Chronic passive venous congestion drives hepatic fibrogenesis via sinusoidal thrombosis and mechanical forces

Microvesicle Tissue Factor Procoagulant Activity Is Elevated and Correlated With Disease Severity in Patients With Cirrhosis

BACKGROUND AND AIMS

Tissue factor-expressing microvesicles (MV-TF) have been found to correlate with thrombotic complications in various diseases. Simultaneously, there is expanding research regarding the effect of the coagulation cascade on liver fibrosis progression. The aim of our manuscript was to evaluate MV-TF activity in patients with cirrhosis and its correlation with disease severity.

METHODS

We prospectively enrolled 82 patients [11 with cirrhosis and hepatocellular cancer (Group 1), 50 with cirrhosis (Group 2) and 21 controls (Group 3)]. Extensive workup for disease staging and exclusion criteria was undertaken. Exclusion criteria included thrombophilia, history of thrombosis, recent hospitalisation, ongoing infection, alcohol dependence, cancer, haematological diseases and use of anticoagulant, antiplatelet or contraceptive drugs. Plasma tissue factor antigen concentration and MV-TF activity were assessed.

RESULTS

MV-TF showed median values of 4.03 [1.57], 3.17 [1.59] and 2.26 [1.23] pg/mL in Groups 1, 2 and 3, respectively. There was a statistically significant difference between Groups 1 and 3 (p < 0.001) and Groups 2 and 3 (p = 0.003), while Group 1 had higher values than Group 2 without statistical significance (p = 0.088). In Group 2, the patients' Child-Pugh (CP) stage was A in 56%, B in 26% and C in 18% of cases. MV-TF activity significantly correlated with decompensated cirrhosis (p = 0.005) and higher CP stage (p = 0.011). Finally, MV-TF activity significantly correlated with 12-month mortality (p = 0.021).

CONCLUSIONS

MV-TF activity is elevated in patients with cirrhosis, showing a significant correlation with disease severity. MV-TF may play a role in the procoagulant imbalance of liver cirrhosis and their contribution in disease progression should be studied further.

Congestion Enriches Intra-hepatic macrophages Through Reverse Zonation of CXCL9 in Liver Sinusoidal Endothelial Cells

BACKGROUND & AIMS

Congestion alters the microenvironment of the liver sinusoid along the portal-central axis. We studied spatial changes in immune cells in the sinusoid that contribute to congestive fibrosis and portal hypertension (PHTN).

METHODS

To visualize the distribution of immune cells in congestive hepatopathy (CH), we performed imaging mass cytometry (IMC) on liver tissue from patients with CH, Fontan-associated liver disease (FALD), and controls. We performed partial ligation of the inferior vena cava (pIVCL) to simulate CH in mice and isolated primary liver cells for single-cell RNA-sequencing (scRNA-seq) to study zonation of liver sinusoidal endothelial cells (LSECs). After pIVCL, mice were treated with intraperitoneal injections of AMG487, an inhibitor of the CXCL9 receptor, or a neutralizing antibody to CXCL9.

RESULTS

Peri-central macrophages are enriched in CH and FALD. Given the role of CXCL9 in macrophage patterning in the liver, we performed RNA in situ hybridization (RNAish) in CH and determined that CXCL9 was highly expressed in LSECs in FALD, suggesting that LSECs recruit macrophages in CH. After pIVCL, treatment with AMG487 or an antibody to CXCL9 attenuated portal pressures, fibrosis, and intra-hepatic macrophages. To study changes in LSECs that promote macrophage chemotaxis, we performed scRNA-seq after pIVCL and sham procedures. Analysis revealed 3 LSEC subpopulations according to sinusoidal location. RNAish identified peri-central LSECs as the predominant source of CXCL9 in FALD. In vitro analyses revealed that β-catenin and hypoxia inducible factor-1 α regulate CXCL9 transcription in peri-central LSECs.

CONCLUSIONS

CXCL9 derived from peri-central LSECs enriches intra-hepatic macrophages in CH and FALD, contributing to congestive fibrosis and PHTN. Strategies to target LSEC-derived CXCL9 may prevent the progression of CH and FALD.

Mitigating lead acetate-induced histopathologic and physiologic disorders in rats receiving vitamin C and glutathione supplement

The present work examines the extreme impact of lead acetate and the preventive function of co-supplementation with vitamin C and glutathione. It hypothesizes that these supplements can alleviate the poisonous effects of lead exposure. Eighty male albino rats, weighing 100 ± 15 g, were categorized into four groups: the control group, the second group receiving daily supplements of 100 mg/kg of body weight glutathione and 1 mg/100 g of body weight vitamin C orally, the third group receiving 100 mg/kg body weight of lead acetate orally daily, and the fourth group receiving similar oral dosages of lead acetate along with glutathione and vitamin C. Lead exposure significantly decreased body weight and relative testis weight, while relative organ weights for the liver, kidney, and spleen increased significantly. Additionally, lead acetate increased plasma glutamic pyruvic transaminase and glutamic oxaloacetic transaminase activities and plasma creatinine concentration (p < 0.05). Lead concentration rose significantly in blood, urine, liver, and kidney (p < 0.05). Examinations revealed that lead acetate exposure induced apoptotic DNA fragmentation in hepatocytes, significantly increasing caspase-3 activity (91 %) and annexin V indicators. Moreover, lead exposure induced a decrease in sperm count and motility, along with an increase in abnormal sperm morphology. However, vitamin C and glutathione supplementation significantly improved these adverse impacts, suggesting their protective function in counteracting the harmful impacts of lead acetate in different organs.

Insight into didecyl dimethyl ammonium bromide toxicity following acute exposure in pullets (Gallus gallusdomesticus)

Didecyl dimethyl ammonium bromide (DDAB) is a quaternary ammonium compound used for the sanitation of drinking water of poultry and water pipelines in farms. There is scarcity of information on the toxicology of DDAB in poultry. This study set out to profile the acute toxicity of DDAB in poultry. Issa brown pullets (n = 34) as experimental birds were orally administered varying doses of DDAB, using a syringe, after 12 h fasting, and observed for toxicity over 14 days. Control birds (n = 10) were similarly given normal saline orally. Toxic signs in the experimental birds were depression, anorexia, adipsia, vocalization with foamy salivation, later emaciation and death. The LD50 was calculated as 458.00 mg/kg. Birds given 2151 mg/kg DDAB died within 24 h, while those treated with 516 mg/kg succumbed on Day 14. At necropsy, grossly, there were necrosis and sloughing of the oesophagus and intestines, pale and friable liver, congested and necrotic lungs, friable popped out kidneys and emaciated carcasses. Microscopically, desquamation and necrosis of the oesophagus, crop, proventriculus and intestines and disruption of the koilin membrane of the gizzard were observed. The lungs, liver and kidneys were congested with mononuclear cellular infiltration plus loss of architecture in the lungs and liver. In conclusion, at high doses, DDAB caused significant toxicity in chickens and these findings provide new information which could serve as a guide in the diagnosis of quaternary ammonium toxicity in chicken. The results could be extrapolated to other quaternary ammonium toxicities in related avian species.

A Meta-Analysis of Cumulative Incidence of Hepatocellular Carcinoma After the Fontan Operation

BACKGROUND

Hepatic complications are increasingly recognized after the Fontan operation. The development of hepatocellular carcinoma (HCC) is associated with high mortality when diagnosed, but its incidence and risk factors are poorly understood. We conducted a systematic review and meta-analysis of the cumulative incidence of HCC after Fontan and associated risk factors.

METHODS

We searched PubMed, CINAHL, and MEDLINE databases for articles reporting the cumulative incidence of HCC after Fontan operation on March 21, 2023. A single-arm random effects meta-analysis was conducted to assess cumulative incidence at 10, 20, and 30 years after Fontan. Meta-analysis of the difference of the medians was used to assess the influence of risk factors on the development of HCC.

