibrogenesis

The renin-angiotensin system is suggested to be important in liver fibrogenesis. It induces hepatic stellate cell proliferation and up-regulates transforming growth factor beta-1 (TGF-beta1) expression. Matrix metalloproteinase-2 (MMP-2) is involved in extracellular matrix remodelling. Fibrosis, a consequence of most chronic liver diseases, may be the result of a disturbed balance between fibrogenesis and fibrolysis. The aim of this study was to investigate the effect of enalapril on liver fibrogenesis induced in rats by bile-duct ligation. Forty-seven rats were divided into two groups: bile-duct ligated (BDL) (n = 24) and BDL + enalapril (n = 23). Fibrosis was evaluated by the Knodell scoring system, and TGF-beta1 and MMP-2 were assessed with immunohistochemistry at the second, fourth and sixth weeks after bile-duct ligation. In the BDL group, TGF-beta1 increased by the second week and this increase continued through weeks 4 and 6. In the BDL + enalapril group, TGF-beta1 was significantly lower than the other group (P < 0.05). MMP-2 progressively decreased after week 2 in the BDL group. In the BDL + enalapril group, MMP-2 was significantly higher than the BDL group at the fourth and sixth weeks. These results suggest that enalapril reduces the liver tissue TGF-beta1 and has an ameliorating effect on the fibrosis markers TGF-beta1 and MMP-2.

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.

Serum Levels of TGF-beta1, TIMP-1 and TIMP-2 in Patients with Lumbar Spinal Stenosis and Disc Herniation

Study Design

The serum levels of transforming growth factor-beta 1 (TGF-β1), tissue inhibitor of matrix metalloproteinase-1 (TIMP-1) and TIMP-2 were measured by enzyme-linked immunosorbent assay.

Purpose

To compare the serum levels of TGF-β1, TIMP-1 and TIMP-2 between patients with lumbar spinal stenosis and disc herniation.

Overview of Literature

It has been reported that increased concentrations of TGF-β1, TIMP-1 and TIMP-2 in the ligamentum flavum might be a possible pathogenesis for ligamentum flavum hypertrophy in spinal stenosis. However, it is not determined whether this phenomenon in spinal stenosis is a local or systemic problem.

Methods

The concentrations of TGF-β1, TIMP-1 and TIMP-2 were quantitatively analyzed by ELISA in the ligamentum flavum and serum of patients with lumbar spinal stenosis (n=16) and disc herniation (n=16). The thickness of ligamentum flavum was measured on axial T1-weigted magnetic resonance image. The biochemical and radiological results were compared for the two conditions.

Results

The thickness of the ligamentum flavum was larger in patients with spinal stenosis compared with that with disc herniation (p=0.001). The mean concentrations of TGF-β1, TIMP-1, and TIMP-2 in the ligamentum flavum were significantly higher in patients with spinal stenosis than those with disc herniation (all, p < 0.05). However, the difference in serum levels of TGF-β1 (p=0.464), TIMP-1 (p=0.146) and TIMP-2 (p=0.794) was not significant between the lumbar spinal stenosis and disc herniation patients.

Conclusions

Despite increased levels of TGF-β1, TIMP-1, and TIMP-2 in the ligamentum flavum of spinal stenosis patients compared to disc herniation patients, the serum levels of TGF-β1, TIMP-1 and TIMP-2 were very similar in both groups. These results indicate that the role of TGF-β1, TIMP-1 and TIMP-2 on hypertrophy of the ligamentum flavum in spinal stenosis patients is a local phenomenon, not systemic.

Expression of MMPs and TIMPs in liver fibrosis - a systematic review with special emphasis on anti-fibrotic strategies

In liver tissue matrix metalloproteinases (MMPs) and their specific inhibitors (tissue inhibitors of metalloproteinases, TIMPs) play a pivotal role in both, fibrogenesis and fibrolysis. The current knowledge of the pathophysiology of liver fibrogenesis with special emphasis on MMPs and TIMPs is presented. A systematic literature search was conducted. All experimental models of liver fibrosis that evaluated a defined anti-fibrotic intervention in vivo or in vitro considering MMPs and TIMPs were selected. The methodological quality of all these publications has been critically appraised using an objective scoring system and the content has been summarized in a table.

Effects of interferon plus ribavirin treatment on NF-kappaB, TGF-beta1, and metalloproteinase activity in chronic hepatitis C

Little is known about the cellular and molecular mechanisms underlying the effects of anti-viral therapy on the regression of liver inflammation and fibrosis in chronic hepatitis C. The aim of this study was to evaluate the effects of interferon alpha and ribavirin in combination therapy on the tissue expression of nuclear-factor kB (NF-kappaB) (a transcription factor coordinating the expression of stress genes involved in immune response and inflammation), of the polypeptide transforming growth factor beta-1 (TGF-beta1) and matrix metalloproteinases 1 (MMP-1) (both of which play an important part in the pathological process of liver fibrogenesis), and on the serum levels of soluble TGF-beta1, tissue inhibitors of metalloproteinases (TIMP)-1, and active endogenous MMP-2 and MMP-9 in paired (pre- and post-treatment) liver biopsy and serum samples of subjects with chronic hepatitis C. Serum levels of TGF-beta1, TIMP-1, MMP-2, and MMP-9 were evaluated by enzyme-linked immunosorbent assay. Liver expression of muscle-specific alpha-actin, NF-kappaB, TGF-beta1, and MMP-1 was studied immunohistochemically using commercially available mono- and polyclonal antisera in an avidin-biotin complex method. Combination therapy induced a reduction in the liver expression of TGF-beta and NF-kappaB and an increased expression of MMP-1, regardless of the virological response to the treatment. The greater expression of MMP-1 and lesser expression of NF-kappaB were both associated with an improvement in fibrosis score. These effects paralleled the significant increase in soluble MMP-9/TIMP-1 ratio in post-therapy sera. Combination therapy with interferon and ribavirin affects the tissue expression of TGF-beta-1 and NF-kappaB and favors metalloproteinase activity, and may thereby modulate hepatic fibrogenetic events.

