The HCV serum proteome: a search for fibrosis protein markers

SWOT analysis of noninvasive tests for diagnosing NAFLD with severe fibrosis: an expert review by the JANIT Forum

Nonalcoholic fatty liver disease (NAFLD) is the most common chronic liver disease. Nonalcoholic steatohepatitis (NASH) is an advanced form of NAFLD can progress to liver cirrhosis and hepatocellular carcinoma (HCC). Recently, the prognosis of NAFLD/NASH has been reported to be dependent on liver fibrosis degree. Liver biopsy remains the gold standard, but it has several issues that must be addressed, including its invasiveness, cost, and inter-observer diagnosis variability. To solve these issues, a variety of noninvasive tests (NITs) have been in development for the assessment of NAFLD progression, including blood biomarkers and imaging methods, although the use of NITs varies around the world. The aim of the Japan NASH NIT (JANIT) Forum organized in 2020 is to advance the development of various NITs to assess disease severity and/or response to treatment in NAFLD patients from a scientific perspective through multi-stakeholder dialogue with open innovation, including clinicians with expertise in NAFLD/NASH, companies that develop medical devices and biomarkers, and professionals in the pharmaceutical industry. In addition to conventional NITs, artificial intelligence will soon be deployed in many areas of the NAFLD landscape. To discuss the characteristics of each NIT, we conducted a SWOT (strengths, weaknesses, opportunities, and threats) analysis in this study with the 36 JANIT Forum members (16 physicians and 20 company representatives). Based on this SWOT analysis, the JANIT Forum identified currently available NITs able to accurately select NAFLD patients at high risk of NASH for HCC surveillance/therapeutic intervention and evaluate the effectiveness of therapeutic interventions.

Perspectives on pediatric congenital aortic valve stenosis: Extracellular matrix proteins, post translational modifications, and proteomic strategies

In heart valve biology, organization of the extracellular matrix structure is directly correlated to valve function. This is especially true in cases of pediatric congenital aortic valve stenosis (pCAVS), in which extracellular matrix (ECM) dysregulation is a hallmark of the disease, eventually leading to left ventricular hypertrophy and heart failure. Therapeutic strategies are limited, especially in pediatric cases in which mechanical and tissue engineered valve replacements may not be a suitable option. By identifying mechanisms of translational and post-translational dysregulation of ECM in CAVS, potential drug targets can be identified, and better bioengineered solutions can be developed. In this review, we summarize current knowledge regarding ECM proteins and their post translational modifications (PTMs) during aortic valve development and disease and contributing factors to ECM dysregulation in CAVS. Additionally, we aim to draw parallels between other fibrotic disease and contributions to ECM post-translational modifications. Finally, we explore the current treatment options in pediatrics and identify how the field of proteomics has advanced in recent years, highlighting novel characterization methods of ECM and PTMs that may be used to identify potential therapeutic strategies relevant to pCAVS.

Serum amyloid P component and pro-platelet basic protein in extracellular vesicles or serum are novel markers of liver fibrosis in chronic hepatitis C patients

Extracellular vesicles (EVs) contain proteins, mRNAs, and microRNAs, and their cargos have emerged as novel diagnostic markers in various diseases. We aimed to discover novel and noninvasive biomarkers of liver fibrosis by proteomic analysis using serum EVs in patients with chronic hepatitis C. We performed shotgun proteomics using serum EVs isolated from 54 patients with histologically assessed liver fibrosis. Shotgun proteomics identified a total of 974 proteins, and 445 proteins were detected in more than half of the patients. Among them, a total of 9 proteins were identified as proteins that tended to increase or decrease with liver fibrosis with a significance of p<0.005 and that were different between F1-2 patients and F3-4 patients with a significance of p<0.01. Among the 9 proteins, targeted proteomics using serum EVs isolated from the sera of another 80 patients with histologically assessed liver fibrosis verified that serum amyloid P component (SAP) and pro-platelet basic protein (PPBP) levels in EVs significantly decreased with the progression of liver fibrosis and were significantly lower in F3-4 patients than in F1-2 patients. The diagnostic accuracies of SAP and PPBP in EVs for the liver fibrosis stage were comparable to those of type IV collagen 7S, hyaluronic acid, and the fibrosis-4 index (FIB-4 index). Moreover, serum SAP and PPBP levels correlated with the levels in EVs, and the ability of serum SAP and PPBP to diagnose liver fibrosis stage was also comparable to the abilities of type IV collagen 7S, hyaluronic acid, and the FIB-4 index. In conclusion, proteomic analysis of serum EVs identified SAP and PPBP as candidate biomarkers for predicting liver fibrosis in patients with chronic hepatitis C. In addition, SAP and PPBP levels in serum are strongly correlated with those in EVs and could represent markers of liver fibrosis.

Serum Mac-2 binding protein level predicts the development of liver-related events and colorectal cancer in patients with NAFLD

We previously demonstrated that Mac-2 binding protein (M2BP) is a useful biomarker for nonalcoholic fatty liver disease (NAFLD), particularly NAFLD fibrosis prediction. In the present study, we investigated the prognostic value of M2BP in patients with NAFLD. A total of 506 patients with biopsy-confirmed NAFLD from 2002 to 2013 were enrolled in this study in Japan. Three hundred fifty-three of these patients with NAFLD were available for follow-up for more than 100 days and showed no liver-related events at the time of entry. Liver-related events were defined as hepatocellular carcinoma (HCC), decompensation, and gastroesophageal varices with variceal treatment. The mean follow-up duration of all the subjects was 2716 ± 1621 days (102-7483 days). Eighteen patients developed new liver-related events (HCC, 8; decompensation, 11; varices, 8). Nine patients developed cardiovascular disease (CVD), and 24 patients developed new cancers in other organs. The median serum M2BP level was 1.603 μg/mL, and we divided our cohort into two groups according to the serum M2BP level: M2BP low group (M2BP Low) and M2BP high group (M2BP Hi). The incidence of HCC was significantly higher in M2BP Hi (n = 8) than in M2BP Low (n = 0). The incidence of liver-related events was significantly higher in M2BP Hi (n = 16) than in M2BP Low (n = 2). The incidences of death, CVD events, and cancer in other organs were not different between the groups. Interestingly, the incidence of colorectal cancer was significantly higher in M2BP Hi (n = 5) than in M2BP Low (n = 0). Conclusion: M2BP is a useful biomarker to predict liver-related events, particularly HCC. Additionally, M2BP is a potential predictive biomarker of colorectal cancer development.

Identification of the suitable candidates for EOB-MRI with the high risk of the presence of non-hypervascular hypointense nodules in patients with HCV infection

OBJECTIVES

Non-hypervascular hypointense nodules (NHHNs) depicted by gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid-enhanced magnetic resonance imaging (EOB-MRI) have a high likelihood of progressing to hepatocellular carcinoma (HCC). The presence of NHHNs is a strong risk factor for HCC development in patients with chronic hepatitis C virus (HCV) infection after the achievement of sustained virologic response (SVR). However, it is difficult for all patients with HCV infection to undergo EOB-MRI for NHHN detection. We therefore explored serum markers that potentially indicate the presence of NHHNs.

METHODS

Three serum markers, alpha-fetoprotein (AFP), FIB-4 index, and Wisteria floribunda agglutinin-positive Mac-2 binding protein glycan isomer (M2BPGi), were measured in 481 patients with HCV infection and no history of HCC who underwent EOB-MRI. The associations between these serum marker levels and the presence of NHHNs were investigated.

RESULTS

All three markers were associated with the presence of NHHNs. M2BPGi predicted the presence of NHHNs more accurately than AFP and FBB-4 index; M2BPGi had the highest area under the receiver operating characteristic curve. Multivariate analysis identified male gender and high M2BPGi as factors associated with the presence of NHHNs. When patients were stratified by the degree of liver fibrosis, M2BPGi increased with the progression of fibrosis. In addition, NHHNs were more prevalently detected in patients with higher M2BPGi (COI > 3.46) in patients with similar fibrosis degree.

CONCLUSIONS

M2BPGi is a serum marker that potentially identifies HCV patients with high risk of the presence of NHHNs, for whom EOB-MRI should be considered.

KEY POINTS

• Non-hypervascular hypointense nodule on EOB-DTPA-enhanced MRI is pre-HCC nodule with high likelihood of progressing to HCC, which is a strong predictor for HCC that develops after the eradication of HCV in patients with HCV infection. • It is difficult for all patients with HCV infection to undergo EOB-MRI for NHHN detection due to limited access, limited availability of MRI equipment, and high costs. • Serum Wisteria floribunda agglutinin-positive Mac-2 binding protein glycan isomer (M2BPGi) levels effectively indicate the presence of NHHNs and can be used to identify patients with high risk of their presence, for whom EOB-DTPA-enhanced MRI should be considered.

