Molecular Mechanisms and Potential New Therapeutic Drugs for Liver Fibrosis

Rocaglamide-A mitigates LPS-induced hepatic inflammation by modulating JNK/AP-1 signaling cascade and ROS production in hepatocytes

Lipopolysaccharide (LPS), a gut-derived endotoxin, is a recognized risk factor for both Non-alcoholic fatty liver disease (NAFLD) and alcoholic liver disease (ALD). Rocaglamide-A (Roc-A), a natural compound derived from the genus Aglaia, is known for its pharmacological and immunosuppressive effects on various cell types. Although our recent investigations have unveiled Roc-A's anti-adipogenic role in adipocytes, its mechanism in hepatic inflammation remains elusive. This study delves into Roc-A's protective effects on LPS-induced hepatic inflammation. Our results demonstrated that Roc-A treatment significantly reduced the LPS-induced production of inflammatory cytokines in hepatocytes. Intriguingly, Roc-A decreased LPS-induced production of reactive oxygen species (ROS), upregulated antioxidant gene expression, and downregulated endoplasmic reticulum (ER) stress-related gene expression. Mechanistically, Roc-A significantly attenuated LPS-induced phosphorylation of c-Jun N-terminal kinase (JNK) and activator protein-1 (AP-1). Notably, this effect was abolished by the JNK activator Anisomycin, while the JNK inhibitor SP600125 enhanced it. Furthermore, Roc-A suppressed the expression of NF-κB target genes, including inducible nitric oxide synthase (iNOS), thereby alleviating iNOS-derived nitric oxide (NO) production. These findings collectively indicate that Roc-A has the potential to alleviate LPS-induced nitrosative/oxidative stress and hepatic inflammation by inhibiting JNK phosphorylation. Thus, Roc-A emerges as a promising anti-inflammatory intervention for LPS-induced hepatic inflammation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s43188-024-00263-y.

Pirfenidone Downregulates eIF6, P311, and TGF-β Expression and Improves Liver Fibrosis Induced by Bile Duct Ligation in Wistar Rats: Evidence for Liver Regeneration

Liver fibrosis (LF) is a clinical disorder characterized by inflammation and excessive accumulation of extracellular matrix (ECM). This study investigates the effects of the antifibrotic compound pirfenidone (PFD) on improving LF through histological changes and modulation of eukaryotic translation initiation factor 6 (eIF6), P311, and transforming growth factor beta (TGF-β) in rats with bile duct ligation (BDL)-induced LF. Rats received daily doses of PFD (200 and 500 mg/kg) for 4 weeks. The study encompassed biochemical, pathological, and immunohistochemical (IHC) analyses. mRNA levels of eIF6, P311, TGF-β, ECM deposition, hepatic stellate cell (HSC) activation, and inflammatory mediator genes were measured by RT-qPCR. Protein levels of eIF6, P311, and TGF-β were detected by western blotting. Compared with the BDL group, PFD dose-dependently reduced hydroxyproline content, liver index, biochemical parameters, fibrosis score, and fibrosis area. PFD also modulated BDL-induced hepatic inflammation, ECM accumulation, and HSC activation. IHC staining of Ki-67 and hepatocyte paraffin-1 revealed that PFD enhanced liver regeneration. The research confirmed that PFD gradually downregulated elevated eIF6, P311, and TGF-β levels in BDL-induced LF. These findings suggest that PFD could be a potential treatment for LF, as it may help attenuate fibrosis and enhance liver regeneration, possibly through the modulation of these specific markers.

Advances in the understanding of the role and mechanism of action of PFKFB3‑mediated glycolysis in liver fibrosis (Review)

Liver fibrosis is a pathophysiologic manifestation of chronic liver disease and a precursor to cirrhosis and hepatocellular carcinoma. Glycolysis provides intermediate metabolites as well as energy support for cell proliferation and phenotypic transformation in liver fibers. 6‑Phosphofructo‑2‑kinase/fructose‑2,6‑bisphosphatase 3 (PFKFB3) is a key activator of glycolysis and plays an important role in the process of glycolysis. The role of PFKFB3‑mediated glycolysis in myocardial fibrosis, renal fibrosis and pulmonary fibrosis has been demonstrated, and the role of PFKFB3 in the activation of hepatic stellate cells by aerobic glycolysis has been proven by relevant experiments. The present study reviews the research progress on the role and mechanism of action of PFKFB3‑mediated glycolysis in the progression of hepatic fibrosis to discuss the role of PFKFB3‑mediated glycolysis in hepatic fibrosis and to provide new ideas for research on PFKFB3 as a target for the treatment of hepatic fibrosis.

Proceedings of the 5th Meeting of Translational Hepatology, organized by the Spanish Association for the Study of the Liver (AEEH)

This is the summary report of the 5th Translational Hepatology Meeting, endorsed by the Spanish Association for the Study of the Liver (AEEH) and held in Seville, Spain, in October 2023. The meeting aimed to provide an update on the latest advances in the field of basic and translational hepatology, covering different molecular, cellular, and pathophysiological aspects of the most relevant clinical challenges in liver pathologies. This includes the identification of novel biomarkers and diagnostic tools, the understanding of the relevance of immune response and inflammation in liver diseases, the characterization of current medical approaches to reverse liver diseases, the incorporation of novel molecular insights through omics techniques, or the characterization of the impact of toxic and metabolic insults, as well as other organ crosstalk, in liver pathophysiology.

