Atorvastatin attenuates hepatic fibrosis in rats after bile duct ligation via decreased turnover of hepatic stellate cells

Current challenges and future perspectives in treating patients with NAFLD-related cirrhosis

Despite the slow, progressive nature of NAFLD, the number of patients with NAFLD-related cirrhosis has significantly increased. Although the management of patients with cirrhosis is constantly evolving, improving the prognosis of patients with NAFLD-related cirrhosis is a challenge because it is situated at the crossroads between the liver, the metabolic, and the cardiovascular diseases. Therefore, the therapeutic interventions should not only target the liver but also the associated cardiometabolic conditions and should be adapted accordingly. The objective of the current review is to critically discuss the particularities in the management of patients with NAFLD-related cirrhosis. We relied on the recommendations of scientific societies and discussed them in the specific context of NAFLD cirrhosis and the surrounding cardiometabolic milieu. Herein, we covered the following aspects: (1) the weight loss strategies through lifestyle interventions to avoid sarcopenia and improve portal hypertension; (2) the optimal control of metabolic comorbidities in particular type 2 diabetes aimed not only to improve cardiovascular morbidity/mortality but also to lower the incidence of cirrhosis-related complications (we discussed various aspects related to the safety of oral antidiabetic drugs in cirrhosis); (3) the challenges in performing bariatric surgery in patients with cirrhosis related to the portal hypertension and the risk of cirrhosis decompensation; (4) the particularities in the diagnosis and management of the portal hypertension and the difficulties in managing patients awaiting for liver transplantation; and (5) the difficulties in developing drugs and conducting clinical trials in patients with NAFLD-related cirrhosis. Moreover, we discussed the emerging options to overcome these obstacles.

Dapagliflozin dampens liver fibrosis induced by common bile duct ligation in rats associated with the augmentation of the hepatic Sirt1/AMPK/PGC1α/FoxO1 axis

Liver fibrosis is considered an epidemic health problem due to different insults that lead to death. Dapagliflozin (DAPA), a sodium-glucose cotransporter-2 (SGLT2) inhibitor, is one of the newer anti-diabetic drugs used to manage type 2 diabetes mellitus (T2DM). DAPA exerted beneficial effects in many human and rat models due to its antioxidant, anti-inflammatory and antifibrotic activities.

AIM

Due to previously reported capabilities related to DAPA, we designed this study to clarify the beneficial role of DAPA in liver fibrosis triggered by common bile duct ligation (CBL) in male rats.

METHODS

For 14 or 28 days after CBL procedures, DAPA was administered to the rats orally at a dose of 10 mg/kg once daily. The effects of DAPA were evaluated by assaying liver enzymes, hepatic oxidant/antioxidant parameters, serum levels of tumor necrotic factor alpha (TNF-α), and AMP-activated protein kinase (AMPK). In addition, we measured the hepatic expression of fibrosis regulator-related genes along with evaluating liver histological changes.

KEY FINDINGS

DAPA successfully decreased hepatic enzymes and malondialdehyde levels, increased superoxide dismutase activity, elevated catalase levels, decreased serum levels of TNF-α, elevated serum levels of AMPK, decreased liver hydroxyproline content, upregulated Sirt1/PGC1α/FoxO1 liver gene expressions, down-regulated fibronectin-1 (Fn-1), collagen-1 genes in liver tissues, and improved the damaged liver tissues. Deteriorated biochemical parameters and histological liver insults associated with CBL were more pronounced after 28 days, but DAPA administration for 14 and 28 days showed significant improvement in most parameters and reflected positively in the histological structures of the liver.

SIGNIFICANCE

The significance of this study lies in the observation that DAPA mitigated CBL-induced liver fibrosis in rats, most likely due to its antioxidant, anti-inflammatory, and antifibrotic effects. These results suggest that DAPA's beneficial impact on liver fibrosis might be attributed to its interaction with the Sirt1/AMPK/PGC1α/FoxO1 pathway, indicating a potential mechanistic action for future exploration.

Statins in Chronic Liver Disease: Review of the Literature and Future Role

Chronic liver disease (CLD) is a major contributor to global mortality, morbidity, and healthcare burden. Progress in pharmacotherapeutic for CLD management is lagging given its impact on the global population. While statins are indicated for the management of dyslipidemia and cardiovascular disease, their role in CLD prevention and treatment is emerging. Beyond their lipid-lowering effects, their liver-related mechanisms of action are multifactorial and include anti-inflammatory, antiproliferative, and immune-protective effects. In this review, we highlight what is known about the clinical benefits of statins in viral and nonviral etiologies of CLD and hepatocellular carcinoma (HCC), and explore key mechanisms and pathways targeted by statins. While their benefits may span the spectrum of CLD and potentially HCC treatment, their role in CLD chemoprevention is likely to have the largest impact. As emerging data suggest that genetic variants may impact their benefits, the role of statins in precision hepatology will need to be further explored.

Statin use in cirrhosis and its association with incidence of portal vein thrombosis

BACKGROUND AND AIM

Statin use has shown a reduction in hepatic decompensation and portal hypertension. Its association with portal vein thrombosis (PVT) incidence is unknown. We aim to compare the incidence of PVT in patients with and without statin use.

METHODS

We excluded patients with a history of hepatocellular cancer, liver transplants, Budd-Chiari syndrome, and intra-abdominal malignancies. Patients with cirrhosis were followed from their first hepatologist clinical encounter (January 1, 2016, to January 31, 2021) for 180 days to determine PVT incidence. We tested the association of statin use with PVT using 1:1 propensity score (PS) matching and Cox proportional hazard regression.

RESULTS

We analyzed 2785 patients with cirrhosis (mean age:61.0 ± 12.3 years, 44.3% female, 63.8% White, mean MELD-Na score:11.7 ± 6.1, and statin use:23.1%). A total of 89 patients developed PVT during the follow-up, which was lower in patients with statin use as compared to no statin use (1.3% vs 3.8%, P = 0.001, unadjusted HR:0.28, 95% CI: 0.13-0.62, P = 0.001). After matching for demographics, comorbidities, and hepatic decompensation events, patients with statin use had a lower risk of developing PVT in 180-day follow-up as compared to those without statin use (HR:0.24, 95% CI: 0.10-0.55, P = 0.001). Subgroup analysis showed that statin use was associated with lower PVT incidence in non-NASH (HR: 0.20, 95% CI: 0.07-0.54, P = 0.002) and decompensated cirrhosis (HR: 0.12, 95% CI:0.03-0.53, P = 0.005) than no statin use.

CONCLUSION

PVT incidence was lower in decompensated cirrhosis patients with statin use than in those with no statin use. However, this finding needs to be further tested in randomized control trials.

Management of liver disease and portal hypertension in cystic fibrosis: a review

INTRODUCTION

Cystic fibrosis (CF)-associated liver disease can significantly affect the quality of life and survival of people with CF. The hepatobiliary manifestations in CF are various, with focal/multilobular biliary cirrhosis more common in children and porto-sinusoidal vascular disease (PSVD) in young adults. Portal hypertensive complications, particularly bleeding from esophagogastric varices and hypersplenism are common, while liver failure is rarer and mainly linked to biliary disease.

AREAS COVERED

This review explores current therapeutic options for CF-associated liver disease, presenting ongoing studies and new insights into parthenogenesis for potential future therapies.

EXPERT OPINION

Monitoring for signs of portal hypertension is essential. Limited evidence supports ursodeoxycholic acid (UDCA) efficacy in halting CF liver disease progression. The effect of cystic fibrosis transmembrane conductance regulator (CFTR) modulators on liver outcomes lacks definitive data, since patients with CF-related liver disease were excluded from trials due to potential hepatotoxicity. A proposed approach involves using UDCA and modulators in early stages, along with anti-inflammatory agents, with further therapeutic strategies awaiting randomized trials. Prevention of portal hypertensive bleeding includes endoscopic sclerotherapy or ligation of esophageal varices. Nonselective beta-blockers may also prevent bleeding and could be cautiously implemented. Other non-etiological treatments require investigation.

Novel preclinical developments of the primary sclerosing cholangitis treatment landscape

INTRODUCTION

Primary sclerosing cholangitis (PSC) is a chronic cholestatic liver disease associated with inflammation, fibrosis, and destruction of intra- and extrahepatic bile ducts. Despite substantial recent advances in our understanding of PSC, the only proven treatment of PSC is liver transplantation. There is an urgent unmet need to find medical therapies for this disorder.

AREAS COVERED

Multiple drugs are currently under evaluation as therapeutic options for this disease. This article summarizes the literature on the various novel therapeutic options that have been investigated and are currently under development for the treatment of PSC.

EXPERT OPINION

In the next decade, more than one drug will likely be approved for the treatment of the disease, and we will be looking at combination therapies for the optimal management of the disease.

