Markers of Basement Membrane Remodeling Are Associated With Higher Mortality in Patients With Known Atherosclerosis

Background Patients with atherosclerosis have a high risk of cardiovascular events and death. Atherosclerosis is characterized by accumulation of lipids, cells and extracellular matrix proteins in the intima. We hypothesized that dysregulated remodeling of the basement membrane proteins may be associated with clinical outcomes in patients with atherosclerosis. Methods and Results Neoepitope fragments of collagen type IV (C4M) and laminin ( LG 1M) were assessed by ELISA s in serum from 787 endarterectomy patients. Matrix metalloproteinase s were measured using proximity extension assay and correlated to C4M and LG 1M levels using Spearman correlations. A total of 473 patients were followed up for 6 years using national registers, medical charts, and telephone interviews. The incidence of cardiovascular events, cardiovascular mortality, and all-cause mortality were associated to levels of C4M and LG 1M using Kaplan-Meier curves and Cox regression analyses. A total of 101 patients had cardiovascular events, 39 died of cardiovascular mortality, and 64 patients died from all-cause mortality. C4M levels were increased in patients with symptomatic carotid atherosclerotic disease before surgery ( P=0.048). High C4M and LG 1M levels were associated with increased risk of all-cause mortality ( P=0.020 and 0.031, respectively) and predicted all-cause death together with glomerular filtration rate and diabetes mellitus. Conclusions High LG 1M and C4M levels were associated with all-cause mortality, together with glomerular filtration rate and diabetes mellitus. These novel biomarkers need further evaluation but might be tools to identify high-risk patients.

3046High levels of MMP-cleaved mimecan is associated to carotid plaque stability and less future cardiovascular events

Introduction

The clinical consequences of atherosclerosis, myocardial infarction and stroke are the most common causes of death globally. Mimecan, a small leucine rich-repeat proteoglycan (SLRP), is cleaved by matrix metalloproteinases (MMPs) and known to be involved in collagen fibrillogenesis and angiogenesis. Circulating levels of MMP-cleaved mimecan (cMIM) has previously been identified as a marker of extracellular matrix remodelling in ApoE−/− knockout mice. The role of mimecan and its degradation in human atherosclerotic plaques has not been explored.

Purpose

We explored whether full-length mimecan and cleaved mimecan (cMIM) are associated to plaque composition and evaluated if they can predict future cardiovascular events.

Methods

Two hundred and eighteen human atherosclerotic plaques were stained for mimecan using immunohistochemistry. cMIM was measured in 202 plaque tissue homogenates using a competitive ELISA assay. Histological components (α-actin, CD68 and glycophorin A) were assessed using immunohistochemistry, neutral lipids were measured using Oil Red O and visible areas of calcium deposits were quantified. Matrix metalloproteinases (MMP-1, -2, -3, -9, -10 and -12), tissue inhibitors of matrix metalloproteinases (TIMP-1 and -2) were analysed in plaque tissue homogenates using ELISA assays and a proximity extension assay. ECM components (glycosaminoglycans, collagen and elastin) were detected with colorimetric assays and the TGF-β1, β2 and β3 were measured by a multiplex assay. Cardiovascular events were registered using national registers, patient records and telephone calls during a follow-up period of 59 months IQR (34–73).

Results

Mimecan was expressed in human atherosclerotic plaques. The expression correlated positively with neutral lipids and intraplaque hemorrhage and inversely with α-actin. In contrast cMIM correlated with α-actin and inversely with neutral lipids. cMIM correlated also with stabilizing extracellular matrix proteins elastin, collagen as well as TGF-β1, β2 and β3. Mimecan correlated to MMP-9 and cMIM correlated to MMP-2 and TIMP-2. Patient with high levels of cMIM had a lower risk of future cardiovascular events which remained significant after adjusting for risk factors (age, gender, diabetes and symptoms) in a multivariate Cox regression

Conclusion(s)

Mimecan was associated with vulnerable plaque features, whereas cMIM was related to stable plaque features. Low levels of cMIM predicted future cardiovascular events, independently of known risk factors. Taken together this suggests a possible role for mimecan and its cleavage in atherosclerosis that needs to be further explored.

Acknowledgement/Funding

Danish Research Foundation, Swedish Research Council, Swedish Heart and Lung Foundation, Skåne University Hospital and more.

Improvement of non-invasive markers of NAFLD from an individualised, web-based exercise program

BACKGROUND

Lifestyle modifications remain the cornerstone of treatment in non-alcoholic fatty liver disease (NAFLD). However, they requently fail related to the inability of patients to implement lasting changes.

AIMS

To evaluate the effects of a short, web-based, individualised exercise program on non-invasive markers of hepatic steatosis, inflammation and fibrosis.

METHODS

Patients with histologically confirmed NAFLD underwent an 8-week, web-based, individualised exercise program that contained bidirectional feedback.

RESULTS

Forty-four patients entered the study and 41 completed the assigned training goal (93.2%). In the completer population, 8 weeks of individualised exercise increased the VO_2peak by 12.2% compared to baseline (P < .001). ALT and AST decreased by 14.3% (P = .002) and 18.2% (P < .001) and remained at this level until follow-up 12 weeks after the intervention. Markers of inflammation including hsCRP, ferritin, and M30 decreased. In parallel, gut microbiota exhibited increased metagenomic richness (P < .05) and at the taxonomic levels Bacteroidetes and Euryarchaeota increased whereas Actinobacteria phylum decreased. Surrogate scores of steatosis and fibrosis including the fatty liver index (FLI), FiB-4, APRI and transient elastography showed significant reductions. In parallel, a marker of procollagen-3 turnover (PRO-C3) decreased while C4M2, reflecting type IV collagen, degradation increased suggesting beneficial hepatic fibrosis remodelling from exercise. Also, an enhancement in health-related quality of life was reported.

