Effectiveness of 1-year pemafibrate treatment on steatotic liver disease: the influence of alcohol consumption.

BACKGROUND/AIMS: Pemafibrate is a selective peroxisome proliferator-activated receptor α modulator that improves serum alanine aminotransferase (ALT) in dyslipidemia patients. We previously reported that pemafibrate significantly improves liver function, serum triglyceride (TG) levels and liver stiffness in non-alcoholic fatty liver disease patients, however the influence of alcohol consumption was not considered. Therefore, we explored pemafibrate efficacy in patients with steatotic liver disease (SLD) and alcohol-associated liver disease (ALD). METHODS: We retrospectively evaluated pemafibrate efficacy on liver enzymes and lipids in metabolic dysfunction-associated SLD (MASLD) (n = 93), MASLD plus increased alcohol intake (MetALD; n = 23) and ALD (n = 22) patients who had taken pemafibrate for at least 48 weeks. Liver shear wave velocity (SWV, n = 75) was also evaluated. RESULTS: In MASLD group, ALT, aspartate aminotransferase (AST), γ-glutamyl transpeptidase (γ-GTP) and TG values were significantly decreased from baseline to week 24 and week 48 ( P  < 0.0001). ALT and TG values in MetALD group and ALT and AST values in ALD group were also significantly decreased from baseline to week 24 and week 48. Study participant SWV values decreased from baseline to week 48. We observed no significant difference in changes to ALT, AST, γ-GTP and TG (value at week 24 or week 48 minus value at baseline) among the three groups. CONCLUSION: Pemafibrate improves liver function and liver stiffness thus making it a promising therapeutic agent for SLD, even in patients with excess alcohol consumption (MetALD and ALD groups).

Serum Zinc-α2-glycoprotein Levels Are Associated with the Hepatorenal Function and Predict the Survival in Cases of Chronic Liver Disease.

Objective Zinc-α2-glycoprotein (ZAG) is secreted by various organs, such as liver, kidney and adipose tissue, is involved in lipolysis, and may contribute to the pathogenesis of chronic liver disease (CLD). We therefore assessed whether or not ZAG is a surrogate marker for the hepatorenal function, body composition and all causes of mortality, as well as complications, including ascites, hepatic encephalopathy (HE) and portosystemic shunts (PSS) in CLD. Methods Serum ZAG levels were measured in 180 CLD patients upon hospital admission. The associations of ZAG levels with the liver functional reserve and clinical parameters were investigated using a multiple regression analysis. Kaplan-Meier analyses were performed to evaluate the associations of the ZAG/creatinine ratio (ZAG/Cr) and prognostic factors with mortality. Results High serum ZAG levels were associated with preserving the liver function and renal insufficiency. A multiple regression analysis showed that the estimated glomerular filtration rate (p<0.0001), albumin-bilirubin (ALBI) score (p=0.0018) and subcutaneous fat area (p=0.0023) had a significant independent correlation with serum ZAG levels. Serum ZAG levels were elevated in the absence of HE (p=0.0023) and PSS (p=0.0003). In all patients and those without hepatocellular carcinoma (HCC), the cumulative mortality rate was significantly decreased in patients with a high ZAG/Cr compared with those with a low ZAG/Cr (p=0.0018 and p=0.0002, respectively). The ZAG/Cr, presence of HCC, ALBI score and psoas muscle index were independent predictors of the prognosis in CLD patients. Conclusion Serum ZAG levels are associated with the hepatorenal function and can be used to predict the survival in CLD patients.

Circulating extracellular vesicles are associated with pathophysiological condition including metabolic syndrome-related dysmetabolism in children and adolescents with obesity.