Precise Investigation of the Efficacy of Multicomponent Drugs Against Pneumonia Infected With Influenza Virus

Background: Viral pneumonia is one of the most serious respiratory diseases, and multicomponent traditional Chinese medicines have been applied in the management of infected patients. As a representative TCM, HouYanQing (HYQ) oral liquid shows antiviral activity. However, the unclear mechanisms, as well as the ambiguous clinical effects, limit widespread application of this treatment. Therefore, in this study, a proteomics-based approach was utilized to precisely investigate its efficacy.

Methods: Based on the efficacy evaluation of HYQ in a mouse model of pneumonia caused by influenza A virus (H1N1) and the subsequent proteomics analysis, specific signatures regulated by HYQ treatment of viral pneumonia were identified.

Results: Experimental verifications indicate that HYQ may show distinctive effects in viral pneumonia patients, such as elevated galectin-3-binding protein and glutathione peroxidase 3 levels.

Conclusion: This study provides a precise investigation of the efficacy of a multicomponent drug against viral pneumonia and offers a promising alternative for personalized management of viral pneumonia.

N-glycan structures of Wisteria floribunda agglutinin-positive Mac2 binding protein in the serum of patients with liver fibrosis†

The extent of liver fibrosis predicts prognosis and is important for determining treatment strategies for chronic hepatitis. During the fibrosis progression, serum levels of Mac2 binding protein (M2BP) increase and the N-glycan structure changes to enable binding to Wisteria floribunda agglutinin (WFA) lectin. As a novel diagnostic marker, glycosylation isomer of M2BP (M2BPGi) has been developed. However, its glycan structures recognized by WFA are unclear. In this study, we analyzed site-specific N-glycan structures of serum M2BP using Glyco-RIDGE (Glycan heterogeneity-based Relational IDentification of Glycopeptide signals on Elution profile) method. We evaluated five sample types: 1) M2BP immunoprecipitated from normal healthy sera (NHS-IP(+)), 2) M2BP immunoprecipitated from sera of patients with liver cirrhosis (stage 4; F4-IP(+)), 3) M2BP captured with WFA from serum of patients with liver cirrhosis (stage 4; F4-WFA(+)), 4) recombinant M2BP produced by HEK293 cells (rM2BP), and 5) WFA-captured rM2BP (rM2BP-WFA(+)). In NHS-IP(+) M2BP, bi-antennary N-glycan was the main structure, and LacNAc extended to its branches. In F4-IP(+) M2BP, many branched structures, including tri-antennary and tetra-antennary N-glycans, were found. F4-WFA(+) showed a remarkable increase in branched structures relative to the quantity before enrichment. In recombinant M2BP, both no sialylated-LacdiNAc and -branched LacNAc structures were emerged. The LacdiNAc structure was not found in serum M2BP. Glycosidase-assisted HISCL assays suggest that, reactivity with WFA of both serum and recombinant M2BP depends on unsialylated and branched LacNAc, and in part of recombinant, depends on LacdiNAc. On M2BPGi, the highly branched LacNAc, probably dense cluster of LacNAc, would be recognized by WFA.

Mapping Novel Biomarkers of Liver Injury by Tissue Proteomic Analysis

Liver damage is a dynamic process, and evaluation of liver injury degree is the key step in disease diagnosis. However, few common markers among different types of liver injury have been reported. Herein, we generated three liver injury mouse models, including Con A-induced, CCl₄-injected, and subjected bile duct ligation mouse models, to simulate different types of liver damage in humans and then performed a label-free mass spectrometry to identify differentially expressed proteins in liver tissues. Interestingly, two proteins, G3BP and ABCC6, were conserved regulated in different liver injury models and are proposed to be biomarkers in liver injury, with G3BP upregulated and ABCC6 downregulated. Overall, our study identified two novel biomarkers of liver injury, and they might be used as potential drug targets of liver damage research studies.

Serum Mac-2 Binding Protein Levels Associate with Metabolic Parameters and Predict Liver Fibrosis Progression in Subjects with Fatty Liver Disease: A 7-Year Longitudinal Study

Background: Mac-2 binding protein (M2BP) is a highly glycosylated secreted glycoprotein that is involved in immune defense and regulation. Our cross-sectional studies indicated that serum M2BP was a useful liver fibrosis biomarker for nonalcoholic fatty liver disease (NAFLD). In this study, we conducted a 7-year longitudinal study to investigate the significance of serum M2BP levels (baseline and at 7-year follow-up) and their relationships with other metabolic parameters of fatty liver disease. Methods: We enrolled 715 study subjects (521 male and 194 female) during health examinations. Study subjects received blood sampling tests and abdominal ultrasound tests at baseline and follow-up. Results: Univariate analyses demonstrated that serum M2BP levels were significantly correlated with various parameters related to metabolic risk (body mass index (BMI), systolic blood pressure, triglyceride, high density lipoprotein (HDL)-cholesterol) and metabolic syndrome diseases (obesity, hypertension, dyslipidemia, diabetes mellitus, fatty liver (FL)). Multiple logistic regression analyses demonstrated that BMI and FL were independent determinants for serum M2BP levels. Baseline serum M2BP levels were significant independent determinants for changes in platelet count, Fibrosis-4 (FIB4) index, and NAFLD fibrosis score. Higher serum M2BP levels (>1.80 μg/mL) strongly correlated with changes in the FIB4-index. Conclusions: The results of this study suggest that changes in serum M2BP levels reflect changes in specific metabolic disease-related parameters, and baseline serum M2BP levels could predict changes in liver fibrosis.

Diagnostic performance of Mac-2 binding protein glycosylation isomer (M2BPGi) in screening liver fibrosis in health checkups

BACKGROUND

Mild-to-moderate fibrosis is rarely diagnosed because the disease is asymptomatic in the early stage. The serum level of Mac-2 binding protein glycosylation isomer (M2BPGi) has been found to increase with the severity of liver fibrosis. The aim of this study was to determine the diagnostic performance of M2BPGi in screening liver fibrosis using magnetic resonance elastography (MRE) as a reference standard and to compare it with using the aspartate aminotransferase-to-platelet ratio (APRI) and the Fibrosis-4 index (FIB-4) in health checkups.

METHODS

This cross-sectional study consecutively selected subjects at health examinations who underwent MRE and M2BPGi testing at eight health promotion centers in Korea between January and September 2019. The serum M2BPGi level was measured using the chemiluminescence enzyme immunoassay method. The measured levels were indexed using the cutoff index (COI). COI values of M2BPGi were compared with the MRE results.

RESULTS

The median (interquartile) values of COI for fibrosis stages F0 (normal liver stiffness), F1 (mild fibrosis), F2 (significant fibrosis), and ≥F3 (advanced fibrosis) were 0.49 (0.34-0.61), 0.48 (0.38-0.68), 0.64 (0.43-1.03), and 1.01 (0.75-1.77), respectively (P < .0001). The AUCs of the COI for the screening of fibrosis stage ≥F1, ≥F2, and ≥F3 were 0.591, 0.698, and 0.853, respectively. Using a threshold of 0.75 for COI to exclude advanced fibrosis had a sensitivity, specificity, and negative predictive value of 80.0%, 77.9%, and 98.9%, respectively. The AUC for excluding advanced fibrosis was better for M2BPGi than for FIB-4 and APRI.

CONCLUSION

Serum M2BPGi was useful for screening significant and advanced fibrosis in health checkups.

Mac-2 binding protein in non-alcoholic fatty liver disease: Is it a reliable diagnostic biomarker? A pilot study

Aim of the study

This study aimed to assess the level of serum Mac-2 binding protein (Mac-2BP) as a non-invasive biomarker for the diagnosis of non-alcoholic fatty liver disease (NAFLD).

Material and methods

Forty patients with NAFLD and 15 healthy sex- and age-matched subjects were included in this pilot study. Serum Mac-2BP level was measured using ELISA. Liver biopsy was taken from 20 patients.

Results

There was no statistically significant difference between patients and controls regarding the level of Mac-2BP (p = 0.209). Mac-2BP had a statistically significant correlation with the grade of lobular inflammation (r = 0.464, p = 0.039). The Mac-2BP cut-off value used for NASH prediction was 9.55 µg/ml, with sensitivity and specificity of 100% and 91.7%, respectively.

Conclusions

This study showed that Mac-2BP is not elevated in NAFLD patients compared to controls. It also demonstrated that the reliability of Mac-2BP as a biomarker for NAFLD diagnosis is still controversial and needs more investigation.