CONCLUSION

The current study underlines the plausibility and potential of an 8 week individualised web-based exercise program in NAFLD. Clinical trial number: NCT02526732.

Safety profile of autologous macrophage therapy for liver cirrhosis

Therapies to reduce liver fibrosis and stimulate organ regeneration are urgently needed. We conducted a first-in-human, phase 1 dose-escalation trial of autologous macrophage therapy in nine adults with cirrhosis and a Model for End-Stage Liver Disease (MELD) score of 10-16 (ISRCTN 10368050). Groups of three participants received a single peripheral infusion of 10⁷, 10⁸ or up to 10⁹ cells. Leukapheresis and macrophage infusion were well tolerated with no transfusion reactions, dose-limiting toxicities or macrophage activation syndrome. All participants were alive and transplant-free at one year, with only one clinical event recorded, the occurrence of minimal ascites. The primary outcomes of safety and feasibility were met. This study informs and provides a rationale for efficacy studies in cirrhosis and other fibrotic diseases.

Biomarkers of collagen synthesis predict progression in the PROFILE idiopathic pulmonary fibrosis cohort

Idiopathic pulmonary fibrosis (IPF) is characterised by excessive extracellular matrix (ECM) deposition and remodelling. Measuring this activity provides an opportunity to develop tools capable of identifying individuals at-risk of progression. Longitudinal change in markers of ECM synthesis was assessed in 145 newly-diagnosed individuals with IPF.Serum levels of collagen synthesis neoepitopes, PRO-C3 and PRO-C6 (collagen type 3 and 6), were elevated in IPF compared with controls at baseline, and progressive disease versus stable disease during follow up, (PRO-C3 p < 0.001; PRO-C6 p = 0.029). Assessment of rate of change in neoepitope levels from baseline to 3 months (defined as 'slope to month 3': HIGH slope, slope > 0 vs. LOW slope, slope < =0) demonstrated no relationship with mortality for these markers (PRO-C3 (HR 1.62, p = 0.080); PINP (HR 0.76, p = 0.309); PRO-C6 (HR 1.14, p = 0.628)). As previously reported, rising concentrations of collagen degradation markers C1M, C3M, C6M and CRPM were associated with an increased risk of overall mortality (HR = 1.84, CI 1.03-3.27, p = 0.038, HR = 2.44, CI 1.39-4.31, p = 0.002; HR = 2.19, CI 1.25-3.82, p = 0.006; HR = 2.13 CI 1.21-3.75, p = 0.009 respectively).Elevated levels of PRO-C3 and PRO-C6 associate with IPF disease progression. Collagen synthesis and degradation biomarkers have the potential to enhance clinical trials in IPF and may inform prognostic assessment and therapeutic decision making in the clinic.

Circulating levels of PRO-C3 reflect liver fibrosis and liver function in HIV positive patients receiving modern cART

Background and aims

Although combined antiretroviral treatment (cART) has improved overall survival of HIV infected patients, liver fibrosis and liver related-mortality still constitute major challenges in HIV positive patients. Collagen accumulates in the liver during fibrogenesis. Recent studies showed that circulating levels of extracellular matrix (ECM) fragments might reflect degree of portal hypertension and fibrosis stage in liver disease. In this study, we analyzed the correlation between liver fibrosis assessed by Fibroscan and levels of the formation and degradation markers of type III and IV collagen in HIV positive patients receiving cART.

Methods

116 HIV positive patients (82.7% male, median age 47 years) were enrolled into the study. Liver stiffness and liver fat content were determined using a Fibroscan with integrated CAP function. We quantified ECM formation and degradation fragments of collagen III and IV: PRO-C3, PRO-C4, C3M and C4M. These fragments were measured in peripheral serum by using specific ELISAs.

Results

Fifteen (12.9%) out of the 116 HIV positive patients had relevant fibrosis with a liver stiffness ≥ 7.1 kPa, and 79 patients had relevant steatosis with a CAP value > 248 dB/m. Circulating PRO-C3 levels significantly correlated with increasing degree of liver fibrosis assessed by Fibroscan (p = 0.0005), as well as with APRI score (p = 0.015). Interestingly, circulating PRO-C3 levels were significantly correlated with bilirubin (p = 0.022), reduced platelet count (p = 0.0008) and low albumin levels (p = 0.001), suggesting the association of type III collagen deposition with impaired liver function. None of the other measured ECM components significantly correlated with fibrosis or steatosis.

Conclusion

The formation marker of type III collagen, PRO-C3 not only reflects liver fibrosis, but might also mirror liver dysfunction in HIV positive patients receiving cART. Therefore, the circulating levels of PRO-C3 might be suitable to monitor progression of liver fibrosis and deterioration of liver function in HIV positive patients receiving cART.