The Metabolomic Footprint of Liver Fibrosis

Both experimental and clinical liver fibrosis leave a metabolic footprint that can be uncovered and defined using metabolomic approaches. Metabolomics combines pattern recognition algorithms with analytical chemistry, in particular, 1H and 13C nuclear magnetic resonance spectroscopy (NMR), gas chromatography-mass spectrometry (GC-MS) and various liquid chromatography-mass spectrometry (LC-MS) platforms. The analysis of liver fibrosis by each of these methodologies is reviewed separately. Surprisingly, there was little general agreement between studies within each of these three groups and also between groups. The metabolomic footprint determined by NMR (two or more hits between studies) comprised elevated lactate, acetate, choline, 3-hydroxybutyrate, glucose, histidine, methionine, glutamine, phenylalanine, tyrosine and citrate. For GC-MS, succinate, fumarate, malate, ascorbate, glutamate, glycine, serine and, in agreement with NMR, glutamine, phenylalanine, tyrosine and citrate were delineated. For LC-MS, only β-muricholic acid, tryptophan, acylcarnitine, p-cresol, valine and, in agreement with NMR, phosphocholine were identified. The metabolomic footprint of liver fibrosis was upregulated as regards glutamine, phenylalanine, tyrosine, citrate and phosphocholine. Several investigators employed traditional Chinese medicine (TCM) treatments to reverse experimental liver fibrosis, and a commentary is given on the chemical constituents that may possess fibrolytic activity. It is proposed that molecular docking procedures using these TCM constituents may lead to novel therapies for liver fibrosis affecting at least one-in-twenty persons globally, for which there is currently no pharmaceutical cure. This in-depth review summarizes the relevant literature on metabolomics and its implications in addressing the clinical problem of liver fibrosis, cirrhosis and its sequelae.

Liver Fibrosis: From Basic Science towards Clinical Progress, Focusing on the Central Role of Hepatic Stellate Cells

The burden of chronic liver disease is globally increasing at an alarming rate. Chronic liver injury leads to liver inflammation and fibrosis (LF) as critical determinants of long-term outcomes such as cirrhosis, liver cancer, and mortality. LF is a wound-healing process characterized by excessive deposition of extracellular matrix (ECM) proteins due to the activation of hepatic stellate cells (HSCs). In the healthy liver, quiescent HSCs metabolize and store retinoids. Upon fibrogenic activation, quiescent HSCs transdifferentiate into myofibroblasts; lose their vitamin A; upregulate α-smooth muscle actin; and produce proinflammatory soluble mediators, collagens, and inhibitors of ECM degradation. Activated HSCs are the main effector cells during hepatic fibrogenesis. In addition, the accumulation and activation of profibrogenic macrophages in response to hepatocyte death play a critical role in the initiation of HSC activation and survival. The main source of myofibroblasts is resident HSCs. Activated HSCs migrate to the site of active fibrogenesis to initiate the formation of a fibrous scar. Single-cell technologies revealed that quiescent HSCs are highly homogenous, while activated HSCs/myofibroblasts are much more heterogeneous. The complex process of inflammation results from the response of various hepatic cells to hepatocellular death and inflammatory signals related to intrahepatic injury pathways or extrahepatic mediators. Inflammatory processes modulate fibrogenesis by activating HSCs and, in turn, drive immune mechanisms via cytokines and chemokines. Increasing evidence also suggests that cellular stress responses contribute to fibrogenesis. Recent data demonstrated that LF can revert even at advanced stages of cirrhosis if the underlying cause is eliminated, which inhibits the inflammatory and profibrogenic cells. However, despite numerous clinical studies on plausible drug candidates, an approved antifibrotic therapy still remains elusive. This state-of-the-art review presents cellular and molecular mechanisms involved in hepatic fibrogenesis and its resolution, as well as comprehensively discusses the drivers linking liver injury to chronic liver inflammation and LF.

WISP-1 Regulates Cardiac Fibrosis by Promoting Cardiac Fibroblasts' Activation and Collagen Processing