Obesity of children and adolescents (OCA) is often accompanied by metabolic syndrome (MetS), which often leads to adult obesity and subsequent complications, yet the entire pathophysiological response is not fully understood. The number and composition of circulating extracellular vesicles (EV) reflect overall patient condition; therefore, we investigated the pathophysiological condition of OCA, including MetS-associated dysmetabolism, using circulating EVs. In total, 107 children and adolescents with or without obesity (boys, n = 69; girls, n = 38; median age, 10 years) were enrolled. Circulating EV number and EV protein composition were assessed via flow cytometry and liquid chromatography tandem-mass spectrometry, respectively. In a multivariate analysis, relative body weight (standardized partial regression coefficient (SPRC) 0.469, P = 0.012) and serum triglyceride level (SPRC 0.548, P < 0.001) were detected as independent parameters correlating with circulating EV number. Proteomic analysis identified 31 upregulated and 45 downregulated EV proteins in OCA. Gene ontology analysis revealed upregulated proteins to be involved in various biological processes, including intracellular protein transport, protein folding, stress response, leukocyte activation, innate immune response, and platelet degranulation, which can modulate lipid and glucose metabolism, skeletal and cardiac muscle development, inflammation, immune response, carcinogenesis, and cancer progression. Notably, several identified EV proteins are involved in neuro-development, neurotransmitter release, and neuro-protective agents in OCA. Circulating EVs were derived from adipocytes, hepatocytes, B cell lymphocytes, and neurons. Circulating EV number is significantly associated with MetS-related dysmetabolism and the EV protein cargo carries a special "signature" that reflects the alteration of various biological processes under the pathophysiological condition of OCA. KEY MESSAGES: Circulating EV number correlates with physical and laboratory parameters for obesity in children and adolescents. Relative body weight and triglyceride are independent factors for increased circulating EVs. EV composition is significantly changed in obesity of children and adolescents. Identified EV composition changes associated with obesity and involves in metabolism, immune response, and cancer progression. Circulating EVs are partially derived from adipocyte, hepatocytes, B cells, and neurons.

Extracellular Vesicles as Therapeutic and Diagnostic Tools for Chronic Liver Diseases.

Chronic liver diseases can lead to fibrotic changes that may progress to the development of cirrhosis, which poses a significant risk for morbidity and increased mortality rates. Metabolic dysfunction-associated steatotic liver disease (MASLD), alcohol-associated liver disease (ALD), and viral hepatitis are prevalent liver diseases that may lead to cirrhosis. The advanced stages of cirrhosis can be further complicated by cancer development or end-stage liver disease and liver failure. Hence, early detection and diagnosis of liver fibrosis is crucial for preventing the progression to cirrhosis and improving patient outcomes. Traditionally, invasive liver biopsy has been considered the gold standard for diagnosing and staging liver fibrosis. In the last decade, research has focused on non-invasive methods, known as liquid biopsies, which involve the identification of disease-specific biomarkers in human fluids, such as blood. Among these alternative approaches, extracellular vesicles (EVs) have emerged as promising diagnostic and therapeutic tools for various diseases, including chronic liver diseases. EVs are released from stressed or damaged cells and can be isolated and quantified. Moreover, EVs facilitate cell-to-cell communication by transporting various cargo, and they have shown the potential to reduce the expression of profibrogenic markers, making them appealing tools for novel anti-fibrotic treatments. This review focuses on the impact of EVs in chronic liver diseases and exploring their potential applications in innovative therapeutic and diagnostic approaches.

Hepatocellular Carcinoma Pseudoprogression Involving the Main Portal Vein, Right Ventricular Invasion, and Exacerbation of Lung Metastases in a Patient on Atezolizumab Plus Bevacizumab.

A 70-year-old man was diagnosed with hepatocellular carcinoma (HCC) with portal vein invasion and lung metastases, for which atezolizumab plus bevacizumab (ATZ/BEV) was initiated. After two months, computed tomography revealed tumor growth accompanied by ascites, right ventricular invasion, exacerbation of the lung metastases, and main portal vein invasion. However, continuation of ATZ/BEV caused remarkable size reductions in all lesions, finally resulting in the disappearance of the vascular invasion and lung metastases after nine cycles of treatment. The tumor growth was considered to reflect pseudoprogression, which is difficult to distinguish from hyperprogression. We herein report a remarkable HCC case of pseudoprogression on ATZ/BEV.