Collagen Formation Assessed by N-Terminal Propeptide of Type 3 Procollagen Is a Heritable Trait and Is Associated With Liver Fibrosis Assessed by Magnetic Resonance Elastography

N-terminal propeptide of type 3 procollagen (PRO-C3) is a biomarker of liver fibrosis in nonalcoholic fatty liver disease (NAFLD). This study examines the association between PRO-C3 concentration and liver fibrosis assessed by magnetic resonance elastography (MRE)-measured stiffness (MRE-stiffness) and the heritability of PRO-C3 concentration in a cohort of twins and families with and without NAFLD. We performed a cross-sectional analysis of a well-characterized prospective cohort of 306 participants, including 44 probands with NAFLD-cirrhosis and their 72 first-degree relatives, 24 probands with NAFLD without advanced fibrosis and their 24 first-degree relatives, and 72 controls without NAFLD and their 72 first-degree relatives. Liver steatosis was assessed by magnetic resonance imaging proton density fat fraction, and liver fibrosis was assessed by MRE-stiffness. Serum PRO-C3 was assessed by competitive, enzyme-linked immunosorbent assay. We assessed the familial correlation of PRO-C3 concentration, the shared gene effects between PRO-C3 concentration and liver steatosis and fibrosis, and the association between PRO-C3 concentration and genetic variants in the patatin-like phospholipase domain-containing 3 (PNPLA3), transmembrane 6 superfamily member 2 (TM6SF2), membrane-bound O-acyltransferase domain-containing (MBOAT), and glucokinase regulator (CGKR) genes. In multivariable-adjusted models including age, sex, body mass index, and ethnicity, serum PRO-C3 correlated strongly with liver fibrosis (r²  = 0.50, P < 0.001) and demonstrated robust heritability (h² , 0.36; 95% confidence interval [CI], 0.07, 0.59; P = 0.016). PRO-C3 concentration and steatosis had a strong genetic correlation (shared genetic determination: 0.62; 95% CI, 0.236, 1.001; P = 0.002), whereas PRO-C3 concentration and fibrosis had a strong environmental correlation (shared environmental determination: 0.55; 95% CI, 0.317, 0.717; P < 0.001). PRO-C3 concentrations were higher in carriers of the TM6SF2 rs58542926-T allele compared with noncarriers: 15.7 (± 10.5) versus 10.8 (± 5.7) ng/L (P = 0.047). Conclusion: Serum PRO-C3 correlates with MRE-assessed fibrosis, is heritable, shares genetic correlation with liver steatosis and shares environmental correlation with liver fibrosis. PRO-C3 concentration appears to be linked to both fibrosis and steatosis and increased in carriers of the TM6SF2 rs58542926 risk allele.

ADAPT: An Algorithm Incorporating PRO-C3 Accurately Identifies Patients With NAFLD and Advanced Fibrosis

Given the high global prevalence of nonalcoholic fatty liver disease (NAFLD), the need for relevant noninvasive biomarkers and algorithms to accurately stage disease severity is a critical unmet medical need. Identifying those with advanced fibrosis (≥ F3) is the most crucial, as these individuals have the greatest risk of adverse, long-term, liver-related outcomes. We aimed to investigate the role of PRO-C3 (a marker of type III collagen formation) as a biomarker for advanced fibrosis in NAFLD. We measured PRO-C3 by enzyme-linked immunosorbent assay in two large independent cohorts with extensive clinical phenotyping and liver biopsy: 150 in the derivation and 281 in the validation cohort. A PRO-C3-based fibrosis algorithm that included age, presence of diabetes, PRO-C3, and platelet count (ADAPT) was developed. PRO-C3 increased with fibrosis stage (Rho 0.50; P < 0.0001) and was independently associated with advanced fibrosis (odds ratio = 1.05; 95% confidence interval [CI] 1.02-1.08; P = 0.003). ADAPT showed areas under the receiver operating characteristics curve of 0.86 (95% CI 0.79-0.91) in the derivation and 0.87 in the validation cohort (95% CI 0.83-0.91) for advanced fibrosis. This was superior to the existing fibrosis scores, aspartate aminotransferase to platelet ratio index (APRI), FIB-4, and NAFLD fibrosis score (NFS) in most comparisons. Conclusion: PRO-C3 is an independent predictor of fibrosis stage in NAFLD. A PRO-C3-based score (ADAPT) accurately identifies patients with NAFLD and advanced fibrosis and is superior to APRI, FIB-4, and NFS.

Effect of NGM282, an FGF19 analogue, in primary sclerosing cholangitis: A multicenter, randomized, double-blind, placebo-controlled phase II trial

BACKGROUND & AIMS

Primary sclerosing cholangitis (PSC) is an inflammatory, cholestatic and progressively fibrotic liver disease devoid of effective medical intervention. NGM282, an engineered, non-tumorigenic FGF19 analogue, potently regulates CYP7A1-mediated bile acid homeostasis. We assessed the activity and safety of NGM282 in patients with PSC.

METHODS

In this double-blind, placebo-controlled phase II trial, 62 patients who had PSC confirmed by cholangiography or biopsy and an elevated alkaline phosphatase (ALP) >1.5 × the upper limit of normal were randomly assigned 1:1:1 to receive NGM282 1 mg, 3 mg or placebo once daily for 12 weeks. The primary outcome was the change in ALP from baseline to week 12. Secondary and exploratory outcomes included changes in serum biomarkers of bile acid metabolism and fibrosis. Efficacy analysis was by intention-to-treat.