Wisteria floribunda agglutinin-positive Mac-2-binding protein and type 4 collagen 7S: useful markers for the diagnosis of significant fibrosis in patients with non-alcoholic fatty liver disease

BACKGROUND AND AIM

The fibrosis stage of liver is associated with the long-term outcomes in patients with non-alcoholic fatty liver disease (NAFLD). However, significant fibrosis, defined as fibrosis stages 2-4, is associated with an elevated risk of progression to severe liver disease; there have been scant reports about diagnosing significant fibrosis. We compare the noninvasive method and aim to identify appropriate liver fibrosis markers for detecting significant fibrosis in NAFLD patients.

METHODS

We compared the usefulness of liver fibrosis markers (Wisteria floribunda agglutinin-positive Mac-2-binding protein [WFA⁺ -M2BP], type 4 collagen 7S, etc.), clinical scoring systems, and liver stiffness measurement obtained using vibration-controlled transient elastography and magnetic resonance imaging-based magnetic resonance elastography in the same individuals and identified the most appropriate noninvasive method for detecting significant fibrosis in 165 patients with liver biopsy-diagnosed NAFLD.

RESULTS

The area under the receiver operating characteristic curve based on the serum cutoff index values of WFA⁺ -M2BP/the serum levels of type IV collagen 7S for the diagnosis of significant fibrosis was 0.832 (95% confidence interval: 0.771-0.894)/0.837 (95% confidence interval: 0.778-0.898). "WFA⁺ -M2BP (cutoff index) ≥ 0.83 or type IV collagen 7S ≥ 5.2 ng/mL" showed a high sensitivity (91.4%) and negative predictive value (87.9%) for the diagnosis of significant fibrosis.

CONCLUSIONS

We showed that serum WFA⁺ -M2BP or type IV collagen 7S levels serve as useful independent markers for detecting significant fibrosis and that use of both WFA⁺ -M2BP and type IV collagen 7S together increased the sensitivity and negative predictive value for the diagnosis of liver fibrosis. These results need to be validated in larger populations from multiple clinical centers.

Candidate Biomarkers of Liver Fibrosis: A Concise, Pathophysiology-oriented Review

Repair of sustained liver injury results in fibrosis (i.e. the accumulation of extracellular matrix proteins), and ultimately the complete distortion of parenchymal architecture of the liver, which we call cirrhosis. Detecting and staging of fibrosis is thus a mainstay in the management of chronic liver diseases, since many clinically relevant decisions, such as starting treatment and/or monitoring for complications including hepatocellular carcinoma, may depend on it. The gold standard for fibrosis staging is liver biopsy, the role of which, however, is questioned nowadays because of cost, hazards and poor acceptance by patients. On the other hand, imaging techniques and/or measurement of direct and indirect serum markers have not proved to be completely satisfactory under all circumstances as alternatives to liver biopsy. Making progress in this field is now more crucial than ever, since treatments for established fibrosis appear on the horizon. Fine dissection of the pathways involved in the pathophysiology of liver diseases has put forward several novel candidate biomarkers of liver fibrosis, such as growth arrest-specific6, Mac-2-binding protein, osteopontin, placental growth factor, growth/differentiation factor 15 and hepatocyte growth factor. All molecules have been suggested to have potential to complement or substitute methods currently used to stage liver diseases. Here, we review the pros and cons for their use in this setting.

Serum quantitative proteomic analysis of patients with keshan disease based on iTRAQ labeling technique: A first term study

Keshan disease (KD), an endemic myocardiopathy, with unknown etiology, is still threatening human health. Proteomics studies of Keshan disease is rarely known. In the current study, isobaric tags for relative and absolute quantitation (iTRAQ) labeling coupled with two-dimensional liquid chromatography-tandem mass spectrometry (2D-LC-MS/MS) was firstly used to screen for the differentially expressed proteins (DEPs) in serum between Keshan disease and healthy residents in endemic area. 27 differentially expressed proteins were quantified, 9 of which were significantly altered (fold change > 1.2 or < 0.8) between the two groups. Bioinformatic analysis revealed that a wide variety of biology process played roles in KD pathophysiology. These differentially expressed proteins were mainly involved in complement coagulation pathways. A significant high serum level of LGALS3BP were observed. Our first term study in KD proteomics provided new view into the molecular mechanisms of KD disease.

Preliminary quantitative proteomics analysis in chronic and latent Keshan disease by iTRAQ labeling approach

Keshan disease is a congestive cardiomyopathy. Dietary selenium deficiency combined with additional stressors are recognized to cause the cardiomyopathies. In this study, clinical condition of individuals with different subtypes including chronic and latent were analyzed. ECG abnormalities, chest radiography, echocardiography and blood selenium concentration were assessed. Subsequently, in effort to uncover proteins that were reliably changed in patients, isobaric tags for absolute and relative quantitation technology was applied. Bioinformatics analysis of the differentially expressed proteins were performed by means of Gene Ontology classification, KEGG pathway, and Ingenuity Pathway Analysis. ELISA experiment was used to detect the interesting proteins. As a result, chronic patients showed more EGC abnormalities compared to Latent. All patients had low blood selenium level. Proteomics data revealed 28 differentially expressed proteins. By ELISA variation, LGALS3BP was increased in chronic patients. PZP was elevated specially in latent patients. The above results might be beneficial for further biomarkers discovery and Keshan disease pathological mechanism study.

Serum Levels of M2BPGi as Short-Term Predictors of Hepatocellular Carcinoma in Untreated Chronic Hepatitis B Patients

This study examines the role of M2BPGi, a novel seromarker for chronic hepatitis, in predicting hepatocellular carcinoma (HCC) among untreated chronic hepatitis B (CHB) patients. In this nested case-control study, 1070 samples were assayed for M2BPGi, including 357 samples from HCC cases, and 713 samples from non-HCC controls, collected at various times throughout follow-up. HCC case samples were stratified according to years prior to diagnosis. Associations between M2BPGi and HCC were examined with multivariate logistic regression. M2BPGi, α-fetoprotein (AFP), and hepatitis B surface antigen (HBsAg) levels were significant independent short-term predictors of HCC, while M2BPGi was insignificant in long-term analyses. Compared to M2BPGi levels <1.0 cut-off index (COI), those with levels ≥2.0 COI had multivariate odds ratios (95% CI) for HCC of 7.40 (2.40-22.78), 6.46 (2.58-16.18), and 2.24 (0.97-5.15), respectively, for prediction of HCC within 1-2, 2-5, and ≥5 years. Higher proportions of individuals had M2BPGi levels ≥2.0 COI in samples closer to HCC diagnosis. Areas under receiver operating characteristic curves for models with M2BPGi, AFP, and HBsAg levels predicting HCC within 1-2, 2-5, and >5 years were 0.84, 0.81, and 0.75. M2BPGi is a strong and independent short-term predictor of HCC in CHB patients.

Use of Mac-2 binding protein as a biomarker for nonalcoholic fatty liver disease diagnosis

In contrast to patients with viral hepatitis, patients with nonalcoholic fatty liver disease (NAFLD) can progress to hepatocellular carcinoma during the initial stages of liver fibrosis. Development and implementation of noninvasive methods for diagnosis and progression prediction are important for effective NAFLD surveillance. Mac-2 binding protein (Mac-2bp) is a useful nonalcoholic steatohepatitis (NASH) diagnosis biomarker and a powerful prediction biomarker for NAFLD fibrosis stage. Wisteria floribunda agglutinin (WFA)-positive Mac-2bp (WFA+-M2BP) is a novel serum fibrosis biomarker for chronic hepatitis C that has clinical validity. Mac-2bp and WFA+-M2BP are also clinical NAFLD biomarker candidates. We examined the efficacy of Mac-2bp and WFA+-M2BP for NAFLD assessment using patients with biopsy-proven NAFLD (n = 510; NAFLD cohort) and subjects who received a health check-up (n = 2,122; check-up cohort). In the NAFLD cohort, we set the fibrosis predicting cutoff values as 1.80 (F1), 2.21 (F2), and 2.24 μg/mL (F3). In the subjects with fatty liver from the check-up cohort (n = 1,291), the serum Mac-2bp levels were >1.80 μg/mL in 38.6% of the subjects (n = 498), and >2.24 μg/mL in 24.6% of the subjects (n = 318). The NAFLD cohort results indicated that Mac-2bp and WFA+-M2BP were equally useful for NASH diagnosis. During the early stages of fibrosis (F1, F2), the increase in Mac-2bp was statistically significant but WFA+-M2BP did not increase. Logistic regression analysis revealed that Mac-2bp was an independent determinant for the prediction of advanced fibrosis stage (≥F2), even when adjusted for WFA+-M2BP. Immunohistochemical staining of Mac-2bp revealed that hepatocytes strongly expressed Mac-2bp in patients with NAFLD. Conclusion: Our results indicated that hepatocyte-derived Mac-2bp would be a useful single biomarker for NASH diagnosis and fibrosis stage prediction in patients with NAFLD. (Hepatology Communications 2017;1:780-791).