The prognostic role of controlling nutritional status and skeletal muscle mass in patients with hepatocellular carcinoma after curative treatment.

BACKGROUND: Nutritional status and skeletal muscle mass affect the prognosis of hepatocellular carcinoma (HCC). Nutritional status is closely associated with skeletal muscle mass. Here, we investigate the effect of controlling preoperative nutritional status and skeletal muscle mass on the prognosis of HCC after curative treatment. METHODS: This retrospective analysis contained 181 patients who received curative treatment of HCC including liver resection or radiofrequency ablation (RFA) therapy. Nutritional status and skeletal muscle mass were evaluated prior to therapy using the controlling nutritional status (CONUT) score and psoas muscle mass index (PMI), respectively. Associations of predictor variables with overall survival (OS) and progression-free survival (PFS) were determined using Cox proportional hazards regression and CHAID decision tree algorithm analysis. RESULTS: A total of 111 patients (61.3%) were determined to be of poor nutritional status and 100 patients (55.2%) had muscle mass depletion. Patients with PS 0, Barcelona clinic liver cancer (BCLC) stage 0, low CONUT score, and high PMI showed significantly better OS than those with PS 1, BCLC stage A, high CONUT score, and low PMI. Multivariate analysis indicated that a high CONUT score [hazard ratio (HR) 4.130; 95% confidence interval (CI), 1.713-9.958; P < 0.01) and low PMI (HR 4.625; 95% CI, 1.704-12.549; P < 0.01) found to be useful for predicting OS in patients after curative treatment of HCC. Regarding PFS, a significant predictor was only tumor numbers in univariate analysis (HR 2.147; 95% CI, 1.350-3.414; P = 0.001). In decision tree analysis, the mortality rate was 28.8%, 12.5%, and 1.9% in patients with a high CONUT score, with a low CONUT score-low PMI, or with a low CONUT score-high PMI, respectively. CONCLUSION: The combined CONUT score and PMI were found to be independent predictors of OS in HCC patients after liver resection or RFA.

Association of lithocholic acid with skeletal muscle hypertrophy through TGR5-IGF-1 and skeletal muscle mass in cultured mouse myotubes, chronic liver disease rats and humans.

Background: Hepatic sarcopenia is one of many complications associated with chronic liver disease (CLD) and has a high mortality rate; however, the liver-muscle axis is not fully understood. Therefore, few effective treatments exist for hepatic sarcopenia, the best of which being branched-chain amino acid (BCAA) supplementation to help increase muscle mass. Our aim was to investigate the molecular mechanism(s) of hepatic sarcopenia focused on bile acid (BA) composition. Methods: The correlation between serum BA levels and psoas muscle mass index (PMI) was examined in 73 CLD patients. Gastrocnemius muscle phenotype and serum BA levels were assessed in CLD rats treated with BCAA. Mouse skeletal muscle cells (C2C12) were incubated with lithocholic acid (LCA), G-protein-coupled receptor 5 (TGR5) agonist or TGR5 antagonist to assess skeletal muscle hypertrophy. Results: In human CLD, serum LCA levels were the sole factor positively correlated with PMI and were significantly decreased in both the low muscle mass group and the deceased group. Serum LCA levels were also shown to predict patient survival. Gastrocnemius muscle weight significantly increased in CLD rats treated with BCAA via suppression of protein degradation pathways, coupled with a significant increase in serum LCA levels. LCA treated C2C12 hypertrophy occurred in a concentration-dependent manner linked with TGR5-Akt pathways based upon inhibition results via a TGR5 antagonist. Conclusions: Our results indicate LCA-mediated skeletal muscle hypertrophy via activation of TGR5-IGF1-Akt signaling pathways. In addition, serum LCA levels were associated with skeletal muscle mass in cirrhotic rats, as well as CLD patients, and predicted overall patient survival. Funding: This research was supported by JSPS KAKENHI Grant Number 22K08011 and 21H02892, and AMED under Grant Number JP21fk0210090 and JP22fk0210115. Maintaining cirrhotic rats were partially supported by Otsuka Pharmaceutical Company.