RESULTS

At 12 weeks, there were no significant differences in the mean change from baseline in ALP between the NGM282 and placebo groups, and therefore, the primary endpoint was not met. However, NGM282 significantly reduced levels of 7alpha-hydroxy-4-cholesten-3-one (a marker of hepatic CYP7A1 activity, LS mean differences -6.2 ng/ml (95% CI -10.7 to -1.7; p = 0.008) and -9.4 ng/ml (-14.0 to -4.9; p <0.001) in the NGM282 1 mg and 3 mg groups, respectively, compared with placebo) and bile acids. Importantly, fibrosis biomarkers that predict transplant-free survival, including Enhanced Liver Fibrosis score and Pro-C3, were significantly improved following NGM282 treatment. Most adverse events were mild to moderate in severity, with gastrointestinal symptoms more frequent in the NGM282 treatment groups.

CONCLUSIONS

In patients with PSC, NGM282 potently inhibited bile acid synthesis and decreased fibrosis markers, without significantly affecting ALP levels.

LAY SUMMARY

We present for the first time, the clinical and laboratory effects of a first-in-class, engineered analogue of the endocrine hormone FGF19 in patients with primary sclerosing cholangitis (PSC). By incorporating non-invasive markers of fibrosis, beyond standard liver injury markers, we show that NGM282 impacted on fibrosis turnover and hepatic inflammation without changing alkaline phosphatase. Our findings demonstrate the complexities of using highly potent rational agents in PSC, and furthermore challenge the dogma about what the appropriate endpoints should be for trials in PSC.

A biomarker of collagen type I degradation is associated with cardiovascular events and mortality in patients with atherosclerosis

OBJECTIVE

Atherosclerosis is characterized by accumulation of lipids, cells and extracellular matrix (ECM) proteins in the arterial wall. Collagen type I (COL1), a component of the arterial ECM, is cleaved by matrix metalloproteinases (MMPs) and known to be remodelled in atherosclerosis. We explored whether the MMP-mediated COL1 biomarker, C1M, was associated with cardiovascular events, cardiovascular mortality and all-cause mortality in a large prospective cohort of patients with known atherosclerosis.

METHODS

Serum from 787 patients who underwent a carotid endarterectomy was included. Circulating levels of C1M were measured in serum. A total of 473 patients were followed for 6 years after surgery. Associations between C1M and incidence of cardiovascular events, cardiovascular mortality and all-cause mortality were assessed by Kaplan-Meier curves and Cox regression analysis.

RESULTS

A total of 101 (21.4%) patients suffered from nonfatal cardiovascular events during the follow-up period, and 64 (13.5%) patients died. Of these, 39 (60.9%) died from cardiovascular diseases. Patients with C1M levels above the median were significantly associated with cardiovascular events, cardiovascular mortality and all-cause mortality (P < 0.001, P = 0.004 and P < 0.001, respectively). C1M was included in the final model for prediction of cardiovascular events (HR 2.15, 95% CI 1.40-3.32, P = 0.001), cardiovascular mortality (HR 2.20, 95% CI 1.07-4.51, P = 0.031) and all-cause mortality (HR 2.98 95% CI 1.67-5.33, P = < 0.001).

CONCLUSIONS

In patients with atherosclerotic carotid lesions, high levels of C1M predicted cardiovascular events, cardiovascular mortality and all-cause mortality. These findings emphasize the importance of remodelling mechanisms in atherosclerosis that are now becoming more and more explored.

Assessment of liver fibrosis progression and regression by a serological collagen turnover profile

There is a need for noninvasive biomarkers that can identify patients with progressive liver fibrosis and monitor response to antifibrotic therapy. An equally important need is identification of patients with spontaneous fibrosis regression, since they may not need treatment nor be included in clinical studies with fibrosis as end point. Circulating biomarkers, originating from defined fragments of the scar tissue itself, may serve as valuable tools for this aspect of precision medicine. We investigated a panel of serological collagen formation and degradation markers to identify patients likely to regress or progress in absence of a therapeutic intervention. Plasma samples from patients with moderate-stage hepatitis C receiving placebo treatment in a phase II trial of the peroxisome proliferator-activated receptor agonist farglitazar were included. The patients had matched liver biopsies at baseline and 52 wk of follow-up. Serological biomarkers of collagen formation (PRO-C3, PRO-C4, PRO-C5) and collagen degradation (C3M, C4M, and C6M) were analyzed. Logistic regression analysis including PRO-C3 and C6M identified subjects with progressive liver fibrosis with an AUROC of 0.91 ( P < 0.0001) and positive and negative predictive values (PPV/NPV) of 75.0%/88.6%. Low levels of PRO-C5 predicted a spontaneous regression phenotype, with an odds ratio of 33.8 times higher compared with patients with high levels ( P < 0.0025) with an AUROC of 0.78 ( P < 0.0001) and PPV/NPV of 60.0%/95.7%. Two collagen fragments (PRO-C3 and C6M) identified liver fibrosis progressors, and one collagen fragment (PRO-C5) identified liver fibrosis regressors. These biomarkers may improve patient stratification and monitor treatment efficacy in studies with fibrosis as clinical end point. NEW & NOTEWORTHY In this study we report two biomarkers of collagen fragments (PRO-C3 and C6M) that are able to identify liver fibrosis progressors while one biomarker (PRO-C5) identified liver fibrosis regressors. In particular, we present three noninvasive biomarkers that can be used to identify patients with progressive liver fibrosis, monitor response to antifibrotic therapy, and also identify the spontaneous liver fibrosis regression phenotype.