RESULTS

Four studies including a total of 1320 patients reported cumulative incidence. The cumulative incidence of HCC at 10, 20, and 30 years after Fontan was 0% (95% CI 0.00-0.01), 2% (0.01-0.06), and 7% (0.03-0.17) respectively. Seven studies including 6,250 patients reported overall incidence of HCC and associated risk factors. At a median 18.4 (IQR 11.9-24.9) years of follow-up, incidence of HCC was 2% (0.01-0.04). Only use of anticoagulation was associated with a lower risk of HCC (RR 0.3, 95% CI 0.1-0.88).

DISCUSSION

By 30 years after Fontan, cumulative incidence of HCC is high (7%). Risk of HCC development prior to 10 years post-Fontan is low (0%), though the decision to defer HCC surveillance in this period may require future investigation based on larger studies. Screening with ultrasound every 6 months starting 20 years post-Fontan is reasonable, however, further research regarding timing, cost-effectiveness, additional risk factors associated with HCC risk, and different screening modalities is required.

Importance of gamma-glutamyl transferase elevation in patients with Fontan-associated liver disease

AIM

In patients with Fontan-associated liver disease (FALD), gamma-glutamyl transferase (GGT) levels are often elevated, however, its clinical importance is unclear. We investigated the relationship between the clinical course of FALD and GGT levels.

METHODS

We enrolled 145 patients with FALD who underwent right-heart catheterization (RHC) and visited our department. Ursodeoxycholic acid (UDCA) was administered to 62 of the patients. Patients with GGT levels <50 and ≥50 U/L were compared. Follow-up RHC was undertaken in 76 patients. Cases in which GGT levels decreased by ≥10% or <50 U/L were defined as improved (n = 33).

RESULTS

Patients with GGT levels ≥50 U/L had significantly lower levels of albumin and higher levels of alanine transaminase (ALT) but no significant differences in RHC factors. Over a 4.6-year period, 43.4% showed improvement in GGT levels. Improved cases had significantly lower total bilirubin (1.1 vs. 1.6 mg/dL), AST (22 vs. 28 U/L), and ALT (18 vs. 27 U/L) levels than nonimproved cases (n = 29, p < 0.05), and the change in platelet count (-0.5 vs. -3.0 × 10-4/μL) was significantly lower in the latter (p = 0.03). The improvement rate was significantly higher in UDCA-treated cases (55.2%) with GGT levels ≥50 U/L compared to cases not treated with UDCA (18.2%, p = 0.04).

CONCLUSION

In cases of FALD with no improvement in GGT level, the platelet count decreased over time, suggesting progression of fibrosis. Physicians should be aware of the importance of a high GGT level in patients with FALD.

Evaluation of diagnostic criteria for mild-to-advanced stages of Fontan-associated liver disease: A nationwide epidemiological survey in Japan

AIM

Fontan-associated liver disease (FALD) is a complication after Fontan surgery, and a common cause of liver tumors and cirrhosis. However, no diagnostic criteria for FALD have been established, leading to an underestimation of its prevalence.

METHODS

We conducted a national survey to elucidate the characteristics of FALD by collecting data from high-volume centers managing patients who had undergone the Fontan surgery in Japan. In total, 1168 patients were enrolled in the study. First, we examined typical liver findings on ultrasonography after the Fontan surgery. Next, we proposed diagnostic criteria for FALD and advanced FALD based on blood tests, imaging, liver tumors, and pathological examinations. We investigated the sensitivity of histologically diagnosed FALD and advanced FALD based on criteria for blood or imaging tests.

RESULTS

Hepatomegaly, hepatic venous dilatation, caudate lobe enlargement, splenomegaly, liver atrophy, ascites, hepatocellular carcinoma, and hepatic tumors other than hepatocellular carcinoma were observed in 37.7%, 29.9%, 18.4%, 33.2%, 3.2%, 6.0%, 0.85%, and 10.0% of patients, respectively. Typical ultrasound findings of FALD included hepatomegaly, hepatic vein dilatation, and splenomegaly, reflecting liver congestion. With the progression of fibrosis, caudate lobe enlargement and splenomegaly became more prominent. Based on these findings, we proposed diagnostic criteria for FALD. Using these criteria, FALD was diagnosed in 1014 (86.8%) of the patients, and all patients with a pathological diagnosis of FALD were successfully identified. Eight patients were found to have pathological cirrhosis, and all were diagnosed with advanced FALD using our criteria based on blood tests or imaging.

CONCLUSION

Our diagnostic criteria facilitate detection of FALD or advanced FALD after the Fontan surgery. The accuracy of these criteria should be further evaluated.

Fontan-associated liver disease: the importance of multidisciplinary teamwork in its management

The Fontan operation, which directly connects the superior and inferior vena cava to the pulmonary artery, is a palliative surgery for children with a functional or anatomic single ventricle. This procedure leads to hemodynamic changes (Fontan circulation) in patients, who tend to develop congestive hepatic fibrosis characterized by sinusoidal fibrosis and dilatation beginning approximately 10 years after the procedure. In addition, in the context of severe fibrosis and cirrhosis, hepato-gastrointestinal complications including hepatocellular carcinoma, focal nodular hyperplasia, and portal hypertension can arise. Fontan-associated liver disease (FALD) encompasses the broad spectrum of liver alterations secondary to postoperative hemodynamic changes, and the effective management of FALD requires contributions from specialists in hepatology, gastroenterology, surgery, radiology, histopathology, and pediatric and adult cardiology. In this article, we outline the pathogenesis of FALD and discuss the importance of a multidisciplinary collaborative approach to its management.

Quantifying and visualizing abdominal hemodynamics in patients with Fontan circulation by 4D phase-contrast flow magnetic resonance imaging at 1.5 T

BACKGROUND

Liver fibrosis has been recognized as a long-term morbidity associated with Fontan circulation (Fontan-associated liver disease, FALD). The pathophysiology of FALD is not completely understood and abnormal flow dynamics may be associated with this condition. Liver hemodynamics can be quantitatively evaluated with four-dimensional phase-contrast flow magnetic resonance imaging (4D PC flow MRI). The study aimed to evaluate suitability of liver 4D PC flow MRI in Fontan patients and relate flow measurements to normal values and FALD severity.

PATIENTS AND METHODS

Twenty-two Fontan patients were examined by 4D PC flow MRI at 1.5 Tesla to assess mesenteric, portal, splenic, and hepatic venous blood flow. Severity of FALD was graded based on routine screening, including abdominal ultrasound and laboratory tests.

RESULTS

Median age was 18.5 (interquartile range, IQR 15.5-20.2) years. FALD was graded as "none or mild" in 16 and as "moderate to severe" in six cases. Ten patients presented at least one feature of portal hypertension (ascites, splenomegaly, or thrombocytopenia). For the entire cohort, blood flow in the superior mesenteric, splenic, and portal vein was lower than reported in the literature. No significant differences were observed in relation to FALD severity. Features of portal hypertension were associated with a higher splenic vein blood flow (0.34 ± 0.17 vs. 0.20 ± 0.07 l/min, p = 0.046). Splenic vein blood flow was negatively correlated to platelet count (r = -0.590, p = 0.005).

CONCLUSIONS

4D PC flow MRI appears suitable to assess liver hemodynamics in Fontan patients and integration into clinical follow-up might help to improve our understanding of FALD.

Portal vein thrombosis: diagnosis, management, and endpoints for future clinical studies

Portal vein thrombosis (PVT) refers to the development of a non-malignant obstruction of the portal vein, its branches, its radicles, or a combination. This Review first provides a comprehensive overview of all aspects of PVT, namely the specifics of the portal venous system, the risk factors for PVT, the pathophysiology of portal hypertension in PVT, the interest in non-invasive tests, as well as therapeutic approaches including the effect of treating risk factors for PVT or cause of cirrhosis, anticoagulation, portal vein recanalisation by interventional radiology, and prevention and management of variceal bleeding in patients with PVT. Specific issues are also addressed including portal cholangiopathy, mesenteric ischaemia and intestinal necrosis, quality of life, fertility, contraception and pregnancy, and PVT in children. This Review will then present endpoints for future clinical studies in PVT, both in patients with and without cirrhosis, agreed by a large panel of experts through a Delphi consensus process. These endpoints include classification of portal vein thrombus extension, classification of PVT evolution, timing of assessment of PVT, and global endpoints for studies on PVT including clinical outcomes. These endpoints will help homogenise studies on PVT and thus facilitate reporting, comparison between studies, and validation of future studies and trials on PVT.