Molecular determination of liver fibrosis by synchrotron infrared microspectroscopy

Liver fibrosis is an adaptive response to various injuries and may eventually progress to cirrhosis. Although there are several non-invasive methods available to monitor the progression of liver fibrogenesis, they cannot reliably detect fibrosis in its early stages, when the process can be stopped or reversed by removing or eliminating the underlying etiological agent that cause the hepatic injury. In this study, early fibrosis alterations were characterized biochemically, morphologically, and spectroscopically in a rat bile duct ligation (BDL) model. Progressive elevations in serum alanine transaminase (ALT), aspartate transaminase (AST), and bilirubin levels in the BDL rats were found indicating the dynamic deterioration of hepatocellular function. Immunofluorescence microscopy using monoclonal anti-collagen III antibody further revealed abnormal intertwined networks of collagen fibres surrounding the portal areas and extending into the lobules towards the central veins in all BDL samples starting from week one. Synchrotron infrared microspectroscopy of liver sections was exploited to generate false color spectral maps based upon a unique and strong collagen absorption at 1340 cm(- 1), revealing a collagen distribution that correlated very well with corresponding images provided by immunofluorescence imaging. We therefore suggest that infrared microspectroscopy may provide an additional and sensitive means for the early detection of liver fibrosis.

Non invasive fibrosis biomarkers reduce but not substitute the need for liver biopsy

Chronic liver diseases are very common worldwide, particularly those linked to viral hepatitis and to alcoholic and non-alcoholic fatty liver. Their natural history is variable and long-term evolution differs in individual patients. Optimised clinical management of compensated chronic liver diseases requires precise definition of the stage of liver fibrosis, the main determinant of prognosis and of most therapeutic decisions. Liver biopsy is the gold standard for assessment of hepatic fibrosis. However, it is invasive with possible complications, costly and prone to sampling errors. Many non-invasive markers of liver fibrosis have been recently proposed and assessed in the clinical setting as surrogates of liver biopsy. Direct markers are based on biochemical parameters directly linked to fibrogenesis while indirect markers use simple or more sophisticated parameters that correlate with liver fibrosis stages. Non-invasive markers of liver fibrosis have been tested in different forms of chronic liver disease and showed variable diagnostic performance, but accuracy rarely was above 75%-80%. Better results were obtained when markers were combined. On this line, we have recently proposed a set of algorithms that combine sequentially indirect non-invasive markers of liver fibrosis, reaching 90%-95% diagnostic accuracy with significant reduction in the need for liver biopsy. Based on available evidence, it can be anticipated that non-invasive markers of liver fibrosis and their combined use will soon become a most useful tool in the clinical management of many forms of chronic liver disease. However, their implementation is expected to reduce, but not to completely eliminate, the need for liver biopsy.

A comparison of gene expression in mouse liver and kidney in obstructive cholestasis utilizing high-density oligonucleotide microarray technology

AIM: To assess the effects of obstructive cholestasis on a wider range of gene expression using microarray technology.

METHODS: Male C57BL/6J mice underwent common bile duct ligation (BDL) and were matched with pair-fed sham-operated controls. After 7 d, the animals were sacrificed and total RNA was isolated from livers and kidneys. Equal amounts of RNA from each tissue were pooled for each group and hybridized to Affymetrix GeneChip^®MG-U74Av2 containing a total of 12 488 probe sets. Data analysis was performed using GeneSpring^®6.0 software. Northern analysis and immunofluorescence were used for validation.

RESULTS: In sham-operated and BDL mice, 44 and 50% of 12 488 genes were expressed in livers, whereas 49 and 51% were expressed in kidneys, respectively. Seven days after BDL, 265 liver and 112 kidney genes with GeneOntology annotation were up-regulated and 113 liver and 36 kidney genes were down-regulated in comparison with sham-operated controls. Many genes were commonly regulated in both tissues and metabolism-related genes represented the largest functional group.

CONCLUSION: Following BDL, microarray analysis reveals a broad range of gene alterations in both liver and kidney.

Association of E-cadherin, matrix metalloproteinases, and tissue inhibitors of metalloproteinases with the progression and metastasis of hepatocellular carcinoma

Molecular markers can provide additional information to traditional histomorphological evaluation for the assessment of tumor progression and predicting the likelihood of invasion and metastasis in various types of malignancies. We studied the association of E-cadherin, matrix metalloproteinases (MMPs), and tissue inhibitors of metalloproteinase with the progression and metastasis of hepatocellular carcinoma. Tissue microarray including six normal livers, 14 cirrhotic livers, 39 macroregenerative nodules, 16 dysplastic nodules, 22 grade I hepatocellular carcinomas, 43 grade II hepatocellular carcinomas, seven grade III hepatocellular carcinomas, and 10 metastatic hepatocellular carcinomas were stained immunohistochemically with antibodies against MMPs -1, -2, -3, -7, -9, tissue inhibitors of metalloproteinase-1, -2, -3, and E-cadherin. The intensities of staining were scored manually by two pathologists and verified by the Chromavision Automated Cellular Imaging System. Compared with normal liver, cirrhotic liver had significantly lower E-cadherin and tissue inhibitors of metalloproteinase-1 but higher MMP-1 and -7, which suggest a more favorable environment for tumor invasion and metastasis. Grade I and grade II hepatocellular carcinomas demonstrated high E-cadherin and decreased MMP-3 and -9, which may explain the rarity of extrahepatic metastasis in low-grade hepatocellular carcinomas despite the high circulatory volume of the liver. The histological progression from dysplastic nodule to well-differentiated hepatocellular carcinoma and to less differentiated tumors was associated with a gradual decrease in tissue expression of E-cadherin, tissue inhibitors of metalloproteinase-2 and -3. Metastatic hepatocellular carcinomas showed significantly lower level of tissue inhibitors of metalloproteinase-1, -2, -3 but higher level of MMP-7. These data suggest that tissue expression of E-cadherin, certain MMPs, and tissue inhibitors of metalloproteinases could be useful markers to predict the progression and metastasis of hepatocellular carcinoma.