Hypertension induces cardiac fibrotic remodelling characterised by the phenotypic switching of cardiac fibroblasts (CFs) and collagen deposition. We tested the hypothesis that Wnt1-inducible signalling pathway protein-1 (WISP-1) promotes CFs' phenotypic switch, type I collagen synthesis, and in vivo fibrotic remodelling. The treatment of human CFs (HCFs, n = 16) with WISP-1 (500 ng/mL) induced a phenotypic switch (α-smooth muscle actin-positive) and type I procollagen cleavage to an intermediate form of collagen (pC-collagen) in conditioned media after 24h, facilitating collagen maturation. WISP-1-induced collagen processing was mediated by Akt phosphorylation via integrin β1, and disintegrin and metalloproteinase with thrombospondin motifs 2 (ADAMTS-2). WISP-1 wild-type (WISP-1+/+) mice and WISP-1 knockout (WISP-1-/-) mice (n = 5-7) were subcutaneously infused with angiotensin II (AngII, 1000 ng/kg/min) for 28 days. Immunohistochemistry revealed the deletion of WISP-1 attenuated type I collagen deposition in the coronary artery perivascular area compared to WISP-1+/+ mice after a 28-day AngII infusion, and therefore, the deletion of WISP-1 attenuated AngII-induced cardiac fibrosis in vivo. Collectively, our findings demonstrated WISP-1 is a critical mediator in cardiac fibrotic remodelling, by promoting CFs' activation via the integrin β1-Akt signalling pathway, and induced collagen processing and maturation via ADAMTS-2. Thereby, the modulation of WISP-1 levels could provide potential therapeutic targets in clinical treatment.

Liver fibrosis: pathological features, clinical treatment and application of therapeutic nanoagents

Liver fibrosis is a reversible damage-repair response, the pathological features of which mainly include damage to hepatocytes, sinusoid capillarization, hepatic stellate cells activation, excessive accumulation of extracellular matrix and inflammatory response. Although some treatments (including drugs and stem cell therapy) for these pathological features have been shown to be effective, more clinical trials are needed to confirm their effectiveness. In recent years, nanomaterials-based therapies have emerged as an innovative and promising alternative to traditional drugs, being explored for the treatment of liver fibrosis diseases. Natural nanomaterials (including extracellular vesicles) and synthetic nanomaterials (including inorganic nanomaterials and organic nanomaterials) are developed to facilitate drug targeting delivery and combination therapy. In this review, the pathological features of liver fibrosis and the current anti-fibrosis drugs in clinical trials are briefly introduced, followed by a detailed introduction of the therapeutic nanoagents for the precise delivery of anti-fibrosis drugs. Finally, the future development trend in this field is discussed.

Research Progress Regarding the Effect and Mechanism of Dietary Polyphenols in Liver Fibrosis

The development of liver fibrosis is a result of chronic liver injuries may progress to liver cirrhosis and liver cancer. In recent years, liver fibrosis has become a major global problem, and the incidence rate and mortality are increasing year by year. However, there are currently no approved treatments. Research on anti-liver-fibrosis drugs is a top priority. Dietary polyphenols, such as plant secondary metabolites, have remarkable abilities to reduce lipid metabolism, insulin resistance and inflammation, and are attracting more and more attention as potential drugs for the treatment of liver diseases. Gradually, dietary polyphenols are becoming the focus for providing an improvement in the treatment of liver fibrosis. The impact of dietary polyphenols on the composition of intestinal microbiota and the subsequent production of intestinal microbial metabolites has been observed to indirectly modulate signaling pathways in the liver, thereby exerting regulatory effects on liver disease. In conclusion, there is evidence that dietary polyphenols can be therapeutically useful in preventing and treating liver fibrosis, and we highlight new perspectives and key questions for future drug development.

Herpetetrone nanosuspensions enhance drug solubility and bioavailability to improve anti-hepatic fibrosis effects

The aim of this study was to enhance the dissolution rate and oral bioavailability of herpetetrone (HPT) by preparing nanosuspensions (NSs) and evaluate the changes in its anti-hepatic fibrosis effect. Herpetetrone nanosuspension (HPT-NS) was prepared using the ultrasound-precipitation technique, and characterised on the basis of mean diameter, zeta potential (ZP), encapsulation efficiency percent (EE%), scanning electron microscopy (SEM), and X-ray powder diffraction (XRPD). In addition, the pharmacokinetics and anti-hepatic fibrosis activity were evaluated. HPT-NS prepared with the optimised formulation was found to be spherical with mean diameter of 177.48 ± 6.13 nm, polydispersity index (PDI) of 0.108 ± 0.002 and ZP of -17.28 ± 2.02 mV. The EE (m/m, %) was 83.25 ± 0.27. XRPD analyses confirmed that the amorphous state of HPT in HPT-NS remained unchanged. The dissolution rate of HPT-NS was significantly higher than that of HPT coarse suspensions (HPT-CSs). Following oral administration, Cmax and AUC0-t of HPT-NS showed a significant increase (p < 0.05). In vitro, HPT inhibited the proliferation of HSC-T6 cells and induced apoptosis by up-regulating the expression of Bax proteins and down-regulating the expression of Bcl-2 and TGF-β1 proteins. Compared with HPT-CS, HPT-NS exhibited a more pronounced anti-fibrotic effect. HPT-NS, as a new drug formulation designed to improve the solubility and bioavailability of the drug, shows promising potential in enhancing the anti-liver fibrosis effect.