Establishment of mouse Mac-2 binding protein enzyme-linked immunosorbent assay and its application for mouse chronic liver disease models

AIM

We identified Mac-2 (galectin-3) binding protein (Mac-2bp) as a novel diagnostic and liver fibrosis predicting biomarker for nonalcoholic steatohepatitis in humans. In mouse models, there are no serum biomarkers predicting liver disease severity. In this study, we developed a mouse Mac-2bp enzyme-linked immunosorbent assay (ELISA) system and determined its efficacy for predicting the severity of liver disease in mouse models, especially in non-alcoholic fatty liver disease (NAFLD) models.

METHODS

We established several rat monoclonal antibodies against mouse Mac-2bp, selected two clones for the ELISA, and checked the accuracy and reproducibility of the ELISA, especially for NAFLD models and liver fibrosis models. We also investigated the relationships between serum levels and hepatic gene expression of Mac-2bp in mouse models.

RESULTS

Our ELISA system had high accuracy and reproducibility (R²  = 0.999). The intra-assay and inter-assay results for the coefficient of variation were 2.0-3.7% and 1.7-6.9%, respectively. The levels of bilirubin, hemoglobin, and chyle did not affect the Mac-2bp serum levels detected by our ELISA kit. In the mouse models, serum Mac-2bp levels increased with liver disease progression (F0/F1/F2/F3, 239.1 ± 36.7 / 259.1 ± 43.0 / 457.5 ± 162.0 / 643.7 ± 116.0 ng/mL; P < 0.0001), and were significantly correlated with hepatic gene expression of Mac-2bp (R = 0.42, P < 0.0001).

CONCLUSION

Our mouse Mac-2bp ELISA system effectively predicts severity of NAFLD and liver fibrosis in mouse models.

Serum levels of Wisteria floribunda agglutinin-positive Mac-2 binding protein reflect the severity of chronic pancreatitis

OBJECTIVES

To evaluate the utility of serum Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA ⁺ -M2BP) level as a marker for chronic pancreatitis (CP).

METHODS

We measured the serum WFA⁺ -M2BP level of 74 patients with CP who had undergone endoscopic retrograde cholangiopancreatography and 30 normal controls (NC) using a glycan sugar chain-based immunoassay and investigated the relationship between serum WFA⁺ -M2BP levels and the Cambridge classification of CP.

RESULTS

Serum WFA⁺ -M2BP level was significantly higher in patients with CP than in NC (0.64 ± 0.28 vs 0.34 ± 0.25, P < 0.001). The levels (expressed as cut-off index) of WFA⁺ -M2BP for the classification of mild, moderate and marked CP were 0.44, 0.63 and 0.87, respectively. Thus, serum WFA⁺ -M2BP levels increased with increasing CP severity. With a cut-off value of 0.34, 0.59 and 0.61, the area under the receiver operating characteristic curve, sensitivity and specificity were 0.829, 91.9% and 63.3% for mild CP; 0.891, 81.8% and 85.0% for moderate CP; and 0.888, 92.0% and 74.7% for marked CP, respectively. Multivariate analysis revealed that elevated serum WFA⁺ -M2BP was independently associated with moderate and marked CP, respectively.

CONCLUSION

Serum WFA⁺ -M2BP level is a useful marker for grading CP severity.

Proteomic profiling of HBV infected liver biopsies with different fibrotic stages

Background

Hepatitis B virus (HBV) is a global health problem, and infected patients if left untreated may develop cirrhosis and eventually hepatocellular carcinoma. This study aims to enlighten pathways associated with HBV related liver fibrosis for delineation of potential new therapeutic targets and biomarkers.

Methods

Tissue samples from 47 HBV infected patients with different fibrotic stages (F1 to F6) were enrolled for 2D-DIGE proteomic screening. Differentially expressed proteins were identified by mass spectrometry and verified by western blotting. Functional proteomic associations were analyzed by EnrichNet application.

Results

Fibrotic stage variations were observed for apolipoprotein A1 (APOA1), pyruvate kinase PKM (KPYM), glyceraldehyde 3-phospahate dehydrogenase (GAPDH), glutamate dehydrogenase (DHE3), aldehyde dehydrogenase (ALDH2), alcohol dehydrogenase (ALDH1A1), transferrin (TRFE), peroxiredoxin 3 (PRDX3), phenazine biosynthesis-like domain-containing protein (PBLD), immuglobulin kappa chain C region (IGKC), annexin A4 (ANXA4), keratin 5 (KRT5). Enrichment analysis with Reactome and Kegg databases highlighted the possible involvement of platelet release, glycolysis and HDL mediated lipid transport pathways. Moreover, string analysis revealed that HIF-1α (Hypoxia-inducible factor 1-alpha), one of the interacting partners of HBx (Hepatitis B X protein), may play a role in the altered glycolytic response and oxidative stress observed in liver fibrosis.

Conclusions

To our knowledge, this is the first protomic research that studies HBV infected fibrotic human liver tissues to investigate alterations in protein levels and affected pathways among different fibrotic stages. Observed changes in the glycolytic pathway caused by HBx presence and therefore its interactions with HIF-1α can be a target pathway for novel therapeutic purposes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12953-017-0114-4) contains supplementary material, which is available to authorized users.

Serum WFA+ -M2BP levels for evaluation of early stages of liver fibrosis in patients with chronic hepatitis B virus infection

BACKGROUND & AIMS

Accurate evaluation of liver fibrosis is crucial for predicting progression of chronic hepatitis B virus (HBV) infection. We assessed the utility of a novel fibrosis glycobiomarker Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA⁺ -M2BP) for evaluating liver fibrosis and disease progression in patients with chronic HBV infection.

METHODS

We enrolled 774 patients with chronic HBV infection, with or without fibrosis, diagnosed by liver biopsy/FibroScan. Patients who underwent liver biopsy (n = 297) were divided into training (n = 221) and validation (n = 76) groups. Serum WFA⁺ -M2BP values were measured and compared with FIB-4 index, aspartate aminotransferase (AST)-to-platelet ratio (APRI) and AST-to-alanine aminotransferase ratio (AAR) using receiver-operating characteristic (ROC) analysis.

RESULTS

Serum WFA⁺ -M2BP levels increased significantly with fibrosis progression (P < 0.0001). Area under the ROC curve of WFA⁺ -M2BP for diagnosing significant fibrosis was higher than that of FIB-4 (P = 0.198), APRI (P = 0.017) and AAR (P < 0.001), with sensitivity and specificity in the training set of 60.5% and 79.8% and validation set of 59.5% and 82.1%, respectively. Serum WFA⁺ -M2BP levels were significantly correlated with FibroScan values (P < 0.0001) and improved the accuracy of FibroScan in assessing significant fibrosis. Changes in WFA⁺ -M2BP levels were parallel with those in FibroScan values during nucleot(s)ide analogues therapy in patients with chronic HBV infection.

CONCLUSIONS

WFA⁺ -M2BP is an accurate serum indicator for assessing early stages of liver fibrosis and may monitor regression of fibrosis during the treatment of chronic HBV infection. WFA⁺ -M2BP provides a simple and reliable alternative or complementary method to liver biopsy and FibroScan.

iTRAQ-Based Proteomics Identification of Serum Biomarkers of Two Chronic Hepatitis B Subtypes Diagnosed by Traditional Chinese Medicine

Background. Chronic infection with hepatitis B virus (HBV) is a leading cause of cirrhosis and hepatocellular carcinoma. By traditional Chinese medicine (TCM) pattern classification, damp heat stasis in the middle-jiao (DHSM) and liver Qi stagnation and spleen deficiency (LSSD) are two most common subtypes of CHB. Results. In this study, we employed iTRAQ proteomics technology to identify potential serum protein biomarkers in 30 LSSD-CHB and 30 DHSM-CHB patients. Of the total 842 detected proteins, 273 and 345 were differentially expressed in LSSD-CHB and DHSM-CHB patients compared to healthy controls, respectively. LSSD-CHB and DHSM-CHB shared 142 upregulated and 84 downregulated proteins, of which several proteins have been reported to be candidate biomarkers, including immunoglobulin (Ig) related proteins, complement components, apolipoproteins, heat shock proteins, insulin-like growth factor binding protein, and alpha-2-macroglobulin. In addition, we identified that proteins might be potential biomarkers to distinguish LSSD-CHB from DHSM-CHB, such as A0A0A0MS51_HUMAN (gelsolin), PON3_HUMAN, Q96K68_HUMAN, and TRPM8_HUMAN that were differentially expressed exclusively in LSSD-CHB patients and A0A087WT59_HUMAN (transthyretin), ITIH1_HUMAN, TSP1_HUMAN, CO5_HUMAN, and ALBU_HUMAN that were differentially expressed specifically in DHSM-CHB patients. Conclusion. This is the first time to report serum proteins in CHB subtype patients. Our findings provide potential biomarkers can be used for LSSD-CHB and DHSM-CHB.

