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

Dynamic analysis of serum MMP-7 and its relationship with disease progression in biliary atresia: a multicenter prospective study

PURPOSE

We aimed to assess the dynamic changing trend of serum matrix metalloproteinase-7 (MMP-7) in biliary atresia (BA) patients from diagnosis to LTx to further elucidate its clinical value in diagnosis and prognoses and its relationship with disease progression.

METHODS

In this multicentre prospective study, 440 cholestasis patients (direct bilirubin level of > 17 μmol/L) were enrolled. Serum MMP-7 levels were measured using an enzyme-linked immunosorbent assay at diagnosis, 1 week, 2 weeks, 1 month, 6 weeks, 2 months, 3 months, 6 months and then every 6 months post-KPE. The medical record at each follow-up visit for post-Kasai portoenterostomy patient was collected and analyzed.

RESULTS

Using a cut-off value of > 26.73 ng/mL, serum MMP-7 had an AUC of 0.954 in BA neonates and 0.983 in BA infants. A genetic mutation (G137D) was associated with low MMP-7 levels in serum of BA patients. MMP-7 showed a mediation effect on the association between inflammation and liver fibrosis in BA patients. Four dynamic patterns of serum MMP-7 post-KPE were associated with prognosis. Serum MMP-7 was the only significant predictor at 6 weeks post-KPE and the most accurate predictor at 3 months post-KPE of survival with the native liver in 2 years.

CONCLUSION

As one of the critical factors associated with BA occurrence and progression, serum MMP-7 can be used for early diagnosis of BA and post-KPE MMP-7 level is the earliest prognostic biomarker so far.

Serum matrix metalloproteinase 7 (MMP7) is a biomarker of fibrosis in patients with non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) affects 25% of the adult population globally. Since liver fibrosis is the most important predictor of liver-related complications in patients with NAFLD, identification of patients with advanced fibrosis among at-risk individuals is an important issue in clinical practice. Transient elastography is the best evaluated non-invasive method used in referral centres to assess liver fibrosis, however serum-based tests, such as the Enhanced Liver Fibrosis (ELF) score, have a practical advantage as first-line tests due to their wider availability and lower cost. We previously identified matrix metalloproteinase 7 (MMP7) as a serum biomarker of histological advanced fibrosis in a mixed-etiology patient cohort. In this study we aimed to determine the association between MMP7 and fibrosis, assessed by transient elastography, in patients with NAFLD. Serum MMP7 levels were measured in a cohort of 228 patients with NAFLD. Associations between MMP7, liver stiffness measurement (LSM), ELF score and clinical parameters were determined using logistic regression modelling. Serum MMP7 was associated with clinically significant fibrosis (LSM ≥ 8.2), independent of age, gender, BMI and diabetes. The addition of MMP7 significantly improved the diagnostic performance of the ELF test, particularly in patients over the age of 60. Combinations of serum biomarkers have the potential to improve the sensitivity and specificity of detection of advanced fibrosis in at-risk patients with NAFLD. We have demonstrated that serum MMP7 is independently associated with clinically significant fibrosis and improves the diagnostic performance of currently available tests in older patients.

A model integrating donor gene polymorphisms predicts fibrosis after liver transplantation

Post-transplant liver fibrosis (PTLF) is a common and severe complication in liver recipients. In this study, we assessed the impact of donor liver genetics on the development of PTLF. A total of 232 patients undergoing liver transplantation were included. Twenty-two single nucleotide polymorphisms (SNPs) associated with liver fibrosis were analyzed. Univariate analysis revealed seven donor SNPs to be associated with PTLF. In a multivariate analysis, independent risk factors of PTLF were genetic variation of donor GRP78 rs430397 (OR = 8.99, p = 0.003), GSTP1 rs1695 (OR = 0.13, p = 0.021), miRNA-196a rs12304647 (OR = 16.01, p =0.001), and TNF-α rs1800630 (OR = 79.78, p = 0.001); blood tacrolimus levels at maintenance > 7 ng/ml (OR =7.48, p <0.001); and post-transplant diabetes mellitus (OR = 7.50, p = 0.001). A predictive model that included donor SNPs showed better prognostic ability for PTLF than a model with only clinical parameters (AUROC: 0.863 vs 0.707, P < 0.001). Given that donor gene SNPs are associated with an increased risk of PTLF, this model integrated with donor gene polymorphisms may help clinicians predict PTLF.