A serological marker of the N-terminal neoepitope generated during LOXL2 maturation is elevated in patients with cancer or idiopathic pulmonary fibrosis

Objectives

Lysyl oxidase like 2 (LOXL2) is associated with poor prognosis in idiopathic pulmonary disease (IPF) and cancer. We developed an Enzyme-linked immunosorbent assay (ELISA) targeting the LOXL2 neo-epitope generated through the release of the signal peptide during LOXL2 maturation.

Design and methods

An ELISA targeting the N-terminal site of the human LOXL2 was developed including technical optimization and validation steps. Serum LOXL2 was measured in patients with breast, colorectal, lung, ovarian, pancreatic and prostate cancer, melanoma, IPF and in healthy controls (n = 16).

Results

A technically robust and specific assay was developed. LOXL2 was detectable in serum from healthy controls and showed reactivity towards recombinant LOXL2. Compared to controls, LOXL2 levels were significantly (p < 0.001–0.05) elevated in serum from patients with breast, colerectal, lung, ovarian and pancreatic cancer (mean range: 49–84 ng/mL), but not in prostate cancer (mean: 36 ng/mL) and malignant melanoma patients (41 ng/mL). Serum LOXL2 was elevated in IPF patients compared to healthy controls (mean: 76.5 vs 46.8 ng/mL; p > 0.001)

Conclusions

A specific ELISA towards the N-terminal neo-epitope site in LOXL2 was developed which detected significantly elevated serum levels from patients with above-mentioned cancer types or IPF compared to healthy controls.

High turnover of extracellular matrix reflected by specific protein fragments measured in serum is associated with poor outcomes in two metastatic breast cancer cohorts

Increased extracellular matrix (ECM) formation and matrix metalloprotease (MMP)-mediated ECM degradation are parts of tumorgenesis and generates collagen fragments that are released into circulation. We evaluated the association of specific collagen fragments measured in serum with outcomes in two independent metastatic breast cancer (MBC) cohorts. ELISAs were used to measure C1M (MMP-generated type I collagen fragment), C3M (MMP-generated type III collagen fragment), C4M (MMP-generated type IV collagen fragment), and PRO-C3 (pro-peptide of type III collagen) in pretreatment serum from a phase 3 randomized clinical trial of second-line hormone therapy (HR+, n = 148), and a first-line trastuzumab-treated cohort (HER2+, n = 55). All sites of metastases were included. The collagen fragments were evaluated by Cox-regression analysis for their association with time-to-progression (TTP) and overall survival (OS). In the HR+ cohort, higher C1M and C3M levels (75th percentile cut-off) were associated with shorter TTP; all fragments were associated with shorter OS. In the HER2+ cohort, higher levels of all fragments were associated with shorter TTP; higher PRO-C3 was associated with shorter OS. In multivariate analysis of the HR+ trial for OS, higher levels of all fragments were significant for reduced OS when added separately (C1M HR = 2.1, p < 0.001; C3M HR = 1.8, p = 0.028; C4M HR = 1.8, p = 0.018; PRO-C3 HR = 1.8, p = 0.017); none other clinical covariates were significant. In conclusion, collagen fragments quantified in pretreatment serum was associated with shorter TTP and OS in two independent MBC cohorts receiving systemic therapy. If validated, quantification of ECM remodeling in serum has potential as prognostic and/or predictive biomarkers in MBC.

A STAT4 variant increases liver fibrosis risk in Caucasian patients with chronic hepatitis B

BACKGROUND

Host genetic modifiers of the natural history of chronic hepatitis B (CHB) remain poorly understood. Recently, a genome-wide association study (GWAS)-identified polymorphism in the STAT4 gene that contributes to the risk for hepatocellular carcinoma (HCC) was shown to be associated with the full spectrum of hepatitis B virus (HBV) outcomes in Asian patients. However, the functional mechanisms for this effect are unknown and the role of the variant in modulating HBV disease in Caucasians has not been investigated.

AIMS

To determine whether STAT4 genetic variation is associated with liver injury in Caucasian patients with CHB and to investigate potential mechanisms mediating this effect.

METHODS

STAT4 rs7574865 was genotyped in 1085 subjects (830 with CHB and 255 healthy controls). STAT4 expression in liver, PBMCs and NK cells, STAT4 phosphorylation and secretion of interferon-gamma (IFN-γ) according to STAT4 genetic variation was examined.

RESULTS

STAT4 rs7574865 genotype was independently associated with hepatic inflammation (OR: 1.42, 95% CI: 1.07-2.06, P = 0.02) and advanced fibrosis (OR: 1.83, 95% CI: 1.19-2.83, P = 0.006). The minor allele frequency of rs7574865 was significantly lower than that in healthy controls. rs7574865 GG risk carriers expressed lower levels of STAT4 in liver, PBMCs and in NK cells, while NK cells from patients with the risk genotype had impaired STAT4 phosphorylation following stimulation with IL-12/IL-18 and a reduction in secretion of IFN-γ.