Serum WFA+ -M2BP levels as a prognostic factor in patients with early hepatocellular carcinoma undergoing curative resection

BACKGROUND & AIMS

Serum tumour markers for hepatocellular carcinoma (HCC) have less prognostic significance in early stage. Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA(+) -M2BP) levels are reportedly associated with hepatocarcinogenic potential in patients with chronic liver diseases. We investigated the prognostic significance of pretreatment serum WFA(+) -M2BP levels in patients with early-stage HCC.

METHODS

A total of 240 patients who underwent hepatic resection for naïve Barcelona Clinic Liver Cancer (BCLC) class 0 or A HCC were analysed. WFA(+) -M2BP and tumour markers for HCC were measured from serum obtained just prior to treatment. Post-operative recurrence and survival rates were compared according to these serum markers, tumour stage and Child-Pugh class.

RESULTS

There was an association between serum WFA(+) -M2BP levels and the fibrosis grade of resected noncancerous liver tissue, whereas no association was found between WFA(+) -M2BP levels and tumour progression or liver function. In a multivariate analysis, pretreatment serum WFA(+) -M2BP level was associated with recurrence and survival, respectively, independent of HCC progression or fibrosis grade of resected noncancerous liver tissue. Recurrence rates after hepatic resection were significantly higher in patients with a pretreatment serum WFA(+) -M2BP ≥ 3.00 than those with a pretreatment serum WFA(+) -M2BP < 3.00 (P = 0.0038). Survival rates were lower in patients with a pretreatment serum WFA(+) -M2BP ≥ 3.00 than those with a pretreatment serum WFA(+) -M2BP < 3.00 (P = 0.0187).

CONCLUSIONS

Serum WFA(+) -M2BP level is a prognostic factor for recurrence and survival, in addition to tumour progression and liver function, in patients with early-stage HCC treated with curative hepatic resection.

Clinicopathological characteristics and diagnostic performance of Wisteria floribunda agglutinin positive Mac-2-binding protein as a preoperative serum marker of liver fibrosis in hepatocellular carcinoma

BACKGROUND

Wisteria floribunda agglutinin positive Mac-2-binding protein (WFA(+)-M2BP) is a novel serum marker of liver fibrosis identified in glycoproteomic biomarker screening studies, and its clinicopathological characteristics have yet to be elucidated sufficiently for clinical utilization.

METHODS

We retrospectively analyzed the clinicopathology data and serum WFA(+)-M2BP levels in 376 hepatocellular carcinoma patients undergoing liver surgery. WFA(+)-M2BP was quantified in frozen serum samples collected at the time of surgery using the FastLec-Hepa method.

RESULTS

Significant independent determinants of serum WFA(+)-M2BP levels included pathological diagnosis of cirrhosis, female gender, hepatitis C virus (HCV) infection, and liver dysfunction characteristics, such as abnormal indocyanine green retention rate at 15 min, platelet counts, albumin levels, alanine aminotransferase levels, and total bilirubin levels. Serum WFA(+)-M2BP levels increased with the pathological fibrosis stage and liver dysfunction severity. HCV infection significantly affected serum WFA(+)-M2BP levels throughout the pathological and functional progression of liver fibrosis, and the effect of gender was significant only in F4 stage patients with severe liver dysfunction. The diagnostic thresholds for cutoff index values for cirrhosis were 1.435 and 4.615 in HCV-negative and HCV-positive patients, respectively. Serum WFA(+)-M2BP levels at the time of operation were a significant predictor of hepatocellular carcinoma recurrence and overall survival in both HCV-negative and HCV-positive patients.

CONCLUSIONS

Serum WFA(+)-M2BP levels reflected both the pathological and functional progression of liver fibrosis comprehensively and continuously. Elevated WFA(+)-M2BP levels were a significant risk factor for tumor recurrence and decreased overall survival after liver surgery independent of HCV infection.

A novel noninvasive diagnostic method for nonalcoholic steatohepatitis using two glycobiomarkers

Nonalcoholic fatty liver disease (NAFLD) is a growing medical problem; thus, discriminating nonalcoholic steatohepatitis (NASH) from NAFLD is of great clinical significance. For the diagnosis of NASH, liver biopsy-proven histological examination is the current gold standard, and noninvasive and reliable biomarkers are greatly needed. Recently, we found that two glycobiomarkers, fucosylated haptoglobin (Fuc-Hpt) and Mac-2 binding protein (Mac2bp), are useful independently for NASH diagnosis. In this study, we confirmed that serum Fuc-Hpt is suitable for the prediction of ballooning hepatocytes and that serum Mac2bp is suitable for the prediction of liver fibrosis severity in 124 biopsy-proven NAFLD patients (training cohort). In addition, we found that the combination of serum Fuc-Hpt and Mac2bp levels was an excellent tool for NASH diagnosis. Using receiver operating characteristic analyses, the area under the receiver operating characteristic curve, sensitivity, and specificity of the combination of these two glycobiomarkers were 0.854, 81.1%, and 79.3%, respectively. We established a prediction model for NASH diagnosis using logistic regression analysis: logit (p)=-2.700+0.00242×Fuc-Hpt+1.225×Mac2bp. To validate the prediction model, another 382 biopsy-proven NAFLD patients were enrolled (validation cohort). In the validation cohort, the area under the receiver operating characteristic curve of this model for NASH diagnosis was 0.844, with 71.4% and 82.3% sensitivity and specificity, respectively. In addition, we investigated the significance of our developed NASH diagnosis model in ultrasound-diagnosed NAFLD subjects who received medical health checkups (n = 803). Our model also could predict NAFLD disease severity in this larger population.

CONCLUSION

The combination of serum Fuc-Hpt and Mac2bp can distinguish NASH from NAFLD patients. Our noninvasive model using two serum glycobiomarkers contributes to a novel NASH diagnostic methodology that could replace liver biopsy.

Association between Wisteria floribunda agglutinin-positive Mac-2 binding protein and the fibrosis stage of non-alcoholic fatty liver disease

BACKGROUND

Accurately evaluating liver fibrosis in patients with non-alcoholic fatty liver disease (NAFLD) is important for identifying those who may develop complications. The aims of this study were (1) to measure serum Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA(+)-M2BP) using the glycan sugar chain-based immunoassay and (2) to compare the results with clinical assessments of fibrosis.

METHODS

Serum WFA(+)-M2BP values were retrospectively evaluated in 289 patients with NAFLD who had undergone liver biopsy. Histological findings were evaluated by three blinded, experienced liver-specific pathologists.

RESULTS

For stages 0 (n = 35), 1 (n = 113), 2 (n = 49), 3 (n = 41), and 4 (n = 51) of liver fibrosis, the serum WFA(+)-M2BP cutoff indexes were 0.57, 0.70, 1.02, 1.57, and 2.96, respectively. Multivariate regression analysis showed that serum WFA(+)-M2BP values were associated with the stage of fibrosis (≥stage 2). The areas under the receiver operating characteristic curve (AUROC), sensitivity, and specificity of serum WFA(+)-M2BP were 0.876, 85.9, and 74.6%, respectively, for severe fibrosis (≥stage 3) and were 0.879, 74.6, and 87.0%, respectively, for cirrhosis. When compared with six non-invasive conventional markers, serum WFA(+)-M2BP had the greatest AUROC for diagnosing severe fibrosis and cirrhosis.

CONCLUSIONS

Serum WFA(+)-M2BP values are useful for assessing the stage of liver fibrosis in patients with NAFLD.

Serum Wisteria Floribunda Agglutinin-Positive Mac-2 Binding Protein Values Predict the Development of Hepatocellular Carcinoma among Patients with Chronic Hepatitis C after Sustained Virological Response

Measurement of Wisteria floribunda agglutinin-positive human Mac-2 binding protein (WFA+-M2BP) in serum was recently shown to be a noninvasive method to assess liver fibrosis. The aim of this study was to evaluate the utility of serum WFA+-M2BP values to predict the development of hepatocellular carcinoma (HCC) in patients who achieved a sustained virological response (SVR) by interferon treatment. For this purpose, we retrospectively analyzed 238 patients with SVR who were treated with interferon in our department. Serum WFA+-M2BP values were measured at pre-treatment (pre-Tx), post-treatment (24 weeks after completion of interferon; post-Tx), the time of HCC diagnosis, and the last clinical visit. Of 238 patients with SVR, HCC developed in 16 (6.8%) patients. The average follow-up period was 9.1 years. The cumulative incidence of HCC was 3.4% at 5 years and 7.5% at 10 years. The median pre-Tx and post-Tx WFA+-M2BP values were 1.69 (range: 0.28 to 12.04 cutoff index (COI)) and 0.80 (range: 0.17 to 5.29 COI), respectively. The WFA+-M2BP values decreased significantly after SVR (P < 0.001). The median post-Tx WFA+-M2BP value in patients who developed HCC was significantly higher than that in patients who did not (P < 0.01). Multivariate analysis disclosed that age (> 60 years), sex (male), pre-Tx platelet count (< 15.0×10(3)/μL), and post-Tx WFA+-M2BP (> 2.0 COI) were associated with the development of HCC after SVR. Conclusion: Post-Tx WFA+-M2BP (> 2.0 COI) is associated with the risk for development of HCC among patients with SVR. The WFA+-M2BP values could be a new predictor for HCC after SVR.