Complement complex 1 subunit q-mediated hepatic stellate cell activation with connective tissue growth factor elevation is a prognostic factor for survival in rat and human chronic liver diseases.

Complement complex 1 subunit q (C1q) has multiple functions, including cell migration, in addition to its traditional complement-activating effect. Research shows C1q is a ligand for frizzled receptors (FZDs). FZD-induced yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ) alternate Wnt signaling activation induces connective tissue growth factor (CTGF) production and hepatic stellate cell (HSC) activation. However, no study exists in which C1q directly induces CTGF in HSCs. Here, we investigated the role of C1q in HSC activation. Human HSCs (LX2) were incubated with C1q to assess HSC activation. C1q and fibrotic markers were assessed using immunohistochemistry, immunoblotting, and quantitative reverse-transcription polymerase chain reaction in cirrhotic rats administered CCl4 for 21 weeks. Serum C1q, liver function, and fibrosis score were measured in 91 patients with chronic liver disease. The correlations between serum C1q and liver function, fibrosis score, and survival prognosis were examined. C1q-activated LX2s showed morphologic changes, up-regulation of CTGF, tissue inhibitors of metalloproteinases (TIMP-1), and alternate Wnt signal genes FZD2, TAZ, and cysteine-rich angiogenic inducer 61 (Cyr61). Cirrhotic rat liver C1q expression correlated with the Azan-positive area and expression of CTGF, TIMP-1, hyaluronan synthase (HAS)1, HAS3, and CD44. Expression of C1q protein and C1q, CTGF, and TIMP-1 genes were higher in deceased cirrhotic rat livers compared to surviving rats. Human serum C1q levels increased in liver cirrhosis compared to chronic hepatitis and correlated with liver fibrosis and functional markers. Ten patients suffered liver-related death over a 66-month observation period. The C1q cut-off value (11 mg/dl) showed patients with serum values < 11 mg/dl had longer rates of survival compared to C1q ≥ 11 mg/dl. Conclusion: C1q-mediated HSC activation in liver fibrosis is associated with CTGF elevation. Additionally, serum C1q may be diagnostic for survival in human chronic liver diseases.

The prognostic potential of fragmented CK18 serum levels in HCC patients reflecting disease progression and overall hepatocyte damage.

Background: Fragmented cytokeratin 18 (fCK18) is released from damaged hepatocytes undergoing apoptosis and is recognized as a liver condition biomarker. We have developed a highly sensitive serum fCK18 CLEIA and reported that serum levels of this caspase-derived protein were significantly associated with hepatocyte ballooning, thus assisting in the accurate diagnosis of nonalcoholic steatohepatitis (NASH). We aim to investigate serum fCK18 levels in a variety of chronic liver diseases and to explore its potential as a prognostic marker of survival in hepatocellular carcinoma (HCC) patients. Methods: Serum fCK18 levels were measured using a highly sensitive CLEIA in 497 chronic liver disease patients (297 outpatients and 200 hospitalized with HCC). Results: In 497 chronic liver disease patients, serum fCK18 levels were significantly correlated with overall liver condition, including ALT, FIB-4 index and albumin-bilirubin (ALBI) score and were significantly increased in patients with HCC. In 200 HCC patients, serum fCK18 levels were significantly correlated with alpha-fetoprotein (AFP) and des-gamma-carboxy prothrombin (DCP), and were significantly associated with HCC stage, whereas FIB-4 index and ALBI score were not changed based on HCC stage. The Survival group had significantly lower levels of serum fCK18, AFP, DCP, FIB-4 index and ALBI score. A ROC analysis yield area under the curve (AUC) value of 0.728 for serum fCK18 is a significantly high value when compared to AUC measurements for other factors. Notably, AUROC values for serum fCK18 levels were constant in the short- and long-term by time-dependent ROC analysis for the prediction of HCC patient survival. HCC patients with serum fCK18 measured at < 1.15 ng/mL, AFP < 7.7 ng/mL, DCP < 133 mAU/mL, ALBI score < -2.97 or FIB-4 index < 6.4 had significantly longer rates of survival when compared to patients with values exceeding these thresholds. Serum fCK18 (HR, 3.5; P < 0.0001), DCP (HR, 3.2; P < 0.0001) and Barcelona Clinic Liver Cancer (BCLC) (HR, 2.4; P = 0.001) values were independent predictors of patient survival. [Conclusion] Serum fCK18 levels reflect overall liver function, the level of liver fibrosis and the progression of HCC, and are a potential predictor of survival in HCC patients.