Diagnostic Accuracy of Serum Matrix Metalloproteinase-7 for Biliary Atresia

The diagnosis of biliary atresia (BA) remains a clinical challenge because affected infants have signs, symptoms, and serum liver biochemistry that are also seen in those with other causes of neonatal cholestasis (non-BA). However, an early diagnosis and prompt surgical treatment are required to improve clinical outcome. Recently, the relative abundance of serum matrix metalloproteinase-7 (MMP-7) was suggested to have discriminatory features for infants with BA. To test the hypothesis that elevated serum concentration of MMP-7 is highly diagnostic for BA, we determined the normal serum concentration of MMP-7 in healthy control infants, and then in 135 consecutive infants being evaluated for cholestasis. The median concentration for MMP-7 was 2.86 ng/mL (interquartile range, IQR: 1.32-5.32) in normal controls, 11.47 ng/mL (IQR: 8.54-24.55) for non-BA, and 121.1 ng/mL (IQR: 85.42-224.4) for BA (P < 0.0001). The area under the curve of MMP-7 for the diagnosis of BA was 0.9900 with a cutoff value of 52.85 ng/mL; the diagnostic sensitivity and specificity were 98.67% and 95.00%, respectively, with a negative predictive value of 98.28%. Conclusion: Serum MMP-7 assay has high sensitivity and specificity to differentiate BA from other neonatal cholestasis, and may be a reliable biomarker for BA.

Large-scale proteomics identifies MMP-7 as a sentinel of epithelial injury and of biliary atresia

Biliary atresia is a progressive infantile cholangiopathy of complex pathogenesis. Although early diagnosis and surgery are the best predictors of treatment response, current diagnostic approaches are imprecise and time-consuming. We used large-scale, quantitative serum proteomics at the time of diagnosis of biliary atresia and other cholestatic syndromes (serving as disease controls) to identify biomarkers of disease. In a discovery cohort of 70 subjects, the lead biomarker was matrix metalloproteinase-7 (MMP-7), which retained high distinguishing features for biliary atresia in two validation cohorts. Notably, the diagnostic performance reached 95% when MMP-7 was combined with γ-glutamyltranspeptidase (GGT), a marker of cholestasis. Using human tissue and an experimental model of biliary atresia, we found that MMP-7 is primarily expressed by cholangiocytes, released upon epithelial injury, and promotes the experimental disease phenotype. Thus, we propose that serum MMP-7 (alone or in combination with GGT) is a diagnostic biomarker for biliary atresia and may serve as a therapeutic target.

Post-surgical resection prognostic value of combined OPN, MMP7, and PSG9 plasma biomarkers in hepatocellular carcinoma

Biomarkers for hepatocellular carcinoma (HCC) following curative resection are not currently sufficient for prognostic indication of overall survival (OS) and disease-free survival (DFS). The aim of this study was to investigate the prognostic performance of osteopontin (OPN), matrix metalloproteinase 7 (MMP7), and pregnancy specific glycoprotein 9 (PSG9) in patients with HCC. A total of 179 prospective patients with HCC provided plasma before hepatectomy. Plasma OPN, MMP7, and PSG9 levels were determined by enzyme-linked immunosorbent assay. Correlations between plasma levels, clinical parameters, and outcomes (OS and DFS) were overall analyzed. High OPN ( ⩾ 149.97 ng/mL), MMP7 ( ⩾ 2.28 ng/mL), and PSG9 ( ⩾ 45.59 ng/mL) were prognostic indicators of reduced OS (P < 0.001, P < 0.001, and P = 0.007, respectively). Plasma PSG9 protein level was an independent factor in predicting OS (P = 0.008) and DFS (P = 0.038). Plasma OPN + MMP7 + PSG9 elevation in combination was a prognostic factor for OS (P < 0.001). OPN was demonstrated to be a risk factorassociated OS in stage I patients with HCC and patients with low α-fetoprotein levels ( < 20 ng/mL). These findings suggested that OPN, MMP7, PSG9 and their combined panels may be useful for aiding in tumor recurrence and mortality risk prediction of patients with HCC, particularly in the early stage of HCC carcinogenesis.