Recent advances in promising drugs for primary prevention of gastroesophageal variceal bleeding with cirrhotic portal hypertension

BACKGROUND

Gastroesophageal variceal bleeding is one of the most severe complications of patients with cirrhosis. Although primary prevention drugs, including non-selective β-blockers, have effectively reduced the incidence of bleeding, their efficacy is limited due to side effects and related contraindications. With recent advances in precision medicine, precise drug treatment provides better treatment efficacy.

DATA SOURCES

Literature search was conducted in PubMed, MEDLINE and Web of Science for relevant articles published up to May 2022. Information on clinical trials was obtained from https://clinicaltrials.gov/ and http://www.chictr.org.cn/.

RESULTS

The in-depth understanding of the pathogenesis and advances of portal hypertension has enabled the discovery of multiple molecular targets for promising drugs. According to the site of action, these drugs could be classified into four classes: intrahepatic, extrahepatic, both intrahepatic and extrahepatic targets and others. All these classes of drugs offer advantages over traditional treatments in prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.

CONCLUSIONS

This review classified and summarized the promising drugs, which prevent gastroesophageal variceal bleeding by targeting specific markers of pathogenesis of portal hypertension, demonstrating the significance of using the precision medicine strategy to discover and develop promising drugs for the primary prevention of gastroesophageal variceal bleeding in patients with cirrhotic portal hypertension.

The Role of Hypoxia-Inducible Factor 1 Alpha in Acute-on-Chronic Liver Failure

Acute-on-chronic liver failure (ACLF) is associated with increased mortality. Specific therapy options are limited. Hypoxia-inducible factor 1 alpha (HIF-1α) has been linked to the pathogenesis of chronic liver disease (CLD), but the role of HIF-1α in ACLF is poorly understood. In the current study, different etiologies of CLD and precipitating events triggering ACLF were used in four rodent models. HIF-1α expression and the intracellular pathway of HIF-1α induction were investigated using real-time quantitative PCR. The results were verified by Western blotting and immunohistochemistry for extrahepatic HIF-1α expression using transcriptome analysis. Exploratory immunohistochemical staining was performed to assess HIF-1α in human liver tissue. Intrahepatic HIF-1α expression was significantly increased in all animals with ACLF, regardless of the underlying etiology of CLD or the precipitating event. The induction of HIF-1α was accompanied by the increased mRNA expression of NFkB1 and STAT3 and resulted in a marked elevation of mRNA levels of its downstream genes. Extrahepatic HIF-1α expression was not elevated. In human liver tissue samples, HIF-1α expression was elevated in CLD and ACLF. Increased intrahepatic HIF-1α expression seems to play an important role in the pathogenesis of ACLF, and future studies are pending to investigate the role of therapeutic HIF inhibitors in ACLF.

Association between Statins Types with Incidence of Liver Cancer: An Updated Meta-analysis

BACKGROUND

Previous studies have found a potential role for statins in liver cancer prevention.

OBJECTIVE

This study aimed to explore the effect of different types of statins on the incidence of liver cancer.

METHODS

Relevant articles were systematically retrieved from PubMed, EBSCO, Web of Science, and Cochrane Library databases from inception until July 2022 to explore the relationship between lipophilic statins or hydrophilic statins exposure and the incidence of liver cancer. The main outcome was the incidence of liver cancer.

RESULTS

Eleven articles were included in this meta-analysis. The pooled results showed a reduced incidence of liver cancer in patients exposed to lipophilic statins (OR=0.54, p < 0.001) and hydrophilic statins (OR=0.56, p < 0.001) compared with the non-exposed cohort. Subgroup analysis showed that both exposures to lipophilic (Eastern countries: OR=0.51, p < 0.001; Western countries: OR=0.59, p < 0.001) and hydrophilic (Eastern countries: OR=0.51, p < 0.001; Western countries: OR=0.66, p=0.019) statins reduced the incidence of liver cancer in Eastern and Western countries, and the reduction was most significant in Eastern countries. Moreover, atorvastatin (OR=0.55, p < 0.001), simvastatin (OR=0.59, p < 0.001), lovastatin (OR=0.51, p < 0.001), pitavastatin (OR=0.36, p=0.008) and rosuvastatin (OR=0.60, p=0.027) could effectively reduce the incidence of liver cancer, unlike fluvastatin, cerivastatin and pravastatin.

CONCLUSION

Both lipophilic and hydrophilic statins contribute to the prevention of liver cancer. Moreover, the efficacy was influenced by the region and the specific type of statins used.

Hepatic Stellate Cell- and Liver Microbiome-Specific Delivery System for Dihydrotanshinone I to Ameliorate Liver Fibrosis

Liver fibrosis is a major contributor to the morbidity and mortality associated with liver diseases, yet effective treatment options remain limited. Hepatic stellate cells (HSCs) are a promising target for hepatic fibrogenesis due to their pivotal role in disease progression. Our previous research has demonstrated the potential of Dihydrotanshinone I (DHI), a lipophilic component derived from the natural herb Salvia miltiorrhiza Bunge, in treating liver fibrosis by inhibiting the YAP/TEAD2 interaction in HSCs. However, the clinical application of DHI faces challenges due to its poor aqueous solubility and lack of specificity for HSCs. Additionally, recent studies have implicated the impact of liver microbiota, distinct from gut microbiota, on the pathogenesis of liver diseases. In this study, we have developed an HSC- and microbiome-specific delivery system for DHI by conjugating prebiotic-like cyclodextrin (CD) with vitamin A, utilizing PEG2000 as a linker (VAP2000@CD). Our results demonstrate that VAP2000@CD markedly enhances the cellular uptake in human HSC line LX-2 and enhances the deposition of DHI in the fibrotic liver in vivo. Subsequently, intervention with DHI-VAP2000@CD has shown a notable reduction in bile duct-like structure proliferation, collagen accumulation, and the expression of fibrogenesis-associated genes in rats subjected to bile duct ligation. These effects may be attributed to the regulation of the YAP/TEAD2 interaction. Importantly, the DHI-VAP2000@CD intervention has also restored microbial homeostasis in the liver, promoting the amelioration of liver inflammation. Overall, our findings indicate that DHI-VAP2000@CD represents a promising therapeutic approach for liver fibrosis by specifically targeting HSCs and restoring the liver microbial balance.

Statins in Cirrhosis: Hope or Hype?

In recent years, studies have demonstrated the benefits of statins in a range of chronic diseases separate from cardiovascular outcomes. Early studies in the context of chronic liver disease have suggested favorable effects of statins leading to slowed fibrosis progression, reduced portal pressures, decreased rates of hepatic decompensation, and improved survival. This has increased interest in the potential role that statins may have in the management of chronic liver disease and cirrhosis, though many questions remain unanswered, including concerns regarding the safety of higher dose statins in patients with advanced decompensated cirrhosis. In this review, we provide an update on the current literature addressing the use of statins in patients with cirrhosis and highlight areas in which additional studies are needed.

Protective effects of statins on the incidence of NAFLD-related decompensated cirrhosis in T2DM

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is a hepatic manifestation of metabolic syndrome and poses a significant threat to patients with type 2 diabetes mellitus (T2DM) and metabolic dysregulation. Statins exert anti-inflammatory, antioxidative and antithrombotic effects that target mechanisms underlying NAFLD. However, the protective effects of the different doses, intensities and types of statins on the incidence of NAFLD-related decompensated liver cirrhosis (DLC) in patients with T2DM remain unclear.

METHODS

This study used the data of patients with T2DM who were non-HBV and non-HCV carriers from a national population database to examine the protective effects of statin use on DLC incidence through propensity score matching. The incidence rate (IR) and incidence rate ratios (IRRs) of DLC in patients with T2DM with or without statin use were calculated.

RESULTS

A higher cumulative dose and specific types of statins, namely rosuvastatin, pravastatin, atorvastatin, simvastatin and fluvastatin, reduced the risk of DLC in patients with T2DM. Statin use was associated with a significant reduction in the risk of DLC (HR: .65, 95% CI: .61-.70). The optimal daily intensity of statin use with the lowest risk of DLC was .88 defined daily dose (DDD).

CONCLUSIONS

The results revealed the protective effects of specific types of statins on DLC risk in patients with T2DM and indicated a dose-response relationship. Additional studies are warranted to understand the specific mechanisms of action of different types of statins and their effect on DLC risk in patients with T2DM.