CONCLUSION

Genetic susceptibility to HBV persistence, hepatic inflammation and fibrosis in Caucasians associates with STAT4 rs7574865 variant. Downstream effects on NK cell function through STAT4 phosphorylation-dependent IFN-γ production likely contribute to these effects.

A fragment of SPARC reflecting increased collagen affinity shows pathological relevance in lung cancer - implications of a new collagen chaperone function of SPARC

The matricellular protein SPARC (secreted proteome acidic and rich in cysteine) is known to bind collagens and regulate fibrillogenesis. Cleavage of SPARC at a single peptide bond, increases the affinity for collagens up to 20-fold. To investigate if this specific cleavage has pathological relevance in fibrotic disorders, we developed a competitive ELISA targeting the generated neo-epitope on the released fragment and quantified it in serum from patients with lung cancer, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD) and healthy subjects. Furthermore, the ability of SPARC to protect fibrillar collagens from proteolytic degradation was investigated in vitro, potentially adding a new collagen chaperone function to SPARC. The fragment was significantly elevated in lung cancer patients when compared to healthy subjects measured in a discovery cohort (p = 0.0005) and a validation cohort (p < 0.0001). No significant difference was observed for IPF and COPD patients compared to healthy subjects. When recombinant SPARC was incubated with type I or type III collagen and matrix metalloproteinase-9, collagen degradation was completely inhibited. Together, these data suggest that cleavage of SPARC at a specific site, which modulates collagen binding, is a physiological mechanism increased during pathogenesis of lung cancer. Furthermore, inhibition of fibrillar collagen degradation by SPARC adds a new chaperone function to SPARC which may play additional roles in the contribution to increased collagen deposition leading to a pro-fibrotic and tumorigenic environment.

Serological markers of extracellular matrix remodeling predict transplant-free survival in primary sclerosing cholangitis

BACKGROUND

Primary sclerosing cholangitis is a progressive liver disease with a remarkably variable course. Biomarkers of disease activity or prognostic models predicting outcome at an individual level are currently not established.

AIM

To evaluate the prognostic utility of four biomarkers of basement membrane and interstitial extracellular matrix remodeling in patients with primary sclerosing cholangitis.

METHODS

Serum samples were available from 138 large-duct primary sclerosing cholangitis patients (of which 102 [74%] with IBD) recruited 2008-2012 and 52 ulcerative colitis patients (controls). The median follow-up time was 2.2 (range 0-4.3) years. Specific biomarkers of type III and V collagen formation (PRO-C3 and PRO-C5, respectively) and type III and IV collagen degradation (C3M and C4M, respectively) were assessed. The Enhanced Liver Fibrosis test, including procollagen type III N-terminal peptide, tissue inhibitor of metalloproteinase-1 and hyaluronic acid was assessed for comparison.

RESULTS

All markers were elevated in primary sclerosing cholangitis compared to ulcerative colitis patients (P < 0.001). PRO-C3 showed the largest difference between the two groups with a threefold increase in primary sclerosing cholangitis compared to ulcerative colitis patients. Patients with high baseline serum levels of all markers, except C3M, had shorter survival compared to patients with low baseline serum levels (P < 0.001). Combining PRO-C3 and PRO-C5 the odds ratio for predicting transplant-free survival was 47 compared to the Enhanced Liver Fibrosis test's odds ratio of 11.

CONCLUSIONS

Extracellular matrix remodeling is elevated in primary sclerosing cholangitis patients compared to ulcerative colitis patients. Furthermore, the interstitial matrix marker PRO-C3 was identified as a potent prognostic marker and an independent predictor of transplant-free survival in primary sclerosing cholangitis.

Development of a Neo-Epitope Specific Assay for Serological Assessment of Type VII Collagen Turnover and Its Relevance in Fibroproliferative Disorders

Type VII collagen is the main component of the anchoring fibrils connecting the basement membrane to the underlying interstitial matrix. Mutations in the type VII collagen gene cause dystrophic epidermolysis bullosa. Increased levels of type VII collagen in the skin have been reported in patients with systemic sclerosis (SSc), whereas reduced levels in the airways have been related to asthma. This indicates that type VII collagen plays an important part in upholding tissue integrity and that its remodeling may lead to pathological states. The aim of this study was to investigate the role of type VII collagen remodeling in fibroproliferative disorders. We produced monoclonal antibody targeting a specific fragment of type VII collagen (C7M) released to the systemic circulation and developed a neo-epitope specific competitive enzyme-linked immunosorbent assay (ELISA). Biological relevance was evaluated in serum from patients with SSc or chronic obstructive pulmonary disease (COPD). The C7M ELISA was technically robust and specific for the C7M neo-epitope. Serum C7M levels were significantly elevated in two cohorts of patients with SSc and in patients with COPD as compared with healthy individuals (P < 0.0001). The C7M ELISA enabled quantification of type VII collagen turnover in serum. Elevated serum C7M levels indicated that the turnover rate of type VII collagen was significantly increased in patients with SSc or COPD, suggesting a pathological role. Thus, the C7M ELISA may become useful in future investigations of type VII collagen turnover in fibroproliferative disorders, and it may prove a valuable tool for evaluating novel anti-fibrotic drugs.