Transforming growth factor-beta-regulated gene transcription and protein expression in human GFAP-negative lamina cribrosa cells

Primary open-angle glaucoma (POAG) is a progressive optic neuropathy, which is a major cause of worldwide visual impairment and blindness. Pathological hallmarks of the glaucomatous optic nerve head (ONH) include retinal ganglion cell axon loss and extracellular matrix (ECM) remodeling of the lamina cribrosa layer. Transforming growth factor-beta (TGF-beta) is an important pro-fibrotic modulator of ECM metabolism, whose levels are elevated in human POAG lamina cribrosa tissue compared with non-glaucomatous controls. We hypothesize that in POAG, lamina cribrosa (LC) glial cells respond to elevated TGF-beta, producing a remodeled ONH ECM. Using Affymetrix microarrays, we report the first study examining the effect of TGF-beta1 on global gene expression profiles in glial fibrillary acidic acid (GFAP)-negative LC glial cells in vitro. Prominent among the differentially expressed genes were those with established fibrogenic potential, including CTGF, collagen I, elastin, thrombospondin, decorin, biglycan, and fibromodulin. Independent TaqMan and Sybr Green quantitative PCR analysis significantly validated genes involved in regulation of cell proliferation (platelet-derived growth factor [PDGF-alpha]), angiogenesis (vascular endothelial growth factor [VEGF]), ECM accumulation and degradation (CTGF, IL-11, and ADAMT-S5), and growth factor binding (ESM-1). Bioinformatic analysis of the ESM-1 promoter identified putative Smad and Runx transcription factor binding sites, and luciferase assays confirmed that TGF-beta1 drives transcription of the ESM-1 gene. TGF-beta1 induces expression and release of ECM components in LC cells, which may be important in regulating matrix remodeling in the lamina cribrosa. In disease states such as POAG, the LC cell may represent an important pro-fibrotic cell type and an attractive target for novel therapeutic strategies.

Hypertrophy of ligamentum flavum in lumbar spinal stenosis associated with increased proteinase inhibitor concentration

BACKGROUND

It is well known that age-related fibrosis, or decreases in the elastin-to-collagen ratio of the ligamentum flavum, along with hypertrophy of the ligamentum flavum, are associated with lumbar spinal stenosis. However, the molecular mechanism by which this fibrosis and hypertrophy develop is unknown. Tissue inhibitors of matrix metalloproteinase (TIMPs) are proteinase inhibitors that suppress extracellular matrix degradation. Elevated TIMP-1 and TIMP-2 expression has been implicated in various fibrotic diseases of the liver, kidney, lung, and heart. These TIMPs can also induce cellular proliferation and inhibit apoptosis in a wide range of cell types. These findings led us to postulate that TIMP-1 and TIMP-2 might also be associated with hypertrophy and fibrosis of the ligamentum flavum in lumbar spinal stenosis.

METHODS

We quantified and localized TIMP expression in ligamentum flavum tissues that had been obtained during surgery from thirty patients with spinal stenosis and from thirty gender-matched control patients with disc herniation. The thickness of the ligamentum flavum at the level of the facet joint was measured on axial T1-weighted magnetic resonance images. In addition, we examined ligamentum flavum tissues for the expression of markers of cellular proliferation and apoptosis.

RESULTS

The ligamentum flavum was significantly thicker in the patients with spinal stenosis (mean, 5.68 mm) than in the patients with disc herniation (mean, 2.70 mm) (p < 0.001). The concentration of TIMP-2 in the ligamentum flavum was significantly higher in the patients with spinal stenosis (mean, 12.62 ng/mL) than in those with disc herniation (mean, 8.85 ng/mL) (p = 0.028). TIMP-1 and TIMP-2 were detected in the cytoplasm of ligamentum flavum fibroblasts. TIMP-1 and TIMP-2 concentrations were associated with hypertrophy of the ligamentum flavum (p = 0.015 and p = 0.003, respectively). None of the samples from the patients with stenosis had evidence of proliferation of ligamentum flavum fibroblasts. The expression of markers for apoptosis was significantly higher in the patients with spinal stenosis (58.8%) than in those with disc herniation (26.6%) (p < 0.001).

CONCLUSIONS

Increased TIMP expression has been implicated in fibrosis and hypertrophy of the extracellular matrix of several organs. Our results suggest that increased expression of TIMP-2 in ligamentum flavum fibroblasts is associated with fibrosis and hypertrophy of the ligamentum flavum in patients with spinal stenosis.

Evaluation of matrix metalloproteinases and their endogenous tissue inhibitors in biliary atresia-associated liver fibrosis

BACKGROUND/PURPOSE

Matrix metalloproteinases (MMPs) and their endogenous tissue inhibitors (TIMPs) are major proteases responsible for remodeling the liver tissue, but their roles in biliary atresia (BA)--associated liver fibrosis are not clear.

METHODS

A DNA microarray containing complementary DNA clones of 10 MMPs and 4 TIMPs was used to compare the expression profiles of the liver cytokines among 3 patients with BA at the time of Kasai procedure (KP) with 3 at the time of liver transplantation (LT). Liver samples from 2 children without liver fibrosis were used as normal controls. Those genes that were differentially expressed by more than 2-fold between groups were further quantified with real time quantitative reverse transcription-polymerase chain reaction (QRT-PCR) and validated with gel electrophoresis.

RESULTS

In normal human liver, messenger RNAs (mRNAs) of TIMP-1, -2, and -3, but not of TIMP-4 and none of the 10 MMPs studied, were expressed in DNA microarray. With progression of liver fibrosis, only mRNA of MMP-7, but not other MMPs, was induced to express at a significantly higher level in the array. Despite its low level of expression, MMP-9 mRNA was significantly upregulated in KP but downregulated in LT, whereas MMP-2, which was not showed in the array, was significantly upregulated in LT than in KP and control in real time QRT-PCR. There was a more than 2-fold increase in TIMP-1 and TIMP-2 mRNA expression in LT over control in the array, which was confirmed in subsequent real time QRT-PCR. The expression of TIMP-3 mRNA was significantly downregulated in KP than in control.

CONCLUSIONS

This study verified differential expression of MMPs and TIMPs in different stages of BA, with emphasis on the role of TIMP-1, -2, and -3 as well as MMP-2, -7, and -9 transcripts in remodeling of liver tissue during the progress of BA-associated liver fibrosis.