The Pathophysiology of Portal Hypertension

This article reviews the pathophysiology of portal hypertension that includes multiple mechanisms internal and external to the liver. This article starts with a review of literature describing the cellular and molecular mechanisms of portal hypertension, microvascular thrombosis, sinusoidal venous congestion, portal angiogenesis, vascular hypocontractility, and hyperdynamic circulation. Mechanotransduction and the gut-liver axis, which are newer areas of research, are reviewed. Dysfunction of this axis contributes to chronic liver injury, inflammation, fibrosis, and portal hypertension. Sequelae of portal hypertension are discussed in subsequent studies.

Prognostic Indicators of Morbidity and Mortality in Children with Congestive Hepatopathy Presenting with Ascites

Objectives: Congestive hepatopathy is a significant complication for children suffering from right-sided heart disease (RHD). We hypothesize that hospitalized pediatric patients with ascites will have congestive hepatopathy leading to advanced liver disease if their cardiac condition is RHD versus non-right-sided heart disease (NRHD). Methods: This is a retrospective cohort study of pediatric patients who presented with an ascites diagnosis (ICD-10 R18) and at least one cardiac diagnosis. Patient demographics, past medical history, laboratory values, imaging results, calculated clinical scores (e.g., APRI, FIB-4), treatment, length of stay (LOS), and death at hospital discharge were analyzed. Results: Of the 136 patients with ascites, 21 patients presented with a primary cardiac disease (12 in RHD and 9 in NRHD). Of these patients, eight (38%) were female, and nine (43%) were White, seven (33%) were Black, and five (24%) were unknown. The RHD group had a mean age of 5.1 Y (vs. 9.5 Y in NRHD). The mean APRI score in RHD patients was 2.87, and it was 0.85 in NRDH. Treatments were similar, with most patients requiring diuretics (11 RHD (92%) vs. 8 NRDH (89%)); 5 RHD (42%) vs. 4 NRDH (44%) required inotropic support. RHD patients had a longer LOS, with an average of 92 days vs. 52 days for NRDH patients. Overall, each group had one death at discharge (8% RHD vs. 11% NRDH). Conclusions: In the realm of children with ascites, the subset grappling with congestive heart disease paints a unique picture. In this context, ascites stands as an elusive predictor of liver decompensation, defying conventional diagnostic pathways.

Neutrophil extracellular traps (NETs) and fibrotic diseases

Fibrosis, a common cause and serious outcome of organ failure that can affect any organ, is responsible for up to 45% of all deaths in various clinical settings. Both preclinical models and clinical trials investigating various organ systems have shown that fibrosis is a highly dynamic process. Although many studies have sought to gain understanding of the mechanism of fibrosis progression, their findings have been mixed. In recent years, increasing evidence indicates that neutrophil extracellular traps (NETs) are involved in many inflammatory and autoimmune disorders and participate in the regulation of fibrotic processes in various organs and systems. In this review, we summarize the current understanding of the role of NETs in fibrosis development and progression and their possibility as therapeutic targets.

Chronic heart failure induces early defenestration of liver sinusoidal endothelial cells (LSECs) in mice

AIM

Chronic heart failure (CHF) is often linked to liver malfunction and systemic endothelial dysfunction. However, whether cardio-hepatic interactions in heart failure involve dysfunction of liver sinusoidal endothelial cells (LSECs) is not known. Here we characterize LSECs phenotype in early and end stages of chronic heart failure in a murine model.

METHODS

Right ventricle (RV) function, features of congestive hepatopathy, and the phenotype of primary LSECs were characterized in Tgαq*44 mice, with cardiomyocyte-specific overexpression of the Gαq protein, at the age of 4- and 12-month representative for early and end-stage phases of CHF, respectively.

RESULTS

4- and 12-month-old Tgαq*44 mice displayed progressive impairment of RV function and alterations in hepatic blood flow velocity resulting in hepatic congestion with elevated GGT and bilirubin plasma levels and decreased albumin concentration without gross liver pathology. LSECs isolated from 4- and 12-month-old Tgαq*44 mice displayed significant loss of fenestrae with impaired functional response to cytochalasin B, significant changes in proteome related to cytoskeleton remodeling, and altered vasoprotective function. However, LSECs barrier function and bioenergetics were largely preserved. In 4- and 12-month-old Tgαq*44 mice, LSECs defenestration was associated with prolonged postprandial hypertriglyceridemia and in 12-month-old Tgαq*44 mice with proteomic changes of hepatocytes indicative of altered lipid metabolism.

CONCLUSION

Tgαq*44 mice displayed right-sided HF and altered hepatic blood flow leading to LSECs dysfunction involving defenestration, shift in eicosanoid profile, and proteomic changes. LSECs dysfunction appears as an early and persistent event in CHF, preceding congestive hepatopathy and contributing to alterations in lipoprotein transport and CHF pathophysiology.

Management of Portal Hypertension in Patients with Hepatocellular Carcinoma on Systemic Treatment: Current Evidence and Future Perspectives

The management of CSPH in patients undergoing systemic treatment for HCC has emerged as a critical concern due to the absence of reliable diagnostic criteria and uncertainties surrounding therapeutic approaches. This review aims to underscore the primary pathophysiological aspects linking HCC and PH, while also addressing the current and emerging clinical strategies for the management of portal hypertension. A review of studies from January 2003 to June 2023 was conducted using the PubMed database and employing MeSH terms, such as "hepatocellular carcinoma", "immune checkpoint inhibitors", "systemic therapy", "portal hypertension", "variceal bleeding" and "tyrosine kinase inhibitors". Despite promising results of tyrosine kinase inhibitors in animal models for PH and fibrosis, only Sorafenib has demonstrated similar effects in human studies, whereas Lenvatinib appears to promote PH development. The impact of Atezolizumab/Bevacizumab on PH remains uncertain, with an increasing risk of bleeding related to Bevacizumab in patients with prior variceal hemorrhage. Given the absence of specific guidelines, endoscopic surveillance during treatment is advisable, and primary and secondary prophylaxis of variceal bleeding should adhere to the Baveno VII recommendations. Furthermore, in patients with advanced HCC, refinement of diagnostic criteria for CSPH and guidelines for its surveillance are warranted.

Fontan-Associated Liver Disease: A Review

Fontan-associated liver disease (FALD) is a chronic complication of the Fontan procedure, a palliative surgery for patients with congenital heart disease that results in a single-ventricle circulation. The success of the Fontan procedure has led to a growing population of post-Fontan patients living well into adulthood. For this population, FALD is a major cause of morbidity and mortality. It encompasses a spectrum of hepatic abnormalities, ranging from mild fibrosis to cirrhosis and hepatocellular carcinoma. The pathophysiology of FALD is multifactorial, involving hemodynamic and inflammatory factors. The diagnosis and monitoring of FALD present many challenges. Conventional noninvasive tests that use liver stiffness as a surrogate marker of fibrosis are unreliable in FALD, where liver stiffness is also a result of congestion due to the Fontan circulation. Even invasive tissue sampling is inconsistent due to the patchy distribution of fibrosis. FALD is also associated with both benign and malignant liver lesions, which may exhibit similar imaging features. There is therefore a need for validated diagnostic and surveillance protocols to address these challenges. The definitive treatment of end-stage FALD is also a subject of controversy. Both isolated heart transplantation and combined heart-liver transplantation have been employed, with the latter becoming increasingly preferred in the US. This article reviews the current literature on the epidemiology, pathophysiology, diagnosis, and management of FALD, and highlights knowledge gaps that require further research.