Development of a New Index to Distinguish Hepatic Encephalopathy through Automated Quantification of Globus Pallidal Signal Intensity Using MRI.

Hyperintensities within the bilateral globus pallidus on T1-weighted magnetic resonance images were present in some liver cirrhosis patients with hepatic encephalopathy. The symptoms of covert hepatic encephalopathy are similar to those of mild dementia. We aimed to develop a new diagnostic index in which to distinguish hepatic encephalopathy from dementia. The globus pallidus signal hyperintensity was quantified using three-dimensional images. In addition, the new index value distribution was evaluated in a cohort of dementia patients. Signal intensity of globus pallidus significantly increased in liver cirrhosis patients with hepatic encephalopathy compared to those without hepatic encephalopathy (p < 0.05), healthy subjects (p < 0.05) or dementia patients (p < 0.001). Only 12.5% of liver cirrhosis patients without hepatic encephalopathy and 2% of dementia patients exceeded the new index cut-off value of 0.994, which predicts hepatic encephalopathy. One dementia patient in our evaluation had a history of liver cancer treatment and was assumed to have concomitant hepatic encephalopathy. The automatic assessment of signal intensity in globus pallidus is useful for distinguishing liver cirrhosis patients with hepatic encephalopathy from healthy subjects and liver cirrhosis patients without hepatic encephalopathy. Our image analyses exclude possible cases of hepatic encephalopathy from patients with neurocognitive impairment, including dementia.

Inhibiting SCAP/SREBP exacerbates liver injury and carcinogenesis in murine nonalcoholic steatohepatitis.

Enhanced de novo lipogenesis mediated by sterol regulatory element-binding proteins (SREBPs) is thought to be involved in nonalcoholic steatohepatitis (NASH) pathogenesis. In this study, we assessed the impact of SREBP inhibition on NASH and liver cancer development in murine models. Unexpectedly, SREBP inhibition via deletion of the SREBP cleavage-activating protein (SCAP) in the liver exacerbated liver injury, fibrosis, and carcinogenesis despite markedly reduced hepatic steatosis. These phenotypes were ameliorated by restoring SREBP function. Transcriptome and lipidome analyses revealed that SCAP/SREBP pathway inhibition altered the fatty acid (FA) composition of phosphatidylcholines due to both impaired FA synthesis and disorganized FA incorporation into phosphatidylcholine via lysophosphatidylcholine acyltransferase 3 (LPCAT3) downregulation, which led to endoplasmic reticulum (ER) stress and hepatocyte injury. Supplementation with phosphatidylcholines significantly improved liver injury and ER stress induced by SCAP deletion. The activity of the SCAP/SREBP/LPCAT3 axis was found to be inversely associated with liver fibrosis severity in human NASH. SREBP inhibition also cooperated with impaired autophagy to trigger liver injury. Thus, excessively strong and broad lipogenesis inhibition was counterproductive for NASH therapy; this will have important clinical implications in NASH treatment.

Extracellular vesicles from pancreatic ductal adenocarcinoma endoscopic ultrasound-fine needle aspiration samples contain a protein barcode.