Expression pattern of matrix metalloproteinases in alcohol- and thermally oxidized sunflower oil-induced toxicity: protective role of an aminothiazole derivative

The matrix metalloproteinases (MMPs) are a family of secreted and membrane-bound zinc endopeptidases. Collectively, these enzymes can degrade all of the components of the extracellular matrix including collagen, fibronectin, laminin, and basement membrane glycoproteins. Regulation in expression and activation of proteinases is one of the most important mechanisms in organ morphogenesis. Fibrosis is a dynamic pathological process with a net accumulation of extracellular matrix proteins. In the present communication, we have investigated the changes that occur in the activity of liver MMPs in normal and in pathological conditions. The activity of MMPs was increased in thermally oxidized sunflower oiland alcohol-treated groups, whereas the activity was decreased in the thermally oxidized oil + alcohol-fed group when compared with the normal control group. The activity was positively modulated when dendrodoine analogue [4-amino-5-benzoyl- 2(4-methoxyphenylamino)thiazole] was administered along with ethanol and thermally oxidized oil, which indicates the protective effect of this drug.

Matrilysin (MMP-7) is a major matrix metalloproteinase upregulated in biliary atresia-associated liver fibrosis

Matrix metalloproteinases (MMPs) are the proteases responsible for tissue remodeling during liver fibrosis caused by various disorders including biliary atresia. However, information regarding the relative contribution of these proteases to liver fibrosis is still limited. We studied matrix metalloproteinase-2 (MMP-2), -7, -9 and -13 mRNA expressions in the liver tissue of early-stage biliary atresia at the time of Kasai's procedure, late-stage biliary atresia at the time of liver transplantation with advanced fibrosis and nondiseased control without liver fibrosis. The results of real-time quantitative reverse transcriptase-PCR analysis revealed that only MMP-2 and -7 expressions were significantly different between groups. MMP-2 was significantly higher in Liver Transplantation group than both in Control (P=0.010) and in Kasai's Procedure (P=0.001) groups, whereas the difference of MMP-2 expression between Control and Kasai's Procedure was not significant. However, the relative expression level of MMP-7 was sequentially elevated when comparing Control, Kasai's Procedure and Liver Transplantation groups, and there was significant (P=0.019) difference when comparing Control and Liver Transplantation groups. Moreover, the fold difference in MMP-7 mRNA was much higher than that in MMP-2 mRNA between groups. The expressions of MMP-7 were further confirmed by agarose gel electrophoresis and Western blotting. Immunohistochemical analysis revealed a significant positive correlation of the scores of MMP-7 immunostaining with the stages of liver fibrosis. In situ hybridization demonstrated that the bile ductular epithelial cells, Kupffer cells and hepatocytes were the major producers of matrix metalloproteinase-7 in the liver. Our results imply that MMP-7 is a major MMP associated with the tissue remodeling during the progression of liver fibrosis in biliary atresia.

Expression of tissue inhibitor of matrix metalloproteinases-1 during aging in rat liver

AIM: To investigate the expression and role of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1) during natural aging in rat liver and to detect the expression of matrix metalloproteinase-2 (MMP-2) and MMP-9.

METHODS: The rats were divided into 3-mo-old group (n = 5), 10-mo-old group (n = 5) and 24-mo-old group (n = 5). Histopathologic changes of liver were observed with HE and Masson stain. The location and protein expressions of TIMP-1 were determined by immunohistochemistry and Western blot; message RNA (mRNA) levels were measured in livers from rats of various ages by semi-quantitative reverse transcriptional polymerase chain reaction (RT-PCR). In addition, the expression of MMP-2 and MMP-9 was assessed by RT-PCR and Western blot.

RESULTS: Histologic examination showed that the aging liver had excessive fatty degeneration and collagen deposition. Immunohistochemical staining showed that TIMP-1 related antigen in livers was located in cytoplasm. The protein expression of TIMP-1 was significantly higher in the oldest animals and the mRNA expression was increased significantly in the 24-mo-old rats (t = 4.61, P = 0.002<0.05, 24-vs 10-mo-old rats; t = 4.31, P = 0.003<0.05, 24- vs 3-mo-old rats). The expression of MMP-2 and MMP-9 had no change during aging; the ratios TIMP-1/MMP-2 and TIMP-1/MMP-9 in aging liver were significantly higher than those in maturation and young livers.

CONCLUSION: TIMP-1 may play an important role in the process of liver aging.

Effects of interferon-alpha on expression of hepatic stellate cell and transforming growth factor-β1 and α-smooth muscle actin in rats with hepatic fibrosis

AIM: To investigate the effect of interferon-α (IFN-α) on preventing or reversing hepatic fibrosis in rat experimental model induced by CCl₄.

METHODS: One hundred and ten Sprague-Dawley rats were divided into five groups: group A (normal controls, n = 18), group B (fibrotic model controls, n = 22), group C (IFN-α prevention, n = 22) initially treated with intra-muscular injection of IFN-α in saline daily at the doses of 1×10⁵ U for 6 wk, group D (IFN-α treatment, n = 24) treated with intra-muscular injection of IFN-α in saline daily at the doses of 1×10⁵ U for 6 wk after the first 6 wk, group E (0.9% sodium chloride treatment control, n = 24) treated with intra-muscular injection of 0.01 mL/kg daily for 6 wk after the first 6 wk. At the end of the experiment, all rats of each group were killed. Samples of the liver obtained by biopsy were subjected to histological, immunohistochemical and electron microscopic studies for the expressions of transforming growth factor-β1 (TGF- β1) and α-smooth muscle actin (α-SMA).

RESULTS: The expressions of TGF-β1, the number of activated hepatic stellate cells and α-SMA in hepatic tissue of group C were significantly less than those of group B (P<0.01). The degree of fibrosis score in group B was also significantly less than that of group C under light microscope (P<0.01).

CONCLUSION: IFN-α can inhibit the production of TGF-β1, decrease HSC activation and stimulate its apoptosis.

Differential expression of matrix metalloproteinases in viral and non-viral chronic liver diseases

BACKGROUND

Fibrosis is a common consequence of chronic liver diseases irrespective of aetiology. Metalloproteinases play an important role in the fibrotic process participating in the balance between collagen synthesis and degradation. We examined whether matrix gelatinases and stromelysins are similarly involved in the development of viral (HCV, HBV) and non-viral (NASH) liver diseases.