Abnormal metabolism in hepatic stellate cells: Pandora's box of MAFLD related hepatocellular carcinoma

Metabolic associated fatty liver disease (MAFLD) is a significant risk factor for the development of hepatocellular carcinoma (HCC). Hepatic stellate cells (HSCs), as key mediators in liver injury response, are believed to play a crucial role in the repair process of liver injury. However, in MAFLD patients, the normal metabolic and immunoregulatory mechanisms of HSCs become disrupted, leading to disturbances in the local microenvironment. Abnormally activated HSCs are heavily involved in the initiation and progression of HCC. The metabolic disorders and abnormal activation of HSCs not only initiate liver fibrosis but also contribute to carcinogenesis. In this review, we provide an overview of recent research progress on the relationship between the abnormal metabolism of HSCs and the local immune system in the liver, elucidating the mechanisms of immune imbalance caused by abnormally activated HSCs in MAFLD patients. Based on this understanding, we discuss the potential and challenges of metabolic-based and immunology-based mechanisms in the treatment of MAFLD-related HCC, with a specific focus on the role of HSCs in HCC progression and their potential as targets for anti-cancer therapy. This review aims to enhance researchers' understanding of the importance of HSCs in maintaining normal liver function and highlights the significance of HSCs in the progression of MAFLD-related HCC.

Metformin ameliorates liver fibrosis induced by congestive hepatopathy via the mTOR/HIF-1α signaling pathway

INTRODUCTION AND OBJECTIVES

Congestive hepatopathy (CH) is a hepatic vascular disease that results in chronic liver congestion, which can lead to liver fibrosis. New uses of metformin have been discovered over the years. However, the function of metformin in congestive liver fibrosis is not yet fully understood. This study aimed to investigate the effect of metformin on liver fibrosis in a mouse model of CH.

MATERIALS AND METHODS

Partial ligation of the inferior vena cava (pIVCL) was used to establish a mouse model of liver congestion. Metformin (0.1%) was added to the daily drinking water of the animals, and the effect of metformin on liver tissue was studied after 6 weeks. Hepatic stellate cells (HSCs) were also stimulated with CoCl2 to investigate the inhibitory impact of metformin on the mammalian target of rapamycin (mTOR)/hypoxia-inducible factor-1α (HIF-1α) pathway.

RESULTS

Metformin attenuated liver congestion; decreased the expression of collagen, fibronectin, α-smooth muscle actin (α-SMA), and HIF-1α; and ameliorated liver fibrosis in pIVCL mice. The proliferation and migration of HSCs were inhibited by metformin in vitro, which prevented α-SMA expression and restrained HSC activation. The expression levels of phosphorylated-mTOR, HIF-1α, and vascular endothelial growth factor were also decreased.

CONCLUSIONS

Metformin inhibits CH-induced liver fibrosis. Functionally, this beneficial effect may be the result of inhibition of HSC activation and of the mTOR/HIF-1α signaling pathway.

EASL-ERN position paper on liver involvement in patients with Fontan-type circulation

Fontan-type surgery is the final step in the sequential palliative surgical treatment of infants born with a univentricular heart. The resulting long-term haemodynamic changes promote liver damage, leading to Fontan-associated liver disease (FALD), in virtually all patients with Fontan circulation. Owing to the lack of a uniform definition of FALD and the competitive risk of other complications developed by Fontan patients, the impact of FALD on the prognosis of these patients is currently debatable. However, based on the increasing number of adult Fontan patients and recent research interest, the European Association for The Study of the Liver and the European Reference Network on Rare Liver Diseases thought a position paper timely. The aims of the current paper are: (1) to provide a clear definition and description of FALD, including clinical, analytical, radiological, haemodynamic, and histological features; (2) to facilitate guidance for staging the liver disease; and (3) to provide evidence- and experience-based recommendations for the management of different clinical scenarios.

Portal Hypertension in Nonalcoholic Fatty Liver Disease: Challenges and Paradigms

Portal hypertension in cirrhosis is defined as an increase in the portal pressure gradient (PPG) between the portal and hepatic veins and is traditionally estimated by the hepatic venous pressure gradient (HVPG), which is the difference in pressure between the free-floating and wedged positions of a balloon catheter in the hepatic vein. By convention, HVPG≥10 mmHg indicates clinically significant portal hypertension, which is associated with adverse clinical outcomes. Nonalcoholic fatty liver disease (NAFLD) is a common disorder with a heterogeneous clinical course, which includes the development of portal hypertension. There is increasing evidence that portal hypertension in NAFLD deserves special considerations. First, elevated PPG often precedes fibrosis in NAFLD, suggesting a bidirectional relationship between these pathological processes. Second, HVPG underestimates PPG in NAFLD, suggesting that portal hypertension is more prevalent in this condition than currently believed. Third, cellular mechanoresponses generated early in the pathogenesis of NAFLD provide a mechanistic explanation for the pressure-fibrosis paradigm. Finally, a better understanding of liver mechanobiology in NAFLD may aid in the development of novel pharmaceutical targets for prevention and management of this disease.

Budd-Chiari Syndrome Caused by Polycythemia Vera: A Case Report

Budd-Chiari syndrome (BCS) is a rare condition characterized by the obstruction of hepatic venous outflow. It has various potential etiologies, with myeloproliferative neoplasms representing the most prevalent pathogenic association. Here, we present the case of a 51-year-old male who manifested abdominal pain and ascites. Subsequent clinical investigation revealed the presence of BCS secondary to a myeloproliferative syndrome, specifically polycythemia vera. This case emphasizes the importance of diagnosing BCS and conducting a thorough investigation into its underlying etiology.

Microvascular Thrombosis and Liver Fibrosis Progression: Mechanisms and Clinical Applications

Fibrosis is an unavoidable consequence of chronic inflammation. Extracellular matrix deposition by fibroblasts, stimulated by multiple pathways, is the first step in the onset of chronic liver disease, and its propagation promotes liver dysfunction. At the same time, chronic liver disease is characterized by alterations in primary and secondary hemostasis but unlike previously thought, these changes are not associated with an increased risk of bleeding complications. In recent years, the role of coagulation imbalance has been postulated as one of the main mechanisms promoting hepatic fibrogenesis. In this review, we aim to investigate the function of microvascular thrombosis in the progression of liver disease and highlight the molecular and cellular networks linking hemostasis to fibrosis in this context. We analyze the predictive and prognostic role of coagulation products as biomarkers of liver decompensation (ascites, variceal hemorrhage, and hepatic encephalopathy) and liver-related mortality. Finally, we evaluate the current evidence on the application of antiplatelet and anticoagulant therapies for prophylaxis of hepatic decompensation or prevention of the progression of liver fibrosis.

Silencing mouse circular RNA circSlc8a1 by circular antisense cA-circSlc8a1 induces cardiac hepatopathy

Circular RNAs (circRNAs) are a group of non-coding RNAs with a unique circular structure generated by back-splicing. It is acknowledged that circRNAs play critical roles in cardiovascular diseases. However, functional studies of circRNAs were impeded due to lack of effective in vivo silencing approaches. Since most circRNAs are produced by protein-coding transcripts, gene editing typically affects the coding activity of the parental genes. In this study, we developed a circular antisense RNA (cA-circSlc8a1) that could silence the highly expressed circRNA circSlc8a1 in the mouse heart but not its parental Slc8a1 linear mRNA. Transgenic cA-circSlc8a1 mice developed congestive heart failure resulting in a significant increase in the body weight secondary to peripheral edema and congestive hepatopathy. To further test the role of circSlc8a1, we generated transgenic mice overexpressing circSlc8a1 and observed a protective effect of circSlc8a1 in a pressure overload model. Mechanistically, we found that circSlc8a1 translocated into mitochondria to drive ATP synthesis. While establishing a transgenic murine model for antisense-mediated circRNA silencing without interfering with the parental linear RNA, our finding revealed the essential role of circSlc8a1 in maintaining heart function and may lay the groundwork of using the circular antisense RNA as a potential gene therapy approach for cardiovascular diseases.