A novel serum marker, glycosylated Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA(+)-M2BP), for assessing liver fibrosis

BACKGROUND

Recently, a novel marker, hyperglycosylated Wisteria floribunda agglutinin-positive Mac-2 binding protein (WFA(+)-M2BP), was developed for liver fibrosis using the glycan "sugar chain"-based immunoassay; however, the feasibility of WFA(+)-M2BP for assessing liver fibrosis has not been proven with clinical samples of hepatitis.

METHODS

Serum WFA(+)-M2BP values were evaluated in 200 patients with chronic liver disease who underwent histological examination of liver fibrosis. The diagnostic accuracy of WFA(+)-M2BP values was compared with various fibrosis markers, such as ultrasound based-virtual touch tissue quantification (VTTQ), magnetic resonance imaging based-liver-to-major psoas muscle intensity ratio (LMR), and serum markers, including hyaluronic acid, type 4 collagen, and aspartate transaminase to platelet ratio index (APRI).

RESULTS

Serum WFA(+)-M2BP levels in patients with fibrosis grades F0, F1, F2, F3, and F4 had cutoff indices 1.62, 1.82, 3.02, 3.32, and 3.67, respectively, and there were significant differences between fibrosis stages F1 and F2, and between F2 and F3 (P < 0.01). The area under the receiver operating characteristic curves for the diagnosis of fibrosis (F ≥ 3) using serum WFA(+)-M2BP values (0.812) was almost comparable to that using VTTQ examination (0.814), but was superior to the other surrogate markers, including LMR index (0.766), APRI (0.694), hyaluronic acid (0.683), and type 4 collagen (0.625) (P < 0.01 each).

CONCLUSIONS

Serum WFA(+)-M2BP values based on a glycan-based immunoassay is an accurate, reliable, and reproducible method for the assessment of liver fibrosis. This approach could be clinically feasible for evaluation of beneficial therapy through the quantification of liver fibrosis in hepatitis patients if this measurement application is commercially realized.

Novel α-2-macroglobulin cleaved fragments as biomarkers of early liver fibrosis in patients with chronic hepatitis C

ABSTRACT 

Aim: Liver biopsy is considered the gold standard for the diagnosis and staging of hepatic fibrosis in patients with chronic hepatitis C and is now progressively replaced by noninvasive procedures. We aimed at improving α-2-macroglobulin diagnostic value for liver fibrosis by identifying new isoforms that may be specifically related to early stages of the pathology. Materials & methods: α-2-Macroglobulin isoforms were characterized in serum samples from patients with chronic hepatitis C and mild (F1) to moderate (F2) fibrosis by proteomic methods. Results: New biological 40 kDa C-terminal α-2-macroglobulin fragments were identified as potential biomarkers of early fibrosis (fold change = 1.55; p < 0.01). Conclusion: The serum concentration of α-2-macroglobulin fragments allows a better differentiation of F1 and F2 fibrosis stages than total α-2-macroglobulin isoforms.

Quantitative chemical proteomics for investigating the biomarkers of dioscin against liver fibrosis caused by CCl4 in rats

2D-DIGE technology was used for screening the biomarkers and drug-targets of dioscin against liver fibrosis in rats caused by CCl₄.

Elevated serum levels of Wisteria floribunda agglutinin-positive human Mac-2 binding protein predict the development of hepatocellular carcinoma in hepatitis C patients

The Wisteria floribunda agglutinin-positive human Mac-2-binding protein (WFA+-M2BP) was recently shown to be a liver fibrosis glycobiomarker with a unique fibrosis-related glycoalteration. We evaluated the ability of WFA+-M2BP to predict the development of hepatocellular carcinoma (HCC) in patients who were infected with the hepatitis C virus (HCV). A total of 707 patients who had been admitted to our hospital with chronic HCV infection without other potential risk factors were evaluated to determine the ability of WFA+-M2BP to predict the development of HCC; factors evaluated included age, sex, viral load, genotypes, fibrosis stage, aspartate and alanine aminotransferase levels, bilirubin, albumin, platelet count, alpha-fetoprotein (AFP), WFA+-M2BP, and the response to interferon (IFN) therapy. Serum WFA+-M2BP levels were significantly increased according to the progression of liver fibrosis stage (P<0.001). In each distinctive stage of fibrosis (F0-F1, F2, F3, and F4), the risk of development of HCC was increased according to the elevation of WFA+-M2BP. Multivariate analysis identified age>57 years, F4, AFP>20 ng/mL, WFA+-M2BP ≥4, and WFA+-M2BP 1-4 as well as the response to IFN (no therapy vs. sustained virological response) as independent risk factors for the development of HCC. The time-dependent areas under the receiver operating characteristic curve demonstrated that the WFA+-M2BP assay predicted the development of HCC with higher diagnostic accuracy than AFP.

CONCLUSION

WFA+-M2BP can be applied as a useful surrogate marker for the risk of HCC development, in addition to liver biopsy.

Serum proteomics of hepatitis C virus infection reveals retinol-binding protein 4 as a novel regulator

Persistent infection of hepatitis C virus (HCV) can lead to liver cirrhosis and hepatocellular carcinoma, which are currently diagnosed by invasive liver biopsy. Approximately 15-20 % of cases of chronic liver diseases in India are caused by HCV infection. In North India, genotype 3 is predominant, whereas genotype 1 is predominant in southern parts of India. The aim of this study was to identify differentially regulated serum proteins in HCV-infected Indian patients (genotypes 1 and 3) using a two-dimensional electrophoresis approach. We identified eight differentially expressed proteins by MS. Expression levels of one of the highly upregulated proteins, retinol-binding protein 4 (RBP4), was validated by ELISA and Western blotting in two independent cohorts. We also confirmed our observation in the JFH1 infectious cell culture system. Interestingly, the HCV core protein enhanced RBP4 levels and partial knockdown of RBP4 had a positive impact on HCV replication, suggesting a possible role for this cellular protein in regulating HCV infection. Analysis of RBP4-interacting partners using a bioinformatic approach revealed novel insights into the possible involvement of RBP4 in HCV-induced pathogenesis. Taken together, this study provided information on the proteome profile of the HCV-infected Indian population, and revealed a link between HCV infection, RBP4 and insulin resistance.

Passive immunization to reduce Campylobacter jejuni colonization and transmission in broiler chickens

Campylobacter jejuni is the most common cause of bacterium-mediated diarrheal disease in humans worldwide. Poultry products are considered the most important source of C. jejuni infections in humans but to date no effective strategy exists to eradicate this zoonotic pathogen from poultry production. Here, the potential use of passive immunization to reduce Campylobacter colonization in broiler chicks was examined. For this purpose, laying hens were immunized with either a whole-cell lysate or the hydrophobic protein fraction of C. jejuni and their eggs were collected. In vitro tests validated the induction of specific ImmunoglobulinY (IgY) against C. jejuni in the immunized hens' egg yolks, in particular. In seeder experiments, preventive administration of hyperimmune egg yolk significantly (P < 0.01) reduced bacterial counts of seeder animals three days after oral inoculation with approximately 104 cfu C. jejuni, compared with control birds. Moreover, transmission to non-seeder birds was dramatically reduced (hydrophobic protein fraction) or even completely prevented (whole-cell lysate). Purified IgY promoted bacterial binding to chicken intestinal mucus, suggesting enhanced mucosal clearance in vivo. Western blot analysis in combination with mass spectrometry after two-dimensional gel-electrophoresis revealed immunodominant antigens of C. jejuni that are involved in a variety of cell functions, including chemotaxis and adhesion. Some of these (AtpA, EF-Tu, GroEL and CtpA) are highly conserved proteins and could be promising targets for the development of subunit vaccines.

Human systems immunology: hypothesis-based modeling and unbiased data-driven approaches

Systems immunology is an emerging paradigm that aims at a more systematic and quantitative understanding of the immune system. Two major approaches have been utilized to date in this field: unbiased data-driven modeling to comprehensively identify molecular and cellular components of a system and their interactions; and hypothesis-based quantitative modeling to understand the operating principles of a system by extracting a minimal set of variables and rules underlying them. In this review, we describe applications of the two approaches to the study of viral infections and autoimmune diseases in humans, and discuss possible ways by which these two approaches can synergize when applied to human immunology.