The Dual-Mode Transition of Myofibroblasts Derived from Hepatic Stellate Cells in Liver Fibrosis

Hepatic stellate cells (HSCs) are the key promoters of liver fibrosis. In response to liver-fibrosis-inducing factors, HSCs express alpha smooth muscle actin (α-SMA) and obtain myofibroblast phenotype. Collagen secretion and high expression of α-SMA with related high cell tension and migration limitation are the main characteristics of myofibroblasts. How these two characteristics define the role of myofibroblasts in the initiation and progression of liver fibrosis is worth exploring. From this perspective, we explored the correlation between α-SMA expression and collagen secretion in myofibroblasts and the characteristics of collagen deposition in liver fibrosis. Based on a reasonable hypothesis and experimental verification, we believe that the myofibroblast with the α-SMAhighcollagenhigh model do not effectively explain the initial stage and progression characteristics of liver fibrosis. Therefore, we propose a myofibroblast dual-mode transition model in fibrotic liver (DMTM model). In the DMTM model, myofibroblasts have dual modes. Myofibroblasts obtain enhanced α-SMA expression, accompanied by collagen expression inhibition in the high-concentration region of TGF-β. At the edge of the TGF-β positive region, myofibroblasts convert to a high-migration and high-collagen secretion phenotype. This model reasonably explains collagen deposition and expansion in the initial stage of liver fibrosis.

Matrisome gene-based subclassification of patients with liver fibrosis identifies clinical and molecular heterogeneities

BACKGROUND AIMS

Excessive deposition and crosslinking of extracellular matrix increases liver density and stiffness, promotes fibrogenesis, and increases resistance to fibrinolysis. An emerging therapeutic opportunity in liver fibrosis is to target the composition of the extracellular matrix or block pathogenic communication with surrounding cells. However, the type and extent of extracellular changes triggering liver fibrosis depend on the underlying etiology. Our aim was to unveil matrisome genes not dependent on etiology, which are clinically relevant to liver fibrosis.

APPROACH RESULTS

We used transcriptomic profiles from liver fibrosis cases of different etiologies to identify and validate liver fibrosis-specific matrisome genes (LFMGs) and their clinical and biological relevance. Dysregulation patterns and cellular landscapes of LFMGs were further explored in mouse models of liver fibrosis progression and regression by bulk and single-cell RNA sequencing. We identified 35 LFMGs, independent of etiology, representing an LFMG signature defining liver fibrosis. Expression of the LFMG signature depended on histological severity and was reduced in regressive livers. Patients with liver fibrosis, even with identical pathological scores, could be subclassified into LFMG Low and LFMG High , with distinguishable clinical, cellular, and molecular features. Single-cell RNA sequencing revealed that microfibrillar-associated protein 4 + activated HSC increased in LFMG High patients and were primarily responsible for the LFMG signature expression and dysregulation.

CONCLUSIONS

The microfibrillar-associated protein 4 + -activated HSC-derived LFMG signature classifies patients with liver fibrosis with distinct clinical and biological characteristics. Our findings unveil hidden information from liver biopsies undetectable using traditional histologic assessments.

Pharmacokinetics, safety, and tolerability of BMS-986263, a lipid nanoparticle containing HSP47 siRNA, in participants with hepatic impairment

BMS-986263 is a retinoid-conjugated lipid nanoparticle delivering small interfering RNA designed to inhibit synthesis of HSP47 protein, a collagen-specific chaperone protein involved in fibrosis development. This is a phase I, open-label, two-part study evaluating pharmacokinetics and safety of BMS-986263 in participants with hepatic impairment (HI). Part 1 (n = 24) of this study enrolled two cohorts with mild and moderate HI and a separate cohort of age- and body mass index (BMI)-matched participants with normal hepatic function. Part 2 enrolled eight participants with severe HI and eight age- and BMI-matched participants with normal hepatic function. All participants received a single intravenous 90 mg BMS-986263 infusion. Compared with normal-matched participants, geometric mean area under the plasma concentration-time curve time zero to the time of the last quantifiable concentration (AUC(0-T) ) and AUC from zero to infinity (AUC(INF) ) of HSP47 siRNA were similar in participants with mild HI and 34% and 163% greater in those with moderate and severe HI, respectively, whereas the maximum plasma concentration was ~25% lower in mild and moderate HI groups but 58% higher in the severe HI group than in the normal group. Adverse events were reported by two of eight, four of eight, and three of eight participants with mild, moderate, or severe HI, respectively; none were reported in the normal-matched group. Overall, single-dose BMS-986263 was generally safe and well-tolerated and dose adjustment is not considered necessary for participants with mild or moderate HI. Although available data do not indicate that dose adjustment should be performed in patients with severe HI; the optimal posology of BMS-986263 in patients with severe HI may be determined later in its clinical development when additional data to establish exposure-safety/efficacy relationship becomes available.

Mining host candidate regulators of schistosomiasis-induced liver fibrosis in response to artesunate therapy through transcriptomics approach

BACKGROUND

Artesunate (ART) has been reported to have an antifibrotic effect in various organs. The underlying mechanism has not been systematically elucidated. We aimed to clarify the effect of ART on liver fibrosis induced by Schistosoma japonicum (S. japonicum) in an experimentally infected rodent model and the potential underlying mechanisms.