Liver Fibrosis Markers Represent Central Venous Pressure in Post-pubertal Patients With Congenital Heart Disease

Background Central venous pressure (CVP) is one of the most important hemodynamic parameters in patients with congenital heart disease (CHD). In adults, it is well-known that liver fibrosis markers reflect CVP, but this is not well-understood in children. We investigated the liver fibrosis markers in pediatric CHD patients and their ability to predict CVP. Methods We studied 160 patients who underwent cardiac catheterization in our hospital between January 2017 and December 2020. The levels of the fibrotic markers, including type IV collagen 7s, procollagen type III peptide, and hyaluronic acid, were measured. Results Procollagen type III peptide was markedly elevated in infants younger than one year of age. From one to 15 years of age, it was slightly lower than in the infant group, with a peak at around 10 years of age. In the age group of 16 years and older, most of its values were generally high. Type IV collagen 7s and hyaluronic acid levels were high in infants, with no significant differences at later ages. Procollagen type III peptide and hyaluronic acid showed no significant correlation with CVP in any of the age groups, whereas type IV collagen 7s significantly correlated with CVP in the age group above one year old. Conclusions We found that elevated liver fibrosis markers, particularly type IV collagen 7s, correlated with central venous pressure in CHD patients older than one year. Measurement of liver fibrosis markers may allow the early detection of changes in CVP and liver function in patients with CHD.

Quantitative liver magnetic resonance imaging: correlation between conventional magnetic resonance imaging, laboratory values, and prognostic indices in Budd-Chiari syndrome

PURPOSE

In Budd-Chiari syndrome (BCS), unevenly distributed parenchymal changes and perfusion abnormalities occur due to hepatic venous outflow obstruction. This study aimed to evaluate the changes in the liver parenchyma in BCS using the quantitative magnetic resonance (MR) techniques of MR elastography, T1 and T2 mapping, and diffusion imaging and correlate the quantitative MR parameters through biochemical results and prognostic indices.

METHODS

Fourteen patients with BCS (seven men and seven women) were examined retrospectively. Liver stiffness (kPa), T1 relaxation times (ms) were achieved using the modified Look-Locker inversion recovery (MOLLI) 3(2)3(2)5 sequence and B1-corrected variable flip angle methods, T2 relaxation times (ms), and apparent diffusion coefficient (ADC) values (mm2/s) were measured using regions of interest placed in the same region in all quantitative methods. Measurements were repeated at the precontrast and postcontrast hepatobiliary phases. The reduction rate (RR; %) and adjusted postcontrast T1 (%) were calculated. The values obtained from different liver parenchyma areas (whole liver, caudate lobe, pathological T2 hyperintense tissue, and relatively preserved normal-appearing tissue) were compared using the Wilcoxon signed-rank test. Spearman's correlation coefficient was used to investigate the correlation between quantitative MR parameters and biochemical parameters/ prognostic scores (Child-Pugh score, Clichy score, and Rotterdam index).

RESULTS

The parenchymal stiffness and precontrast T1 values of the caudate lobe were significantly lower than those of the remainder of the parenchyma, whereas the adjusted postcontrast T1 percentages (MOLLI) were significantly higher (P ≤ 0.027). The parenchymal stiffness value, T1 and T2 values, percentages of RR (MOLLI), and adjusted postcontrast T1 values for the pathological tissue and relatively normal tissue were significantly different (P < 0.028). No significant difference was found in terms of ADC values between any of the distinct regions of the liver. A strong correlation was detected between the Child-Pugh score, Clichy score, and precontrast T1 values obtained through the MOLLI sequence (r = 0.867, P = 0.012, r = 0.821, P = 0.023, respectively). No correlation was found between the whole liver stiffness values and the laboratory parameters, fibrosis markers, prognostic indices, or MR parameters. A significant correlation was identified between creatinine levels and several T1 parameters and the T2 relaxation time (r ≥ 0.661, P ≤ 0.052).

CONCLUSION

Tissue stiffness and T1 relaxation values are high in the areas identified as fibrosis compared with those in the relatively preserved parenchyma. The T1 relaxation time can offer quantitative information for assessing segmental functional changes and prognosis in BCS.ion for assessing segmental functional changes and prognosis in BCS.

Biomechanics in liver regeneration after partial hepatectomy

The liver is a complicated organ within the body that performs wide-ranging and vital functions and also has a unique regenerative capacity after hepatic tissue injury and cell loss. Liver regeneration from acute injury is always beneficial and has been extensively studied. Experimental models including partial hepatectomy (PHx) reveal that extracellular and intracellular signaling pathways can help the liver recover to its equivalent size and weight prior to an injury. In this process, mechanical cues possess immediate and drastic changes in liver regeneration after PHx and also serve as main triggering factors and significant driving forces. This review summarized the biomechanics progress in liver regeneration after PHx, mainly focusing on PHx-based hemodynamics changes in liver regeneration and the decoupling of mechanical forces in hepatic sinusoids including shear stress, mechanical stretch, blood pressure, and tissue stiffness. Also discussed were the potential mechanosensors, mechanotransductive pathways, and mechanocrine responses under varied mechanical loading in vitro. Further elucidating these mechanical concepts in liver regeneration helps establish a comprehensive understanding of the biochemical factors and mechanical cues in this process. Proper adjustment of mechanical loading within the liver might preserve and restore liver functions in clinical settings, serving as an effective therapy for liver injury and diseases.

Clinical and prognostic implications of hyaluronic acid in hospitalized patients with heart failure

We investigated the clinical and prognostic implications of hyaluronic acid, a liver fibrosis marker, in patients with heart failure. We measured hyaluronic acid levels on admission in 655 hospitalized patients with heart failure between January 2015 and December 2019. Patients were stratified into three groups according to hyaluronic acid level: low (< 84.3 ng/mL, n = 219), middle (84.3-188.2 ng/mL, n = 218), and high (≥ 188.2 ng/mL, n = 218). The primary endpoint was all-cause death. The high hyaluronic acid group had higher N-terminal pro-brain-type natriuretic peptide levels, larger inferior vena cava, and shorter tricuspid annular plane systolic excursion than the other two groups. During the follow-up period (median 485 days), 132 all-cause deaths were observed: 27 (12.3%) in the low, 37 (17.0%) in the middle, and 68 (31.2%) in the high hyaluronic acid (P < 0.001) groups. Cox proportional hazards analysis revealed that higher log-transformed hyaluronic acid levels were significantly associated with all-cause death (hazard ratio, 1.38; 95% confidence interval, 1.15-1.66; P < 0.001). No significant interaction was observed between hyaluronic acid level and reduced/preserved left ventricular ejection fraction on all-cause death (P = 0.409). Hyaluronic acid provided additional prognostic predictability to pre-existing prognostic factors, including the fibrosis-4 index (continuous net reclassification improvement, 0.232; 95% confidence interval, 0.022-0.441; P = 0.030). In hospitalized patients with heart failure, hyaluronic acid was associated with right ventricular dysfunction and congestion and was independently associated with prognosis regardless of left ventricular ejection fraction.

Pulmonary artery banding in sheep: a novel large animal model for congestive hepatopathy

Congestive hepatopathy is becoming increasingly recognized among Fontan-palliated patients. Elevated central venous pressure is thought to drive the pathologic progression, characterized by sinusoidal dilatation, congestion, and fibrosis. A clinically relevant large animal model for congestive hepatopathy would provide a valuable platform for researching novel biomarkers, treatment, and prevention. Here, we report on a titratable, sheep pulmonary artery banding model for this disease application. Pulmonary artery banding was achieved by progressively inflating the implanted pulmonary artery cuff. Right ventricular catheter was implanted to draw venous blood samples and measure pressure. The pulmonary artery cuff pressure served as a surrogate for the intensity of pulmonary artery banding and was measured weekly. After about 9 wk, animals were euthanized, and the liver was harvested for histopathological assessment. Nine animal subjects received pulmonary artery banding for 64 ± 8 days. Four of the nine subjects exhibited moderate to severe liver injury, and three of those four exhibited bridging fibrosis. Increasing pulmonary artery cuff pressure significantly correlated with declining mixed venous oxygen saturation (P = 3.29 × 10-5), and higher congestive hepatic fibrosis score (P = 0.0238), suggesting that pulmonary artery banding strategy can be titrated to achieve right-sided congestion and liver fibrosis. Blood analyses demonstrated an increase in plasma bile acids, aspartate aminotransferase, and γ-glutamyltransferase among subjects with moderate to severe injury, further corroborating liver tissue findings. Our large animal pulmonary artery banding model recapitulates congestive hepatopathy and provides a basis to bridge the current gaps in scientific and clinical understanding about the disease.NEW & NOTEWORTHY We present here a large animal platform for congestive hepatopathy, a disease growing in clinical prevalence due to the increasing number of Fontan-palliated patients. Further data are needed to develop a better clinical management strategy for this poorly characterized patient population. Previous reports of animal models to study this disease have mostly been in small animals with limited fidelity. We show that congestive hepatopathy can be replicated in a chronic, progressive pulmonary artery banding model in sheep. We also show that the banding strategy can be controlled to titrate the level of liver injury. To date, we do not know of any other large animal model that can achieve this level of control over disease phenotype and clinical relevance.