Tumor Abnormality-Oriented Nanomedicine Design

Anticancer nanomedicines have been proven effective in mitigating the side effects of chemotherapeutic drugs. However, challenges remain in augmenting their therapeutic efficacy. Nanomedicines responsive to the pathological abnormalities in the tumor microenvironment (TME) are expected to overcome the biological limitations of conventional nanomedicines, enhance the therapeutic efficacies, and further reduce the side effects. This Review aims to quantitate the various pathological abnormalities in the TME, which may serve as unique endogenous stimuli for the design of stimuli-responsive nanomedicines, and to provide a broad and objective perspective on the current understanding of stimuli-responsive nanomedicines for cancer treatment. We dissect the typical transport process and barriers of cancer drug delivery, highlight the key design principles of stimuli-responsive nanomedicines designed to tackle the series of barriers in the typical drug delivery process, and discuss the "all-into-one" and "one-for-all" strategies for integrating the needed properties for nanomedicines. Ultimately, we provide insight into the challenges and future perspectives toward the clinical translation of stimuli-responsive nanomedicines.

Effect of statins on the recurrence of hepatocellular carcinoma after liver transplantation: An illusion revealed by exposure density sampling

BACKGROUND

Statins have been reported to reduce overall death and hepatocellular carcinoma (HCC) recurrence in liver transplantation (LT) recipients. However, previous retrospective studies have significant flaws in immortal time bias.

METHODS

Using data from 658 patients who received LT for HCC, we matched 140 statin users with statin nonusers in a 1:2 ratio at the time of the first statin administration after LT using the exposure density sampling (EDS). The propensity score, calculated using baseline variables (including explant pathology), was used for EDS to equilibrate both groups. HCC recurrence and overall death were compared after adjusting for information at the time of sampling.

RESULTS

Among statin users, the median time to statin start was 219 (IQR 98-570) days, and intensity of statins was mainly moderate (87.1%). Statin users and nonusers sampled using EDS showed well-balanced baseline characteristics, including detailed tumour pathology, and similar HCC recurrence with cumulative incidences of 11.3% and 11.8% at 5 years, respectively (p = .861). In multivariate Cox models (HR 1.04, p = .918) and subgroup analyses, statins did not affect HCC recurrence. Conversely, statin users showed a significantly lower risk of overall death than nonusers (HR 0.28, p < .001). There was no difference in the type and intensity of statin usage between statin users who experienced HCC recurrence and those who did not.

CONCLUSION

Upon controlling immortal time bias by EDS, statins did not affect HCC recurrence but reduced mortality after LT. Statin usage is encouraged for survival benefits but not for preventing HCC recurrence in LT recipients.

Biased Quantification of Rat Liver Fibrosis-Meta-Analysis with Practical Recommendations and Clinical Implications

For liver fibrosis assessment, the liver biopsy is usually stained with Masson's trichrome (MT) or picrosirius red (PSR) to quantify liver connective tissue (LCT) for fibrosis scoring. However, several concerns of such semiquantitative assessments have been raised, and when searching for data on the amount of LCT in healthy rats, the results vastly differ. Regarding the ongoing reproducibility crisis in science, it is necessary to inspect the results and methods, and to design an unbiased and reproducible method of LCT assessment. We searched the Medline database using search terms related to liver fibrosis, LCT and collagen, rat strains, and staining methods. Our search identified 74 eligible rat groups in 57 studies. We found up to 170-fold differences in the amount of LCT among healthy Wistar and Sprague-Dawley rats, with significant differences even within individual studies. Biased sampling and quantification probably caused the observed differences. In addition, we also found incorrect handling of liver fibrosis scoring. Assessment of LCT using stereological sampling methods (such as systematic uniform sampling) would provide us with unbiased data. Such data could eventually be used not only for the objective assessment of liver fibrosis but also for validation of noninvasive methods of the assessment of early stages of liver fibrosis.

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.

Anti-fibrotic effects of statin drugs: a review of evidence and mechanisms

Fibrosis is a pathological repair process common among organs, that responds to damage by replacement of tissue with non-functional connective tissue. Despite the widespread prevalence of tissue fibrosis, manifesting in numerous disease states across myriad organs, therapeutic modalities to prevent or alleviate fibrosis are severely lacking in quantity and efficacy. Alongside development of new drugs, repurposing of existing drugs may be a complementary strategy to elect anti-fibrotic compounds for pharmacologic treatment of tissue fibrosis. Drug repurposing can provide key advantages to de novo drug discovery, harnessing the benefits of previously elucidated mechanisms of action and already existing pharmacokinetic profiles. One class of drugs a wealth of clinical data and extensively studied safety profiles is the statins, a class of antilipidemic drugs widely prescribed for hypercholesterolemia. In addition to these widely utilized lipid-lowering effects, increasing data from cellular, pre-clinical mammalian, and clinical human studies have also demonstrated that statins are able to alleviate tissue fibrosis originating from a variety of pathological insults via lesser-studied, pleiotropic effects of these drugs. Here we review literature demonstrating evidence for direct effects of statins antagonistic to fibrosis, as well as much of the available mechanistic data underlying these effects. A more complete understanding of the anti-fibrotic effects of statins may enable a clearer picture of their anti-fibrotic potential for various clinical indications. Additionally, more lucid comprehension of the mechanisms by which statins exert anti-fibrotic effects may aid in development of novel therapeutic agents that target similar pathways but with greater specificity or efficacy.

Association between statin exposure and short-term mortality in patients with high-grade acute-on-chronic liver failure

Background & Aims

Acute-on-chronic liver failure (ACLF) carries a high short-term mortality for patients with cirrhosis. Prior literature suggests that statin exposure may reduce the likelihood of ACLF events. However, it is unclear if statin exposure is associated with ACLF-related mortality. This study sought to determine the association between statin use and short-term mortality among patients hospitalised with ACLF.

Methods

This was a retrospective cohort study of Veterans Health Administration (VHA) patients diagnosed with cirrhosis between 2008 and 2021 and hospitalised with high-grade (2 or 3) ACLF. Patients were stratified into those with and without continuous statin exposure for at least 90 days prior to hospitalisation. Multivariable logistic regression models were created to determine the adjusted association between statin exposure and 28-day and 90-day mortality. Categorical statin dose exposure, converted to simvastatin equivalents, was also explored.

Results

A total of 11,731 patients with cirrhosis hospitalised with Grade 2 or 3 ACLF were included in the analytic cohort, 26% of whom had statin exposure. In adjusted logistic regression models, statin use was associated with 18% lower odds of ACLF-related 28-day mortality (odds ratio [OR] 0.82, 95% CI 0.73-0.93, p = 0.001) and 24% lower odds of 90-day mortality (OR 0.76, 95% CI 0.68-0.86, p <0.001). Increasing statin dose exposure was also associated with further reductions in 90-day mortality (e.g. OR 0.81, 95% CI 0.70-0.93 for 10-40 mg vs. 0 mg and OR 0.72, 95% CI 0.60-0.87 for 80 mg vs. 0 mg, p <0.001).

Conclusions

In this large, retrospective cohort study, statin exposure before high-grade ACLF hospitalisation was associated with reduced odds of 28-day and 90-day mortality in patients with cirrhosis. A statin dose-dependent reduction in 90-day ACLF-related mortality was also observed.

Impact and Implications

Statins have been identified as a class of medications with potential beneficial effects for patients with cirrhosis. In this large, retrospective cohort study of patients with cirrhosis who seek care at the Veterans Health Administration, statin use was associated with a decrease in short term (28-day and 90-day) mortality as a result of acute-on-chronic liver failure. Future prospective studies are needed to further clarify the relative safety and efficacy of statin therapy in reducing morbidity and mortality associated with acute-on-chronic liver failure in patients with cirrhosis.

Understanding the Potential Role of Nanotechnology in Liver Fibrosis: A Paradigm in Therapeutics

The liver is a vital organ that plays a crucial role in the physiological operation of the human body. The liver controls the body's detoxification processes as well as the storage and breakdown of red blood cells, plasma protein and hormone production, and red blood cell destruction; therefore, it is vulnerable to their harmful effects, making it more prone to illness. The most frequent complications of chronic liver conditions include cirrhosis, fatty liver, liver fibrosis, hepatitis, and illnesses brought on by alcohol and drugs. Hepatic fibrosis involves the activation of hepatic stellate cells to cause persistent liver damage through the accumulation of cytosolic matrix proteins. The purpose of this review is to educate a concise discussion of the epidemiology of chronic liver disease, the pathogenesis and pathophysiology of liver fibrosis, the symptoms of liver fibrosis progression and regression, the clinical evaluation of liver fibrosis and the research into nanotechnology-based synthetic and herbal treatments for the liver fibrosis is summarized in this article. The herbal remedies summarized in this review article include epigallocathechin-3-gallate, silymarin, oxymatrine, curcumin, tetrandrine, glycyrrhetinic acid, salvianolic acid, plumbagin, Scutellaria baicalnsis Georgi, astragalosides, hawthorn extract, and andrographolides.

Emerging Therapeutic Targets for Portal Hypertension

Purpose of Review

Portal hypertension is responsible of the main complications of cirrhosis, which carries a high mortality. Recent treatments have improved prognosis, but this is still far from ideal. This paper reviews new potential therapeutic targets unveiled by advances of key pathophysiologic processes.