METHODS

The effect of ART on hepatic stellate cells (HSCs) was assessed using CCK-8 and Annexin V-FITC/PI staining assays. The experimental model of liver fibrosis was established in the Mongolian gerbil model infected with S. japonicum cercariae and then treated with 20 mg/kg or 40 mg/kg ART. The hydroxyproline (Hyp) content, malondialdehyde (MDA) content, superoxide dismutase (SOD) and glutathione peroxidase (GPX) activities in liver tissue were measured and histopathological changes of liver tissues were observed. Whole-transcriptome RNA sequencing (RNA-seq) of the liver tissues was performed. Differentially expressed genes (DEGs) were identified using bioinformatic analysis and verified by quantitative PCR (qPCR) and western blot assay.

RESULTS

ART significantly inhibited the proliferation and induce the apoptosis of HSCs in a dose-dependent manner. In vivo, Hyp content decreased significantly in the ART-H group compared to the model (MOD) group and GPX activity was significantly higher in the ART-H group than in the MOD group. Besides, ART treatment significantly reduced collagen production (p <0.05). A total of 158 DEGs and 44 differentially expressed miRNAs related to ART-induced anti-schistosomiasis liver fibrosis were identified. The qPCR and western blot results of selected DEGs were consistent with the sequencing results. These DEGs were implicated in key pathways such as immune and inflammatory response, integrin-mediated signaling and toll-like receptor signaling pathways.

CONCLUSION

ART is effective against liver fibrosis using Mongolian gerbil model induced by S. japonicum infection. We identified host candidate regulators of schistosomiasis-induced liver fibrosis in response to ART through transcriptomics approach.

Cross-talk between gut microbiota and liver steatosis: Complications and therapeutic target

Liver steatosis is the most widespread chronic liver condition. Its global incidence is rising swiftly and is currently estimated to be 24%. Liver steatosis is strongly related with numerous metabolic syndrome characteristics, like obesity, insulin resistance, hyperlipidemia, and hypertension. The gastrointestinal tract contains about 100 trillion commensal organisms and more than 7,000 distinct bacterial strains. Fat deposition in the liver without secondary causes is known as liver steatosis. Dysregulation of the gut flora is one of the factors connected to the onset of fatty liver disease. Dietary choices may alter constitution of the microbiome and cause gut microbiome dysbiosis, particularly due to the intake of food high in fructose sugars, animal products, and saturated fats. Various gut bacteria cause nutrient metabolism in multiple ways, setting off different inflammatory cascades that encourage liver disease and pathways that help fat build up in the liver. Due to their relatively stable nature, genetic factors may not be responsible for the constant increase in liver steatosis incidence. Genetic factors set the stage for liver steatosis pathogenesis. This review will offer an overview of our present knowledge of the roles played by gut microbiota in regulating the development of liver steatosis, potential side effects, and potential treatment targets.

Antagonizing the irreversible thrombomodulin-initiated proteolytic signaling alleviates age-related liver fibrosis via senescent cell killing

Cellular senescence is a stress-induced, stable cell cycle arrest phenotype which generates a pro-inflammatory microenvironment, leading to chronic inflammation and age-associated diseases. Determining the fundamental molecular pathways driving senescence instead of apoptosis could enable the identification of senolytic agents to restore tissue homeostasis. Here, we identify thrombomodulin (THBD) signaling as a key molecular determinant of the senescent cell fate. Although normally restricted to endothelial cells, THBD is rapidly upregulated and maintained throughout all phases of the senescence program in aged mammalian tissues and in senescent cell models. Mechanistically, THBD activates a proteolytic feed-forward signaling pathway by stabilizing a multi-protein complex in early endosomes, thus forming a molecular basis for the irreversibility of the senescence program and ensuring senescent cell viability. Therapeutically, THBD signaling depletion or inhibition using vorapaxar, an FDA-approved drug, effectively ablates senescent cells and restores tissue homeostasis in liver fibrosis models. Collectively, these results uncover proteolytic THBD signaling as a conserved pro-survival pathway essential for senescent cell viability, thus providing a pharmacologically exploitable senolytic target for senescence-associated diseases.

Liver Fibrosis Resolution: From Molecular Mechanisms to Therapeutic Opportunities

The liver is a critical system for metabolism in human beings, which plays an essential role in an abundance of physiological processes and is vulnerable to endogenous or exogenous injuries. After the damage to the liver, a type of aberrant wound healing response known as liver fibrosis may happen, which can result in an excessive accumulation of extracellular matrix (ECM) and then cause cirrhosis or hepatocellular carcinoma (HCC), seriously endangering human health and causing a great economic burden. However, few effective anti-fibrotic medications are clinically available to treat liver fibrosis. The most efficient approach to liver fibrosis prevention and treatment currently is to eliminate its causes, but this approach's efficiency is too slow, or some causes cannot be fully eliminated, which causes liver fibrosis to worsen. In cases of advanced fibrosis, the only available treatment is liver transplantation. Therefore, new treatments or therapeutic agents need to be explored to stop the further development of early liver fibrosis or to reverse the fibrosis process to achieve liver fibrosis resolution. Understanding the mechanisms that lead to the development of liver fibrosis is necessary to find new therapeutic targets and drugs. The complex process of liver fibrosis is regulated by a variety of cells and cytokines, among which hepatic stellate cells (HSCs) are the essential cells, and their continued activation will lead to further progression of liver fibrosis. It has been found that inhibiting HSC activation, or inducing apoptosis, and inactivating activated hepatic stellate cells (aHSCs) can reverse fibrosis and thus achieve liver fibrosis regression. Hence, this review will concentrate on how HSCs become activated during liver fibrosis, including intercellular interactions and related signaling pathways, as well as targeting HSCs or liver fibrosis signaling pathways to achieve the resolution of liver fibrosis. Finally, new therapeutic compounds targeting liver fibrosis are summarized to provide more options for the therapy of liver fibrosis.