BACKGROUND: The survival rate of pancreatic ductal adenocarcinoma (PDAC) is very poor because early detection is difficult. Extracellular vesicles (EVs) are released from cells associating with the cellular condition and circulated in the blood. We aimed to identify EV proteins from endoscopic ultrasound-fine needle aspiration (EUS-FNA) biopsy samples in order to develop novel biomarkers for PDAC. METHODS: Extracellular vesicles were isolated from EUS-FNA samples of 40 PDAC patients and six autoimmune pancreatitis (AIP) patients to be used as a control. EV proteins were identified using nanoLC-MS/MS. RESULTS: Intact EVs approximately 200 nm in diameter were detected from EUS-FNA samples. We identified 2059 or 1032 EV proteins in PDAC or AIP, respectively, and 1071 EV proteins were detected only in PDAC. One hundred and fifty-three EV proteins were significantly different between PDAC and AIP: 64 proteins were down-regulated in PDAC whereas 89 EV proteins were up-regulated in PDAC including mucins, keratins, Ras-related proteins, and olfactomedin-4, which proteins have been reported to be elevated in PDAC tissue/blood, or cultured pancreatic cancer cell lines. Notably, in the 89 up-regulated PDAC EV proteins we identified novel proteins including ADP-ribosylation factor 3, CD55, pyruvate kinase, and lipopolysaccharide-induced tumor necrosis factor. Out of 89 proteins, a total of 13 proteins including Ras-related proteins were significantly elevated in PDAC stages II-IV compared to PDAC stage I, including Ras-related proteins, moesin, and CD55. CONCLUSIONS: The EV proteins obtained from EUS-FNA samples contain a PDAC-specific protein barcode. The EV proteins identified from EUS-FNA samples include promising biomarkers for the diagnosis and clinical staging of PDAC.

Serum Copeptin and Zinc-α2-glycoprotein Levels Are Novel Biomarkers of Tolvaptan Treatment in Decompensated Cirrhotic Patients with Ascites.

Objective The efficacy of tolvaptan, an orally active vasopressin V2-receptor antagonist, has recently been reported in patients with massive ascites unresponsive to conventional diuretics. However, the effect of tolvaptan varies among patients. Recently, the prognostic role of the tolvaptan response in cases of decompensated liver cirrhosis (LC) has been attracting increasing attention. Using serum copeptin (vasopressin precursor), zinc-α2-glycoprotein (ZAG), cystatin C (renal biomarker), neutrophil gelatinase-associated lipocalin (NGAL) and liver-type fatty acid-binding protein (L-FABP), we explored which factors portend a good response to tolvaptan in LC patients with ascites. Methods We enrolled 113 LC patients and divided them into the tolvaptan treatment group and non-treatment group. Tolvaptan (3.75 or 7.5 mg/day) was administrated to 38 LC patients with ascites, and a follow-up assessment was performed after a 7-day tolvaptan treatment regimen. Results We determined the predictive ability for kidney and/or liver damage of serum copeptin, ZAG, cystatin C, NGAL and L-FABP levels in all patients. After 7-day tolvaptan treatment, 19 patients had lost more than 1.5 kg of body weight (Responders), while 19 showed no marked change in their body weight (Non-responders). Basal blood urea nitrogen (BUN) (p=0.0014), serum copeptin (p=0.0265) and serum ZAG levels (p=0.0142) were significantly higher in the Non-responders than in the Responders. BUN (odds ratio 7.43, p=0.0306), copeptin (odds ratio 9.12, p=0.0136) and ZAG (odds ratio 7.43, p=0.0306) were determined to be predictive factors of drug responsiveness using a multivariate logistic regression analysis. Conclusion Serum BUN, copeptin and ZAG levels predict the patient response to tolvaptan, even when measured prior to treatment.

Development of a highly sensitive chemiluminescent enzyme immunoassay for fragmented cytokeratin 18 using new antibodies.