Acute decompensation boosts hepatic collagen type III deposition and deteriorates experimental and human cirrhosis

Patients with end-stage liver disease develop acute decompensation (AD) episodes, which become more frequent and might develop into acute-on-chronic liver failure (ACLF). However, it remains unknown how AD induces acceleration of liver disease. We hypothesized that remodeling of collagen type III plays a role in the acceleration of liver cirrhosis after AD and analyzed its formation (Pro-C3) and degradation (matrix metalloproteinase-degraded type III collagen [C3M]) markers in animal models and human disease. Bile duct ligation induced different stages of liver fibrosis in rats. Fibrosis development (hydroxyprolin content, sirius red staining, α-smooth muscle actin immunohistochemistry, messenger RNA of profibrotic cytokines), necroinflammation (aminotransferases levels), fibrolysis (matrix metalloproteinase 2 expression and activity, C1M, C4M), and Pro-C3 and C3M were analyzed 2, 3, 4, 5, and 6 weeks after bile duct ligation (n = 5 each group). In 110 patients with decompensated liver cirrhosis who underwent a transjugular intrahepatic portosystemic shunt procedure for AD, clinical and laboratory parameters as well as Pro-C3 and C3M were measured in blood samples from portal and hepatic veins and were collected just before the transjugular intrahepatic portosystemic shunt placement and 1-3 weeks later. Animal studies showed increased markers of collagen type III deposition with fibrosis, necroinflammation, and decompensation of liver cirrhosis, defined as ascites development. Higher Pro-C3 levels were associated with injury, disease severity scores (Model for End-Stage Liver Disease, Child-Pugh, chronic liver failure-C AD), ACLF development, and mortality. C3M decreased with AD and the chronic liver failure-C AD score. Collagen type III deposition ratio increased with the risk of ACLF development and mortality. Conclusion: We show for the first time that AD boosts collagen type III deposition in experimental and human cirrhosis, possibly contributing to the worsened outcome in patients with decompensated cirrhosis. (Hepatology Communications 2018;2:211-222).

Biomarkers of collagen turnover are related to annual change in FEV1 in patients with chronic obstructive pulmonary disease within the ECLIPSE study

Background

Change in forced expiratory volume in one second (FEV₁) is important for defining severity of chronic obstructive pulmonary disease (COPD). Serological neoepitope markers of collagen turnover may predict rate of change in FEV₁.

Methods

One thousand COPD subjects from the observational, multicentre, three-year ECLIPSE (Evaluation of COPD Longitudinally to Identify Predictive Surrogate Endpoints) study (NCT00292552, trial registration in February 2006) were included. Matrix metalloproteinase (MMP)-generated fragments of collagen type I, and type VI (C1M and C6M) were assessed in month six serum samples. A random-coefficient model with both a random intercept and a random slope was used to test the ability of the markers to predict post-dose bronchodilator FEV₁ (PD-FEV₁) change over two years adjusting for sex, age, BMI, smoking, bronchodilator reversibility, prior exacerbations, emphysema and chronic bronchitis status at baseline.

Results

Annual change of PD-FEV₁ was estimated from a linear model for the two-year study period. Serum C1M and C6M were independent predictors of lung function change (p = 0.007/0.005). Smoking, bronchodilator reversibility, plasma hsCRP and emphysema were also significant predictors. The effect estimate between annual change in PD-FEV₁ per one standard deviation (1SD) increase of C1M and C6M was +10.4 mL/yr. and +8.6 mL/yr. C1M, and C6M, had a significant association with baseline FEV₁.

Conclusion

We demonstrated that markers of tissue turnover were significantly associated with lung function change. These markers may function as prognostic biomarkers and possibly as efficacy biomarkers in clinical trials focusing on lung function change in COPD.

Trial registration

NCT00292552, Retrospectively registered, trial registration in February 2006.

Electronic supplementary material

The online version of this article (10.1186/s12890-017-0505-4) contains supplementary material, which is available to authorized users.

The good and the bad collagens of fibrosis - Their role in signaling and organ function

Usually the dense extracellular structure in fibrotic tissues is described as extracellular matrix (ECM) or simply as collagen. However, fibrosis is not just fibrosis, which is already exemplified by the variant morphological characteristics of fibrosis due to viral versus cholestatic, autoimmune or toxic liver injury, with reticular, chicken wire and bridging fibrosis. Importantly, the overall composition of the ECM, especially the relative amounts of the many types of collagens, which represent the most abundant ECM molecules and which centrally modulate cellular functions and physiological processes, changes dramatically during fibrosis progression. We hypothesize that there are good and bad collagens in fibrosis and that a change of location alone may change the function from good to bad. Whereas basement membrane collagen type IV anchors epithelial and other cells in a polarized manner, the interstitial fibroblast collagens type I and III do not provide directional information. In addition, feedback loops from biologically active degradation products of some collagens are examples of the importance of having the right collagen at the right place and at the right time controlling cell function, proliferation, matrix production and fate. Examples are the interstitial collagen type VI and basement membrane collagen type XVIII. Their carboxyterminal propeptides serve as an adipose tissue hormone, endotrophin, and as a regulator of angiogenesis, endostatin, respectively. We provide an overview of the 28 known collagen types and propose that the molecular composition of the ECM in fibrosis needs careful attention to assess its impact on organ function and its potential to progress or reverse. Consequently, to adequately assess fibrosis and to design optimal antifibrotic therapies, we need to dissect the molecular entity of fibrosis for the molecular composition and spatial distribution of collagens and the associated ECM.