Blocking BAFF Alleviates Hepatic Fibrosis in Schistosoma japonicum-Infected Mice

Schistosomiasis is an immunopathogenic disease characterized by egg granuloma and fibrosis. The hepatic fibrosis of schistosomiasis is caused by the coordinated action of local immune cells, liver-resident cells and related cytokines around the eggs of the liver. B-cell-activating factor (BAFF), expressed in many cells, is an essential factor for promoting the survival, differentiation, and maturation of cells. The overexpression of BAFF is closely related to many autoimmune diseases and fibrosis, but has not been reported to play a role in liver fibrosis caused by schistosomiasis. In the study, we found that, during Schistosoma japonicum (S. japonicum) infection in mice, the level of BAFF and its receptor BAFF-R progressively increased, then decreased with the extension of infection time, which was consistent with the progression of hepatic granuloma and fibrosis. Anti-BAFF treatment attenuated the histopathological damage in the liver of infected mice. The average areas of individual granulomas and liver fibrosis in anti-BAFF treatment mice were significantly lower than those in control mice, respectively. Anti-BAFF treatment increased the IL-10, decreased IL-4, IL-6, IL-17A, TGF-β, and downregulated the antibody level against S. japonicum antigens. These results suggested that BAFF acts a strong player in the immunopathology of schistosomiasis. Anti-BAFF treatment may influence Th2 and Th17 responses, and reduce the inflammatory reaction and fibrosis of schistosomiasis liver egg granuloma. It is suggested that BAFF might be a prospective target for the development of new methods to treat schistosomiasis liver fibrosis.

Extracellular vesicles: emerging roles, biomarkers and therapeutic strategies in fibrotic diseases

Extracellular vesicles (EVs), a cluster of cell-secreted lipid bilayer nanoscale particles, universally exist in body fluids, as well as cell and tissue culture supernatants. Over the past years, increasing attention have been paid to the important role of EVs as effective intercellular communicators in fibrotic diseases. Notably, EV cargos, including proteins, lipids, nucleic acids, and metabolites, are reported to be disease-specific and can even contribute to fibrosis pathology. Thus, EVs are considered as effective biomarkers for disease diagnosis and prognosis. Emerging evidence shows that EVs derived from stem/progenitor cells have great prospects for cell-free therapy in various preclinical models of fibrotic diseases and engineered EVs can improve the targeting and effectiveness of their treatment. In this review, we will focus on the biological functions and mechanisms of EVs in the fibrotic diseases, as well as their potential as novel biomarkers and therapeutic strategies.

Diagnosis of Liver Fibrosis Using Artificial Intelligence: A Systematic Review

Background and Objectives: The development of liver fibrosis as a consequence of continuous inflammation represents a turning point in the evolution of chronic liver diseases. The recent developments of artificial intelligence (AI) applications show a high potential for improving the accuracy of diagnosis, involving large sets of clinical data. For this reason, the aim of this systematic review is to provide a comprehensive overview of current AI applications and analyze the accuracy of these systems to perform an automated diagnosis of liver fibrosis. Materials and Methods: We searched PubMed, Cochrane Library, EMBASE, and WILEY databases using predefined keywords. Articles were screened for relevant publications about AI applications capable of diagnosing liver fibrosis. Exclusion criteria were animal studies, case reports, abstracts, letters to the editor, conference presentations, pediatric studies, studies written in languages other than English, and editorials. Results: Our search identified a total of 24 articles analyzing the automated imagistic diagnosis of liver fibrosis, out of which six studies analyze liver ultrasound images, seven studies analyze computer tomography images, five studies analyze magnetic resonance images, and six studies analyze liver biopsies. The studies included in our systematic review showed that AI-assisted non-invasive techniques performed as accurately as human experts in detecting and staging liver fibrosis. Nevertheless, the findings of these studies need to be confirmed through clinical trials to be implemented into clinical practice. Conclusions: The current systematic review provides a comprehensive analysis of the performance of AI systems in diagnosing liver fibrosis. Automatic diagnosis, staging, and risk stratification for liver fibrosis is currently possible considering the accuracy of the AI systems, which can overcome the limitations of non-invasive diagnosis methods.