Recent Findings

Recent research highlighted the importance of suppressing etiologic factors and a safe lifestyle and outlined new mechanisms modulating portal pressure. These include intrahepatic abnormalities linked to inflammation, fibrogenesis, vascular occlusion, parenchymal extinction, and angiogenesis; impaired regeneration; increased hepatic vascular tone due to sinusoidal endothelial dysfunction with insufficient NO availability; and paracrine liver cell crosstalk. Moreover, pathways such as the gut-liver axis modulate splanchnic vasodilatation and systemic inflammation, exacerbate liver fibrosis, and are being targeted by therapy. We have summarized studies of new agents addressing these targets.

Summary

New agents, alone or in combination, allow acting in complementary mechanisms offering a more profound effect on portal hypertension while simultaneously limiting disease progression and favoring regression of fibrosis and of cirrhosis. Major changes in treatment paradigms are anticipated.

Integrative analysis implicates the significance of m6A in the liver fibrosis of biliary atresia by regulating THY1

Whether N6-methyladenosine (m6A) is involved in biliary atresia (BA) remains undefined. Herein, we comprehensively evaluated the m6A profile in BA. When compared with normal controls, BA had an elevated m6A level with upregulated m6A writers. The m6A level was correlated with liver function, stage of fibrosis and jaundice clearance in BA. Methylated RNA immunoprecipitation sequencing (MeRIP-seq) demonstrated an altered m6A topology in BA. MeRIP-seq and RNA sequencing filtered out 130 m6A-modified genes, which were enriched in fibrogenetic pathways. MeRIP-qPCR in vivo and interventions of LX-2 and primary HSCs in vitro validated the regulatory role of m6A on COL1A1 and THY1. THY1+ myofibroblasts expanded in portal area of BA, and highly expressed profibrogenic genes (COL1A1, MMP2, PDGFRA, and DCN). THY1 was correlated with liver fibrosis and jaundice clearance in BA. Bulk array (GSE46960, GSE15235), single-cell RNA sequencing (GSE136103), primary HSC interventions, and co-immunoprecipitation revealed that THY1 was correlated with extracellular matrix organization, promoted HSC activation, showed higher interactions with integrins on myeloid cells in cholestatic fibrosis, and was correlated with native liver survival in BA. Our study highlights the significance of m6A in BA-induced liver fibrogenesis by regulating THY1, shedding new light on the novel therapies to alleviate liver fibrosis by targeting m6A/THY1 axis in BA.

Dissecting the multifaceted impact of statin use on fatty liver disease: a multidimensional study

BACKGROUND

Statin use could benefit patients with non-alcoholic fatty liver disease (NAFLD), but the evidence is segmented and inconclusive. This multidimensional study comprehensively investigated the potential benefits and mechanism-of-action of statins in NAFLD.

METHODS

A cross-sectional investigation was performed within the Rotterdam Study (general population; n = 4.576) and the PERSONS cohort (biopsy-proven NAFLD patients; n = 569). Exclusion criteria were secondary causes for steatosis and insufficient data on alcohol, dyslipidemia or statin use. Associations of statin use with NAFLD (among entire general population), fibrosis and NASH (among NAFLD individuals and patients) were quantified. These results were pooled with available literature in meta-analysis. Last, we assessed statins' anti-lipid and anti-inflammatory effects in 3D cultured human liver organoids and THP-1 macrophages, respectively.

FINDINGS

Statin use was inversely associated with NAFLD in the Rotterdam study compared to participants with untreated dyslipidemia. In the PERSONS cohort, statin use was inversely associated with NASH, but not with fibrosis. The meta-analysis included 7 studies and indicated a not significant inverse association for statin use with NAFLD (pooled-Odds Ratio: 0.69, 95% Confidence Interval: 0.46-1.01) and significant inverse associations with NASH (pooled-OR: 0.59, 95% CI: 0.44-0.79) and fibrosis (pooled-OR: 0.48, 95% CI: 0.33-0.70). In vitro, statins significantly reduced lipid droplet accumulation in human liver organoids and downregulated expression of pro-inflammatory cytokines in macrophages.

INTERPRETATION

Pooled results demonstrated that statin use was associated with a lower prevalence of NASH and fibrosis and might prevent NAFLD. This may be partially attributed to the anti-lipid and anti-inflammatory characteristics of statins. Given their under-prescription, adequate prescription of statins may limit the disease burden of NAFLD.

FUNDING

ZonMw, KWF, NWO, SLO, DGXII, RIDE, National and regional government, Erasmus MC and Erasmus University.

Current and investigational drugs in early clinical development for portal hypertension

Introduction

The development of portal hypertension leads to a majority of complications associated with chronic liver disease. Therefore, adequate treatment of portal hypertension is crucial in the management of such patients. Current treatment options are limited and consist mainly of medications that decrease the hyperdynamic circulation, such as non-selective beta blockers, and treatment of hypervolemia with diuretics. Despite these options, mortality rates have not improved over the last two decades. Newer, more effective treatment options are necessary to help improve survival and quality of life in these patients.

Areas covered

Multiple preclinical models and clinical studies have demonstrated potential efficacy of a variety of new treatment modalities. We introduce treatment options including the use of vasodilation promotors, vasoconstriction inhibitors, anticoagulants, antiangiogenics, and anti-inflammatory drugs. We examine the most recent studies for treatment options within these drug classes and offer insights as to which show the most promise in this field.

Methodology

Published studies that identified novel medical treatment options of portal hypertension were searched using PubMed (https://pubmed.ncbi.nlm.nih.gov/). Clinical trials listed in Clinicaltrials.gov were also searched with a focus on more recent and ongoing studies, including those with completed recruitment. Searching with key terms including "portal hypertension" as well as individually searching specific treatment medications that were listed in other publications was carried out. Finally, current societal guidelines and recent review articles relevant to the management of portal hypertension were evaluated, and listed references of interest were included.

Conclusion

Many ongoing early phase studies demonstrate promising results and may shape the field of portal hypertension management in future. As concrete results become available, larger RCTs will be required before making definitive conclusions regarding safety and efficacy and whether or not they can be incorporated into routine clinical practice. Statins, anticoagulants, and PDE inhibitors have been among the most studied and appear to be most promising.

Use of statins after liver transplantation is associated with improved survival: results of a nationwide study

BACKGROUND

There is limited information on the effects of statins on the outcomes of liver transplantation (LT), regarding either their use by LT recipients or donors.

AIM

To analyse the association between statin exposure and recipient and graft survival.

METHODS

We included adult LT recipients with deceased donors in a nationwide prospective database study. Using a multistate modelling approach, we examined the effect of statins on the transition hazard between LT, biliary and vascular complications and death, allowing for recurring events. The observation time was 3 years.

RESULTS

We included 998 (696 male, 70%, mean age 54.46 ± 11.14 years) LT recipients. 14% of donors and 19% of recipients were exposed to statins during the study period. During follow-up, 141 patients died; there were 40 re-LT and 363 complications, with 66 patients having two or more complications. Treatment with statins in the recipient was modelled as a concurrent covariate and associated with lower mortality after LT (HR = 0.35; 95% CI 0.12-0.98; p = 0.047), as well as a significant reduction of re-LT (p = 0.004). However, it was not associated with lower incidence of complications (HR = 1.25; 95% CI = 0.85-1.83; p = 0.266). Moreover, in patients developing complications, statin use was significantly associated with decreased mortality (HR = 0.10; 95% CI = 0.01-0.81; p = 0.030), and reduced recurrence of complications (HR = 0.43; 95% CI = 0.20-0.93; p = 0.032).

CONCLUSIONS

Statin use by LT recipients may confer a survival advantage. Statin administration should be encouraged in LT recipients when clinically indicated.

Evaluation of statins as a new therapy to alleviate chronotropic dysfunction in cirrhotic rats

AIMS

Liver cirrhosis defines by regenerative nodules and fibrotic septa, causing a complication called cirrhotic cardiomyopathy (CCM) with chronotropic hypo-responsiveness. In addition to lowering cholesterol levels, statins yield antioxidant and anti-inflammatory effects. In liver diseases animal models, statins have been shown to decrease hepatic inflammation, fibrogenesis, and portal pressure (PP). Therefore, we evaluated the atorvastatin effect on the heart in cirrhotic rats.

MATERIALS AND METHODS

Bile duct ligation (BDL) or sham operation performed on male Wistar rats and grouped as cirrhotic; BDL/Saline, BDL/Ator-7d(days) (Atorvastatin 15 mg/kg/day), and BDL/Ator-14d groups, or control; Sham/Saline, Sham/Ator-7d, and Sham/Ator-14d groups. Corrected QT interval (QTc interval), chronotropic responses, serum brain natriuretic peptides (BNP), heart tumor necrosis factor-α (TNF-α), nuclear factor erythroid 2-related factor 2 (Nrf2), and malondialdehyde (MDA) levels were studied along with atrial Ras homolog family member A (RhoA) and endothelial nitric oxide synthase (eNOS) gene expression.