Anticoagulation in Patients with Liver Cirrhosis: Friend or Foe?

Concepts regarding the status of the coagulation process in cirrhosis are rapidly changing. Instead of a disease defined by excessive bleeding risk, recent studies have shown cirrhosis to be associated with a fragile state of rebalanced hemostasis, easily swayed in either direction, thrombosis, or bleeding. These findings, combined with the ever-growing population of patients with cirrhosis with an indication for anticoagulation (AC) and the emergence of the non-alcoholic fatty liver disease epidemic, have prompted a reexamination of the use of AC in patients with cirrhosis, either as a treatment for a concurrent thrombotic disorder or even as a possible therapeutic option that could influence the natural course of the disease and its complications. In recent years, a significant number of studies have been formulated to evaluate these possibilities. These studies evaluated, among others, the efficacy and safety of AC in thrombotic disorders or thrombotic complications of cirrhosis, its effect on survival, and the class of anticoagulants which is more suitable for patients with cirrhosis, depending on disease severity. This review examines recent studies investigating the use of AC in patients with cirrhosis and attempts to provide a simple guide for clinicians regarding the use of AC in patients with cirrhosis and its potential risks and benefits.

Fontan-associated liver disease: Diagnosis, surveillance, and management

The Fontan operation is a lifesaving procedure for patients with functional single-ventricle congenital heart disease, where hypoplastic left heart syndrome is the most frequent anomaly. Hemodynamic changes following Fontan circulation creation are now increasingly recognized to cause multiorgan affection, where the development of a chronic liver disease, Fontan-associated liver disease (FALD), is one of the most important morbidities. Virtually, all patients with a Fontan circulation develop liver congestion, resulting in fibrosis and cirrhosis, and most patients experience childhood onset. FALD is a distinctive type of congestive hepatopathy, and its pathogenesis is thought to be a multifactorial process driven by increased nonpulsatile central venous pressure and decreased cardiac output, both of which are inherent in the Fontan circulation. In the advanced stage of liver injury, complications of portal hypertension often occur, and there is a risk of developing secondary liver cancer, reported at young age. However, FALD develops with few clinical symptoms, a surprisingly variable degree of severity in liver disease, and with little relation to poor cardiac function. The disease mechanisms and modifying factors of its development are still not fully understood. As one of the more important noncardiac complications of the Fontan circulation, FALD needs to be diagnosed in a timely manner with a structured monitoring scheme of disease development, early detection of malignancy, and determination of the optimal time point for transplantation. There is also a clear need for consensus on the best surveillance strategy for FALD. In this regard, imaging plays an important role together with clinical scoring systems, biochemical workups, and histology. Patients operated on with a Fontan circulation are generally followed up in cardiology units. Ultimately, the resulting multiorgan affection requires a multidisciplinary team of healthcare personnel to address the different organ complications. This article discusses the current concepts, diagnosis, and management of FALD, with special emphasis on the role of different imaging techniques in the diagnosis and monitoring of disease progression, as well as current recommendations for liver disease surveillance.

Mild Acquired von Willebrand Syndrome and Cholestasis in Pediatric and Adult Patients with Fontan Circulation

Background: Hemodynamic alterations in Fontan patients (FP) are associated with hemostatic dysbalance and Fontan-associated liver disease. Studies of other hepatopathologies indicate an interplay between cholestasis, tissue factor (TF), and von Willebrand factor (VWF). Hence, we hypothesized a relationship between the accumulation of bile acids (BA) and these hemostatic factors in FP. Methods: We included 34 FP (Phenprocoumon n = 15, acetylsalicylic acid (ASA) n = 16). BA were assessed by mass spectrometry. TF activity and VWF antigen (VWF:Ag) were determined by chromogenic assays. VWF collagen-binding activity (VWF:CB) was assessed via ELISA. Results: Cholestasis was observed in 6/34 FP (total BA ≥ 10 µM). BA levels and TF activity did not correlate (p = 0.724). Cholestatic FP had lower platelet counts (p = 0.013) from which 5/6 FP were not treated with ASA. VWF:Ag levels were increased in 9/34 FP and significantly lower in FP receiving ASA (p = 0.044). Acquired von Willebrand syndrome (AVWS) was observed in 10/34-FP, with a higher incidence in cholestatic FP (4/6) (p = 0.048). Conclusions: Cholestasis is unexpectedly infrequent in FP and seems to be less frequent under ASA therapy. Therefore, ASA may reduce the risk of advanced liver fibrosis. FP should be screened for AVWS to avoid bleeding events, especially in cholestatic states.

Improving Management of Portal Hypertension: The Potential Benefit of Non-Etiological Therapies in Cirrhosis

Portal hypertension is the consequence of cirrhosis and results from increased sinusoidal vascular resistance and hepatic blood inflow. Etiological therapies represent the first intervention to prevent a significant increase in portal pressure due to chronic liver damage. However, other superimposed pathophysiological drivers may worsen liver disease, including inflammation, bacterial translocation, endothelial dysfunction, and hyperactivation of hemostasis. These mechanisms can be targeted by a specific class of drugs already used in clinical practice. Albumin, rifaximin, statins, aspirin, and anticoagulants have been tested in cirrhosis and were a topic of discussion in the last Baveno consensus as non-etiological therapies. Based on the pathogenesis of portal hypertension in cirrhosis, our review summarizes the main mechanisms targeted by these drugs as well as the clinical evidence that considers them a valid complementary option to manage patients with cirrhosis and portal hypertension.

Origins of abnormal placentation: why maternal veins must not be forgotten

The importance of uterine microvascular adaptations during placentation in pregnancy has been well established for decades. Inadequate dilatation of spiral arteries is associated with gestational complications, such as preeclampsia and/or intrauterine growth restriction. More recently, it has become clear that trophoblast cells invade and adapt decidual veins and lymphatic vessels 1 month before spiral arteries become patent and before intervillous space perfusion starts. Normal intervillous space hemodynamics is characterized by high volume flow at low velocity and pressure in the interseptal compartments surrounding the chorionic villi, hereby facilitating efficient maternal-fetal exchange. In case of shallow decidual vein dilatation, intervillous arterial supply exceeds venous drainage. This will cause congestion in the interseptal compartments with subsequently reduced perfusion and increased pressure. An efficient mechanism to counteract venous congestion and safeguard the viability of the conceptus is by reducing arterial inflow via shallow dilatation of the spiral arteries. This review made the case for intervillous space congestion as an unexplored trigger for inadequate spiral artery dilatation during the placentation process, eventually leading to abnormal systemic circulatory dysfunctions. An abnormal maternal venous function can result from an abnormal maternal immune response to paternal antigens with an imbalanced release of vasoactive mediators or can exist before conception. To get the full picture of abnormal placentation, maternal veins must not be forgotten.

Peripheral-dominant liver fibrosis and tumor distribution in a mouse model of congestive hepatopathy

AIM

Congestive hepatopathy often leads to liver fibrosis and hepatocellular carcinoma. Imaging modalities provided clinical evidence that elevation of liver stiffness and tumor occurrence are mainly induced in the periphery of the liver in patients with congestive hepatopathy. However, clinical relevance of liver stiffness and liver fibrosis is unclear because liver congestion itself increases liver stiffness in congestive hepatopathy. It also unclear which factors configure such regional disparity of tumor development in patients with congestive hepatopathy. To answer these questions, we evaluated the macroscopic spatial distribution of liver fibrosis and tumors in the murine model of congestive hepatopathy.