Preclinical Models and Promising Pharmacotherapeutic Strategies in Liver Fibrosis: An Update

Liver fibrosis represents one of the greatest challenges in medicine. The fact that it develops with the progression of numerous diseases with high prevalence (NAFLD, viral hepatitis, etc.) makes liver fibrosis an even greater global health problem. Accordingly, it has received much attention from numerous researchers who have developed various in vitro and in vivo models to better understand the mechanisms underlying fibrosis development. All these efforts led to the discovery of numerous agents with antifibrotic properties, with hepatic stellate cells and the extracellular matrix at the center of these pharmacotherapeutic strategies. This review focuses on the current data on numerous in vivo and in vitro models of liver fibrosis and on various pharmacotherapeutic targets in the treatment of liver fibrosis.

Engineered fibrotic liver-targeted truncated transforming growth factor β receptor type II variant for superior anti-liver fibrosis therapy

Truncated transforming growth factor β receptor type II (tTβRII) is a promising anti-liver fibrotic candidate because it serves as a trap for binding excessive TGF-β1 by means of competing with wild type TβRII (wtTβRII). However, the widespread application of tTβRII for the treatment of liver fibrosis has been limited by its poor fibrotic liver-homing capacity. Herein, we designed a novel tTβRII variant Z-tTβRII by fusing the platelet-derived growth factor β receptor (PDGFβR)-specific affibody Z_PDGFβR to the N-terminus of tTβRII. The target protein Z-tTβRII was produced using Escherichia coli expression system. In vitro and in vivo studies showed that Z-tTβRII has a superior specific fibrotic liver-targeting potential via the engagement of PDGFβR-overexpressing activated hepatic stellate cells (aHSCs) in liver fibrosis. Moreover, Z-tTβRII significantly inhibited cell migration and invasion, and downregulated fibrosis- and TGF-β1/Smad pathway-related protein levels in TGF-β1-stimiluated HSC-T6 cells. Furthermore, Z-tTβRII remarkably ameliorated liver histopathology, mitigated the fibrosis responses and blocked TGF-β1/Smad signaling pathway in CCl₄-induced liver fibrotic mice. More importantly, Z-tTβRII exhibits a higher fibrotic liver-targeting potential and stronger anti-fibrotic effects than either its parent tTβRII or former variant BiPPB-tTβRII (PDGFβR-binding peptide BiPPB modified tTβRII). In addition, Z-tTβRII shows no significant sign of potential side effects in other vital organs in liver fibrotic mice. Taken together, we conclude that Z-tTβRII with its a high fibrotic liver-homing potential, holds a superior anti-fibrotic activity in liver fibrosis in vitro and in vivo, which may be a potential candidate for targeted therapy for liver fibrosis.

Metabolic Hijacking of Hexose Metabolism to Ascorbate Synthesis Is the Unifying Biochemical Basis of Murine Liver Fibrosis

We wished to understand the metabolic reprogramming underlying liver fibrosis progression in mice. Administration to male C57BL/6J mice of the hepatotoxins carbon tetrachloride (CCl4), thioacetamide (TAA), or a 60% high-fat diet, choline-deficient, amino-acid-defined diet (HF-CDAA) was conducted using standard protocols. Livers collected at different times were analyzed by gas chromatography-mass spectrometry-based metabolomics. RNA was extracted from liver and assayed by qRT-PCR for mRNA expression of 11 genes potentially involved in the synthesis of ascorbic acid from hexoses, Gck, Adpgk, Hk1, Hk2, Ugp2, Ugdh, Ugt1a1, Akr1a4, Akr1b3, Rgn and Gulo. All hepatotoxins resulted in similar metabolic changes during active fibrogenesis, despite different etiology and resultant scarring pattern. Diminished hepatic glucose, galactose, fructose, pentose phosphate pathway intermediates, glucuronic acid and long-chain fatty acids were compensated by elevated ascorbate and the product of collagen prolyl 4-hydroxylase, succinate and its downstream metabolites fumarate and malate. Recovery from the HF-CDAA diet challenge (F2 stage fibrosis) after switching to normal chow was accompanied by increased glucose, galactose, fructose, ribulose 5-phosphate, glucuronic acid, the ascorbate metabolite threonate and diminished ascorbate. During the administration of CCl4, TAA and HF-CDAA, aldose reductase Akr1b3 transcription was induced six- to eightfold, indicating increased conversion of glucuronic acid to gulonic acid, a precursor of ascorbate synthesis. Triggering hepatic fibrosis by three independent mechanisms led to the hijacking of glucose and galactose metabolism towards ascorbate synthesis, to satisfy the increased demand for ascorbate as a cofactor for prolyl 4-hydroxylase for mature collagen production. This metabolic reprogramming and causal gene expression changes were reversible. The increased flux in this pathway was mediated predominantly by increased transcription of aldose reductase Akr1b3.