Increased MMP-7 expression in biliary epithelium and serum underpins native liver fibrosis after successful portoenterostomy in biliary atresia

The molecular mechanisms underlying progressive liver fibrosis following surgical treatment of biliary atresia (BA) remain unclear. Our aim was to address hepatic gene and protein expression and serum levels of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs) after successful portoenterostomy (PE), and relate them to histological signs of liver injury, clinical follow‐up data and biochemical markers of hepatic function. LIver biopsies and serum samples were obtained from 25 children after successful PE at median age of 3.3 years. Serum MMP concentrations were determined by enzyme‐linked immune sorbent assay. Hepatic gene expression of MMPs and TIMPs was analyzed using real‐time reverse‐transcription PCR. Liver expression of MMP‐7 and cytokeratin‐7 was studied using immunohistochemistry. Despite effective clearance of biochemical and histological cholestasis following PE, BA patients showed increased hepatic gene expression of MMP‐7 (29‐fold, p < 0.001), MMP‐2 (3.1‐fold, p < 0.001), MMP‐14 (1.7‐fold, p = 0.007), and TIMP‐1 (1.8‐fold, p < 0.001), when compared to controls. Similar to a biliary epithelial marker cytokeratin‐7, expression of MMP‐7 localized in biliary epithelium of bile ducts and ductal proliferations and periportal hepatocytes and was increased (p < 0.001) in relation to controls. BA patients had 6‐fold higher serum levels of MMP‐7 (p < 0.001), which correlated positively with hepatic MMP‐7 gene (r = 0.548, p = 0.007) and protein (r = 0.532, p = 0.007) expression. Patients showed a positive correlation between biliary MMP‐7 expression and Metavir fibrosis stage (r = 0.605, p = 0.001) and portal fibrosis grade (r = 0.606, p = 0.001). Neither similarly increased MMP‐7 expression nor correlation with liver fibrosis was observed in patients with intestinal failure‐associated liver disease and comparable Metavir stage. In conclusion, our findings support an unique role of altered hepatic expression of MMP‐7 in the progression of liver fibrosis after successful PE and introduce a potential therapeutic target to pharmacologically extend native liver survival by inhibiting MMP‐7 hyperactivity. Serum MMP‐7 may be a valuable postoperative prognostic tool in BA.

Liver fibrosis: from animal models to mapping of human risk variants

Liver fibrosis is the sequel of chronic liver diseases and the main reason for increased mortality in affected patients. The extent of liver fibrosis displays great interindividual variation, even after controlling for exogenous factors. Thus, host genetic factors are considered to play an important role in the process of liver scarring. From a genetic perspective, liver fibrosis is a complex trait with many genes contributing to the expression of the phenotype. In genetically manipulated and inbred animals several risk loci for liver fibrosis have been identified. Some of these loci have been replicated in case-control studies of patients with hepatitis C infection. In humans, genetic risk loci were identified by single marker studies, haplotype studies or the combination of single markers. Recently, the first genome-wide association studies have also been performed in patients with liver diseases. Some of the identified gene variants have been functionally characterized in vitro, thereby opening the potential for novel therapeutic approaches and risk stratification.