METHODS

Chronic liver congestion was induced by partial ligation of the suprahepatic inferior vena cava. Distribution of liver congestion, fibrosis, and tumors in partial ligation of the suprahepatic inferior vena cava mice were assessed by histological findings, laser microdissection (LMD)-based qPCR and enhanced computed tomography. LMD-based RNA-sequencing was performed to identify causal factors that promote tumor development in congestive hepatopathy.

RESULTS

Liver fibrosis was mainly induced in the periphery of the liver and co-localized with distribution of liver congestion. Liver tumors were also induced in the periphery of the liver where liver congestion and fibrosis occurred. LMD-based RNA-sequencing revealed the upregulation of extracellular matrix/collagen fibril-, wound healing-, angiogenesis-, morphogenesis-, and cell motility-related signaling pathways in periphery of liver compared with liver center.

CONCLUSIONS

Our findings showed the experimental relevance of liver congestion, fibrosis, and tumor development in congestive hepatopathy, and may provide important locational information. Macroscopic regional disparity observed in this murine model should be considered to manage patients with congestive hepatopathy.

Mechanotransduction in the pathogenesis of non-alcoholic fatty liver disease

Mechanobiology is a domain of interdisciplinary research that aims to explore the impact of physical force, applied externally or internally, on cell and tissue function, including development, growth, and differentiation. Mechanotransduction is a term that describes how cells sense physical forces (such as compression, stretch, and shear stress), convert them into biochemical signals, and mount adaptive responses integrated by the nucleus. There is accumulating evidence that mechanical forces extensively inform the biological behaviour of liver cells in health and disease. Recent research has elucidated many cellular and molecular mechanisms involved in this process including the pleiotropic control and diverse effects of the paralogous transcription co-activators YAP/TAZ, which play a prominent role in mechanotransduction. The liver sinusoids represent a unique microenvironment in which cells are exposed to mechanical cues originating in the cytoskeleton and at interfaces with adjacent cells, the extracellular matrix, and vascular or interstitial fluids. In non-alcoholic fatty liver disease (NAFLD), hepatocellular lipid accumulation and ballooning, activation of inflammatory responses, dysfunction of liver sinusoidal endothelial cells, and transdifferentiation of hepatic stellate cells into a pro-contractile and pro-fibrotic phenotype have been associated with aberrant cycles of mechanosensing and mechanoresponses. The downstream consequences of disrupted mechanical homeostasis likely contribute to the progression of NAFLD and promote the development of portal hypertension, cirrhosis, and hepatocellular carcinoma. Identification of molecular targets involved in pathogenic mechanotransduction will allow for the development of novel strategies to prevent the progression of liver disease in NAFLD.

Budd-Chiari Syndrome Management: Controversies and Open Issues

Budd-Chiari Syndrome (BCS) is due to thrombosis of hepatic veins (HVs), inferior vena cava (IVC) or both, leading to impaired hepatic venous outflow [...].

Lead nitrate toxicity: its effects on hepatic extracellular matrix fibers, filamentous cytoskeleton and the mitigative potentials of Morinda lucida extract

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Lead nitrate accumulation cause severe deleterious effect on the cellular and cytoskeletal structure of the liver.

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Efficacy of Morinda lucida, a medicinal plant, in the mitigation of lead nitrate-induced cellular, cytoskeletal and extracellular alterations in the liver was investigated in Wistar rats.

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Morinda lucida significantly reversed lead-nitrate-induced hepatocellular, cytoskeletal and extracellular changes in Wistar rats.

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Possible ameliorative property of Morinda lucida could be due to the antioxidant and membrane stabilizing properties of its phenolic compounds.

In this study, the effect of orally administered methanolic extract of Morinda lucida stem bark (MLSB) was tested for its efficacy to reverse lead nitrate-induced hepatotoxicity in Wistar rats. Thirty-six female rats were assigned into six groups (n = 6). Rats in group I received 2.2 mL/kg distilled water for 28 days, those in group II received 30 mg/kg lead nitrate for 14 days while those in groups III to VI received 30 mg/kg lead nitrate for 14 days followed by a treatment with 100, 250, 500 mg/kg BW MLSB extract and 0.2 mL/100 kg rats silymarin respectively for 14 days. They were sacrificed after 28 days after which biochemical, histological, and immunohistochemical parameters were examined. The results of this study showed a reduction of catalase and superoxide dismutase activities by lead nitrate. Deranged hepatic histomorphology was also observed intracellularly and extracellularly in lead nitrate-treated rats. Altered vimentin arrangement was also observed in lead nitrate-treated rats. However, 250 mg/kg BW dose of Morinda lucida significantly reversed some of these changes while the 500 mg had some toxic effect on liver tissue. We concluded that the extract at 250mg/kg BW dose may be a potential treatment for conditions associated with lead toxicity and other metallic particles.

Mechanotransduction-induced glycolysis epigenetically regulates a CXCL1-dominant angiocrine signaling program in liver sinusoidal endothelial cells in vitro and in vivo

BACKGROUND & AIMS

Liver sinusoidal endothelial cells (LSECs) are ideally situated to sense stiffness and generate angiocrine programs that potentially regulate liver fibrosis and portal hypertension. We explored how specific focal adhesion (FA) proteins parlay LSEC mechanotransduction into stiffness-induced angiocrine signaling in vitro and in vivo.

METHODS

Primary human and murine LSECs were placed on gels with incremental stiffness (0.2 kPa vs. 32 kPa). Cell response was studied by FA isolation, actin polymerization assay, RNA-sequencing and electron microscopy. Glycolysis was assessed using radioactive tracers. Epigenetic regulation of stiffness-induced genes was analyzed by chromatin-immunoprecipitation (ChIP) analysis of histone activation marks, ChIP sequencing and circularized chromosome conformation capture (4C). Mice with LSEC-selective deletion of glycolytic enzymes (Hk2fl/fl/Cdh5cre-ERT2) or treatment with the glycolysis inhibitor 3PO were studied in portal hypertension (partial ligation of the inferior vena cava, pIVCL) and early liver fibrosis (CCl4) models.

RESULTS

Glycolytic enzymes, particularly phosphofructokinase 1 isoform P (PFKP), are enriched in isolated FAs from LSECs on gels with incremental stiffness. Stiffness resulted in PFKP recruitment to FAs, which paralleled an increase in glycolysis. Glycolysis was associated with expansion of actin dynamics and was attenuated by inhibition of integrin β1. Inhibition of glycolysis attenuated a stiffness-induced CXCL1-dominant angiocrine program. Mechanistically, glycolysis promoted CXCL1 expression through nuclear pore changes and increases in NF-kB translocation. Biochemically, this CXCL1 expression was mediated through spatial re-organization of nuclear chromatin resulting in formation of super-enhancers, histone acetylation and NF-kB interaction with the CXCL1 promoter. Hk2fl/fl/Cdh5cre-ERT2 mice showed attenuated neutrophil infiltration and portal hypertension after pIVCL. 3PO treatment attenuated liver fibrosis in a CCl4 model.

CONCLUSION

Glycolytic enzymes are involved in stiffness-induced angiocrine signaling in LSECs and represent druggable targets in early liver disease.

LAY SUMMARY

Treatment options for liver fibrosis and portal hypertension still represent an unmet need. Herein, we uncovered a novel role for glycolytic enzymes in promoting stiffness-induced angiocrine signaling, which resulted in inflammation, fibrosis and portal hypertension. This work has revealed new targets that could be used in the prevention and treatment of liver fibrosis and portal hypertension.

Sphingosine-1-phosphate promotes tumor development and liver fibrosis in mouse model of congestive hepatopathy

BACKGROUND AND AIMS

Chronic liver congestion reflecting right-sided heart failure (RHF), Budd-Chiari syndrome, or Fontan-associated liver disease (FALD) is involved in liver fibrosis and HCC. However, molecular mechanisms of fibrosis and HCC in chronic liver congestion remain poorly understood.