Pharmacological modulation of ferroptosis as a therapeutic target for liver fibrosis

Liver fibrosis, which is characterized by the excessive deposition of extracellular matrix (ECM) materials (primarily fibrillar collagen-I), is an abnormal repair reaction and pathological outcome of chronic liver diseases caused by alcohol abuse, non-alcoholic fatty liver disease, and chronic hepatitis B and C virus infections. Liver fibrosis often progresses to liver cirrhosis and hepatocellular carcinoma. Ferroptosis, characterized by lipid peroxidation, is a form of iron-dependent non-apoptotic cell death, and recent studies have reported that ferroptosis contribute to the development of liver fibrosis. Moreover, several agents have demonstrated therapeutic effects in experimental liver fibrosis models by inducing hepatic stellate cell (HSCs) ferroptosis. This review delineates the specific mechanism by which ferroptosis contributes to the development of liver fibrosis. Specifically, we focused on the different types of therapeutic agents that can induce HSCs ferroptosis and summarize their pharmacological effectiveness for liver fibrosis treatment. We suggest that HSCs ferroptosis may be a potential useful target of novel therapies for preventing and treating liver fibrosis.

microRNAs-based diagnostic and therapeutic applications in liver fibrosis

Liver fibrosis is a process of over-extracellular matrix (ECM) aggregation and angiogenesis, which develops into cirrhosis and hepatocellular carcinoma (HCC). With the increasing pressure of liver fibrosis, new therapeutics to cure this disease requires much attention. Exosome-cargoed microRNAs (miRNAs) are emerging approaches in the precision of the liver fibrotic paradigm. In this review, we outlined the different types of hepatic cells derived miRNAs that drive intra-/extra-cellular interactive communication in liver fibrosis with different physiological and pathological processes. Specifically, we highlighted the possible mechanism of liver fibrosis pathogenesis associated with immune response and angiogenesis. In addition, potential clinical biomarkers and different stem cell transplant-derived miRNAs-based therapeutic strategies in liver fibrosis were summarized in this review. miRNAs-based approaches might help researchers devise new candidates for the cell-free treatment of liver fibrosis. This article is categorized under: RNA in Disease and Development > RNA in Disease.

Enzymes of Fibrosis in Chronic Liver Disease

Introduction: Liver fibrosis has been extensively studied at the cellular and molecular level, but very few data exist on the final enzymatic stages of collagen synthesis (prolyl hydroxylase, PH) and degradation (matrix metalloproteinases, MMPs), particularly in primary biliary cholangitis (PBC). Aim: We studied enzyme activities in liver tissue from patients with chronic liver diseases and compared them to normal livers. Patients: Eighteen patients with PBC of early and late stages (Ludwig’s classification) and seven on treatment with ursodeoxycholate (UDCA) were studied and compared to 34 patients with alcoholic liver disease (ALD), 25 patients with chronic viral liver disease and five normal biopsies. Sera were available from a total of 140 patients. Methods: The tritiated water released from the tritiated proline was measured in PH assessment. 14C intact and heat-denatured collagen substrates were used to measure collagenase and gelatinases, respectively. 3H Elastin was the substrate for elastase. In serum, ELISAs were used for MMP-1, TIMP-1, and TIMP-2 measurements while MMP-2 and MMP-9 were estimated by zymography. Results: PH was significantly increased in early and late PBC. Collagenase was reduced only in the late stages (p < 0.01), where the ratio PH/collagenase was increased. UDCA treatment restored values to almost normal. Gelatinases were reduced in late stages (p < 0.05). In contrast to PBC and ALD fibrosis, collagen synthesis is not increased in viral fibrosis. The balance shifted towards collagen deposition due to reduced degradation. Interestingly, gelatinolytic activity is not impaired in ALD. Elastase was similar to controls in all diseases studied. TIMP-1 was reduced in early PBC and viral and alcoholic hepatitis and cirrhosis (p < 0.001). Conclusions: (1) There is evidence that collagen synthesis increases in the early stages of PBC, but the collagenolytic mechanism may compensate for the increased synthesis. (2) In viral disease, fibrosis may be due to decreased degradation rather than increased synthesis. (3) The final biochemical stages of liver fibrosis may be quantitatively different according to underlying etiology.

Anti-fibrotic effect of extracellular vesicles derived from tea leaves in hepatic stellate cells and liver fibrosis mice

Background

Activation of hepatic stellate cells (HSCs) is essential for the pathogenesis of liver fibrosis, there is no effective drug used to prevent or reverse the fibrotic process.

Methods

With human hepatic stellate cell line LX-2 and mouse model of CCl₄-induced liver fibrosis, we investigated the anti-fibrotic effect to liver fibrosis of extracellular vesicles (EVs) extracted from tea leaves through cytological tests such as cell proliferation, cell migration, and cell fibrotic marker.

Results

It was found that tea-derived EVs (TEVs) inhibited HSCs activation. In CCl₄-induced liver fibrosis model, TEVs treatment can significantly improve the pathological changes of liver tissue, inhibit collagen deposition, reduce the number of lipid droplets in liver tissue, and reduce serum AST and ALT levels. In addition, TEVs inhibited TGF-β1 signaling and miR-44 in TEVs had the potential inhibitory effect on liver fibrosis.

Conclusions

Taken together, our work suggesting that TEVs are novel therapeutic potential for liver fibrosis.