METHODS

Hepatic mRNA levels of matrix metalloproteinase MMP-2, MMP-9, MMP-10 and MMP-11 isolated from liver biopsies were measured by semi-quantitative RT-PCR. Seventy-three patients were examined in this study: non-diseased controls (10), patients with chronic hepatitis B (14), chronic hepatitis C (33) and non-alcoholic steatohepatitis (16).

RESULTS

A significant increase of MMP-9 and MMP-10 expression was found in patients with non-viral (non-alcoholic steatohepatitis) liver disease. Patients with chronic hepatitis B and hepatitis C showed an increase in MMP-2 mRNA expression compared to controls. Moreover, chronic hepatitis B and hepatitis C patients had significantly different mRNA expression patterns.

CONCLUSIONS

These findings indicate that matrix metalloproteinases are differentially involved in the fibrotic process of viral and non-viral chronic liver diseases. Differences exist between HBV and HCV chronic hepatitis. Differences between early and late fibrosis indicate that in future studies, careful staging of patients is mandatory for interpretation of results.

Matrilysin (MMP-7) expression in renal tubular damage: association with Wnt4

BACKGROUND

Matrilysin, a secreted matrix metalloproteinase and target gene of Wnt signaling, functions in epithelial repair and host defense, but no role in renal injury has been described.

METHODS

Matrilysin expression was assessed in human kidney specimens by immunohistochemistry, and in experimental renal injury in mice by immunohistochemistry, Northern blotting, and RNase protection assays (RPA). A relationship to Wnt4, which is also induced in renal injury, was determined by RPA and in situ hybridization.

RESULTS

Matrilysin was not detected in the normal human renal tubular epithelium by immunohistochemistry. However, prominent staining was detected in sections from autosomal-dominant polycystic kidney disease in the cyst lining epithelium, atrophic tubules, and cyst micropolyps, and from hydronephrosis in dilated and atrophic tubules. Matrilysin expression was also induced by acute folic acid nephropathy and unilateral ureteral obstruction (UUO) in the mouse, and expression increased as acute injury progressed to tubulointerstitial fibrosis. Matrilysin staining was primarily localized to epithelium of distal tubule/collecting duct origin in both human and murine renal disease. Wnt signaling can induce matrilysin expression, and we found that the pattern of matrilysin expression during progression of renal fibrosis in the mouse after UUO or folic acid nephropathy, and in the jck model of murine polycystic kidney disease, closely paralleled that of Wnt4.

CONCLUSION

These observations suggest that matrilysin may have a role in renal tubular injury and progression of tubulointerstitial fibrosis, and that Wnt4 may regulate matrilysin expression in the kidney.

Dynamic changes in the expression of matrix metalloproteinases and their inhibitors, TIMPs, during hepatic fibrosis induced by alcohol in rats

AIM: To determine the dynamic changes in the expression of matrix metalloproteinases (MMPs) and the endogenous tissue inhibitors of MMPs inhibitors (TIMPs) during hepatic fibrosis induced by alcohol.

METHODS: Male Sprague-Dawley rats were randomly divided into normal, 4 d, 2 wk, 4 wk, 9 wk and 11 wk groups, and the model rats were fed with a mixture of alcohol by gastric infusion at the designed time, respectively, then decollated and their livers were harvested for the examination of MMP-2, MMP-3, MMP-9, MMP-13, TIMP-1 and TIMP-2 by immunoh-istochemistry, zymograghy and Western blotting, respectively.

RESULTS: Normal rats had moderate expression of MMP-2, which was decreased in the model rats except in the 11 wk group, where MMP-2 expression slightly increased. MMP-3 had the similar changing pattern to MMP-2 despite weaker expression. MMP-9 expression decreased in the 4 d and 2 wk groups, rose in the 4 wk group, decreased again in the 9 wk group and returned to normal levels in the 11 wk group. MMP-13 expression decreased in the 4 d and 2 wk groups, and returned to normal levels in the 4 wk, 9 wk and 11 wk groups. TIMP-1 expression decreased in the 4 d and 2 wk groups, but sharply increased in the 4 wk group and sustained at a high level even after modeling was stopped for 2 wk. In normal rats TIMP-2 expression was strong. However, it decreased as soon as modeling began, and then gradually rose, but remained to a level lower than that in normal rats even after modeling was stopped for 2 wk.

CONCLUSION: MMP-2 may not always expresses at a high level during hepatic fibrosis. MMP-13 and MMP-3 are acutely affected by TIMP-1. In this model TIMP-1 is the most powerful factor imposed on capillarization and peri-sinusoidal fibrosis. TIMP-2 is the most effective regulator on the metabolism of type IV collagen located in the basement of sinus.

Effect of lamivudine treatment on plasma levels of transforming growth factor β1, tissue inhibitor of metalloproteinases-1 and metalloproteinase-1 in patients with chronic hepatitis B

AIM: Transforming growth factor (TGF)-β₁, metalloproteinase (MMP)-1 and its tissue inhibitor (TIMP)-1 are considered predictive biomarkers of chronic hepatitis activity and fibrosis. The aim of this study was to evaluate the effect of lamivudine treatment on the plasma levels of these peptides in patients with chronic hepatitis B.

METHODS: TGF-β₁, MMP-1 and TIMP-1 plasma concentrations were measured with an enzyme immunoassay in 40 patients treated with lamivudine for 48 wk. Elimination of HBV-DNA and HBV antigens was evaluated 24 wk after treatment completion.

RESULTS: Baseline TGF-β₁ (29.6 ± 2.2 ng/mL) and TIMP-1 (1578 ± 93 ng/mL) significantly exceeded normal values (18.3 ± 1.6 ng/mL and 1102 ± 67 ng/mL respectively). Lamivudine treatment resulted in a significant decrease of TGF-β₁ and TIMP-1 during treatment with an increase after 24 wk of treatment. Pretreatment MMP-1 levels (6.7 ± 0.7 ng/mL) were significantly lower than normal values (11.9 ± 0.9 ng/mL) and increased during treatment and follow-up. A significant correlation was noted between TGF-β₁ or TIMP-1 and aminotransferases as well as fibrosis scored in liver biopsy specimens. There were no statistically significant differences of TGF-β₁, TIMP-1 and MMP-1 between four groups at baseline, 24 and 48 wk of treatment. TGF-β₁ and TIMP-1 levels increased significantly in non-responders and normalized in responders at wk 72. MMP-1 also normalized in responders and decreased to values significantly lower than normal in non-responders.