KEY FINDINGS

The chronotropic responses decreased in BDL/Saline and increased in BDL/Ator-7d group. The QTc interval, BNP, TNF-α, and MDA levels increased in BDL/Saline and decreased in BDL/Ator-14d group. The Nrf2 level did not change in BDL/Saline and increased in BDL/Ator-14d group. The liver inflammation and fibrosis increased in BDL/Saline and did not affect BDL/Ator-7d and BDL/Ator-14d groups. The RhoA expression was down-regulated in BDL/Saline, BDL/Ator-7d, and BDL/Ator-14d groups. The eNOS expression did not change in BDL/Saline and down-regulated in BDL/Ator-14d group.

SIGNIFICANCE

Atorvastatin alleviates the chronotropic hypo-responsiveness and down-regulates the atrial RhoA and eNOS gene expression along with anti-inflammatory, antioxidant, and anti-stress effects in CCM.

Statin use and risk of progression to liver cirrhosis in chronic hepatitis B independent of conventional risk factors: A nationwide study

Many studies have elucidated the protective associations of statin use with liver cancer or mortality, but studies examining statin's effect on the risk of progression to liver cirrhosis considering medical/metabolic conditions or lifestyle factors are lacking. We aimed to assess statin's benefit independent of conventional risk factors. We identified 25,033 pairs of statin users (using statins for ≥90 days) and nonusers among patients with chronic hepatitis B (CHB) in the Republic of Korea's National Health Insurance Service database from 2010 to 2018. The primary endpoint was progression to cirrhosis from an inactive carrier or simple CHB. The cumulative probability was plotted using the Kaplan-Meier method. Adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) were estimated using the multivariable Cox proportional hazard model. During a 218,472 person-year follow-up, 2210 incident cases of progression to cirrhosis occurred. The 5-year cumulative risks were 4.0% and 6.3% in statin users and nonusers, respectively (p < 0.001). Statin use was significantly associated with a decreased risk of progression to cirrhosis (aHR, 0.59; 95% CI, 0.55-0.65; p < 0.001), after adjusting for age, sex, hypertension, diabetes, dyslipidemia, antiviral therapy, aspirin use, metformin use, nonstatin medication for dyslipidemia, smoking, drinking, obesity, exercise, and liver dysfunction. This protective association was still significant in a dose-response manner and with different time lags for outcomes. Conclusion: Statin use is associated with a decreased risk of progression to cirrhosis among patients with CHB, independent of metabolic and lifestyle factors. Future studies are required to validate this observation.

Treatment With Simvastatin and Rifaximin Restores the Plasma Metabolomic Profile in Patients With Decompensated Cirrhosis

Patients with decompensated cirrhosis, particularly those with acute-on-chronic liver failure (ACLF), show profound alterations in plasma metabolomics. The aim of this study was to investigate the effect of treatment with simvastatin and rifaximin on plasma metabolites of patients with decompensated cirrhosis, specifically on compounds characteristic of the ACLF plasma metabolomic profile. Two cohorts of patients were investigated. The first was a descriptive cohort of patients with decompensated cirrhosis (n = 42), with and without ACLF. The second was an intervention cohort from the LIVERHOPE-SAFETY randomized, double-blind, placebo-controlled trial treated with simvastatin 20 mg/day plus rifaximin 1,200 mg/day (n = 12) or matching placebo (n = 13) for 3 months. Plasma samples were analyzed using ultrahigh performance liquid chromatography-tandem mass spectroscopy for plasma metabolomics characterization. ACLF was characterized by intense proteolysis and lipid alterations, specifically in pathways associated with inflammation and mitochondrial dysfunction, such as the tryptophan-kynurenine and carnitine beta-oxidation pathways. An ACLF-specific signature was identified. Treatment with simvastatin and rifaximin was associated with changes in 161 of 985 metabolites in comparison to treatment with placebo. A remarkable reduction in levels of metabolites from the tryptophan-kynurenine and carnitine pathways was found. Notably, 18 of the 32 metabolites of the ACLF signature were affected by the treatment. Conclusion: Treatment with simvastatin and rifaximin modulates some of the pathways that appear to be key in ACLF development. This study unveils some of the mechanisms involved in the effects of treatment with simvastatin and rifaximin in decompensated cirrhosis and sets the stage for the use of metabolomics to investigate new targeted therapies in cirrhosis to prevent ACLF development.

Intercellular crosstalk of liver sinusoidal endothelial cells in liver fibrosis, cirrhosis and hepatocellular carcinoma

Intercellular crosstalk among various liver cells plays an important role in liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Capillarization of liver sinusoidal endothelial cells (LSECs) precedes fibrosis and accumulating evidence suggests that the crosstalk between LSECs and other liver cells is critical in the development and progression of liver fibrosis. LSECs dysfunction, a key event in the progression from fibrosis to cirrhosis, and subsequently obstruction of hepatic sinuses and increased intrahepatic vascular resistance (IHVR) contribute to development of portal hypertension (PHT) and cirrhosis. More importantly, immunosuppressive tumor microenvironment (TME), which is closely related to the crosstalk between LSECs and immune liver cells like CD8+ T cells, promotes advances tumorigenesis, especially HCC. However, the connections within the crosstalk between LSECs and other liver cells during the progression from liver fibrosis to cirrhosis to HCC have yet to be discussed. In this review, we first summarize the current knowledge of how different crosstalk between LSECs and other liver cells, including hepatocytes, hepatic stellate cells (HSCs), macrophoges, immune cells in liver and extra cellular matrix (ECM) contribute to the physiological function and the progrssion from liver fibrosis to cirrhosis, or even to HCC. Then we examine current treatment strategies for LSECs crosstalk in liver fibrosis, cirrhosis and HCC.

Statin exposure is associated with reduced development of acute-on-chronic liver failure in a Veterans Affairs cohort

BACKGROUNDS & AIMS

There is a need to identify therapies that prevent the development of acute-on-chronic liver failure (ACLF) in patients with cirrhosis. This study sought to evaluate the association between statin exposure and the risk of developing ACLF in a large national cohort of patients with cirrhosis.

METHODS

We performed a retrospective cohort study of patients diagnosed with cirrhosis within the Veterans Health Administration from 2008 and 2018. Patients were stratified into 3 groups based on statin exposure (statin naïve, existing statin user, and new statin initiator). Cox proportional hazards regression models with inverse probability treatment weighting and marginal structural models were utilized to comprehensively address potential confounding in estimating the association between time-updated statin exposure and first occurrence of high-grade ACLF.

RESULTS

The cohort included 84,963 patients, of whom 26.9% were on a statin at baseline. A total of 8,558 (10.1%) patients with cirrhosis were hospitalized with high-grade ACLF over a median follow-up time of 51.6 months (IQR 27.5-81.4). Time-updated statin use was associated with a significant reduction in the hazard of developing ACLF (hazard ratio [HR] 0.62, 95% CI 0.59-0.65, p <0.001). Increasing doses of statin were associated with progressively reduced hazard of developing ACLF (HR 0.75, 95% CI 0.66-0.86, p <0.001 for <20 mg vs. 0 mg of time-updated statin exposure, in simvastatin equivalents; HR 0.61, 95%, CI 0.58-0.64, p <0.001 for >20 mg vs. 0 mg statin exposure). Furthermore, every additional 5 months of statin exposure was associated with a 9% reduced hazard of high-grade ACLF (HR 0.91, 95% CI 0.90-0.92, p <0.001).

CONCLUSIONS

In this large, retrospective, cohort study in patients with cirrhosis, statin use was significantly associated with reduced development of high-grade ACLF.

LAY SUMMARY

Statin therapy has been shown to have numerous beneficial effects in patients with chronic liver disease. This study demonstrated a strong association between statin therapy and a reduced risk of acute-on-chronic liver failure development in patients with cirrhosis. The results of this study support the promising role that statins may play in future prevention of acute-on-chronic liver failure in patients with cirrhosis.

Liver Fibrosis-From Mechanisms of Injury to Modulation of Disease

The Transregional Collaborative Research Center "Organ Fibrosis: From Mechanisms of Injury to Modulation of Disease" (referred to as SFB/TRR57) was funded for 13 years (2009-2021) by the German Research Council (DFG). This consortium was hosted by the Medical Schools of the RWTH Aachen University and Bonn University in Germany. The SFB/TRR57 implemented combined basic and clinical research to achieve detailed knowledge in three selected key questions: (i) What are the relevant mechanisms and signal pathways required for initiating organ fibrosis? (ii) Which immunological mechanisms and molecules contribute to organ fibrosis? and (iii) How can organ fibrosis be modulated, e.g., by interventional strategies including imaging and pharmacological approaches? In this review we will summarize the liver-related key findings of this consortium gained within the last 12 years on these three aspects of liver fibrogenesis. We will highlight the role of cell death and cell cycle pathways as well as nutritional and iron-related mechanisms for liver fibrosis initiation. Moreover, we will define and characterize the major immune cell compartments relevant for liver fibrogenesis, and finally point to potential signaling pathways and pharmacological targets that turned out to be suitable to develop novel approaches for improved therapy and diagnosis of liver fibrosis. In summary, this review will provide a comprehensive overview about the knowledge on liver fibrogenesis and its potential therapy gained by the SFB/TRR57 consortium within the last decade. The kidney-related research results obtained by the same consortium are highlighted in an article published back-to-back in Frontiers in Medicine.