Cathepsin-S degraded decorin are elevated in fibrotic lung disorders - development and biological validation of a new serum biomarker

Background

Decorin is one of the most abundant proteoglycans of the extracellular matrix and is mainly secreted and deposited in the interstitial matrix by fibroblasts where it plays an important role in collagen turnover and tissue homeostasis. Degradation of decorin might disturb normal tissue homeostasis contributing to extracellular matrix remodeling diseases. Here, we present the development and validation of a competitive enzyme-linked immunosorbent assay (ELISA) quantifying a specific fragment of degraded decorin, which has potential as a novel non-invasive serum biomarker for fibrotic lung disorders.

Methods

A fragment of decorin cleaved in vitro using human articular cartilage was identified by mass-spectrometry (MS/MS). Monoclonal antibodies were raised against the neo-epitope of the cleaved decorin fragment and a competitive ELISA assay (DCN-CS) was developed. The assay was evaluated by determining the inter- and intra-assay precision, dilution recovery, accuracy, analyte stability and interference. Serum levels were assessed in lung cancer patients, patients with idiopathic pulmonary fibrosis (IPF), patients with chronic obstructive pulmonary disease (COPD) and healthy controls.

Results

The DCN-CS ELISA was technically robust and was specific for decorin cleaved by cathepsin-S. DCN-CS was elevated in lung cancer patients (p < 0.0001) and IPF patients (p < 0.001) when compared to healthy controls. The diagnostic power for differentiating lung cancer patients and IPF patients from healthy controls was 0.96 and 0.77, respectively.

Conclusion

Cathepsin-S degraded decorin could be quantified in serum using the DCN-CS competitive ELISA. The clinical data indicated that degradation of decorin by cathepsin-S is an important part of the pathology of lung cancer and IPF.

Nidogen-1 Degraded by Cathepsin S can be Quantified in Serum and is Associated with Non-Small Cell Lung Cancer

Loss of basement membrane (BM) integrity is typically associated with cancer. Nidogen-1 is an essential component of the BM. Nidogen-1 is a substrate for cathepsin-S (CatS) which is released into the tumor microenvironment. Measuring nidogen-1 degraded by CatS may therefore have biomarker potential in cancer. The aim of this study was to investigate if CatS-degraded nidogen-1 was detectable in serum and a possible biomarker for cancer, a pathology associated with disruption of the BM. A competitive enzyme-linked immunosorbent assay (NIC) was developed with a monoclonal mouse antibody specific for a CatS cleavage site on human nidogen-1. Dilution and spiking recovery, inter- and intravariation, as well as accuracy were evaluated. Serum levels were evaluated in patients with breast cancer, small cell lung cancer (SCLC), and non-SCLC (NSCLC) and in healthy controls. The results indicated that the NIC assay was specific for nidogen-1 cleaved by CatS. Inter- and intraassay variations were 9% and 14%, respectively. NIC was elevated in NSCLC as compared to healthy controls (P<.001), breast cancer (P<.01), and SCLC (P<.5). The diagnostic power (area under the receiver operating characteristics) of NIC for NSCLC as compared to all other samples combined was 0.83 (95% confidence interval: 0.71-0.95), P<.0001. In conclusion, nidogen-1 degraded by CatS can be quantified in serum by the NIC assay. The current data strongly suggest that cathepsin-S degradation of nidogen-1 is strongly associated with NSCLC, which needs validation in larger clinical cohorts.

Serum endotrophin identifies optimal responders to PPARγ agonists in type 2 diabetes

AIMS/HYPOTHESIS

The treatment of type 2 diabetes with full peroxisome proliferator-activated receptor gamma (PPARγ) agonists improves insulin sensitivity, but is associated with weight gain, heart failure, peripheral oedema and bone loss. Endotrophin, the C-terminal fragment of the α3 chain of procollagen type VI (also called Pro-C6), is involved in both adipose tissue matrix remodelling and metabolic control. We established a serum assay for endotrophin to assess if this novel adipokine could identify type 2 diabetic patients who respond optimally to PPARγ agonists, improving the risk-to-benefit ratio.

METHODS

The BALLET trial (NCT00515632) compared the glucose-lowering effects and safety of the partial PPARγ agonist balaglitazone with those of pioglitazone in individuals with type 2 diabetes on stable insulin therapy. The per protocol population (n = 297) was stratified into tertiles based on baseline endotrophin levels. Participants were followed-up after 26 weeks, after which correlational analysis was carried out between endotrophin levels and measures of glucose control. This is a secondary post hoc analysis.

RESULTS

Endotrophin was significantly associated with therapeutic response to balaglitazone and pioglitazone. At week 26, only individuals in the upper two tertiles showed significant reductions in HbA_1c and fasting serum glucose compared with baseline. The OR for a 1% and a 0.5% reduction in HbA_1c for individuals in the upper two tertiles were 3.83 (95% CI 1.62, 9.04) p < 0.01, and 3.85 (95% CI 1.94, 7.61) p < 0.001, respectively. Endotrophin levels correlated with adipose tissue mass, insulin resistance and fatty liver index. Notably, PPARγ-associated adverse effects, such as moderate-to-severe lower extremity oedema, only occurred in the lower tertile.

CONCLUSIONS/INTERPRETATION

Elevated endotrophin serum levels predict response to two insulin sensitisers and reduce the risk of associated adverse effects, thereby, identifying patients with type 2 diabetes who may profit from PPARγ agonist treatment.