CONCLUSION: These findings support the role of TGF-β₁, TIMP-1 and MMP-1 in the pathogenesis of chronic hepatitis B. Because of their association with hepatic injury and antiviral treatment efficacy, determination of these peptides may be useful in disease management.

Influence of serum collected from rat perfused with compound Biejiaruangan drug on hepatic stellate cells

AIM: To observe the effect of compound Biejiaruangan decoction (CBJRGC) (composite prescription of Carapax trionycis for softening the liver) on proliferation, activation, excretion of collagen and cytokine of hepatic stellate cells (HSCs) and to find the mechanism of prevention and treatment of hepatic fibrosis by CBJRGC.

METHODS: Using MTT, immunohistochemistry and image analysis technology, the related indexes for proliferation, activation, excretion of collagen and cytokine of hepatic stellate cells were detected in 24 h, 48 h, and 72 h after adminstration of different dosages of CBJRGC.

RESULTS: Statistical analysis showed that serum collected from rat perfused with CBJRGC could restrain the proliferation of HSC in 48 h and 72 h especially in high and medium dosage groups, markedly decrease the expression of desmin, synapsin and platelet derived growth factor (PDGF) in HSC in 24 h, 48 h and 72 h, as well as the expression of α-SMA, collagen III, TIMP and TGFβ1 in 48 h and 72 h, decrease the excretion of collagen I in 72 h. CBJRGC serum had no significant effect on collagens I, III and TIMP in 24 h.

CONCLUSION: CBJRGC serum has a good curative effect on hepatic fibrosis. Its main mechanism may be related to the following factors. The drug serum can restrain the proliferation and activation of HSC, decrease the number of activated HSC and the total number of HSC, the excretion of collagens I, III, enhance the degradation of collagen and restore the balance of synthesis and degradation of collagen, inhibit the expression of transforming growth factor β1 (TGFβ1) and platelet derived growth factor (PDGF) in HSC, block and delay the process of hepatic fibrosis. Synapsin is a new marker of activation of HSC, which provides a theoretical and testing basis for neural regulation in the developing process of hepatic fibrosis.

Circulating matrix metalloproteinases 1, 2, 9 and their inhibitors TIMP-1 and TIMP-2 as serum markers of liver fibrosis in patients with chronic hepatitis C: comparison with PIIINP and hyaluronic acid

OBJECTIVES

Histological examination of liver biopsy is currently required in the management of patients with chronic hepatitis C. Our aim was to evaluate the diagnostic utility of a panel of circulating markers in detecting the stage of fibrosis.

METHODS

One hundred and ninety four-patients who had undergone a percutaneous liver biopsy before antiviral treatment, and 194 age- and sex-matched healthy subjects were studied. Serum levels of hyaluronate, procollagen type III N-terminal peptide (PIIINP), matrix metalloproteinases (MMP)-1, MMP-2, MMP-9 and their tissue inhibitors of metalloproteinases (TIMP)-1 and TIMP-2 were determined by RIA and ELISA. Histological lesions were staged according to the METAVIR score.

RESULTS

Hyaluronate, PIIINP, TIMP-1, and TIMP-2 serum levels were significantly higher in patients than in controls. Six markers were significantly correlated with fibrosis: MMP-2 (r = 0.28; p < 0.01), TIMP-1 (r = 0.42; p < 0.001), HA (r = 0.50; p < 0.001), PIIINP (r = 0.62; p < 0.0001), MMP-1 (r = -0.32; p < 0.01), and MMP-9 (r = -0.22; p < 0.05). By multivariate analysis, only PIIINP and MMP-1 were independently associated with fibrosis, and were combined using the equation of the logistic regression model. Using receiver-operating characteristics analysis, the area under the curve of the score to discriminate mild (FO/F1) from significant fibrosis (F2/F3/F4) was 0.82, with a sensitivity of 60% for a specificity of 92%.

CONCLUSION

Our results suggest that combining two serum markers reflecting fibrogenesis (PIIINP) and fibrolysis (MMP-1) may provide a useful tool for evaluating liver fibrosis.

Diagnostic value of platelet derived growth factor-BB, transforming growth factor-β1, matrix metalloproteinase-1, and tissue inhibitor of matrix metalloproteinase-1 in serum and peripheral blood mononuclear cells for hepatic fibrosis

AIM: Noninvasive diagnosis of hepatic fibrosis has become the focus because of the limited biopsy, especially in the surveillance of treatment and in screening hepatic fibrosis. Recently, regulatory elements involved in liver fibrosis, such as platelet derived growth factor-BB (PDGF-BB), transforming growth factor-β₁ (TGF-β₁), matrix metalloproteinase-1 (MMP-1), and tissue inhibitor of matrix metalloproteinase-1 (TIMP-1), have been studied extensively. To determine whether these factors or enzymes could be used as the indices for the diagnosis of hepatic fibrosis, we investigated them by means of receiver operating characteristic (ROC) curve.

METHODS: Serum samples from sixty patients with chronic viral hepatitis B and twenty healthy blood donors were assayed to determine the level of PDGF-BB, TGF-β₁, MMP-1, and TIMP-1 with ELISA, and HA, PCIII, C-IV, and LN level with RIA. The message RNA (mRNA) expression of TIMP-1 and MMP-1 in peripheral blood mononuclear cells (PBMCs) was detected by RT-PCR and Northern blot hybridization. Liver biopsy was performed in all patients. The biopsy samples were histopathologically examined. The trial was double-blind controlled.