L-carnitine ameliorates bile duct ligation induced liver fibrosis via reducing the nitrosative stress in experimental animals: preclinical evidences

Bile duct ligation (BDL) has been extensively used in studying the mechanisms of fibrogenesis and anti-fibrotic drugs. Considering the liver regenerative capacity and the diverse results from BDL, the present study aimed to evaluate the protective effect of L-carnitine on bile duct ligation-induced liver fibrosis in experimental rats. Rats were randomly divided into seven groups (n = 6). The bile duct was ligated and serum aspartate transaminase (AST), alanine transaminase (ALT), total bilirubin and albumin, hepatic hydroxyproline (HP), reduced glutathione (GSH), and malondialdehyde (MDA) and cytokines were measured. iNOS expression was measured by using Western blot and finally, liver tissue was processed for histopathological analysis (H&E staining)". The level of iNOS was increased in the control group, whereas a decrease in the level of iNOS was found in the L-carnitine treated group. In the present study, we found that bile duct ligation in rats showed an increase in body and liver weight, while treatment with carnitine showed normal body and liver weight. Serum AST, ALT, total bilirubin, HP, GSH, MDA, and cytokines were increased in bile duct ligated rats. In addition, L-carnitine treated rats showed a reduction in oxidative stress as well as inhibiting the release of cytokines in a dose-dependent manner and showed protection against bile duct ligation. The study concludes that L-carnitine has a protective effect against the liver fibrosis induced by bile duct ligation.

The Hepatic Sinusoid in Chronic Liver Disease: The Optimal Milieu for Cancer

Simple Summary

During the development of chronic liver disease, the hepatic sinusoid undergoes major changes that further compromise the hepatic function, inducing persistent inflammation and the formation of scar tissue, together with alterations in liver hemodynamics. This diseased background may induce the formation and development of hepatocellular carcinoma (HCC), which is the most common form of primary liver cancer and a major cause of mortality. In this review, we describe the ways in which the dysregulation of hepatic sinusoidal cells—including liver sinusoidal cells, Kupffer cells, and hepatic stellate cells—may have an important role in the development of HCC. Our review summarizes all of the known sinusoidal processes in both health and disease, and possible treatments focusing on the dysregulation of the sinusoid; finally, we discuss how some of these alterations occurring during chronic injury are shared with the pathology of HCC and may contribute to its development.

Abstract

The liver sinusoids are a unique type of microvascular beds. The specialized phenotype of sinusoidal cells is essential for their communication, and for the function of all hepatic cell types, including hepatocytes. Liver sinusoidal endothelial cells (LSECs) conform the inner layer of the sinusoids, which is permeable due to the fenestrae across the cytoplasm; hepatic stellate cells (HSCs) surround LSECs, regulate the vascular tone, and synthetize the extracellular matrix, and Kupffer cells (KCs) are the liver-resident macrophages. Upon injury, the harmonic equilibrium in sinusoidal communication is disrupted, leading to phenotypic alterations that may affect the function of the whole liver if the damage persists. Understanding how the specialized sinusoidal cells work in coordination with each other in healthy livers and chronic liver disease is of the utmost importance for the discovery of new therapeutic targets and the design of novel pharmacological strategies. In this manuscript, we summarize the current knowledge on the role of sinusoidal cells and their communication both in health and chronic liver diseases, and their potential pharmacologic modulation. Finally, we discuss how alterations occurring during chronic injury may contribute to the development of hepatocellular carcinoma, which is usually developed in the background of chronic liver disease.

Development of Anti-fibrotic Therapy in Stricturing Crohn's Disease: Lessons from Randomized Trials in Other Fibrotic Diseases

Intestinal fibrosis is considered an inevitable complication of Crohn's disease (CD) that results in symptoms of obstruction and stricture formation. Endoscopic or surgical treatment is required to treat the majority of patients. Progress in the management of stricturing CD is hampered by the lack of effective anti-fibrotic therapy; however, this situation is likely to change because of recent advances in other fibrotic diseases of the lung, liver and skin. In this review, we summarized data from randomized controlled trials (RCT) of anti-fibrotic therapies in these conditions. Multiple compounds have been tested for the anti-fibrotic effects in other organs. According to their mechanisms, they were categorized into growth factor modulators, inflammation modulators, 5-hydroxy-3-methylgultaryl-coenzyme A (HMG-CoA) reductase inhibitors, intracellular enzymes and kinases, renin-angiotensin system (RAS) modulators and others. From our review of the results from the clinical trials and discussion of their implications in the gastrointestinal tract, we have identified several molecular candidates that could serve as potential therapies for intestinal fibrosis in CD.

Cyclic GMP in Liver Cirrhosis-Role in Pathophysiology of Portal Hypertension and Therapeutic Implications

The NO-cGMP signal transduction pathway plays a crucial role in tone regulation in hepatic sinusoids and peripheral blood vessels. In a cirrhotic liver, the key enzymes endothelial NO synthase (eNOS), soluble guanylate cyclase (sGC), and phosphodiesterase-5 (PDE-5) are overexpressed, leading to decreased cyclic guanosine-monophosphate (cGMP). This results in constriction of hepatic sinusoids, contributing about 30% of portal pressure. In contrast, in peripheral arteries, dilation prevails with excess cGMP due to low PDE-5. Both effects eventually lead to circulatory dysfunction in progressed liver cirrhosis. The conventional view of portal hypertension (PH) pathophysiology has been described using the "NO-paradox", referring to reduced NO availability inside the liver and elevated NO production in the peripheral systemic circulation. However, recent data suggest that an altered availability of cGMP could better elucidate the contrasting findings of intrahepatic vasoconstriction and peripheral systemic vasodilation than mere focus on NO availability. Preclinical and clinical data have demonstrated that targeting the NO-cGMP pathway in liver cirrhosis using PDE-5 inhibitors or sGC stimulators/activators decreases intrahepatic resistance through dilation of sinusoids, lowering portal pressure, and increasing portal venous blood flow. These results suggest further clinical applications in liver cirrhosis. Targeting the NO-cGMP system plays a role in possible reversal of liver fibrosis or cirrhosis. PDE-5 inhibitors may have therapeutic potential for hepatic encephalopathy. Serum/plasma levels of cGMP can be used as a non-invasive marker of clinically significant portal hypertension. This manuscript reviews new data about the role of the NO-cGMP signal transduction system in pathophysiology of cirrhotic portal hypertension and provides perspective for further studies.

Portal hypertension in cirrhosis: Pathophysiological mechanisms and therapy

Portal hypertension, defined as increased pressure in the portal vein, develops as a consequence of increased intrahepatic vascular resistance due to the dysregulation of liver sinusoidal endothelial cells (LSECs) and hepatic stellate cells (HSCs), frequently arising from chronic liver diseases. Extrahepatic haemodynamic changes contribute to the aggravation of portal hypertension. The pathogenic complexity of portal hypertension and the unsuccessful translation of preclinical studies have impeded the development of effective therapeutics for patients with cirrhosis, while counteracting hepatic and extrahepatic mechanisms also pose a major obstacle to effective treatment. In this review article, we will discuss the following topics: i) cellular and molecular mechanisms of portal hypertension, focusing on dysregulation of LSECs, HSCs and hepatic microvascular thrombosis, as well as changes in the extrahepatic vasculature, since these are the major contributors to portal hypertension; ii) translational/clinical advances in our knowledge of portal hypertension; and iii) future directions.