APPROACH AND RESULTS

Here, we first demonstrated that chronic liver congestion promoted HCC and metastatic liver tumor growth using murine model of chronic liver congestion by partial inferior vena cava ligation (pIVCL). As the initial step triggering HCC promotion and fibrosis, gut-derived lipopolysaccharide (LPS) appeared to induce LSECs capillarization in mice and in vitro. LSEC capillarization was also confirmed in patients with FALD. Mitogenic factor, sphingosine-1-phosphate (S1P), was increased in congestive liver and expression of sphingosine kinase 1, a major synthetase of S1P, was increased in capillarized LSECs after pIVCL. Inhibition of S1P receptor (S1PR) 1 (Ex26) and S1PR2 (JTE013) mitigated HCC development and liver fibrosis, respectively. Antimicrobial treatment lowered portal blood LPS concentration, LSEC capillarization, and liver S1P concentration accompanied by reduction of HCC development and fibrosis in the congestive liver.

CONCLUSIONS

In conclusion, chronic liver congestion promotes HCC development and liver fibrosis by S1P production from LPS-induced capillarized LSECs. Careful treatment of both RHF and liver cancer might be necessary for patients with RHF with primary or metastatic liver cancer.

Anticoagulation in Cirrhosis: Evidence for the Treatment of Portal Vein Thrombosis and Applications for Prophylactic Therapy

The clinical utility of anticoagulation for patients with cirrhosis and asymptomatic portal vein thrombosis (PVT) is widely debated. Complex hemostatic derangements in cirrhosis that increase risk of both bleeding and thrombosis, as well as a lack of randomized controlled data, limit conclusive assessments regarding optimal management of anticoagulation in this setting. In this review, we summarize the relevant literature pertaining to PVT in cirrhosis, including the effect of untreated PVT on the natural progression of liver disease and the overall impact of anticoagulation on clot burden and other relevant clinical outcomes. Apart from patients who are symptomatic or listed for liver transplantation, data supporting anticoagulation for the treatment of PVT is limited and without clear consensus guidelines. In patients with cirrhosis without PVT, emerging evidence for the role of prophylactic anticoagulation to mitigate the progression of fibrosis suggests an optimal risk-benefit tradeoff with decreased rates of liver decompensation and mortality, without a heightened risk of bleeding. In summation, as our understanding of the role of both prophylactic and therapeutic anticoagulation in cirrhosis continues to evolve, ongoing risk stratification of patients with asymptomatic PVT demands further attention.

Risk factors for Fontan-associated hepatocellular carcinoma

Aims

The incidence of hepatocellular carcinoma (HCC) in patients with Fontan-associated liver disease (i.e., FALD-HCC) has increased over time. However, the risk factors for HCC development remain unclear. Here, we compared the levels of non-invasive markers to the survival rate of FALD-HCC patients.

Methods

From 2003 to 2021, 154 patients (66 men, 42.9%) developed liver disease after undergoing Fontan procedures. HCC was diagnosed in 15 (9.7%) (8 men, 53.3%) at a median age of 34 years (range, 21–45 years). We compared FALD-HCC and non-HCC cases; we generated marker level cutoffs using receiver operating characteristic curves. We sought to identify risk factors for HCC and mortality.

Results

The incidence of HCC was 4.9% in FALD patients within 20 years after the Fontan procedure. Compared with non-HCC patients, FALD-HCC patients exhibited higher incidences of polysplenia and esophageal varices. At the time of HCC development, the hyaluronic acid (HA) level (p = 0.04) and the fibrosis-4 index (p = 0.02) were significantly higher in FALD-HCC patients than in non-HCC patients; the total bilirubin (T-BIL) level (p = 0.07) and the model for end-stage liver disease score [excluding the international normalized ratio (MELD-XI)] (p = 0.06) tended to be higher in FALD-HCC patients. Within approximately 20 years of the Fontan procedure, 10 patients died (survival rate, 96.9%). Kaplan–Meier curve analysis indicated that patients with T-BIL levels ≥ 2.2 mg/dL, HA levels ≥ 55.5 ng/mL, and MELD-XI scores ≥ 18.7 were at high risk of HCC, a generally poor prognosis, and both polysplenia and esophageal varices. Multivariate Cox regression analyses indicated that the complication of polysplenia [Hazard ratio (HR): 10.915] and a higher MELD-XI score (HR: 1.148, both p < 0.01) were independent risk factors for FALD-HCC.

Conclusions

The complication of polysplenia and a MELD-XI score may predict HCC development and mortality in FALD patients.

Human amniotic mesenchymal stem cells-derived IGFBP-3, DKK-3, and DKK-1 attenuate liver fibrosis through inhibiting hepatic stellate cell activation by blocking Wnt/β-catenin signaling pathway in mice

Background

Liver fibrosis is an outcome of restoring process in chronic liver injury. Human amniotic mesenchymal stem cells (hAMSCs) derived from amniotic membrane have multilineage differentiation, immunosuppressive, and anti-inflammatory potential which makes them suitable for treating liver fibrosis. This study aimed to explore the effect and mechanism of hAMSCs on liver fibrosis.

Methods

hAMSCs were transplanted into carbon tetrachloride (CCl₄)-induced liver fibrosis mice via tail vein, and the effects of hAMSCs on hepatic fibrosis were assessed. The effects of hAMSCs and hAMSCs conditional medium (CM) on the activation of hepatic stellate cells (HSCs) were investigated in vivo and in vitro. Antibody array assay was used to identify the cytokines secreted by hAMSCs that may inhibit the activation of HSCs. Finally, the underlying mechanisms were explored by assessing IGF-1R/PI3K/AKT and GSK3β/β-catenin signaling pathways in the activated HSCs (LX-2) with hAMSCs and hAMSCs transfected with corresponding siRNAs.

Results

Our results showed that hAMSCs possessed the characterizations of mesenchymal stem cells. hAMSCs significantly reduced liver fibrosis and improved liver function in mice by inhibiting HSCs activation in vivo. Both hAMSCs and hAMSC-CM remarkably inhibited the collagen deposition and activation of LX-2 cells in vitro. Antibody array assay showed that insulin-like growth factor binding protein-3 (IGFBP-3), Dickkopf-3 (DKK-3), and Dickkopf-1 (DKK-1) were highly expressed in the co-culture group and hAMSC-CM group compared with LX-2 group. Western blot assay demonstrated that IGFBP-3, DKK-3, and DKK-1 derived from hAMSCs inhibit LX-2 cell activation through blocking canonical Wnt signaling pathway.

Conclusions

Our results demonstrated that IGFBP-3, Dkk3, and DKK-1 secreted by hAMSCs attenuated liver fibrosis in mice through inhibiting HSCs activation via depression of Wnt/β-catenin signaling pathway, suggesting that hAMSCs or hAMSC-CM provides an alternative therapeutic approach for the treatment of liver fibrosis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13287-022-02906-z.

Angiotensin receptor blocker alleviates liver fibrosis by altering the mechanotransduction properties of hepatic stellate cells

Angiotensin receptor blockers have been reported to be beneficial to liver fibrosis, but the relevant molecular and cellular mechanisms remain unclear. We herein investigated whether low-dose angiotensin receptor blocker alleviated liver fibrosis through mechanotransduction regulation. Hydrostatic pressure-induced liver fibrosis model was established in mice by ligating partially the inferior vena cava, and then randomly received a very low dose of losartan (0.5 mg/kg) or placebo treatment for 8 weeks. We found that losartan administration interfered the expression of several mechanotransductive molecules, and effectively alleviated liver fibrosis. Using a commercial device, we further confirmed that ex vivo loading of hepatic stellate cells to 50 mmHg hydrostatic pressure for 24 h significantly upregulated RhoA, ROCK, AT1R, and p-MLC2, which was effectively attenuated by adding 10 nM losartan in medium. Our in vivo and ex vivo experimental data suggest that low-dose angiotensin receptor blockers may alleviate hydrostatic pressure-induced liver fibrosis by altering the mechanotransduction properties of hepatic stellate cells.NEW & NOTEWORTHY Our ex vivo and in vivo experiments clearly indicated that low-dose losartan alleviated liver fibrosis, likely by modulating the mechanotransduction properties of HSCs. Uncovering the biomechanical signaling pathway of ARB treatment on liver fibrosis will be helpful to develop novel molecular targeting therapy for liver diseases.