RESULTS: The serum level of PDGF-BB, TIMP-1, the ratio of TIMP-1 and MMP-1 (TIMP-1/MMP-1), mRNA expression of TIMP-1 (TIMP-1mRNA), and the ratio of TIMP-1mRNA and MMP-1mRNA (TIMP-1mRNA/MMP-1mRNA) in patients was significantly higher than those in the healthy blood donors (t = 2.514-11.435, P = 0.000-0.016). The serum level of PDGF-BB, TIMP-1, TIMP-1/MMP-1, and TIMP-1mRNA was positively correlated with fibrosis stage and inflammation grade (r = 0.239-0.565, P = 0.000-0.033), while the serum level of MMP-1 was negatively correlated with fibrosis stage and inflammation grade, and TIMP-1mRNA/MMP-1mRNA was positively correlated with inflammation grade. Through the analysis by ROC curve, serum PDGF-BB was the most valuable marker, and its sensitivity was the highest among the nine indices. The markers with the highest specificity were TIMP-1mRNA and TIMP-1mRNA/MMP-1mRNA in PBMCs. The area under the curve (AUC) of PDGF-BB, TIMP-1mRNA, TIMP-1mRNA/MMP-1mRNA, TIMP-1/MMP-1, HA, PCIII, TIMP-1, C-IV, and LN was 0.985, 0.876, 0.792, 0.748, 0.728, 0.727, 0.726, 0.583, and 0.463, respectively. The sensitivity and the specificity in the parallel test was 99.0% and 95.0% when serum PDGF-BB, TIMP-1mRNA and TIMP-1mRNA/MMP-1mRNA was detected simultaneously.

CONCLUSION: Serum level of PDGF-BB, TIMP-1mRNA, TIMP-1mRNA/MMP-1mRNA in PBMCs, and serum level of TIMP-1 and TIMP-1/MMP-1 can be used as the indices for the diagnosis of hepatic fibrosis, but the former three are more useful. The combination of serum PDGF-BB, TIMP-1mRNA and TIMP-1mRNA/MMP-1mRNA in PBMCs is even more efficient in screening liver fibrosis.

Matrix Metalloproteinases and Tissue Inhibitors of Metalloproteinases in Sera and Tissue of Patients with Dupuytren’s Disease

Dupuytren's contracture is a fibroproliferative disorder characterized by progressive deposition of mature collagen fibers. In other fibrotic diseases affecting organs such as the liver, lung, heart, and skin, matrix metalloproteinases (MMPs) and their natural inhibitors, the tissue inhibitors of metalloproteinases (TIMPs), play an important role. In this study, serum concentrations of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 were determined in 22 patients (five women and 17 men; average age, 67 +/- 11 years) with Dupuytren's disease using an enzyme-linked immunosorbent assay. Tissue samples were obtained for standard histological and immunohistochemical analyses. Sera and samples of palmar fascia from 20 patients (13 women and seven men; average age, 60 +/- 15 years) who had undergone hand surgery for carpal tunnel syndrome were used as the control group. Statistical analysis was performed using the Mann-Whitney test. Patients with Dupuytren's contracture presented with a TIMP-1 concentration of 437 +/- 160 ng/ml, a significantly higher TIMP-1 concentration than that seen in the control patients, who had a concentration of 321 +/- 70 ng/ml (p < 0.05). Patients with a proliferative active disease (n = 14) had a significantly higher TIMP-1 concentration (525 +/- 136 ng/ml) than patients (n = 8) with a contracture in the late involutional and residual phase (286 +/- 41 ng/ml; p < 0.05). There were no significant differences in the TIMP-2, MMP-1, MMP-2, and MMP-9 serum concentrations between patients with palmar fibromatosis and the control group. Patients with Dupuytren's disease had a significantly lower MMP-to-TIMP ratio (1.1 +/- 0.3; p < 0.05) than the control group (1.5 +/- 0.35). Patients with an active palmar fibromatosis presented a significantly (p < 0.05) reduced ratio (1 +/- 0.2) compared with those in later phases (1.4 +/- 0.3). TIMP-1 and TIMP-2 could be detected in tissue of patients with Dupuytren's contracture, with an accumulation in proliferative areas. MMPs could be detected locally in Dupuytren's tissue in a few patients, with less positive staining than for TIMPs. In the control group, there was just little or no staining for TIMPs and MMPs. The data indicate that the physiological balance between MMPs and their natural inhibitors is disturbed in patients with a proliferative active Dupuytren's disease. The decrease in the systemic MMP-to-TIMP ratio can cause increased synthesis and deposition of collagen, leading to palmar fibromatosis.

Altered expression of genes involved in hepatic morphogenesis and fibrogenesis are identified by cDNA microarray analysis in biliary atresia

Biliary atresia (BA) is characterized by a progressive, sclerosing, inflammatory process that leads to cirrhosis in infancy. Although it is the most common indication for liver transplantation in early childhood, little is known about its etiopathogenesis. To elucidate factors involved in this process, we performed comprehensive genome-wide gene expression analysis using complementary DNA (cDNA) microarrays. We compared messenger RNA expression levels of approximately 18,000 human genes from normal, diseased control, and end-stage BA livers. Reverse-transcription polymerase chain reaction (RT-PCR) and Northern blot analysis were performed to confirm changes in gene expression. Cluster and principal component analysis showed that all BA samples clustered together, forming a distinct group well separated from normal and diseased controls. We further identified 35 genes and ESTs whose expression differentiated BA from normal and diseased controls. Most of these genes are known to be associated with cell signaling, transcription regulation, hepatic development, morphogenesis, and fibrogenesis. In conclusion, this study serves to delineate processes that are involved in the pathogenesis of BA.

Cloning and expression of tissue inhibitor of metalloproteinases-1 (TIMP-1) gene in Chinese

AIM

To clone the Chinese gene of TIMP-1 and express the fusion protein MBP-TIMP-1.

METHODS

The fragment of TIMP-1 gene from the liver tissue of indigenous Hunan residents was amplified by RT-nest-PCR and it was cloned, sequenced by gene recombinations techniques. Fusion protein MBP-TIMP-1 was expressed in E.coli, analysed by SDS-PAGE and Western blot and purified by affinity chromatography.

RESULTS

The sequence of cloned Chinese TIMP-1 gene was 624 bp. It is homologous with the reported other human TIMP-1 gene sequence. Fusion protein MBP-TIMP-1 was 66 kd and is of the antigenicity of TIMP-1. The MBP-TIMP-1 was purified by affinity chromatography.

CONCLUSION

The Chinese gene of TIMP-1 was cloned and MBP-TIMP-1 was expressed and purified successfully in vitro. It may be useful to the diagnosis of liver fibrosis.