Addition of statins to the standard treatment in patients with cirrhosis: Safety and efficacy

This review summarizes the safety and efficacy of statins in patients with cirrhosis. Due to concerns about the safety of statins in patients with impaired liver function, they have recently been investigated as a potential treatment option in cirrhosis. The most clinically significant adverse event is statin-related myopathy, and this may be related to the high serum statin concentrations in the setting of severely impaired liver function. Rhabdomyolysis is the most serious and potentially life-threatening manifestation. It has recently been demonstrated that the recommended dose of simvastatin in patients with decompensated cirrhosis would be 20 mg/d because higher values, such as 40 mg/d, are associated with many adverse events, especially muscle injury. Likewise, simvastatin should not be administered to patients with Model for End-stage Liver Disease score > 12 and/or Child-Pugh class C because of the high risk of severe muscle injury. Due to the pleiotropic effects, the focus on statins has shifted from being considered harmful to something useful. Through these effects, statins could prevent liver-related morbidity and mortality in cirrhotic patients. Observational studies in large populations of patients with cirrhosis have shown that treatment with statins to decrease high cholesterol levels was associated with a reduced risk of hepatic decompensation, hepatocellular carcinoma development and death. The few randomized controlled trials in patients with cirrhosis and portal hypertension showed that statins lower portal pressure, quite likely through a reduction in hepatic resistance. Another large randomized controlled trial in patients with variceal bleeding showed that simvastatin in addition to standard of care did not prevent rebleeding but improved survival rate. Despite these encouraging outcomes, the quality of the evidence regarding the use of statins is low or very low due to the observational characteristics of most of the studies involved. Therefore, it is advisable to perform further randomized controlled trials on a large series of patients with hard clinical endpoints, using different statin types and varying doses. The objectives would be to prevent liver-related morbidity and mortality rather than treating cirrhosis complications to take additional information that makes it possible to add statins to the standard of care of these patients.

Fibrosis Regression After Eradication of Hepatitis C Virus: From Bench to Bedside

Hepatitis C virus (HCV) infection and its complications have been the major cause of cirrhosis and its complications for several decades in the Western world. Until recently, treatment for HCV with interferon-based regimens was associated with moderate success but was difficult to tolerate. More recently, however, an arsenal of novel and highly effective direct-acting antiviral (DAA) drugs has transformed the landscape by curing HCV in a broad range of patients, including those with established advanced fibrosis, cirrhosis, comorbidities, and even those with complications of cirrhosis. Fibrosis is a dynamic process comprising both extracellular matrix deposition, as well as its degradation. With almost universal sustained virologic response (SVR) (ie, elimination of HCV), it is timely to explore whether HCV eradication can reverse fibrosis and cirrhosis. Indeed, fibrosis in several types of liver disease is reversible, including HCV. However, we do not know with certainty in whom fibrosis regression can be expected after HCV elimination, how quickly it occurs, and whether antifibrotic therapies will be indicated in those with persistent cirrhosis. This review summarizes the evidence for reversibility of fibrosis and cirrhosis after HCV eradication, its impact on clinical outcomes, and therapeutic prospects for directly promoting fibrosis regression in patients whose fibrosis persists after SVR.

Substance-P prevents the cholestatic liver injury by regulating inflammatory responses

Substance-P (SP) is a neuropeptide that modulates immune responses and accelerates tissue repair in critical inflammatory disease. Liver fibrosis and cirrhosis are the ultimate outcomes of almost all chronic liver diseases caused by viral infection, steatohepatitis, autoimmune, and cholestatic injury. Despite the development of new drugs, liver transplantation is still the only fundamental treatment; thus, new therapeutic approaches to mitigate liver fibrosis and chronic inflammation are constantly being needed. The aim of this study was to examine the effect of SP on liver damage due to cholestatic stress. To induce cholestatic injury, common bile duct ligation (CBDL) was attempted, followed by systemic application of SP. SP treatment increased IL-10 and decreased TNF-α in serum with increasing levels of circulating regulatory T cells (Tregs) from the early stage of CBDL. Moreover, SP decreased CBDL-induced TGF-β1 expression in the circulation. This could create anti-inflammatory/anti-fibrotic environment under CBDL, which might ameliorate the progression of liver fibrosis in CBDL. Histological and molecular analysis revealed that SP treatment reduced ductular reaction, hepatic damage, and apoptotic hepatocytes, accompanied by diminishing type I collagen and upregulating MMP-9. These studies found that SP is a promising therapeutic candidate for immune-related liver disease as well as cholestatic liver disease, by providing hepatic protective effects via immune suppression.

Liver stiffness across different chronic liver disease under therapy with statin in a real life cohort

INTRODUCTION

Statins have been associated with improved clinical outcomes in patients with viral hepatitis and after variceal bleeding. Still, the clinical benefit of statins is not well defined for different liver diseases. Moreover, associations between statin use and liver stiffness as well as event free survival have not been established.

METHODS

Liver stiffness was evaluated in 6490 patients with liver disease (January 2012 till December 2016). Two hundred thirty-four of those received statin therapy, 468 controls without statins were selected by a 1:2 case by case matching using age, sex, underlying liver disease and BMI.

RESULTS

Statins were given to 234 patients with chronic virus hepatitis (n = 104), nonalcoholic fatty liver disease (n = 52), autoimmune liver disease including autoimmune hepatitis, primary biliary cholangitis and primary sclerosing cholangitis (n = 31) and hepatitis of unknown origin (n = 47). Follow-up data were available for 96 and 119 pairs (mean follow-up 2 years). Statin users showed reduced inflammatory activity. Elevated liver enzymes were reported in 57% of statin-treated compared with 70% of controls (mean alanine aminotransferase level 53 vs. 74 U/l; P < 0.001). Statin use was well tolerated in this cohort. Mean liver stiffness values were 10.7 kPa (SEM 0.7) and 15.5 kPa (SEM 0.7) accordingly (P < 0.0001). Decompensation was less likely to occur in the statin group, both groups do not defer in the incidence of liver tumor occurrence, transplantation or death (odds ratio = 1, P = nonsignificant).

CONCLUSIONS

Use of statins was well tolerated irrespective of liver disease. Statin users showed reduced hepatic inflammatory activity, less severe markers of liver stiffness and portal hypertension. There might be a beneficial effect of statin on the risk to experience hepatic decompensation.

Differential inflammasome activation predisposes to acute-on-chronic liver failure in human and experimental cirrhosis with and without previous decompensation

OBJECTIVE

Systemic inflammation predisposes acutely decompensated (AD) cirrhosis to the development of acute-on-chronic liver failure (ACLF). Supportive treatment can improve AD patients, becoming recompensated. Little is known about the outcome of patients recompensated after AD. We hypothesise that different inflammasome activation is involved in ACLF development in compensated and recompensated patients.

DESIGN

249 patients with cirrhosis, divided into compensated and recompensated (previous AD), were followed prospectively for fatal ACLF development. Two external cohorts (n=327) (recompensation, AD and ACLF) were included. Inflammasome-driving interleukins (ILs), IL-1α (caspase-4/11-dependent) and IL-1β (caspase-1-dependent), were measured. In rats, bile duct ligation-induced cirrhosis and lipopolysaccharide exposition were used to induce AD and subsequent recompensation. IL-1α and IL-1β levels and upstream/downstream gene expression were measured.

RESULTS

Patients developing ACLF showed higher baseline levels of ILs. Recompensated patients and patients with detectable ILs had higher rates of ACLF development than compensated patients. Baseline CLIF-C (European Foundation for the study of chronic liver failure consortium) AD, albumin and IL-1α were independent predictors of ACLF development in compensated and CLIF-C AD and IL-1β in recompensated patients. Compensated rats showed higher IL-1α gene expression and recompensated rats higher IL-1β levels with higher hepatic gene expression. Higher IL-1β detection rates in recompensated patients developing ACLF and higher IL-1α and IL-1β detection rates in patients with ACLF were confirmed in the two external cohorts.

CONCLUSION

Previous AD is an important risk factor for fatal ACLF development and possibly linked with inflammasome activation. Animal models confirmed the results showing a link between ACLF development and IL-1α in compensated cirrhosis and IL-1β in recompensated cirrhosis.

Co-Medication and Nutrition in Hepatocellular Carcinoma: Potentially Preventative Strategies in Hepatocellular Carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is one of the leading causes of cancer-related death worldwide, with about 841,000 new cases and 782,000 deaths annually. Given the clearly defined population at risk, mostly patients with liver cirrhosis, prevention of HCC could be highly effective.

SUMMARY

Besides regular ultrasound surveillance, numerous publications have suggested protective effects of diverse drugs and nutrients. However, none of those preventive options has made it into clinical routine or practice guidelines. We therefore summarize the current status of preventive effects of drugs such as statins, acetylsalicylic acid (ASA), and metformin, but also dietary aspects and nutrients such as coffee, tea, and vitamin D supplementation. A successful implementation of some of these strategies may potentially lead to improved prevention of HCC development in patients with liver cirrhosis. Key Messages: Accumulating data suggest that particularly ASA, antidiabetic therapies, and statins may substantially decrease HCC incidence in patients at risk.

Curcumin exerts hepatoprotection via overexpression of Paraoxonase-1 and its regulatory genes in rats undergone bile duct ligation

OBJECTIVES

Curcumin is described as an antioxidant, hepato-protective and antifibrotic in liver fibrosis, although its mechanism is still not known. One of the models of the chronic liver disease stemming from oxidative stress and the generation of free radical has been considered to be bile duct ligation (BDL). Paraoxonase 1 (PON1) is a prominent antioxidant enzyme. Therefore, the objective of the present research is to assess the effects of curcumin on upregulation of PON1 in BDL rats.