Serum Mac-2 binding protein levels as a novel diagnostic biomarker for prediction of disease severity and nonalcoholic steatohepatitis

PURPOSE

Mac-2 binding protein (Mac-2 bp) is one of the major fucosylated glycoproteins, which we identified with glycol-proteomic analyses. We previously reported that fucosylated glycoproteins are secreted into bile, but scarcely secreted into sera in normal liver and hypothesized that the fucosylation-based sorting machinery would be disrupted in ballooning hepatocytes due to the loss of cellular polarity. In the present study, we investigated the availability of Mac-2 bp for differential diagnosis of nonalcoholic steatohepatitis (NASH) from nonalcoholic fatty liver disease (NAFLD) as a biomarker.

EXPERIMENTAL DESIGN

Serum Mac-2 bp levels were determined with our developed ELISA kit. Our cohort of 127 patients with NAFLD had liver biopsy to make a histological diagnosis of NASH and simple fatty liver.

RESULTS

Mac-2 bp levels were significantly elevated in NASH patients compared with non-NASH (simple steatosis) patients (2.132 ± 1.237 vs. 1.103 ± 0.500 μg/mL, p < 0.01). The area under the receiver-operating characteristic curve for predicting NASH by Mac-2 bp was 0.816. Moreover, multivariate logistic regression analyses showed Mac-2 bp levels could predict the fibrosis stage and the presence of ballooning hepatocytes in NAFLD patients.

CONCLUSIONS AND CLINICAL RELEVANCE

These results support the potential usefulness of measuring Mac-2 bp levels in clinical practice as a biomarker for NASH.

Differentially Expressed Proteins in Chronic Active Hepatitis, Cirrhosis, and HCC Related to HCV Infection in Comparison With HBV Infection: A proteomics study

BACKGROUND

Hepatocellular carcinoma is a highly progressive cancer in the case of late diagnosis which is frequently associated with HBV and HCV viral infections.

OBJECTIVES

To identify differentially expressed serum proteins among three main stages of HCV infection and healthy individuals, and their comparisons with sera from patients with the same stage of HBV infection.

PATIENTS AND METHODS

Two-dimensional polyacrylamide gel electrophoresis combined with liquid chromatography-tandem mass spectrometry was performed on 47 sera from healthy volunteers, those with chronic active hepatitis, cirrhosis and HCC patients associated with HBV and HCV infections.

RESULTS

Among these, 62 spots were differentially expressed (≥ 1.5 fold; P < 0.05), of which 42 spots that corresponded to 15 proteins were identified by liquid chromatography-tandem mass spectrometry. CD5-like antigen (CD5L) was differentially expressed between cirrhosis and HCC patients with HCV infection. Leucine-rich α2-glycoprotein (LRG) and haptoglobin (HP) α2 isoforms differed in the HCC that was associated with either HCV or HBV infections.

CONCLUSIONS

CD5L might be a useful biomarker for early diagnosis of HCC in HCV cirrhotic patients. LRG and HP α2 isoforms could be potential markers for distinguishing viral HCC. Our results also further support the presence of varying molecules involved in hepatocarcinogenesis in HBV when compared with HCV infection.

A combined proteomics and computational approach provides a better understanding of HCV-induced liver disease

HCV is a major cause of chronic liver disease worldwide and is a formidable therapeutic challenge. Recently, Diamond et al. analyzed the proteomic profiles of liver samples from HCV-positive liver transplant recipients, supplemented with an independent metabolite analysis. They used a computational approach, which highlighted the enriched functional themes and topological attributes associated with the protein association network based on their clinical data and suggested a crucial role of oxidative stress in fibrosis progression in HCV infection. Their findings provide new insights into the mechanisms that regulate the progression of HCV-associated liver fibrosis, which may be useful for identification of suitable biomarkers to evaluate the onset and severity of hepatic fibrosis and the development of new therapeutic and anti-HCV strategies.

A serum "sweet-doughnut" protein facilitates fibrosis evaluation and therapy assessment in patients with viral hepatitis

Although liver fibrosis reflects disease severity in chronic hepatitis patients, there has been no simple and accurate system to evaluate the therapeutic effect based on fibrosis. We developed a glycan-based immunoassay, FastLec-Hepa, to fill this unmet need. FastLec-Hepa automatically detects unique fibrosis-related glyco-alteration in serum hyperglycosylated Mac-2 binding protein within 20 min. The serum FastLec-Hepa counts increased with advancing fibrosis and illustrated significant differences in medians between all fibrosis stages. FastLec-Hepa is sufficiently sensitive and quantitative to evaluate the effects of PEG-interferon-α/ribavirin therapy in a short post-therapeutic interval. The obtained fibrosis progression is equivalent to -0.30 stages/year in patients with sustained virological response, and 0.01 stages/year in relapse/nonresponders. Furthermore, long-term follow-up of the severely affected patients found hepatocellular carcinoma developed in patients after therapy whose FastLec-Hepa counts remained above a designated cutoff value. FastLec-Hepa is the only assay currently available for clinically beneficial therapy evaluation through quantitation of disease severity.

Immunization with the immunodominant Helicobacter suis urease subunit B induces partial protection against H. suis infection in a mouse model

Helicobacter (H.) suis is a porcine and human gastric pathogen. Previous studies in mice showed that an H. suis infection does not result in protective immunity, whereas immunization with H. suis whole-cell lysate (lysate) protects against a subsequent experimental infection. Therefore, two-dimensional gel electrophoresis of H. suis proteins was performed followed by immunoblotting with pooled sera from H. suis- infected mice or mice immunized with lysate. Weak reactivity against H. suis proteins was observed in post-infection sera. Sera from lysate-immunized mice, however, showed immunoreactivity against a total of 19 protein spots which were identified using LC-MS/MS. The H. suis urease subunit B (UreB) showed most pronounced reactivity against sera from lysate-immunized mice and was not detected with sera from infected mice. None of the pooled sera detected H. suis neutrophil-activating protein A (NapA). The protective efficacy of intranasal vaccination of BALB/c mice with H. suis UreB and NapA, both recombinantly expressed in Escherichia coli (rUreB and rNapA, respectively), was compared with that of H. suis lysate. All vaccines contained choleratoxin as adjuvant. Immunization of mice with rUreB and lysate induced a significant reduction of H. suis colonization compared to non-vaccinated H. suis-infected controls, whereas rNapA had no significant protective effect. Probably, a combination of local Th1 and Th17 responses, complemented by antibody responses play a role in the protective immunity against H. suis infections.

Protective effect of Phellinus linteus polysaccharide extracts against thioacetamide-induced liver fibrosis in rats: a proteomics analysis

Background

The hepatoprotective potential of Phellinus linteus polysaccharide (PLP) extracts has been described. However, the molecular mechanism of PLP for the inhibition of liver fibrosis is unclear. This study aims to investigate the molecular protein signatures involved in the hepatoprotective mechanisms of PLP via a proteomics approach using a thioacetamide (TAA)-induced liver fibrosis rat model.

Methods

Male Sprague–Dawley rats were divided into three groups of six as follows: Normal group; TAA group, in which rats received TAA only; and PLP group, in which rats received PLP and TAA. Liver fibrosis was induced in the rats by repeated intraperitoneal injections of TAA at a dose of 200 mg/kg body weight twice a week for 4 weeks. PLP was given orally at a dose of 50 mg/kg body weight twice a day from the beginning of the TAA treatment until the end of the experiment. The development of liver cirrhosis was verified by histological examination. Liver proteomes were established by two-dimensional gel electrophoresis. Proteins with significantly altered expression levels were identified by matrix-assisted laser desorption/ionization-time of flight/time of flight mass spectrometry and the differentially expressed proteins were validated by immunohistochemical staining and reverse transcription polymerase chain reaction.

Results

Histological staining showed a remarkable reduction in liver fibrosis in the rats with PLP treatment. A total of 13 differentially expressed proteins including actin, tubulin alpha-1C chain, preprohaptoglobin, hemopexin, galectin-5, glutathione S-transferase alpha-4 (GSTA4), branched chain keto acid dehydrogenase hterotetrameric E1 subunit alpha (BCKDHA), glutathione S-transferase mu (GSTmu); glyceraldehyde-3-phosphate dehydrogenase (GAPDH); thiosulfate sulfurtransferase (TFT); betaine-homocysteine S-methyltransferase 1 (BHMT1); quinoid dihydropteridine reductase (QDPR); ribonuclease UK114 were observed between the TAA and PLP groups. These proteins are involved in oxidative stress, heme and iron metabolism, cysteine metabolism, and branched-chain amino acid catabolism.