Fragmented cytokeratin 18 (fCK18) released from epithelial cells undergoing apoptosis is widely studied in various diseases. However, fCK18 measurement is not utilized in clinical practice due to imprecise disease-state cutoff values. Therefore, we set out to generate new monoclonal antibodies (mAbs) and a recombinant fCK18 (rfCK18) calibrator in an effort to develop a highly sensitive chemiluminescent enzyme immunoassay (CLEIA). New capture mAb (K18-624) had a high binding ability compared to the current commercial antibody. New detection mAb (K18-328) recognized 323S-340G of CK18. A rfCK18 was expressed in the soluble fraction of E. coli when the N-terminal region (260 amino acid residues) of CK18 was truncated. Analysis of performance and measurement of human fCK18 were evaluated using K18-624 and K18-328 in a highly sensitive CLEIA. The coefficients of variation (CV) for within-run and between-day repeatability were below 10% and the recoveries were in the range of 15%. The detection sensitivity was 0.056 ng/mL. Serum fCK18 levels were significantly increased in non-alcoholic steatohepatitis (NASH) patients when compared to healthy individuals. Our new fCK18 mAbs showed high affinity and sensitivity. CLEIA using our new antibodies will be useful in measuring fCK18 in human blood thereby generating accurate clinical diagnoses of human liver diseases.

The Role of Elevated Liver-Type Fatty Acid-Binding Proteins in Liver Diseases.

Liver-type fatty acid-binding protein (L-FABP) is mainly expressed in the liver as well as the proximal tubular epithelial cells in the kidney. In general, the proteins and enzymes existing within the hepatocytes have the potential to become biomarkers, for instance alanine aminotransferase, which reflects hepatocellular damage. However, due to reduced hepatocellular function in late stage of chronic liver diseases (e.g. cirrhosis), proteins and enzymes relating to hepatocellular damage are not always accurate measures of disease progression. Recently, several publications have demonstrated elevated serum L-FABP levels during the progression of human liver diseases, including hepatocellular carcinoma (HCC), and were a prognostic factor for survival in acute and chronic liver disease patients. However, the study regarding serum L-FABP levels and hepatic L-FABP expression in liver diseases is not sufficient to understand the molecular mechanism of L-FABP during the progression of these disease states. In this review, we focus on the use of serum and/or hepatic L-FABP expression as a biomarker in human liver diseases, including mechanistic potential in HCC.

Serum copeptin level is a biomarker associated with ascites retention and the formation of a portosystemic shunt in chronic liver disease.

BACKGROUND AND AIM: Copeptin is a stable cleavage product of the arginine vasopressin precursor and is equimolarly secreted with arginine vasopressin. We aimed to assess whether copeptin is the surrogate marker for complications related chronic liver disease (CLD) such as ascites, hepatic encephalopathy (HE), portosystemic shunts (PSSs), and all causes of mortality in CLD. METHODS: Serum copeptin was measured in 170 CLD patients upon hospital admission. The association of copeptin levels with liver enzymes, liver functional reserve, and clinical parameters was investigated. Cox proportional hazard regression, logistic regression, and Kaplan-Meier analyses were performed to evaluate the associations of copeptin and ascites, HE and PSS formation, and prognostic factors with short-term (1 year) and long-term (4 years) mortality. RESULTS: Serum copeptin levels were significantly correlated with liver and renal function, elevated in parallel with liver disease progression, and also associated with HE. Serum copeptin, albumin-bilirubin score and hepatocellular carcinoma were independent predictors of PSS formation and decreased rate of survival. Serum copeptin and albumin-bilirubin scores were independent predictors of ascites retention. The short-term and long-term cumulative mortality rate was significantly decreased in patients with serum copeptin >5.5 or >4.8 pmol/mL compared with patients in whom serum copeptin levels were <5.5 or <4.8 pmol/mL (P < 0.0001; P < 0.0001). CONCLUSIONS: Serum copeptin level is a predictor for ascites retention and HE and PSS formation associated with portal hypertension. Moreover, serum copeptin level may be useful in predicting the rate of survival in patients with CLD.

Hepatocyte pyroptosis and release of inflammasome particles induce stellate cell activation and liver fibrosis.