METHODS

As predicted, the rats have been divided into the four groups of Sham, Sham + Cur (curcumin), BDL and BDL + Cur. We evaluated the efficacy of curcumin (100 mg/kg/day) on protein and gene expression of PON1 and regulatory genes contributed to the gene expression PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and regulation PON1 activity gene expression of Apo A1.

RESULTS

Curcumin attenuated alterations in liver histology, hepatic enzymes and the mRNA expression of fibrotic markers (p<0.05). In addition, curcumin increased significantly mRNA, protein expression of PON1 and mRNA of the genes that are contributed to the expression of PON1 such as Sp1, PKCα, SREBP-2, AhR, JNK and increased PON1 activity through upregulation of Apo A1 (p<0.05).

CONCLUSIONS

Cirrhosis progression may be inhibited by treatment with curcumin through the increased influence the expression and activity of PON1.

Lifestyle and Environmental Approaches for the Primary Prevention of Hepatocellular Carcinoma

Patients with chronic liver disease are at increased risk of developing hepatocellular carcinoma (HCC). Most patients diagnosed with HCC have limited treatment options and a poor overall prognosis, with a 5-year survival less than 15%. Preventing the development of HCC represents the most important strategy. However, current guidelines lack specific recommendations for primary prevention. Lifestyle factors may be central in the pathogenesis of HCC, and primary prevention strategies focused on lifestyle modification could represent an important approach to the prevention of HCC. Both experimental and epidemiologic studies have identified promising chemopreventive agents for the primary prevention of HCC.

Cirrhotic portal hypertension: From pathophysiology to novel therapeutics

Portal hypertension and bleeding from gastroesophageal varices is the major cause of morbidity and mortality in patients with cirrhosis. Portal hypertension is initiated by increased intrahepatic vascular resistance and a hyperdynamic circulatory state. The latter is characterized by a high cardiac output, increased total blood volume and splanchnic vasodilatation, resulting in increased mesenteric blood flow. Pharmacological manipulation of cirrhotic portal hypertension targets both the splanchnic and hepatic vascular beds. Drugs such as angiotensin converting enzyme inhibitors and angiotensin II type receptor 1 blockers, which target the components of the classical renin angiotensin system (RAS), are expected to reduce intrahepatic vascular tone by reducing extracellular matrix deposition and vasoactivity of contractile cells and thereby improve portal hypertension. However, these drugs have been shown to produce significant off-target effects such as systemic hypotension and renal failure. Therefore, the current pharmacological mainstay in clinical practice to prevent variceal bleeding and improving patient survival by reducing portal pressure is non-selective -blockers (NSBBs). These NSBBs work by reducing cardiac output and splanchnic vasodilatation but most patients do not achieve an optimal therapeutic response and a significant proportion of patients are unable to tolerate these drugs. Although statins, used alone or in combination with NSBBs, have been shown to improve portal pressure and overall mortality in cirrhotic patients, further randomized clinical trials are warranted involving larger patient populations with clear clinical end points. On the other hand, recent findings from studies that have investigated the potential use of the blockers of the components of the alternate RAS provided compelling evidence that could lead to the development of drugs targeting the splanchnic vascular bed to inhibit splanchnic vasodilatation in portal hypertension. This review outlines the mechanisms related to the pathogenesis of portal hypertension and attempts to provide an update on currently available therapeutic approaches in the management of portal hypertension with special emphasis on how the alternate RAS could be manipulated in our search for development of safe, specific and effective novel therapies to treat portal hypertension in cirrhosis.

Phosphodiesterases in the Liver as Potential Therapeutic Targets of Cirrhotic Portal Hypertension

Liver cirrhosis is a frequent condition with high impact on patients' life expectancy and health care systems. Cirrhotic portal hypertension (PH) gradually develops with deteriorating liver function and can lead to life-threatening complications. Other than an increase in intrahepatic flow resistance due to morphological remodeling of the organ, a functional dysregulation of the sinusoids, the smallest functional units of liver vasculature, plays a pivotal role. Vascular tone is primarily regulated by the nitric oxide-cyclic guanosine monophosphate (NO-cGMP) pathway, wherein soluble guanylate cyclase (sGC) and phosphodiesterase-5 (PDE-5) are key enzymes. Recent data showed characteristic alterations in the expression of these regulatory enzymes or metabolite levels in liver cirrhosis. Additionally, a disturbed zonation of the components of this pathway along the sinusoids was detected. This review describes current knowledge of the pathophysiology of PH with focus on the enzymes regulating cGMP availability, i.e., sGC and PDE-5. The results have primarily been obtained in animal models of liver cirrhosis. However, clinical and histochemical data suggest that the new biochemical model we propose can be applied to human liver cirrhosis. The role of PDE-5 as potential target for medical therapy of PH is discussed.

Simvastatin-loaded polymeric micelles are more effective and less toxic than conventional statins in a pre-clinical model of advanced chronic liver disease

Chronic liver disease (CLD) has no effective treatments apart from reducing its complications. Simvastatin has been tested as vasoprotective drug in experimental models of CLD showing promising results, but also limiting adverse effects. Two types of Pluronic® carriers loading simvastatin (PM108-simv and PM127-simv) as a drug delivery system were developed to avoid these toxicities while increasing the therapeutic window of simvastatin. PM127-simv showed the highest rates of cell internalization in rat liver sinusoidal endothelial cells (LSECs) and significantly lower toxicity than free simvastatin, improving cell phenotype. The in vivo biodistribution was mainly hepatic with 50% of the injected PM found in the liver. Remarkably, after one week of administration in a model of CLD, PM127-simv demonstrated superior effect than free simvastatin in reducing portal hypertension. Moreover, no signs of toxicity of PM127-simv were detected. Our results indicate that simvastatin targeted delivery to LSEC is a promising therapeutic approach for CLD.

The Role of Macrophage-Inducible C-Type Lectin in Different Stages of Chronic Liver Disease

The macrophage-inducible C-type lectin (mincle) is part of the innate immune system and acts as a pattern recognition receptor for pathogen-associated molecular patterns (PAMPS) and damage-associated molecular patterns (DAMPs). Ligand binding induces mincle activation which consequently interacts with the signaling adapter Fc receptor, SYK, and NF-kappa-B. There is also evidence that mincle expressed on macrophages promotes intestinal barrier integrity. However, little is known about the role of mincle in hepatic fibrosis, especially in more advanced disease stages. Mincle expression was measured in human liver samples from cirrhotic patients and donors collected at liver transplantation and in patients undergoing bariatric surgery. Human results were confirmed in rodent models of cirrhosis and acute-on-chronic liver failure (ACLF). In these models, the role of mincle was investigated in liver samples as well as in peripheral blood monocytes (PBMC), tissues from the kidney, spleen, small intestine, and heart. Additionally, mincle activation was stimulated in experimental non-alcoholic steatohepatitis (NASH) by treatment with mincle agonist trehalose-6,6-dibehenate (TDB). In human NASH, mincle is upregulated with increased collagen production. In ApoE deficient mice fed high-fat western diet (NASH model), mincle activation significantly increases hepatic collagen production. In human cirrhosis, mincle expression is also significantly upregulated. Furthermore, mincle expression is associated with the stage of chronic liver disease. This could be confirmed in rat models of cirrhosis and ACLF. ACLF was induced by LPS injection in cirrhotic rats. While mincle expression and downstream signaling via FC receptor gamma, SYK, and NF-kappa-B are upregulated in the liver, they are downregulated in PBMCs of these rats. Although mincle expressed on macrophages might be beneficial for intestinal barrier integrity, it seems to contribute to inflammation and fibrosis once the intestinal barrier becomes leaky in advanced stages of chronic liver disease.

Efficient drug and gene delivery to liver fibrosis: rationale, recent advances, and perspectives

Liver fibrosis results from chronic damages together with an accumulation of extracellular matrix, and no specific medical therapy is approved for that until now. Due to liver metabolic capacity for drugs, the fragility of drugs, and the presence of insurmountable physiological obstacles in the way of targeting, the development of efficient drug delivery systems for anti-fibrotics seems vital. We have explored articles with a different perspective on liver fibrosis over the two decades, then collected and summarized the information by providing corresponding in vitro and in vivo cases. We have discussed the mechanism of hepatic fibrogenesis with different ways of fibrosis induction in animals. Furthermore, the critical chemical and herbal anti-fibrotics, biological molecules such as micro-RNAs, siRNAs, and growth factors, which can affect cell division and differentiation, are mentioned. Likewise, drug and gene delivery and therapeutic systems on in vitro and in vivo models are summarized in the data tables. This review article enlightens recent advances in emerging drugs and nanocarriers and represents perspectives on targeting strategies employed in liver fibrosis treatment.