Evolving challenges in hepatic fibrosis

Continued elucidation of the mechanisms of hepatic fibrosis has yielded a comprehensive and nuanced portrait of fibrosis progression and regression. The paradigm of hepatic stellate cell (HSC) activation remains the foundation for defining events in hepatic fibrosis and has been complemented by progress in a number of new areas. Cellular sources of extracellular matrix beyond HSCs have been identified. In addition, the role of chemokine, adipokine, neuroendocrine, angiogenic and NAPDH oxidase signaling in the pathogenesis of hepatic fibrosis has been uncovered, as has the contribution of extracellular matrix stiffness to fibrogenesis. There is also increased awareness of the contribution of innate immunity and greater understanding of the complexity of gene regulation in HSCs and myofibroblasts. Finally, both apoptosis and senescence have been recognized as orchestrated programs that eliminate fibrogenic cells during resolution of liver fibrosis. Ironically, the progress that has been made has highlighted the growing disparity between advances in the experimental setting and their translation into new diagnostic tools and treatments. As a result, focus is shifting towards overcoming key translational challenges in order to accelerate the development of new therapies for patients with chronic liver disease.

Pathway-focused arrays reveal increased matrix metalloproteinase-7 (matrilysin) transcription in trachomatous trichiasis

PURPOSE

Several genes that are associated with protection from or susceptibility to trachomatous trichiasis (TT) have been identified through genetic association studies. Yet there have been few studies in which gene expression profiles were assessed in TT cases and disease-free controls. The purpose was to identify genes that are differentially expressed in the upper tarsal conjunctiva of subjects with TT.

METHOD

Pathway-focused gene arrays were used to screen conjunctival RNA expression of 226 gene transcripts of interest. The screening was followed by validation of differentially expressed genes by qRT-PCR on an independent set of samples. Three different techniques were then used to test for quantitative differences in the recovered conjunctival protein fraction.

RESULTS

Focused arrays identified a set of 13 differentially expressed genes. Validation by qRT-PCR confirmed differential expression in four of these genes (COL1A1, COL7A1, MMP7, and TLR6). Increased expression of MMP7 was the only consistent differentially regulated gene in the conjunctival samples of trichiasis subjects. MMP7 was present in isolated conjunctival proteins and in the tissue culture supernatants of peripheral blood lymphocytes after stimulation.

CONCLUSIONS

There is an imbalance in extracellular matrix turnover with minimal contribution of adaptive immune responses at this stage of trichiasis. There was little evidence of broad differential expression in genes characteristic of polar responses of adaptive T cells or macrophages. The control of the MMP7 response and its activity appears significant in the fibrotic changes observed in TT.

Prevalence of genetic polymorphisms in the promoter region of the alpha-1 antitrypsin (SERPINA1) gene in chronic liver disease: a case control study

Background

Alpha-1 antitrypsin (A1AT) deficiency, caused by the Z allele (p.E342K) and S allele (p.E264V) in the SERPINA1 gene, can induce liver and pulmonary disease. Different mechanisms appear to be responsible for the pathogenesis of these divergent disease expressions. The c.-1973T >C polymorphism located in the SERPINA1 promoter region is found more frequent in A1AT deficiency patients with liver disease compared to patients with pulmonary disease, but data are lacking regarding contribution to the development of liver diseases caused by other aetiologies.

Aim

To study the prevalence of c.-1973T >C, Z allele and S allele in a cohort of patients with liver disease of various aetiologies compared with healthy controls and to evaluate its effect on disease progression.

Methods

A total of 297 patients with liver disease from various aetiologies and 297 age and gender matched healthy controls were included. The c.-1973T >C polymorphism and Z and S alleles of the SERPINA1 gene were analyzed by real-time PCR.

Results

c.-1973T >C was similarly distributed between patients with liver disease of various origins and healthy controls. Furthermore, the distribution of c.-1973T >C was independent from aetiology subgroup. In patients with liver disease mean ages at of onset of liver disease were 44.4, 42.3 and 40.7 years for the c.-1973 T/T, T/C and C/C genotype respectively (NS). S allele heterozygosity was increased in patients with drug induced liver injury (DILI), (OR 4.3; 95%CI 1.1-17.2).

Conclusion

In our study, c.-1973T >C polymorphism was not a risk factor for liver disease of various aetiologies. In addition, S allele heterozygosity might contribute to the development of DILI.