Conclusion

The proteomics data indicate that P. linteus may be protective against TAA-induced liver fibrosis via regulation of oxidative stress pathways, heat shock pathways, and metabolic pathways for amino acids and nucleic acids.

Proteomics approaches to fibrotic disorders

This review provides an introduction to mass spectrometry based proteomics and discusses several proteomics approaches that are relevant in understanding the pathophysiology of fibrotic disorders and the approaches that are frequently used in biomarker discovery.

Investigation of plasma biomarkers in HIV-1/HCV mono- and coinfected individuals by multiplex iTRAQ quantitative proteomics

The analysis of plasma samples from HIV-1/HCV mono- and coinfected individuals by quantitative proteomics is an efficient strategy to investigate changes in protein abundances and to characterize the proteins that are the effectors of cellular functions involved in viral pathogenesis. In this study, the infected and healthy plasma samples (in triplicate) were treated with ProteoMiner beads to equalize protein concentrations and subjected to 4-plex iTRAQ labeling and liquid chromatography/mass spectrometry (LC-MS/MS) analysis. A total of 70 proteins were identified with high confidence in the triplicate analysis of plasma proteins and 65% of the proteins were found to be common among the three replicates. Apolipoproteins and complement proteins are the two major classes of proteins that exhibited differential regulation. The results of quantitative analysis revealed that APOA2, APOC2, APOE, C3, HRG proteins were upregulated in the plasma of all the three HIV-1 mono-, HCV mono-, and coinfected patient samples compared to healthy control samples. Ingenuity pathway analysis (IPA) of the upregulated proteins revealed that they are implicated in the hepatic lipid metabolism, inflammation, and acute-phase response signaling pathways. Thus, we identified several differentially regulated proteins in HIV-1/HCV mono and coinfected plasma samples that may be potential biomarkers for liver disease.

Genomics and proteomics in liver fibrosis and cirrhosis

Genomics and proteomics have become increasingly important in biomedical science in the past decade, as they provide an opportunity for hypothesis-free experiments that can yield major insights not previously foreseen when scientific and clinical questions are based only on hypothesis-driven approaches. Use of these tools, therefore, opens new avenues for uncovering physiological and pathological pathways. Liver fibrosis is a complex disease provoked by a range of chronic injuries to the liver, among which are viral hepatitis, (non-) alcoholic steatohepatitis and autoimmune disorders. Some chronic liver patients will never develop fibrosis or cirrhosis, whereas others rapidly progress towards cirrhosis in a few years. This variety can be caused by disease-related factors (for example, viral genotype) or host-factors (genetic/epigenetic). It is vital to establish accurate tools to identify those patients at highest risk for disease severity or progression in order to determine who are in need of immediate therapies. Moreover, there is an urgent imperative to identify non-invasive markers that can accurately distinguish mild and intermediate stages of fibrosis. Ideally, biomarkers can be used to predict disease progression and treatment response, but these studies will take many years due to the requirement for lengthy follow-up periods to assess outcomes. Current genomic and proteomic research provides many candidate biomarkers, but independent validation of these biomarkers is lacking, and reproducibility is still a key concern. Thus, great opportunities and challenges lie ahead in the field of genomics and proteomics, which, if successful, could transform the diagnosis and treatment of chronic fibrosing liver diseases.

Mass spectrometry of peptides and proteins from human blood

It is difficult to convey the accelerating rate and growing importance of mass spectrometry applications to human blood proteins and peptides. Mass spectrometry can rapidly detect and identify the ionizable peptides from the proteins in a simple mixture and reveal many of their post-translational modifications. However, blood is a complex mixture that may contain many proteins first expressed in cells and tissues. The complete analysis of blood proteins is a daunting task that will rely on a wide range of disciplines from physics, chemistry, biochemistry, genetics, electromagnetic instrumentation, mathematics and computation. Therefore the comprehensive discovery and analysis of blood proteins will rank among the great technical challenges and require the cumulative sum of many of mankind's scientific achievements together. A variety of methods have been used to fractionate, analyze and identify proteins from blood, each yielding a small piece of the whole and throwing the great size of the task into sharp relief. The approaches attempted to date clearly indicate that enumerating the proteins and peptides of blood can be accomplished. There is no doubt that the mass spectrometry of blood will be crucial to the discovery and analysis of proteins, enzyme activities, and post-translational processes that underlay the mechanisms of disease. At present both discovery and quantification of proteins from blood are commonly reaching sensitivities of ∼1 ng/mL.

Usefulness of a novel serum proteome-derived index FI-PRO (fibrosis-protein) in the prediction of fibrosis in chronic hepatitis C

BACKGROUND

Liver biopsy is an imperfect standard for the assessment of chronic hepatitis C liver fibrosis. In this study, the diagnostic role of proteome-derived protein markers and the usefulness of a protein-based index were assessed.

METHODS

Characteristics, clinical biochemistry, and protein markers of patients with chronic hepatitis C from a study (n=62) and validation group (n=73) were statistically assessed according to fibrosis severity. Multivariate models were built using linear discriminant analysis for the prediction of minor fibrosis (F0-F1), moderate fibrosis (F2-F3), and cirrhosis (F4). The best model was validated and diagnostic performance was compared with the aspartate aminotransferase-to-platelet ratio index based on their receiver operator characteristic curves.

RESULTS

Statistical analysis resulted in significant outcomes for both clinical and protein markers. The best multivariate model was based on four protein markers: α-2-macroglobulin (A2M), haptoglobin, hemopexin, and galectin-3-binding protein. A2M and hemopexin were the primary predictors according to this model. A novel index A2M/hemopexin [fibrosis-protein (FI-PRO) index] showed a diagnostic performance rate of 0.80-0.92 for the detection of significant fibrosis (F2-F4) and advanced fibrosis (F3-F4) in the validation group, which was better compared with aspartate aminotransferase-to-platelet ratio index. FI-PRO had an overall positive predictive value of 86% for significant fibrosis and a negative predictive value of at least 90% for advanced fibrosis.

CONCLUSION

Proteome-derived protein markers were successfully implemented in clinical diagnosis of hepatitis C fibrosis, which resulted in the FI-PRO index. The efficiency and usability of FI-PRO should be validated in large-scale, prospective studies.

High predictive accuracy of an unbiased proteomic profile for sustained virologic response in chronic hepatitis C patients

Chronic hepatitis C (CHC) infection is a leading cause of endstage liver disease. Current standard-of-care (SOC) interferon-based therapy results in sustained virological response (SVR) in only one-half of patients, and is associated with significant side effects. Accurate host predictors of virologic response are needed to individualize treatment regimens. We applied a label-free liquid chromatography mass spectrometry (LC-MS)-based proteomics discovery platform to pretreatment sera from a well-characterized and matched training cohort of 55 CHC patients, and an independent validation set of 41 CHC genotype 1 patients with characterized IL28B genotype. Accurate mass and retention time methods aligned samples to generate quantitative peptide data, with predictive modeling using Bayesian sparse latent factor regression. We identified 105 proteins of interest with two or more peptides, and a total of 3,768 peptides. Regression modeling selected three identified metaproteins, vitamin D binding protein, alpha 2 HS glycoprotein, and Complement C5, with a high predictive area under the receiver operator characteristic curve (AUROC) of 0.90 for SVR in the training cohort. A model averaging approach for identified peptides resulted in an AUROC of 0.86 in the validation cohort, and correctly identified virologic response in 71% of patients without the favorable IL28B "responder" genotype.

CONCLUSION

Our preliminary data indicate that a serum-based protein signature can accurately predict treatment response to current SOC in most CHC patients.

Hepatitis C virus-induced oxidative stress and mitochondrial dysfunction: a focus on recent advances in proteomics

The natural history of chronic hepatitis C virus (HCV) infection presents two major aspects. On one side, the illness is by itself benign, whereas, on the other side, epidemiological evidence clearly identifies chronic HCV infection as the principal cause of cirrhosis, hepatocellular carcinoma, and extrahepatic diseases, such as autoimmune type II mixed cryoglobulinemia and some B cell non-Hodgkin's lymphomas. The mechanisms responsible for the progression of liver disease to severe liver injury are still poorly understood. Nonetheless, considerable biological data and studies from animal models suggest that oxidative stress contributes to steatohepatitis and that the increased generation of reactive oxygen and nitrogen species, together with the decreased antioxidant defense, promotes the development of hepatic and extrahepatic complications of HCV infection. The principal mechanisms causing oxidative stress in HCV-positive subjects have only been partially elucidated and have identified chronic inflammation, iron overload, ER stress, and a direct activity of HCV proteins in increasing mitochondrial ROS production, as key events. This review summarizes current knowledge regarding mechanisms of HCV-induced oxidative stress with its long-term effects in the context of HCV-related diseases, and includes a discussion of recent contributions from proteomics studies.