Liver extracellular matrix in health and disease

Liver fibrosis is the hallmark of every chronic liver disease. It is also the major factor of morbidity and mortality due to the development of cirrhosis and its complications including hepatocellular carcinoma. But even at the beginning of the process of liver fibrosis and due to the strategic position of the extracellular matrix at the interface between blood flow and epithelial compartment, any quantitative or qualitative modification of extracellular matrix will rapidly affect structure and function of the liver. The development of several animal models of liver fibrosis as well as isolation and cultivation of hepatic stellate cells, the major fibrogenic cell type in the liver, led to the gathering of recent knowledge on the mechanism of liver fibrosis. Activation of hepatic stellate cells is a key event in this process and many details on this finely tuned mechanism are now available. In addition to these experimental data, experience from chronic hepatitis C now allows the development of new concepts and perspectives such as liver fibrosis regression and antifibrotic therapies.

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Effect of Chinese herb Shuangjiawuling on expression of TIMPs in rat with liver fibrosis

AIM: To explore the effect of Chinese herb Shuangjiawuling in preventing hepatic fibrosis in rat with liver fibrosis.

METHODS: Rat immunogenic liver fibrosis model was induced by administration human serum albumin (HSA 200 g/L) intravenously, 80 rats were randomly divided into 5 groups. Shuangjiawuling was taken orally simultaneously with (group A), immediately after (group B), or 3 months after (group C) administration of HAS intravenously. Colchine tablets were taken orally with the administration of HAS (group D), normal rats were used as control (Group E). The pathological changes of liver tissue were observed by HE and Von-Gieson staining. The hepatic mRNA and protein of TIMP-1 and TIMP-2 were analyzed by in site hybridization and immunohistochemistry.

RESULTS: Hepatic fibrosis developed gradually and became obviously on the third month after administration of HAS. And strong expressions of TIMP-1 and TIMP-2 were observed, however, its expression and hepatic fibrosis were reduced dramatically following administration of Shuangjiawuling and colchine tablets. The effect of Shuangjiawuling in preventing fibrosis was superior to that of colchine tablets (P<0.05), and its effect in group A, B, and C decreased in order.

CONCLUSION: Chinese herb Shuangjiawuling can inhibit the development of hepatic fibrosis and the expression of TIMPs, and promoted the effect of the degradation of the extracellular matrix.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

Role of liver biopsy in management of chronic hepatitis C: a systematic review

This systematic review addresses 2 questions pertinent to the need for pretreatment liver biopsy in patients with chronic hepatitis C: how well do liver biopsy results predict treatment outcomes for chronic hepatitis C? How well do biochemical blood tests and serologic measures of fibrosis predict the biopsy findings in chronic hepatitis C? Medline and other electronic databases were searched from January 1985 to March 2002. Additional articles were sought in references of pertinent articles and recent journals and by querying experts. Articles were eligible for review if they reported original human data from a study that used virological, histological, pathologic, or clinical outcome measures. Paired reviewers assessed the quality of each eligible study and abstracted data. Studies suggested that advanced fibrosis or cirrhosis on initial liver biopsy is associated with a modestly decreased likelihood of a sustained virological response (SVR) to treatment. Also, studies relatively consistently showed that serum aminotransferases have modest value in predicting fibrosis on biopsy; that extracellular matrix tests hyaluronic acid and laminin may have value in predicting fibrosis, and that panels of tests may have the greatest value in predicting fibrosis or cirrhosis. Biochemical and serologic tests were best at predicting no or minimal fibrosis, or at predicting advanced fibrosis/cirrhosis, and were poor at predicting intermediate levels of fibrosis. Thus, evidence suggests that liver biopsy may have some usefulness in predicting efficacy of treatment in patients with chronic hepatitis C, and biochemical blood tests and serologic tests currently have only modest value in predicting fibrosis on liver biopsy.

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.

The proMMP-2 activation rate in patients with chronic viral liver disease

BACKGROUND

We previously showed that serum promatrix metalloproteinase-2 (proMMP-2) concentrations were increased in cirrhotic patients, reflecting the increase in liver proMMP-2 concentrations. We examined whether the increased proMMP-2 concentration reflects the biological matrix metalloproteinase-2 (MMP-2) activity.

METHODS

We measured serum concentrations of active MMP-2 and proMMP-2, and calculated the active MMP-2/proMMP-2 ratio as an index of the proMMP-2 activation rate in chronic viral liver disease.

RESULTS

The serum active MMP-2 concentrations were not altered in chronic liver disease, although the serum proMMP-2 concentration was markedly increased in cirrhotic patients. The active MMP-2/proMMP-2 ratio decreased with the grade of liver fibrosis, and was negatively correlated with serum levels of tissue inhibitor of metalloproteinases (TIMP)-2.

CONCLUSION

The proMMP-2 activation rate may be inhibited by the increased TIMP-2 in liver cirrhosis (LC), resulting in the accumulation of basement membrane collagens.

Matrix metalloproteinase-9 and tissue inhibitors of matrix metalloproteinase-1 in plasma of patients co-infected with HCV and HIV

BACKGROUND

Accelerated progression of hepatic fibrosis has been shown in patients co-infected with hepatitis C virus (HCV) and HIV. Liver fibrosis is a dynamic process in which the altered balance between matrix metalloproteinases (MMPs) and their specific inhibitors (TIMPs) may play a major role.

METHOD

The involvement of MMP-9 and TIMP-1 in HCV liver disease progression in patients co-infected with HIV was evaluated. Plasma concentrations of human MMP-9 and TIMP-1 were assessed in 76 HIV-infected patients; 27 were co-infected with HCV and 49 were HCV negative. 18 healthy donors were included as controls.

RESULTS

Patients with HIV infection exhibited a striking increase in TIMP-1 levels; this is more evident in patients with advanced CD4 depletion. There was no elevation in the plasma concentrations of the MMP-9. The highest levels of TIMP-1 were found in the HIV/HCV co-infected patients. The values of TIMP-1 in HIV-infected patients with chronic HCV hepatitis were significantly higher than in HIV-positive individuals without HCV infection, even including those with low CD4 count. No significant differences were seen in the MMP-9 levels.

CONCLUSION

These findings suggest that the altered balance between circulating MMP-9 and TIMP-1 during HIV infection may play an important role in exacerbating liver fibrosis progression in patients co-infected with HCV.