BACKGROUND & AIMS: Increased hepatocyte death contributes to the pathology of acute and chronic liver diseases. However, the role of hepatocyte pyroptosis and extracellular inflammasome release in liver disease is unknown. METHODS: We used primary mouse and human hepatocytes, hepatocyte-specific leucine 351 to proline Nlrp3KICreA mice, and GsdmdKO mice to investigate pyroptotic cell death in hepatocytes and its impact on liver inflammation and damage. Extracellular NOD-, LRR-, and pyrin domain-containing protein 3 (NLRP3) inflammasomes were isolated from mutant NLRP3-YFP HEK cells and internalisation was studied in LX2 and primary human hepatic stellate cells. We also examined a cohort of 154 adult patients with biopsy-proven non-alcoholic fatty liver disease (Sir Charles Gairdner Hospital, Nedlands, Western Australia). RESULTS: We demonstrated that primary mouse and human hepatocytes can undergo pyroptosis upon NLRP3 inflammasome activation with subsequent release of NLRP3 inflammasome proteins that amplify and perpetuate inflammasome-driven fibrogenesis. Pyroptosis was inhibited by blocking caspase-1 and gasdermin D activation. The activated form of caspase-1 was detected in the livers and in serum from patients with non-alcoholic steatohepatitis and correlated with disease severity. Nlrp3KICreA mice showed spontaneous liver fibrosis under normal chow diet, and increased sensitivity to liver damage and inflammation after treatment with low dose lipopolysaccharide. Mechanistically, hepatic stellate cells engulfed extracellular NLRP3 inflammasome particles leading to increased IL-1ß secretion and α-smooth muscle actin expression. This effect was abrogated when cells were pre-treated with the endocytosis inhibitor cytochalasin B. CONCLUSIONS: These results identify hepatocyte pyroptosis and release of inflammasome components as a novel mechanism to propagate liver injury and liver fibrosis development. LAY SUMMARY: Our findings identify a novel mechanism of inflammation in the liver. Experiments in cell cultures, mice, and human samples show that a specific form of cell death, called pyroptosis, leads to the release of complex inflammatory particles, the NLRP3 inflammasome, from inside hepatocytes into the extracellular space. From there they are taken up by other cells and thereby mediate inflammatory and pro-fibrogenic stress signals. The discovery of this mechanism may lead to novel treatments for chronic liver diseases in the future.

Characterization and Proteome of Circulating Extracellular Vesicles as Potential Biomarkers for NASH.

Nonalcoholic fatty liver disease (NAFLD) is currently one of most common forms of chronic liver disease globally. NAFLD represents a wide spectrum of liver involvement from nonprogressive isolated steatosis to nonalcoholic steatohepatitis (NASH), characterized by liver necroinflammation and fibrosis and currently one of the top causes of end-stage liver disease and hepatocellular carcinoma. At present, there is a lack of effective treatments, and a central barrier to the development of therapies is the requirement for an invasive liver biopsy for diagnosis of NASH. Discovery of reliable, noninvasive biomarkers are urgently needed. In this study, we tested whether circulating extracellular vesicles (EVs), cell-derived small membrane-surrounded structures with a rich cargo of bioactive molecules, may serve as reliable noninvasive "liquid biopsies" for NASH diagnosis and assessment of disease severity. Total circulating EVs and hepatocyte-derived EVs were isolated by differential centrifugation and size-exclusion chromatography from serum samples of healthy individuals, patients with precirrhotic NASH, and patients with cirrhotic NASH. EVs were further characterized by flow cytometry, electron microscopy, western blotting, and dynamic light scattering assays before performing a proteomics analysis. Our findings suggest that levels of total and hepatocyte-derived EVs correlate with NASH clinical characteristics and disease severity. Additionally, using proteomics data, we developed understandable, powerful, and unique EV-based proteomic signatures for potential diagnosis of advanced NASH. Conclusion: Our study shows that the quantity and protein constituents of circulating EVs provide strong evidence for EV protein-based liquid biopsies for NAFLD/NASH diagnosis.